United States
Department of
Agriculture

Animal and
Plant Health
Inspection
Service

Environmental
Protection
Agency
proceedings of the
Symposium on the Imported Fire Ant
June 7-10, 1982
Atlanta, Georgia

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This publication is the result of a Symposium called  and  sponsored  by the
U. S. Environmental Protection Agency and  the U.  S. Department  of
Agriculture, Animal and Plant Health Inspection Service.   The opinions,
conclusions and recommendations are those  of the  participants and are
advisory to the two agencies.  The papers  published herein have been
printed as submitted and have not been subjected  to review by either
agency prior to publication; therefore, the views expressed do  not
necessarily reflect those of EPA or USDA,  and no  official endorsement
should be inferred.

Trade and company names are used in this publication  solely to  provide
specific, information.  Mention of a trade  or company  name does  not
constitute a warranty or an endorsement by the U. S.  Department of
Ariculture to the exclusion of other products or  organizations  not
mentioned.

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         PROCEEDINGS OF THE
  SYMPOSIUM ON THE IMPORTED FIRE ANT
             June 7 -10, 1982
       ATLANTA AMERICAN HOTEL
           ATLANTA, GEORGIA
       SYMPOSIUM COORDINATOR:
             Fred H. Tschirley

                EDITOR:
           Susan L. Battenfield
     ORGANIZED AND MANAGED BY:
 Jhter-Society Consortium far Plant Protection

            SPONSORED BY:
     Environmental Protection Agency
USD A, Animal, Plant Health Inspection Service

          September  1982

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                                 ACKNOWLEDGEMENTS
   There are always  many  who contribute
to the success  of  any endeavor.   That is
especially  true  for the Imported Fire Ant
Symposium  because its conception, gesta-
tion,  and  birth  occurred in such  a short
time.  Labor pains were particularly intense
for panel chairmen.   They were first  con-
tacted during the last full week in  March.
That they agreed readily to devote  time to
an important public  issue commends their
professionalism  and their sense of responsi-
bility to  society. We  are grateful for their
efforts.  Equal dedication was exhibited  by
panel members.  The  Symposium would not
have  been  possible without the  time and
talent  they  contributed so unstintingly.  All
chairmen and members of panels are listed
in the appropriate  panel  reports.   We  owe
each a debt of gratitude.
   The unsung heroes of  any large meeting
are always those who arrange the amenities
most  of  us take for  granted.  Travel ar-
rangements,  hotel  accomodations,  meeting
rooms, and a  host of other  details don't
simply happen.  They  were provided by the
untiring efforts of the business office of the
Inter-Society Consortium  for Plant  Protec-
tion,  in  the persons of Raymond Tarleton
and his able, ever pleasant assistant, Dottie
Ginsburg. A principal factor in keeping the
Coordinator coordinated was my secretary,
Doreen Kebler.  Her assistance was invalu-
able.
   Attention to numerous details during the
Symposium, editing, and processing this re-
port required the  sure touch of Susan Bat-
tenfield.  Panel reports written rapidly and
under stress during the course of the Sympo-
sium  necessarily  required   editorial  skill.
The results of  Susan's efforts are apparent.
Her assistance was invaluable.
   Lastly, the genesis and  support of the
Imported  Fire  Ant  Symposium  came  from
the Environmental  Protection Agency  and
the Animal Plant  Health Inspection Service
of  the U.S.  Department  of Agriculture.
That  they recognized the fire ant  and its
management as a serious scientific, social,
and political issue was expected.  That they
joined forces to host a Symposium at  which
the many  diverse  attitudes and  points of
view relating to management of the fire ant
could be discussed openly was not  expected.
Their willingness to  risk criticism in an open
forum signifies a maturity of judgment and
an  awareness  of  social responsibility that
augers  well  for the  resolution  of honest
disputes in the  future.  We  commend their
action and hope that other agencies, organi-
zations, and groups, whether they be gov-
ernmental, the federal, state or local  level,
or in the private sector, will recognize  the
                                           ii

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value of open discussion of differences in a
spirit of resolving disputes rather than per-
petuating them  through an adversarial pro-
cess.
   Many others contributed importantly to
the success of the Symposium.   Failure to
mention their contributions does not reflect
insensitivity  to their  help,  rather  a  con-
straint  of  time  and space.  We are  indeed
grateful to all.
Fred H. Tschirley
Coordinator
                                           ill

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                     TABLE OF CONTENTS
                                                                 Page

EXECUTIVE SUMMARY	      1
OPENING REMARKS
     Charles Jeter, EPA	      9
     John Ferris, ISCPP	     10
     John Todhunter, EPA	     11
     Jim Lee, USDA	     13
     Walter R. Tschinkel, Florida State University	     16
     Reagan Brown, Commissioner of Agric., Texas	     36
     Carolyn Carr, Sierra Club	     40
PANEL REPORTS
     I.   Socio-Economic Factors  Relating  to  the IFA and  its
            Management(J. Charles Headley, Chairman)	     41
     II.   The Theory of Population  Dynamics (Dean  L. Haynes,
            Chairman)	     51
     III.  Population  Dynamics  of  the  IFA  (Fowden G. Maxwell,
            Chairman)	     67
     IV.  Environmental Toxicology (Robert L. Metcalf, Chairman) .  .     75
     V.   Management of Established vs. Introduced Pests (Harold T.
            Reynolds, Chairman)	     82
     VI.  IFA Management Strategies (Richard J. Sauer, Chairman) .  .     91
LIST OF REGISTRANTS
APPENDICES
     A.   Chemistry and Properties  of Fire Ant Venoms (Murray S.
            Blum)	   116
     B.   The Medical Aspects of the Imported Fire Ant (William H.
            Schmid, Allergist)	   119
     C.   A Brief History of Chemical Control of the Imported Fire
            Ant (R. L. Metcalf)	   122
     D.   Impact of  the Imported  Fire Ant Control Programs on
            Wildlife and Quality of the Environment (Maureen K.
            Hinkle)	   130
     E.   Ferriamicide: A Toxicological Summary (Earl L. Alley)  .  .  .   144
     F.   A  Brief  Overview of the  Requirements  for  Pesticide
            Registration (D. J. Severn)	   154

                                 iv

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Table of Contents (continued)
                                                                   Page

     G.  Environmental   Toxicology  of   Pesticide   Application
            Programs (H. N. Nigg)	    157
     H.  Models for Decision-Making (John Wood)	    159
     I.   Chemicals Currently Under Investigation for Possible IF A
            Use (Panel IV)	    161
     J.  Comments on Ferriamicide and the IFA Problem (Mississip-
            pi Department of Agriculture and Commerce)	    187
     K.  Fire Ant Fact Sheet (EPA)	    190
     L.  Eradication: An Assessment of  Concept and Practice (Ed-
            ward N. Smith)	    201
     M.  Biological Control: Its Historical Use vs. Prospective Value
            to Control the Imported Fire Ant (Frank E. Gilstrap)...    214
     N.  Impact and Management of Introduced Pests  in Agriculture
            (Marcos Kogan)	    226
     O.  Some Considerations for  the  Eradication and Management
            of  Introduced  Insect  Pests in  Urban  Environments
            (Gordon W. Frankie, Raymond Gill,  Carlton S. Koehler,
            Donald Dilly, Jan O. Washborn, Philip Ham man)	    237

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Executive Summary

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                                 EXECUTIVE SUMMARY
                                    Fred H. Tschirley
INTRODUCTION
   The imported fire ants (IFA), SoZenopsis
richteri Forel and Solenopsis invicta Buren
were  introduced from South America  into
the United States in the early 1900's and the
late  1930's,  respectively, at  the  port  of
Mobile, Alabama. Their area of infestation
has expanded dramatically since introduc-
tion.   In  the late  1940's and  early  1950's,
they  were  present from Miami,  Florida,
west  to San Antonio, Texas, and  north to
Memphis,  Tennessee,  and  eastern  North
Carolina.   Today, they are  found  on about
240 million acres in 10 states.  S.   invicta,
the red fire  ant, occupies over 95%  of the
infested area; S. richteri, the black fire ant,
is found  in  northern  Mississippi and  Ala-
bama.  The spread of the IFA has  occurred
despite extensive  state  and  federal  pro-
grams designed for  its control.
    The potential future distribution of the
IFA  is open to some  question.  There is
general agreement  that northward extension
of  the  present area  of  infestation  has
reached its limit, although  some extension
may  occur along the eastern coast.  West-
ward spread cannot be accurately predicted
because all of the biotic and abiotic  factors
influencing establishment are  not  known.
Warm rains, which occur in New Mexico and
Arizona, are  necessary to  trigger  mating
flights and ensure nest excavation.  South-
ern California lacks summer rains, but has
extensive  irrigation  acreage   that  may
trigger  mating flights.   Thus, expansion  of
the IFA range westward to California and
then  northward  along  the  coast through
Oregon and Washington is not certain, but
neither is it improbable.

NATURE OF THE PROBLEM
   IFA infestations  occur in many habitats:
field   and   vegetable   crops,   nurseries,
orchards, hay fields, forests, and unmanaged
wildlands.  That the IFA is a pest is unques-
tioned; that it is truly  an economic pest  of
agriculture  has not been adequately  docu-
mented.
    Data concerning the agricultural impact
of the IFA do not support a conclusion of  its
being an economic pest, although reports
indicate livestock  losses from  IFA  stings.
Other reports document reductions  in hay
yield and quality,  and yield reductions for
field crops (soybeans) where ants are abun-
dant   or  where  seed  has  not  been well
covered at planting.  Damage to equipment
and  conversion  to  alternate   harvesting

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 equipment (hay, for example)  due to  IFA
 mounds are unquestioned adverse economic
 impacts.  The IFA are a nuisance for crops
 that are hand-harvested, but no  studies have
 documented  the economic  impact  of  this
 factor.   On  the other  hand,  the IFA is
 considered to be a key predator of Heliothis
 species in cotton production, is  an excellent
 predator  of  the sugarcane  borer  (saving
 growers one  or two insecticide  applications
 per season),  preys on the banded cucumber
 beetle and  sweet  potato weevil in  sweet
 potatoes,  and  is an  important  predator of
 many detrimental insects in soybeans.   The
 IFA  is also  an excellent predator of  ticks,
 hornflies,  and  stable flies.   In  many  areas
 IFA  predation has  reduced lone star tick
 populations to the point where  they are no
 longer considered to be an economic pest.
   Although  costs  and  benefits of IFA in
 agriculture   have  been  documented,  the
 available data  base is too limited to permit
 a conclusive  cost/benefit analysis.  An eco-
 nomic analysis of  one  county  in  Florida
 established a cost/benefit ratio of 5.6:1, but
 the  extent  to  which  that study  can  be
 extrapolated  to other agricultural  areas is
unknown.
   Young birds and  other forms of wildlife
that  nest on or in the ground are vulnerable
to IFA attack during their early hours of
life.   There are documented cases of young
quail  and newly born rabbits being killed by
the  IFA, but  there is  no  indication that
populations   of  those  species  have  been
reduced.
   Human health  consequences may be the
most important adverse effect of IFA infes-
tations.   Because urban  as well  as rural
areas are infested, about 40 million people
are in potential conflict with the IFA. The
IFA   was so  named  because  the  venom
induces a painful, fiery sensation.   The ant
grips the skin with  its mandibles  and may
sting its victim  multiple times in a circular
pattern  around   the  point   of   mandible
attachment.  The aggressive nature of the
ant  when a  mound  is disturbed commonly
results  in attack  by numerous ants so that
10 to 30 stings are  common.  Many people
experience only local reaction and tempor-
ary discomfort.  In others a sterile pustule
develops within 24 hours, which is clinically
diagnostic.  Although the venom  is bacteri-
cidal,  secondary  infections  as a result  of
scratching may occur.  A  small  percentage
of persons stung, probably 1% or less, exper-
ience a systemic  anaphylactic reaction  of
variable severity.   Some such  individuals
may  require hospitilization, and the reaction
may  be life threatening.   One author cites
17 deaths due to fire ant venom.  Hypersen-
sitive individuals can be desensitized.
   The perceived  severity of the IFA  as a
nuisance or  public health pest  problem was
delineated in two telephone surveys  con-

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ducted by the American Cyanamid Corpora-
tion  in  1980 and  1981.   The surveys indi-
cated  that  about  one  million  households
treated with  insecticides  for IFA control;
the balance (22%) were using gasoline, boil-
ing water, or  cultural methods;  73%  of the
respondents  treated  lawns, 58%  gardens,
54%  pastures,  19%  row  crops,  and  4%
woods.  The higher percentages recorded for
lawn  and garden  treatment suggest  that
nuisance and  public health reasons are  the
primary motivations for treatment because
an economic  return would not be  expected
for those habitats, especially lawns.

PESTICIDES FOR IFA CONTROL
    Large-scale eradication programs  for the
IFA were initiated in 1958.  Heptachlor and
dieldrin were applied at a rate  of  2  Ib. per
acre  (later  reduced to  1.25 Ib.  per acre) to
about 20 million acres over a 5-year  period.
Effects on  wildlife species were disastrous
and were a  significant reason for public dis-
enchantment  with  the use  of pesticides.
Despite  the  massive eradication  attempt,
the area infested by the IFA increased from
90 to 126  million acres during the  5-year
period.
    Mirex, applied in a bait, represented a
decided  improvement  over the  previous
treatments because  the rate of the active
ingredient could be reduced to 1.7 grams per
acre (0.00374 Ib. per acre) without reducing
IFA  control.   A massive eradication  pro-
gram, over a 12-year period,  on the entire
126  million acre area of  infestation  was
planned at a cost of $200  million.  Problems
arose, however, when mirex was found to be
persistent in the  environment, bioaccumula-
tive, and later shown to cause hepatocarcin-
omas in mice.   Subsequently,  the use of
mirex was lessened until  1978 when all in-
secticidal uses were cancelled.
   Ten  insecticides are currently registered
for IFA control by broadcast  application on
non-agricultural  crops,  for  mound  treat-
ment, and for treatment  of nursery stock;
several  have conditional registration or  have
registration pending. In addition, five insect
growth  regulators  are being  developed for
possible use as IFA control agents.   More
detail for the products is provided in Appen-
dix I.  The  toxicant of greatest concern is
ferriamicide.  Mirex is the active ingredient
in   ferriamicide,  but   the   formulation
contains   amine   and   ferrous   chloride
components to reduce environmental persis-
tence and propylene  glycol to suppress the
production  of  chlordecone,  a  degradation
product.  Ferriamicide does  indeed have a
shorter  environmental  half  life; however,
the presence of chlordecone in shelf samples
and  the  discovery that  photomirex  is  a
degradation   product    of   ferriamicide
immediately caused concern.  Both chlorde-
cone and photomirex are highly  toxic and

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carcinogenic in test animals.

CURRENT MANAGEMENT OPTIONS
   The technology now available for manag-
ing the  IFA  in  a variety of  habitats  is
limited.  Insecticides are the primary man-
agement tool; 16  are now registered for one
or  more  uses of  which  two  have  state
registrations  under  Section  24(c)  of the
FIFRA,  and   3   have  experimental  use
permits.   Seven  have a registration or a
request  for  an  experimental  use permit
pending.   Boiling water is  appropriate for
some limited situations.  Mound  leveling can
be effective,  but the necessity for  timing
the   treatment   just   before   freezing
temperatures occur limits the effectiveness
of the method severely.
   There is agreement that an  educational
program  needs to be  conducted to  ensure
that necessary  and  accurate  information
about the  IFA is available  to  the public.
The  need is  dictated  by the  fact  that the
IFA is an emotional issue; therefore,  accur-
ate,  objective, and unsensationalized infor-
mation  assumes  even greater  importance.
In all   educational  efforts,  a distinction
should  be made between  perceived problems
and demonstrable effects.

THE ENIGMA
   The red fire ant has been in  the U.S. for
about 50 years. Serious efforts to control  or
eradicate the pest  have occured during the
last 25 years.  Despite  the passage of time
and the expenditure of  more than $100 mil-
lion  of  local,  state, and federal funds  to
control  the IFA, the area of infestation is
larger  than  ever before  and  is growing.
Moreover,  the  magnitude of the IFA  prob-
lem  cannot be defined  with any degree  of
precision.  There are both costs and benefits
to agriculture associated with the presence
of the IFA. In urban situations,  where there
is  a  greater  probability  of IF A/human  con-
tact (and therefore conflict), the IFA has no
demonstrated  benefits,  but  the costs  in
terms  of public health considerations  are
not inconsequential.  Some half dozen chem-
icals  used  for  IFA   control  have  been
cancelled,  others are currently registered
for specific situations, and still others are in
the  developmental  process  with hope  of
eventual registration.  Biological control of
the IFA  is  not now possible; physical and
cultural manipulation, once thought to deter
colony establishment,  now  appear  to  be
generally ineffective; flooding and  burning
do not destroy or kill IFA  colonies.   Inte-
grated pest management, defined as the use
of a variety of management methods, can
only be  applied intellectually because only
chemicals  have  given  temporary   relief.
Nevertheless, logic dictates  that some non-
chemical   control  is  operating.    Mound
density  varies  within the range of infesta-

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tion, even in disturbed areas that are known
to be more readily invaded.  Present knowl-
edge, however, cannot  identify  the opera-
tive factors.
   In terms of information presented,  the
IF A  Symposium  was more notable for its
exposition of what is not known but needs to
be  known,  than  for   what  is   known—a
humbling   comment  on  the  wisdom   of
humans.   Consider if you will (1) Panel I's
two-plus  pages  listing  the types  of  data
needed  to estimate the costs and benefits
associated with the IF A; (2) twelve specific
research recommendations in Panel in for
developing information  that must  be known
before informed management strategies can
be applied in  a  diverse set of habitats; (3)
seven specific recommendations by Panel IV
to elucidate toxicologic questions relating
to the IFA venom  and  to insecticides used
for  control; and (4) another seven  recom-
mendations from  Panel VI,  which  quickly
discovered  that   chemicals  are  the   only
proven  technology available  for manage-
ment!     Adding   the  recommendations of
Panels n  and  V,  whose subject matter was
much broader than just the IFA, completes
the  litany of  the unknown.   How can one
avoid being impressed,  annoyed, frustrated,
and  dumbfounded by such a comprehensive
exposition of our ignorance?
   The litany of the  unknown should not
cast a shadow of reproach on research that
has been done on the chemistry of the toxin,
the biology of the IFA, and methods for its
control.  The literature on the IFA contains
numerous  papers   describing  exemplary
research, which forms the basis for what we
know about  the IFA today.   In  addition,
carefully  crafted  research  programs  have
been recently initiated that have promise of
soon answering many of the questions that
remain unresolved.  A valid criticism of past
efforts  is that research lagged far behind
action programs.   Even today,  many states
within the area of infestation do not have an
active IFA research program.  Only recently
has  there been a  comprehensive review of
IFA research, which forms  the basis for a
research effort that is broader in scope and
addresses  critically  important  areas  of
knowledge that are now wanting.

FUTURE DECISION-MAKING
    A message coming through clearly from
the  symposium is that population  and  com-
munity dynamics of a pest, whether native
or introduced, involve an extremely complex
interaction   of biotic and  abiotic  compo-
nents.  Any program designed to deal with a
pest, whether  it  be doing  nothing on one
extreme  to eradication  attempts  on the
other extreme, carries an element of uncer-
tainty and may result in failure. The proba-
bility  of failure necessitates conducting an
integrated   research  program  concurrent

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 with  the  earliest  management  programs.
 The management program must  be flexible
 in the sense of changing strategies as knowl-
 edge of the pest and its interactions with its
 environment evolves.
    This does not imply that decision-makers
 should  or  will  have  the  luxury of  doing
 nothing until adequate knowledge is devel-
 oped  to permit an  adequately informed
 course  of action.  It  does mean that deci-
 sion-makers should anticipate the possibility
 of major modifications based on the infor-
 mation developed by a concurrent  research
 program, rather than  establishing policy (a
 plan to deal with a pest) and then designing
 a  research program that supports the policy.
    The importance  of  early  detection of a
 pest  is  paramount.   A  new pest  that is
 geographically restricted  and  numerically
 limited  may  be handled  relatively easily.
 There  are  notable examples of  successful
 pest eradications while the pest's geographic
 range of infestation was  still limited. The
 failure  of eradication efforts against pests
 that were  widely  established  are  equally
 notable.  In  that  context,  the  fact that
 about 84%  of  newly-detected homopterans
 in California originated from urban infesta-
 tions is a matter of prime  importance (Ap-
 pendix O).  It begs the question of  whether
 monitoring efforts for new pests  should  be
 concentrated in  urban  areas.  If data for
homopterans can be extrapolated to other
 pests  species, we must  also  consider that
 eradication will be more difficult in densely
 populated  areas.  Moreover,  by the time a
 serious pest is  detected in an agricultural
 area,  the  population may already be suffi-
 ciently large and geographically extensive
 to severely limit management options.
    Our society  has a  reputation of being
 overly  enamored with  "quick-fix technol-
 ogy."  Define the mouse  and we'll build a
 better mousetrap.  That sort  of engineering
 approach  to resolving  problems  is fraught
 with many difficulties  when  applied to the
 biological realm.  The quick-fix is, however,
 an  important component of  our society's
 consciousness.  Its power as a driving force
 must  be recognized.  Persons affected by a
 perceived threat, whether relief from a nui-
 sance  or  protection  from  an economic  or
 public  health threat, demand  action.  Those
 who provide funding at the local,  state, and
 federal levels to support programs  in re-
 sponse  to  public demands  are  mightily
 attracted by quick-fix technology  because it
 promises to solve the problem quickly. Even
 if  the problem  is not  resolved,  the  overt
 show  of force that characterizes quick-fix
 solutions demonstrates  a  responsiveness  to
 public  concerns.
   Modifying the quick-fix response by pub-
 lic decision-makers will not be easy. Single-
issue   politics  is a  potent  force in our
society.   Would  public  decision-makers  in

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the  early  and mid  1950's have survived  a
decision to allocate funds equitably between
an  action program  and a  comprehensive
research program on the IFA?  The question
is rhetorical, but important.  The wisdom of
hindsight  permits the conclusion that,  had
an  equitable  allocation  of  funds between
research  and  eradication occurred in  the
1950's,  the IFA  would probably still be  a
problem, but most likely it would not be the
pervasive  scientific-social-political  issue
that it is today.
   Because so much is  yet  unknown  about
the IFA, a decision on fund allocation now is
not  substantially  different  than it  would
have been in the 1950's.   We, however, do
have  the  advantage of  knowing that  the
eradication attempt was not successful.
   Yet the problem  of the IFA remains and
its  geographic  range of infestation will
probably spread  beyond  its  current limits.
What an ideal opportunity,  having the IFA
Symposium  for  support, to   develop  an
action-education-research program designed
by the best minds available from the scien-
tific, educational, social, and political sec-
tors.    A  good  beginning has been  made
toward  establishing  communication among
the various sectors  of society involved in
the fire ant issue. If that communication is
now  aborted, the IFA Symposium will have
been just another meeting of  concerned citi-
zens without any perceivable impact on  the
affairs of humans.
    One  looks  to the  future  and  wonders
what and how decisions will be made about
the  inevitable  serious pest we will have to
deal with in the years ahead.  The agencies
that  supported the  IFA Symposium  have a
stake in the unknown pest scenario of the
future.   While EPA's primary  responsibility
relating to pests is the registration of pesti-
cides, the agency also has a responsibility to
comment on  environmental impact  state-
ments.  It cannot do so intelligently without
an  acute awareness and  appreciation for
biology and  all  its  complexities—the data
needs and the correct questions to be asked
for  informed  decision-making.   USDA has
broad responsibilities for  research and edu-
cation relating to pests,  and it is directly
involved  in  conducting  quarantine,  pest
management,   and  eradication   programs.
The decisions USDA  must  make are difficult
scientifically,  socially,   and   politically.
Decisions must be based on sound knowledge
of  biological  and   ecological  components.
Both agencies can benefit from drawing on
the  large  and  diverse  body  of expertise
resident  in  the land-grant college system
and  other  academic institutions.  Decisions
made in  isolation are breeding grounds for
dispute.  Decisions based on a broad founda-
tion of knowledge are much more likely to
avoid dispute.
   The  process  of  direct communication

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among those with different opinions on how
to  manage the  fire  ant,  which  was  the
guiding  principle of  the  IFA  Symposium,
provided  encouraging indicators  that dis-
putes can  be resolved through discussion of
differences in  a  non-adversarial setting.
Occasional  sharp exchanges among  those
with differing points  of view were welcome
events.   Such exchanges must  occur  before
understanding of  a different  position and
then resolution  of  differences are possible.
Clearly,  neither broad scale  eradication at-
tempts by  using insecticides  nor a complete
cessation of chemical control are tenable
management options  for  the IFA.  That  a
single  symposium  will  heal  the  wounds
inflicted  over  many  years  of adversarial
strife is a vain and overly sanguine expecta-
tion, however.   Dialogue among disputants
must continue and expand if the success of
the  IFA   Symposium  is  to have lasting
impact.
   Guidelines for decision-making relating
to the IFA, to other current pests, and those
of the future are contained as recommenda-
tions in the panel reports of the IFA Sympo-
sium.  I commend to you those recommenda-
tions.     The   broader   issue,   implicitly
addressed by the Symposium, is  a method-
ology for dispute resolution.   Dispute cannot
and should  not  be avoided;  our ability to
resolve dispute must be at the top of soci-
ety's priority list.   To that end,  the IFA
Symposium has been a hopeful beginning.

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Opening Remarks

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                                 WELCOMING REMARKS
                                     Charles R. Jeter
                                EPA Regional Administrator
                                     Atlanta, Georgia
   Welcome to Atlanta, the fire ant capital
of the world, at least  for this week.  Seri-
ously,  the  Intersociety Consortium has put
together a very impressive program.  It  is
my hope  that  we  will end the week with
some answers  on  how  to deal  with the
imported fire ant problem.  The experts are
here. It should be a productive week.
   I will not take much  of your time, but I
would like to take this  opportunity  to re-
mind you that the overriding mission of the
Environmental Protection Agency is to safe-
guard the health of the American people and
to protect our natural  environment.  This is
the mission for which  EPA was founded and
the  cause  to  which this Administration  is
dedicated.   Good  science is one  of the
Agency's goals.  That,  along with regulatory
reform, improved  management, elimination
of backlogs and strengthened partnerships
with state and local governments, will help
us fulfill our mission.
   Good  science  is  a  key element.   We
believe that there  cannot be good  regulation
without  good  science.   Without adequate
scientific understanding, steps necessary for
the  protection of human health might never
be taken.
    Our  concern for   better application  of
science has led to a more comprehensive in-
volvement  of  EPA's science  advisory board
in the development of new regulations. This
body of eminent American scientists will be
asked to review the scientific adequacy of
Agency regulations  and generally become
more involved in Agency activities. As part
of this  new approach to the better  use of
information we  are  aggressively seeking
peer review of Agency scientific reports.
   Other  actions in  this area  include the
preparation of health assessments for seven
chemical solvents.  The  information will be
submitted to the Science Advisory Board for
public  and peer review.  Several other pro-
jects that  influence the Agency's approach
to health and risk assessment are in varying
stages of completion.
   We've  made significant gains in the other
areas mentioned earlier, but  there's no time
to elaborate.  I wanted especially to men-
tion our attempts to improve the quality of
our science and to underscore that EPA now
insists that any proposed  regulation  whose
rationale  depends on scientific  assumptions
is subjected to a  thorough peer review by
knowledgeable scientists to test the validity
of those assumptions.
   Again,  welcome to Atlanta.   Come visit
the regional office while you're  here.  And
have a good meeting. Thank  you.

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                                   OPENING REMARKS
                                        John Ferris
                                         President
                        InterSociety Consortium for Plant Protection
   I am  here  this morning by virtue of my
position as chairman of the Executive Coun-
cil of the InterSociety Consortium for Plant
Protection (ISCPP).   The  Consortium  is
made up  of representatives  from the four
main U.S. plant protection societies:  Ento-
mological Society  of America,  American
Phytopathological Society, Society  of Ne-
matologists, and Weed Science  Society  of
America. Each of  these societies is repre-
sented on the Executive Council by their
Vice-President (or  President-elect),  Presi-
dent, and immediate past President.  The
Executive Council of the ISCPP meets two
or  three times  each year  in  Washington,
D.C.  One of  our objectives is to "provide
sound scientific advice to organizations and
agencies  concerned with establishing  poli-
cies, regulations and improved  methods for
plant protection."  And this is our role, our
involvement,  in organizing  this Imported
Fire Ant Symposium.
   The subject  matter  of  the  panels  has
been selected  with  the intention of covering
all  aspects  of the  IF A problem.  Dr.  Fred
Tschirley, symposium coordinator,  will  go
into detail  with you about  the topics as-
signed   to  each  panel,   and   how   the
symposium is  to proceed.   What I  wish to
emphasize now is  that  many of  the panel
members, who are also members  of one  or
more ISCPP constituent societies, are here
as agricultural research scientists.  You can
expect to hear from them what they believe
to be the latest facts about the fire ant.
   However,  there are  two  caveats  you
should be aware of:  the first is that a given
set of scientific facts can be used to support
divergent conclusions by  twisting,  distor-
tion,  or  selected  emphasis of these facts.
The second is  that what seems to be scienti-
fically true today may no longer seem to  be
true  at some  future time because  of  new
evidence or better interpretation of existing
data.
   What this symposium is striving for is  an
unbiased  presentation  of  the   scientific
facts, as we   now perceive them.   These
facts can then be  used to determine what
additional information is needed to solve the
fire ant problem on a long-term basis.  And
this  will probably  require a lot of  additional
research to provide some very specific bits
of information. A more  immediate goal  of
this  symposium is to provide  decision mak-
ers with the information necessary to  deal
with the IFA on a  daily basis until a holistic
approach  to   control  this   pest  can   be
developed.
                                           10

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                                 OPENING REMARKS
                                   John A. Todhunter
                            Environmental Protection Agency
   It's a pleasure to be here  with  you in
Atlanta  this  morning.   I  must  confess,
though, that not being  from this  region, I
was  reminded of the story  of  the Yankee
fisherman who,  fancying himself the com-
plete angler, journeyed south of the  Mason-
Dixon to test  his skills in  your lakes  and
rivers. He had for a guide a  Senior Southern
Gentleman named Homer who  knew better
than  anyone what was  biting  and  where.
After a few  outings and major successes,
our  Yankee angler,  not crediting  Homer
with contributing to  any  of  his  success,
struck off for a stream that  Homer knew
had  no fish.  The Yankee cast out into the
current  which quickly took his line down-
stream.  The angler began to reel in and met
resistance.   Quickly he pulled to  set the
hook and cried out to Homer "I got  it, I got
it!   And Lord is it strong!"  Well, old Homer
stepped out into  the stream and saw  that
the  line was snagged around  a submerged
boulder  that had been there since  the Ice
 Age.  Homer yelled, "You got  it,  all right,"
 to  the  Yankee  fisherman.   "You  got  old
 Dixie and a helluva git you got1"
    I guess that story has several morals, but
 the one I had in mind is the  one that teaches
 us that  for all our experience and expertise,
we  can still learn more.   That  is why I
congratulate  Charles  Jeter,  John  Ferris,
Harry  Mussman,   Walt Tschinkel,  Reagan
Brown, Carolyn Carr, Fred Tschirley and  all
of you  for  making this  symposium on the
imported fire ant a reality.
   The  imported fire ant, as Jim Buck Ross
once observed, is just what it is:  imported—
the black ant variety from Uruguay, and the
red ant  from Brazil.  They have been around
since the twenties and thirties, and by the
fifties  they began to  move beyond  their
point of entry around  Mobile to nine south-
ern states and  Puerto  Rico.  The  fire ant,
imported or not,  has become a  major  prob-
lem for the people of  the South.  Over 230
million  acres are  now  infested.  Their sting
has been felt by humans and livestock in  the
thousands.  Millions of dollars in crop losses,
medical expenses  and  in means to combat
them have been incurred.
    With apologies to Pogo, we have met  the
enemy  and this time, they aren't us. So why
this symposium?   You may recall  that last
February, I announced that  EPA and USD A
would sponsor a Symposium on the Imported
Fire Ant.  This  decision was prompted by
the State  of  Mississippi's  application  for
 conditional registration of  the insecticide
                                           11

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                                           12
Ferriamicide. It became clear to me at that
time that we could  not evaluate the Ferri-
amicide  application  in isolation from all of
the many issues  that surround the control of
the fire ant.  What we needed then and need
now is information.  And we expect we will
receive that information from  the partici-
pants of this Symposium.  In essence, what
we have today  assembled is a  multi-disci-
plinary task  force of experts.  Their task,
over the next four days,  is  to examine  the
fire ant and the best possible method to rid
ourselves of its harmful effects.
    This is no simple charge, as we are all
aware.  Because there is no simple,  risk-free
solution  to this  problem that we know  of.
But try we must.  Because our efforts here
will affect  the  decisions of the  EPA and
USDA  in this matter.
    As  you begin  your  deliberations, I  ask
you to consider  a number of things.  First,
keep in mind that FIFRA  is  a risk benefit
statute not a zero-risk statute.
    Second, remember that regulatory deci-
sions  in  the  final analysis  are subjective.
There  are a  number of considerations that
affect  them—not the least is the  level  of
risk that our citizenry is willing to accept.
    Third, consider the impact of science on
the regulatory process.  Simply put, it is  not
possible to make a good regulatory decision
that is based on bad science.
   I am not  asking you for unanimity,  I
 know better than that.
    What  I am asking you  for  is your best
 scientific effort, leaving behind partisanship
 and past  disagreements.  Because what we
 produce by way of information at this Sym-
 posium will not only play a powerful role in
 the decisions of EPA and the USDA, but will
 affect for many years to come  the environ-
 ment of  the South  and the  lives  of  its
inhabitants.
   I wish to  thank you all for your partici-
pation and anticipate your guidance in this
matter.

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                  INTRODUCTION BY THE ANIMAL AND PLANT HEALTH
                 INSPECTION SERVICE, CO-SPONSOR OF THE SYMPOSIUM
                              ON THE IMPORTED FIRE ANT
                                      James O. Lee
                                 Associate Administrator
                                      VSDA, APHIS
   Good morning!  We are pleased to be co-
sponsoring  the  Symposium  on the Imported
Fire Ant  here  in Atlanta this  week.   Dr.
Mussman sends his regrets for being unable
to be  with you  today and  sends  his best
wishes for the Symposium.
   Two species of imported  fire ants  were
brought to  the United States  about 40 to 60
years ago,  and  they  have become a pest of
agriculture, a health hazard,  and a nuisance
to those persons in infested areas. The U.S.
Department of  Agriculture (USDA), Animal
and   Plant  Health  Inspection  Service
(APHIS), and Plant  Protection and Quaran-
tine  (PPQ),  are responsible for program ac-
tions designed  to locate the ants through
survey activities, to prevent  or  retard long
distance  spread through  the  application of
regulatory  procedures, and to reduce popu-
lations by applying control treatments, me-
thods development, and  environmental mo-
nitoring.
   The imported fire ant can  cause  eco-
nomic losses to agricultural lands as well as
nuisance and health effects to humans.  Ag-
ricultural economic  losses due  to  fire ant
damage are based on surveys and from ex-
trapolation of data.  The agricultural  losses
attributable to the imported fire ant  have
been documented for most  of  the affected
states.   In  Florida,  Georgia,  and  North
Carolina, losses due to reduced  efficiency of
mechanical reaping of soybeans and damage
to   equipment   have   been   reported.
Estimates of  losses  ranged  from $2.43 to
$4.70 per acre, when the yield of infested
fields was compared  with that of uninfested
fields.    Reports  of  other crop  damage
include  destruction  of  corn in Mississippi,
Alabama,  and Florida; okra  in Florida; and
peanuts and  other crops in Alabama.  In
addition to the direct damage to plants and
equipment, the presence of the  imported
fire ants in a field reduces worker producti-
vity.
   Individual adverse human health effects
occur from the imported fire  ant  by:  (1)
causing discomfort,  irritation,  and the for-
mation of a pustule at  the site  of the sting;
(2) secondary  infections that may occur at
the site of the pustule and that may lead to
gangrene and subsequent amputation of the
affected appendage;  (3) mortality in certain
hypersensitive  individuals;  and (4) limiting
normal work  and recreational  activities in
heavily infested areas.  Individual responses
to stings  range from  very  mild  localized
reactions  of  redness and tiny  pustule  for-
                                          13

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                                           14
mations, to severe systemic reactions that
require hospitalization and  medical treat-
ment.  These responses depend on the initial
sensitivity of the individual to imported fire
ant venom and to increased sensitivity that
may develop as  a  result of multiple sting
episodes.
   Several sets of alternatives for control
of the imported  fire ant have  been consi-
dered, including  alternative control agents,
alternative methods of application, admini-
strative alternatives, and alternative  fund-
ing sources.  The control  of imported fire
ants may  be achieved by the use  of chemi-
cals, by biological  means,  or by other me-
thods.  To date, greatest emphasis has been
placed on  the  development  and testing  of
chemical  control insecticides.    Chemical
toxicants  may  be classified as:  (1) proven
agents, the use of which have been restrict-
ed or banned; and (2) new  agents  that have
not been applied  on a large scale.  Unfortu-
nately, there is no in-between at the present
time.
   The imported fire ant control program
may be administered in several alternative
ways:   a   federal   program,    a  joint
federal/state   initiative,  or  independent
state  programs.   A  program  administered
exclusively by federal agencies is thought to
be undesirable.  On the other hand, a series
of   independent   state  programs  would
probably not yield  optimum results.  State
boundaries  are  man-made  and   are  not
recognized by  the  imported fire  ant.  The
optimum administrative approach therefore
would be a federal program involving state
governments and agencies.  In this way, the
wishes of individual states may be respected
while the  resources of all are  pooled  to
formulate   a   cohesive   overall  control
program.
   The  statutory  authorities vested in the
U.S.  Department of Agriculture  pertaining
to program actions concerning the imported
fire ant include the following:
-  Organic  Act  of  the   Department  of
   Agriculture,   September  21,  1944,  as
   amended (Title 7, USC, section 147a);
-  Plant  Quarantine  Act  of  August  20,
   1912, as amended (Title 7, USC, sections
   151-165, 167); and
-  Federal Plant Pest Act of May 23, 1957,
   as  amended  (Title  7,   USC,  sections
   150aa-150JJ).
   The  imported  fire ant  control program
may be funded by the  federal government,
state   governments,   or  private  citizens
(farmers and householders).   Historically,
funding  of  programs  has  been  shared
between states and the federal government.
   Based on an  analysis of alternatives, the
preferred   alternative  for   control  of  the
imported  fire   ant  is one  that  uses  an
available and environmentally safe material
applied  by an effective yet  comparatively
inexpensive  method.    The  aim  of   the
cooperative imported fire ant program  is to
locate  infestations  of imported  fire  ants
through visual surveys,  to retard the spread

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                                          15
of imported fire ants by regulating specified
articles that are known to present a risk of
spread,  to  reduce  the likelihood of other
areas becoming infested, and to control the
ant population in areas already infested.
   Remaining issues and concerns identified
are;   concern  for  human  health  and well-
being   resulting   from   increasing   ant
populations,  that agency  program  actions
should have total  eradication of imported
fire   ants   as  the  objective  rather  than
control, restrictions on the use of pesticides
to  their  fullest  potential  reduces  the
likelihood of complete control, a need for
continued   federal/state   cooperative   im-
ported fire ant  program,  concern  for  the
environmental  effects of using a pesticide,
and  concern  about  long-term effects  of
using an insecticide that  has not been fully
tested.
   USDA/APHIS continues  to have  a great
concern for the impact of the imported fire
ant.   The future of any operational control
program  remains in the hands of  all of us.
Thank you for  your time and good luck for
the rest of the week.

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                           HISTORY AND BIOLOGY OF FIRE ANTS
                                     Walter R. Tschinkel
                                   Florida State University
     In the time available, it is not possible to
  summarize  fire  ant biology in detail, and
  even if it were,  such detail would probably
  defeat the purpose of this keynote address.
  Instead,  I  have  chosen to make a  more
  conceptual  interpretation of the available
  facts about fire ants and to use these facts
  to paint  a general  picture of the biological
  nature and function of fire ants.  The inter-
 pretation is not  an  exclusive one,  even
 starting from the facts available. Consider-
 ing the  number  and size  of  our  gaps  of
 knowledge,  the  future   may very well see
 changes of interpretation.
    The facts upon which I base my talk are
 the results of the work of many people over
 more than three  decades.   Complete  attri-
 bution is  impossible in such a short review,
 and to those who  feel inadequatedly cited, I
 apologize.
    Because there  are many non-biologists in
 the  audience,  let me  begin with  a  brief
 description of the individual and colony life
 cycles.  Fire ants  belong  to the  insect order
 Hymenoptera, which also includes the bees
 and  wasps.   As a result, the three groups
 share most of the major  life cycle charac-
 teristics.   Most  importantly,  fire ants,  like
other  Hymenoptera,  are  holometabolous;
that is, they develop through  a  complete
metamorphosis.  The individual  begins life
 as  an egg, which hatches  into  a legless,
 grublike  larval stage.  The larva  is a stage
 specialized  for feeding  and growing,  and
 almost all growth occurs during this period.
 As in all insects, growth is accomplished by
 periodic  molting, or shedding of the cuticle
 (skin).   Having reached  its final  size,  the
 larva  undergoes  a metamorphic  molt  and
 becomes  a pupa in  which  various  adult
 structures,  such as legs  and possibly wings,
 become apparent  for  the first  time.   The
 pupal stage is transitional between  the larva
 and the adult  that emerges during the final
 molt.  In insects in general, the adult  stage
 is specialized for reproduction and dispersal,
 but with ants only some adult individuals  are
 capable of reproduction (queens  and males),
 the remainder are a sterile worker  caste.  In
 all  hymenopteran  societies,  all   socially
 functional   individuals   are   genetically
 female,   with  males  serving only to  in-
 seminate  females on mating flights.
   The social unit of fire ants is the colony,
 and colonies, like individuals, pass through a
 characteristic life cycle  with phases analo-
 gous  to  birth,  growth,  reproduction,  and
 death.  Fire  ants are very typical of ants in
 general with regard  to  their  life cycle.
 Briefly, it  is  as follows.   In addition  to
 workers and  a  queen,  mature  colonies  con-
tain  winged  males and females  capable of
                                           16

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                                          17
flight and reproduction.  These are termed
variously the  alates, sexuals, OP  reproduc-
tives.  On a warm day following a rainy day,
the workers open holes in the nest  through
which  the alates exit on  the  mating flight.
Mating takes  place  300 to 800 feet in the
air.  Mated females  descend to the ground,
break off their wings and proceed to search
for a place to dig the founding nest.  In this
founding nest, a vertical tunnel 2 to 5 inches
deep, they seal themselves in order to rear
their first brood of  workers.   They do this
entirely without  feeding by  utilizing re-
serves stored  in their bodies in the  form of
fat bodies, wing muscles, and food stored in
the  crop.   The first  worker  brood takes
about a month to develop and are the small-
est individuals (minims) in the entire colony
cycle.  They open the nest, begin to forage
for food, rear more workers,  and care for
the queen.  Hereafter, the queen essentially
becomes an egg-laying machine.
    The colony grows rapidly by the produc-
tion of workers who gradually enlarge the
original vertical  tunnel  into multiple  pas-
sages  and chambers and eventually  into the
familiar large mound of spongelike,  convolu-
ted passages.   Colony maturity is  attained
when   sexuals  are   once  again produced.
When  these sexuals  leave on  mating flights,
the colony cycle  is  closed. Mature colonies
of fire ants consist  of an average of  about
60,000 workers,  weighing 70  to 80 grams,
but colonies of up to 150,000  or more have
been reported.
   In 1972,  Buren recognized that what was
previously considered a single species of fire
ant actually consisted of two species, both
introduced to the USA from South America.
The first was Solenopsis richteri Forel and,
the  second  was  an undescribed   species,
which  Buren, with  characteristic   whimsy,
named Solenopsis  invicta Buren.  This sec-
ond ant is greatly  predominant and  has been
given the unfortunate common name of  the
red imported fire  ant.  Logic would require
that,  in its homeland in Brazil,  this  ant
would  have  to be  called the "exported fire
ant."   I suggest that we not defeat  Linnaeus
and  his  wonderful Latin  binomial  system.
Let us call it simply the fire ant, S.   invicta.
   Solenopsis invicta is at home in an  ex-
tensive, seasonally flooded plain forming the
headwaters  of two rivers in southern Brazil,
an  area called the  Pantanal.   Solenopsis
richteri  is  at home in Uruguay,  parts of
Argentina,  and Brazil (Fig.  1).   Both were
introduced  to the  United States by unknown
means  at  Mobile,  Alabama.   Solenopsis
richteri  was first  recorded in  1918  and
spread slowly northward into Mississippi  and
Alabama.    Sometime  between  1933  and
1945,  perhaps around 1940,  S. invicta  ap-
peared in  the  Mobile  harbor area  and
proceeded to spread more rapidly, displacing
S. richteri  from most of its range.  Spread
of both species was both by natural mating
flights and  man-aided through the  transport
of nursery stock.  Thus, by  1953, the range
of the fire  ants (remember  the two species

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            18
Homeland Areas of Fire Ants
       -r
i. m ».,. o
  82:113-124).
                                        ss

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                                          19
were  not yet  distinguished in these early
reports) consisted of a continuous area from
the Gulf coast to central Alabama and Mis-
sissippi and  a  large  number of  incipient
populations    associated    with    nurseries
throughout the Southeast (Fig. 2).  Appear-
ance  of such  incipient populations ceased
after the fire ant quarantine of 1956  was
imposed.   By  the mid-70's, these incipient
populations had coalesced, and the fire  ants
occupied  most of the  warmer parts of the
Southeast as  far  west as Texas and  as far
south  as  Corpus  Christi  (Fig. 3).  Most of
this range is  that of  S.  invicta,  S. richteri
being   presently  restricted   to   parts  of
northern Mississippi and Alabama.
    There has been much speculation  on fu-
ture spread and the ultimate range of fire
ants.  Climate is one of the primary limiting
factors to the ranges of many insect  spe-
cies, and  the study  of  Pimm and Bartell
(1980) is interesting from this point of view.
These authors studied the climatic charac-
teristics  of  the  areas into  which the fire
ant,  S. invicta,  spread  between 1965 and
 1976.   They created composite climatic va-
riables  describing  a   region's temperature
 (Factor 1)  and wetness  (Factor  2).   From
 Fig. 4, it can be seen that during this period
 the fire ant  spread   mainly into climatic
 zones that were warmer and drier,  mostly in
 Texas.  There was some small spread into
 warmer,   wetter  regions,  implying  that
. northward spread has reached its limit. Fi-
 nally,  there  is no  occupation at all of re-
gions that are cold and dry.
   There is  other  evidence that  the  nor-
thern range limit has been reached. Morrill
(1977)  reports great winter kill of fire ant
colonies  in  piedmont  Georgia during the
winter of 1976-77.  Colonies in unprotected
locations suffered  94% mortality in  pied-
mont Georgia, while comparable colonies in
southern Georgia showed only  20% mortali-
ty.  Clearly,  winter harshness must be  more
and more limiting to fire ant populations as
they  proceed  northward.   The period for
successful colony  establishment   also be-
comes shorter as one  proceeds north, fur-
ther limiting northward spread.   All evi-
dence  thus indicates that S. invicta will not
spread significantly further north.
   On the other  hand, some continued west-
ward spread seems to  be occurring,  but  its
limits  are not yet clear. Pimm and Bartell
suggest  that parts  of  Texas will  eventually
be occupied but that  the ant will not pro-
ceed north of the 0°F isoline.   A  number of
people have  suggested that  the  ant  could
spread all the way across the Southwest to
California and  the  West  Coast,  but  these
judgements are based  almost exclusively on
temperature and sometimes the  total  rain-
fall  characteristics  of these  areas.  An as
yet  undiscussed  factor is  the necessity of
summer   rains for  fire ant  reproduction.
Mating flights normally occur only on  warm
days after rain, the rain being necessary not
only to  trigger mating flights but to ensure
successful excavation  of the  founding nest

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   ,5s*-"
                                              Fig. 2. The range of S. invicta and S.  rich-
                                                     teri in the USA in 1953.  The two
                                                     species  were not  yet distinguished
                                                     at  this  time.   The  broken  circles
                                                     represent   secondary  populations,
                                                     mostly centered  at and limited to
                                                     commercial  nurseries (from  Wilson,
                                                     E. O., and W. L. Brown.  1958.  Evo-
                                                     lution  12:211-218).
Fig. 3.
The  ranges of S.  invicta
and  S.   richteri  in the
USA in 1974.  Solenopsis
richteri  is  represented
by  the  darker  shading
(from Buren et al.  1974.
J.  N.Y.  Entomol.  Soc.
82:113-124).
   1965 IKWitionil
   1966

   1968
   1970
   I97J
   i'i/.t
   I97C
   1978
                     S
                     u
                                                          Distribution of Imported Fire Ants
                                      FACTOR 2       Fig. 4.  The "climate space" occupied by  S.
                                                           invicta in 1965  (cross-hatched) and
                                                           1976 (shaded).  Factor  1  is a com-
                                                           posite       climatic       variable
                                                           representing    temperature,    and
                                                           Factor 2  wetness.   The  numbers
                                                           represent  counties  in  Texas  into
                                                           which the ant  will probably spread
                                                           (from Pimm,  S.  L.,  and  D.    P.
                                                           Bartell).   1980.  Environ. Entomol.
                                                           9:653-659).
                                                  20

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                                           21
 and survival  through the  founding period.
 No study has yet considered the timing of
 rain  as a  possible  range-limiting  factor.
 How frequent must warm rain be for main-
 tenance and spread of populations?  Can the
 fire ant reproduce in regions such  as  Cali-
 fornia that  get  almost exclusively cold win-
 ter rains, followed by rainless summers?  A
 careful study of such factors will probably
 show that the potential  range of S.  invicta
 is considerably less than many have  suggest-
 ed.
    All  studies of future range have dwelt
 almost  exclusively on abiotic factors.  Bi-
 otic factors limiting spread are almost to-
 tally  arcane.    As the ant  spreads  toward
 subtropical  Texas and Mexico, it encounters
 an ever richer ant fauna, possibly containing
 components with  habits similar to  its own.
 How will such interactions  with other  ants,
 or for that matter, any other biotic commu-
 nity, influence its success in these regions?
 There are essentially  no data.
    Overall  then,  we can summarize range
 information by  concluding that the ant has
 reached its  nothern  range-limit and is still
spreading westward.  The ultimate  western
 and southern  range-limits   cannot  yet  be
predicted because we lack  so much  biotic
and abiotic information.

ECOLOGICAL NATURE
    Let  us turn now to the ecological nature
of S.  invicta.  1 want to develop  the  case
here that S. invicta, ecologically speaking,
 is a weed species, and as such, shows many
 of  the  biological properties  of  weeds  in
 general.  Weeds are animal or plant species
 that are adapted for  the opportunistic ex-
 ploitation of ecologically disturbed habitats.
 Naturally, these are created by flood, fire,
 and storm, and consist  of  new sandbanks,
 slumps and landslides,  burns, and  windfalls.
 Man however, creates vast stretches of such
 disturbed  habitat  by  clearing forests for
 agriculture, domestic,  and other uses.  The
 plant and animal communities  that  occupy
 such  disturbed  habitats  are  called  early
 secondary or early succession  communities,
 because,  left  alone,   all such  areas  will
 gradually revert  to the  dominant  climax
 communities,  mostly deciduous forest in the
 Southeast.  Because such early succession
 communities  are ephemeral,  and because
 they are, to a large degree, underexploited
 and understocked, the weed species utilizing
 these habitats are adapted for very rapid,
 scramble-type  of exploitation with  an em-
 phasis  on high reproductive  rates  and effi-
 cient dispersal rather than competition with
 other members of the community.
   Let me discuss  each  of the  weed-like
 properties of the fire ant in turn.  First, the
 fire ant  is clearly and dramatically associa-
 ted  with  ecologically  disturbed   habitat,
 most of  it created by man. Thus, S.  invicta
 is  abundant in old fields, pastures,  lawns,
roadsides, and  any other open,  sunny habi-
tat.   It  shares these  habitats with many
other weedy plant and animal species, from

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                                            22
human crops  to lawn and pasture grasses,
goldenrods, and  dog-fennel.  Humans are the
fire  ant's greatest friend,  even though the
sentiment may not be returned.
   On the other hand, the fire ant is absent
or rare in late succession or climax commu-
nities  such  as   mature  deciduous or pine
forest.  When it is found in these communi-
ties, it is usually associated with local dis-
turbance such as windfalls and roads.
   Although the fire ant's need for open sun
has  often been suggested  as the primary
cause of this pattern of occurrence, in reali-
ty this is only one of many correlated fac-
tors, and we must admit  to having almost  no
hard knowledge of  the  biotic  and abiotic
causes of its  distribution.  Suffice it to say,
S. invicta,  like other  weeds, is associated
with open, disturbed habitats.
    A  second weedy  property  is  the high
reproductive  rate that  has  evolved in  re-
sponse to the  spotty,  rather unpredictable
and  ephemeral  availability of suitable habi-
tat  (in  the  absence of  man-made  disturb-
ance).  Success in such  a  situation goes  to
the  animals  and plants  that "git thar  the
fustest with the mostest," with  little atten-
tion paid to competition within the commu-
nity.  Fire ants, like other weeds, achieve a
high reproductive rate in  part by very high
investment  of  resources  in  reproductives.
From  the meager data available,  I estimate
that S.  invicta allocates  30  to 40%  of  its
annual production in sexuals.  This is quite
similar  to  the  allocation  to  seeds found  in
weedy species of goldenrod, and much high-
er than  non-weedy  goldenrods adapted  for
competition in late-succession communities
(Fig. 5).   Thus,  the  average fire ant  colony
in north Florida produces about 4,500  sex-
uals per year. Although very little informa-
tion is available for comparison, this seems
quite on the high side for ants in general and
is almost certainly an adaptation  to its
weedy habits.
   0.5^

   0.44 -

   0.36 -
L«
O
«  0.28
o
>
1  0.20
g
I  °-16

   0.08

   0
                            S. nemoralis
          S. speciosai
                    /'^l  N\ /S. speciosa
                  ,'/ P\   r
                               S. canadensis

                                  S. nigosa


                                S. rugosa
           0.5   0    0.5   1.0   1.5
         log dry weight of aerial tissue (g)
 Fig. 5.  Reproductive  effort  (proportion  of
         production invested in seeds or sex-
         uals) in relation to size of organism
         for  goldenrods and fire ants (large
         black circle).  Each enclosed area is
         represented by the individuals  of  a
         single  population on a dry site (en-
         closed in  dotted  curve), a wet site
         (with horizontal shading), or a hard-
         wood site  (vertical  shading) (modi-
         fied from Ito, Y.   1980.  Compara-
         tive   Ecology,   Cambridge   Univ.
         Press).

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                                            23
    A  third weedy property is effectiveness
 of dispersal and  colonization.  In the  ab-
 sence of man-made disturbance, secondary
 habitat is scattered and unpredictable.  Its
 exploitation  depends   on   the  ability   to
 scatter  propagules  (sexuals or  seeds) over
 wide areas on  the  chance  that a  few will
 find their way to an  appropriate  site and
 colonize it.  The fire  ant achieves this end
 by producing a large number of dispersing
 sexuals, as already  mentioned.  The sexuals
 are released from the  colonies to take part
 in  high-altitude,  dispersive  mating flights
 occurring throughout a large portion of the
 year  (Fig. 6).   The  queens often fly or are
 wind-carried 1/4 to  1/2 mile or more before
 settling to the ground, although  most settle
 at  shorter  distances.   Although data  are
 mostly  unavailable,   my impression is that
 the newly mated queens settle preferential-
 ly in disturbed, partly vegetated  habitats,
 effectively colonizing them.
   The ecological disturbance on which fire
 ants depend may not need to  be gross, but
 can be rather a specific disturbance of the
 ant community  only. This phenomenon was
 first observed by Summerlin, Hung and Vin-
 son (1977), who treated with  mirex an ant
 community in which S. invicta was  a minor
 component. The mirex killed  almost all of
the ground-nesting ants, but after recoloni-
zation, S.  invicta and another  weedy spe-
cies,   Cononryrma   tnsana,   had   greatly
increased dominance over  all species (Fig.
7).   Many  of  the native  species  did not
reappear  in the  course  of  this study.  Be-
cause the fire  ant has such a great advan-
tage over other ants in  colonizing,  removal
of the native ants resulted in a community
consisting mostly of fire ants and another
weedy ant species.
   These  results were recently  experimen-
tally confirmed by Buren and Stimac (per-
sonal communication), who treated one set
of plots with mirex, one  with  Amdro and
left  one  untreated  as  a  control.    Plots
treated with  either insecticide  showed  a
reduction in all ant species, but  were recol-
onized  to much higher  levels and greater
dominance  by  fire  ants.   Untreated plots
showed either no change or decline in fire
ants.  Clearly,  the specific  ecological stress
or disturbance  of the ant  community with
insecticide allowed the  fire ant to  increase
its size and dominance over native ants.
   Buren  et al.  (in press)  have provided a
computer-simulation  model  of  how  this
takeover  might  proceed.    They  reasoned
that there  are  a limited  number  of sites
available  for  ants in a habitat, and  these
sites can  be occupied by fire  ants  or other
ants.   In a fully stocked habitat, an  ant of
any species  can appear in an area only if a
site  becomes  available  through  death of a
resident colony or appearance of a new site.
The probability that a particular species will

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 £
  ;
           ;
           .
           i
                                                           Fig. 6.  Occurrence   and  size   of
                                                                  mating  flights  throughout
                                                                  the  year in  N.   Florid*
                                                                  (from NJorrill, W. L.  1974-
                                                                  Environ.  Entomol.   3:265--
                                                                  271).
Fig. 7. Changes in an ant commu-
       nity after treatment with
            ^.  Ten  other species
       are lumped together.  The
       two weed species, S. (nvic-
       ta and Conomyrma fnsana,
            • town separately (from
       Summerlin et  al.    1977.
            ron.  Entomol.   6:193-
       197).
f  \
    •^
      ^ A
                                                                                      SKClO
                                                    j   A  s   o


-------
 succeed in occupying fin  available site will
 depend upon its relative ability  to colonize,
 an ability  in  which we know  the fire ant
 holds a many-fold advantage over most na-
 tive  ants  because  of the large  number  of
 sexuals it produces.  Because colonization
 by any species depends on the availability  of
 sites, the rate at  which sites become avail-
 able, in  combination  with  the  colonizing
 advantage of  the  fire  ant, will determine
 the rate at which the fire ant will increase
 its dominance  in an area.  Whether the sites
 are made  available by  natural colony mor-
 tality or by insecticide  treatment is imma-
 terial.  Buren  et  al. showed that imposition
 of 95% annual  mortality through insecticide
 treatment  would cause a population consist-
 ing of 1%  fire ants and 99% other ants  to
 convert to  one consisting of 99% fire ants
 and 1% other ants  in only four or five  years.
 Lower annual  mortality  rates  lead  to  an
 exponential increase in  the  time it  takes
 fire ants  to reach the same level of  domi-
 nance.  Thus,  simple as  this model  is,  it
 explains the basic experimental  findings of
 Buren and Stimac, and is supported by much
 biological information on fire ants.
    The  implications of  these  studies  are
 clear:  Large-scale, unspecific control pro-
grams  such  as those   utilizing  mirex  or
 Amdro actually aid rather than hinder the
establishment and  spread of the fire ant and
accentuate  its  dominance  over native ants.
 The reversal of this  dominance  appears to
 be very  slow  and  is poorly understood at
 present.   Clearly,  the relationship of  the
 fire ant to other native ants in its communi-
 ty is  an area  of utmost  importance about
 which we know very little.  No program to
 manage fire ants can hope to succeed with-
 out such knowledge.
    The fourth  and fifth weedy properties of
 S. invicta are rapid growth and early repro-
 duction.  Fire ants achieve rapid growth by
 an emphasis on cooperation  rather  than
 competition during the founding and incipi-
 ent colony  period.  Thus, a number of newly
 mated queens may share excavation of  the
 founding nest and rearing  of the  first brood
 of minims.  This cooperation, called pleome-
 trosis,  increases  the  chances  of surviving
 the founding period and results in incipient
 colonies with  about three  times as many
 minim  workers as  colonies founded by a
 single  queen (haplometrosis).   Because of
 the nature of exponential growth,  this initial
 boost  is  maintained throughout  the early
growth period,  so that  after 1/3  of a year,
 pleometrotically  founded  colonies are still
 three times as large as haplometrotic  ones
(Fig. 8), a  clear advantage in  competition
and survival of winter or drought.
   Once past the  incipient period,  colony
growth is rapid, requiring about three years
to reach upper colony size limits, and repro-
duction is early (Fig. 9). At the end of two

-------
  1000,
g  100 ^
*
o
g
    10
          19 OUEENJ ( «>BI

          10 ( n-tl



          I l»-
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                                           27
 desperately needs attention.
    An interesting aspect of fire ant colonies
 as they grow is that they change from being
 rather poor competitors, in fact from co-
 operators, to being rather good competitors.
 The most obvious aspect of this change  is
 that   colonies become territorial  as  they
 grow.  That is, they defend a plot of ground
 against  all other fire ant colonies, and pos-
 sibly to some  unknown extent against some
 other  ant species as well. The size of these
 colony  territories  is  proportional  to  the
 number of  workers in the  colony, and  a
 consequence of territorial behavior is  that
 fire ant populations  reach an  upper limit
 determined by the territory size of mature
 colonies.  A typical figure for pasture land
 seems  to  be about 20 to 25  colonies  per
 acre.   Establishment  of new fire ant colo-
 nies within territories occupied  by  mature
 colonies is probably impossible, for the resi-
 dent workers kill newly mated queens  that
 land in their territory.
    A final,  brief point concerning the ecolo-
 gical nature of the fire ant is its seasonali-
 ty.   Solenopsis  invicta  is  a tropical  ant
lacking  a  true hibernation,  yet  it  shows
strong seasonal!ty in many aspects of colony
life. Most evidence indicates that this sea-
sonality is probably imposed upon a basically
unseasonal life cycle  by seasonal fluctua-
tions  in  temperature and, to some degree,
rainfall.   The influence of temperature on
 ecology and  life  cycle  may be  one more
 underappreciated factor in fire ant biology.
 We  are accustomed to thinking  of the ef-
 fects of temperature on the rates  of various
 processes, but there are ample hints for fire
 ants that temperature effects are often in
 the  nature of thresholds  or triggers.  Ex-
 amples of  processes  whose occurrence  as
 well as rate is  controlled  by temperature
 would  be  worker brood  production,  alate
 brood  production, mating flights, and  suc-
 cessful colony founding.  Such knowledge is
 of obvious importance to  our understanding
 of  the  potential  and realized  ecological
 range of the fire ant.
   Summing up  the ecological nature of S.
 invicta, we conclude that  it is an  opportun-
 istic, weed species  depending on  ecological
 disturbance for its continued existence and
 success.

 COLONY FUNCTION
   By   colony function, I  mean  simply the
 general internal  workings and social  rela-
 tionships within  the colony,  including beha-
 vioral,  physiological, and morphological as-
 pects.   A useful  organizing principle for my
 remarks is to consider  colony life  from the
 point of view of production.  Organisms (and
 colonies) carry out the production of  new
 biomass in such a  way  as  to  maximize
reproductive success,  this being  merely  a
restatement  of  the principles  of natural

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                                          28
selection.  Production of any kind requires
some degree  of control, as any factory own-
er knows, so let  us  look at colony function
from the points  of  view  of production  and
its control.
   By production, I  mean the obtainment of
raw  material in the form of  food, water,  and
air  and their conversion into new biomass.
There are two  primary  localities for  the
production of new biomass in the colony: (1)
the queen produces new biomass in the form
of  eggs.   A queen in  a  large colony is
capable of producing her own weight in eggs
every  24 hours  or  less.   (2) The  larvae
produce  new biomass as  they grow  to  be-
come  new  individuals,  either workers  or
sexuals.   Under  some conditions, colonies
are capable of tripling their biomass (mainly
workers) in a month.
   Under the heading of  control, I   would
place a variety of behavioral and physiologi-
cal   phenomena,  many  of  which have  re-
ceived substantial research attention.  As
related to production, control  deals with
problems of the routing of materials (where
does it go, and when?), rates of production
(how  fast?),  and allocation  of  resources,
including labor (how much to each subcom-
ponent?).
   A  partial list  of  control mechanisms
would include: (1) pheromones (chemical sig-
nals); (2) various  behavioral interactions; (3)
trophic relations (food flow and use); and (4)
therm ©regulation.  This list is not complete,
but will suffice for this general discussion.
   Pheromones have received a good deal of
attention and a number of effects have been
attributed  to  pheromonal  action.   Because
the queen is the only reproductive individual
in the  colony,  there  is  widespread belief
that she must  also be the center of much of
colony coordination.  At least three biologi-
cal characteristics of  queens  have  been at-
tributed to pheromones presumably secreted
by her.  The  first  and most  obvious queen
attribute is her attractiveness to her work-
ers.  In a normal colony,  the queen is always
mobbed by a  dense retinue of workers who
cluster around her, groom her, feed her,  and
whisk away any eggs she may lay.  A number
of workers (human)  have shown  that  the
attractiveness  of the  queen  appears to be
the result of  a  pheromone secreted by  her
and  extractable from her body.  More re-
cently,  Vandermeer and others (1980) have
shown  that the contents of the queen's poi-
son sac are similarly attractive to workers,
and  it is  possible,  though not yet  certain,
that this is the same attractant described by
earlier workers.
   A  second   and  third  attribute of  the
queen  is that  her presence prevents winged
female sexuals (alates) from breaking off
their wings (de-alation) and undergoing ova-
rian development.  Fletcher and Blum (1981)
have recently presented evidence  that both

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                                          29
of these effects  are  caused  by pheromones
produced by the queen.  Whether all three of
these effects are caused by a single chemi-
cal compound or by several  is, at present,
unknown.    If  the fire ant parallels  the
honeybee, there are probably several phero-
mones with  complex  actions  and interac-
tions, and  the  unraveling  of this chemical
annd  biological  Gordian  knot  will occupy
years to come.
   A number of  other pheromones also aid
in colony control. Let me  list them briefly,
pointing  out that  many  additional phero-
mones probably still  await  discovery.   (1)
Larvae and pupae are  coated with a surface
pheromone that causes workers to recognize
them and  presumably to  respond appropri-
ately to them  by feeding them, grooming
them,  and transporting them  to favorable
locations  within  the  nest.   This chemical
signal acts only upon  contact, and its nature
is not yet  known.  (2) Workers recognize
dead ants by chemical signals that the  latter
emit, and  respond by removing the   dead
from the nest.  While this case stretches the
definition  of  pheromones   somewhat,  the
death signals are, at  least  in part, chemical
and appear within an hour of death.   (3) I
have mentioned the territorial nature of fire
ant colonies.  Although little hard evidence
has  ever  been advanced,  it has long been
believed that recognition of colony member-
ship is mediated  by a characteristic colony
odor shared by all members of a colony and
different  from  that  of  members  of  other
colonies.  (4)  Recruitment of food and new
nest-sites is mediated by a trail-pheromone
produced in the Dufour's gland in the gaster
of  workers.   In the  early sixties,  Wilson
(1962) showed that a fire ant forager return-
ing from a  food find  applies  a pheromonal
trail to the  substrate using the sting.  Nest-
mates follow  this trail outward to find the
food, and may  in their turn  reinforce the
trail  upon their own return  to  the nest.
Each worker's contribution is both attrac-
tive and ephemeral, lasting perhaps 20 min-
utes or  so, so  that the relative rates of trail
reinforcement and loss determine the level
of pheromone in the trail, and this in turn
determines how  many workers are recruited
to  the  food.    This  chemical  recruitment
system  regulates the mass response  of the
colony  to  the  food  (or  nest-site)  and is
capable of quite fine adjustments to varying
quantity, quality and distance  of food.
   While on the subject  of recruitment  and
foraging,  I  should mention   that  fire  ant
foragers do not generally sally forth directly
from the nest.  Rather, the entire  territory
is underlain by  an anastamosing system  of
underground foraging tunnels.  Recruitment
probably actually takes place from  the exits
of  these  foraging  tunnels throughout  the
foraging territory.
   Behaviorally  and morphologically,  colony

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                                           30
 function  is dominated by an  intricate  divi-
 sion  of labor based  upon caste  (queen  or
 worker) and worker size and age.  The basic
 division of labor, as in  all social insects, is
 that  of reproduction—the queen lays all the
 eggs  and the workers do all the work.  With-
 in  the  worker caste,  however, labor is fur-
 ther  subdivided on the basis of  worker size
 and  age  (Fig.  10).   In  a  mature  colony,
 workers range in size such that the largest
 weigh about 10 times as much as the small-
 est.  Colonies  begin life  with only  small
 workers but  as  they grow, the proportion
 and size of larger workers gradually increas-
 es, and there  is no indication that  this trend
 ever stops. This phenonemon adds a develop-
 mental-time dimension to any discussion of
 division of labor by size that has heretofore
 not been  recognized.   In any  case,  several
 general differences in behavior are apparent
 between  large   and  small  workers—large
 workers carry and  handle larger  particles
 and brood,  they are more likely to cut up
 insect prey, less likely  to  feed  on liquid
 food,  and less likely to function in brood and
 queen care.
    Large  workers live much longer than do
small workers, but all workers pass through
a series of changes in the labor they carry
out as they grow older.  These  age-related
changes are superimposed upon and modified
by  the  division  of labor by  size already
discussed.   Early in their adult lives, work-
Fig. 10.  Division  of  labor by  worker size
         and age in S. invicta.  Top: Sixe-
         frequency distribution  of  worker
         size in colonies  during growth and
         maturity (after Wood and Tschinkel
         1981.  Insectes  Soc.   28:117-128).
         Middle:  Age, size, task, and loca-
         tion in nest.  Age on vertical  axis,
         size (head width) on horizontal axis
         (data from Miranda, J.,  and S.  B.
         Vinson 1981.  Anim.  Behaviour 29:
         410-420).   Bottom: Size of particle
         carried by worker  in  relation  to
         worker size.  Note log scale (data
         from Wilson, E.  O. 1978.  J.  Kan-
        sas Entom. Soc. 51:615-636).

-------
                                          31
ers act as nurses,  taking care of the queen
and brood, and are thus found mostly in the
brood  area.   Small workers spend  a larger
proportion of their lives as nurses than do
large  workers,  the largest essentially not
functioning as nurses.  As the workers age,
they leave the brood  area  and move to the
peripheral nest areas  to take up their roles
as reserves, for want  of a better name.  As
such, they receive  food from foragers re-
turning to the nest,  transfer it to the nurses,
and take  part in  the many  other nest func-
tions such as construction, sanitation, de-
fense,  and others.  During this period, large
workers are more likely to  store liquid food
in their  crops for  longer periods  than are
small workers.  Only  during  the  last 25 to
40% of their lives do workers  ever leave the
nest to forage.   During this final  period,
small workers are more likely to forage on
liquids  and larger  workers  on  solids  and
insects.
   It should  be  noted that none  of these
behavioral differences with age and size are
sharp,  and that there  appears to  be a good
deal of flexibility  of  roles built  into  the
system.   We should  also  not forget that
these patterns have been  worked  out for
small colonies, and  that there may be both
quantitative and qualitative changes in them
as the colony grows and ages.
   Let's  turn  now  to  the flow of  the food
throughout the colony, the so-called trophic
relationships.  Most of the fire ant's natural
diet is insects and other small invertebrates,
although carrion, honeydew,  and  some plant
material are also taken.  Only about  10 to
20%  of the colony acts as foragers  at  any
given time, so that  the  food they collect
must  be shared with  the other 80 to 90% of
the colony.  Workers  themselves  utilize only
a small proportion  of the colony's food,  and
what  they do utilize is primarily carbohy-
drates and sugars.  The bulk  of utilization is
by the two most  important producers in the
colony,  the queen  and the larvae,  both of
which get the lion's share of  the protein as
well.  Once foragers have brought the food
back to the nest, it enters a subtle complex
web of exchanges,  conversions, and process-
es (Fig. 11), that we are finally beginning to
unravel,   thanks  to  the  work  of   such
researchers  as  Howard,   Sorenson,   and
others.  Foragers pass the food to a group of
younger workers called reserves,  who in turn
transport  it from the nest periphery to the
brood and queen area where they share it
with  the  nurse  workers.   Nurses are  the
youngest class of workers, who carry out the
functions  of brood and queen care and hence
are usually found in the brood area.  Nurses
probably convert some of the food to gland-
ular secretions, and they pass both these and
liquid food to the second  and  third stage
larvae and to the queen, all of whom  subsist
entirely  on a liquid diet.   Solid  food is

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                                          32
               IARVU I
 LARVAE II, III
                 FOOD
Fig.  11.  Trophic relationships  within  col-
         onies  of S. invicta.   Arrows indi-
         cate the direction of food flow.
passed to the fourth stage larvae, who pro-
cess it, utilize part, and  probably pass some
of it back to the workers in partly digested
form.  They may also pass back glandular
secretions of an  unknown nature as well as
excreted material. The queen may also pass
back excreted or secreted material, but she
obviously produces eggs from what she eats.
Many of  the eggs hatch, which is what eggs
should do, but there is evidence that some
may be eaten by the  newly hatched, first-
stage larvae, an added complexity in trophic
relations.   We  have recently found  that
larvae are needed for continued egg-laying
by the queen.
   The image that is emerging with respect
to the  flow and  use of food  is  that  the
various members of the colony are all pieces
of a  whole metabolic  system  where each
plays a  distinct metabolic behavioral role
and all are interdependent.  As yet, we have
only a dim idea of how this metabolic labor
is subdivided and specialized  among colony
members, but  we know enough to  see  the
beauty and sophistication of it.

IMPORTANT UNANSWERED QUESTIONS
   There are many  important unanswered
questions concerning the biology of S.  in-
victa,  and  their discussion  could  occupy
whole  conferences.   Let  me deal with  a
sampling of some questions I feel are impor-
tant or interesting.
   I.   Certainly one  of  the largest  holes in
the fabric of our knowledge of fire ants is in
the area of the  population dynamics of colo-
nies.   In Fig. 12, I  present a hypothetical
survivorship curve based upon my  impres-
sions  and  very  sketchy data.   The  curve
incorporates the  following characteristics:
(a)  very high  mortality during the mating
flight and colony founding period, with per-
haps as  little  as 0.1% survival; (b)  reduced
but still substantial  and steady colony mor-
tality during the growth phase; and (c) rela-

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                                             33
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           . (MURE COLOtlM
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                TVm« -»
   Fig.  12.  Hypothetical survivorship curve for
            colonies  of  S. invicta.   Note  that
            the proportion surviving is on a log
            scale.
   lively low mortality during the colony matu-
   rity  stage.   We have absolutely no idea of
   what happens to colonies when they get old,
   so I have entered this phase as a dotted line.
   Is there increased mortality during this peri-
   od?  While this survivorship curve may  turn
   out  to be  more  or  less correct in its  out-
   lines, we have no quantitative data on age-
   specific  mortality  during  any of  the life
   cycle phases. This kind of "life-table" infor-
   mation is absolutely  necessary for an ecolo-
   gical understanding of the fire ant, let alone
   a management program.  Ultimately, if we
   are to manage it  intelligently, we will need
   this  kind of information for each of the
   different environments  that  the fire ant
occupies.
   II.   The relationship to native ants has
already been mentioned.  Although  an ex-
otic, the fire ant is a member of a biological
community,  relating  in  some manner to
other members of  that community.  I have
already provided compelling  evidence  that
its relation to other ants is a key component
in our understanding of fire ant ecology, yet
only scattered,  generally unquantitative in-
formation is available.
   HI.  While  we know generally what fire
ants eat,  we have only  poor quantitative
knowledge of the impact of their feeding on
the community in which they live.  Further-
more, individual colonies show idiosyncratic
food preferences whose meaning and origin
we  do  not understand.  Surely,  this  is an
important  aspect of any bait-based fire ant
control method.
   IV.  The process of colonization of avail-
able  habitat  is poorly understood.    How
much control do queens exercise over the
sites  in which  they settle after a  mating
flight?     How  are  these sites selected?
Which site and other physical characteris-
tics influence  success of  colony foundation
and  how  much?   The founding period  is
obviously one of the most vulnerable stages
of colony  life,  so  that, from the manage-
ment point of view, knowledge of this period
seems imperative.
    V.  The number  of mated  queens during

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                                          34
various parts of the life cycle is emerging as
an important question.   I have mentioned
that colonies are often founded by  groups of
mated queens in cooperation, and we have
some dim idea of what might be the advan-
tages of such behavior, though none are as
yet quantitatively characterized.   We know
that,  during the post-founding period,  the
workers  kill all but one queen, so that the
colony enters the growth phase with a single
queen. It is therefore interesting  that ma-
ture  colonies often  have  more  than  one
inseminated queen, capable, under  the right
conditions, of laying  eggs.   In most of the
fire  ant's  range, these  extra queens  are
inhibited from laying eggs, but can take the
place of the colony queen-mother if she is
lost or dies. In some of the western parts of
its range,  all  of  the mated queens  in  a
colony may lay eggs (polygyny), and a colony
may contain hundreds or  even thousands of
laying queens.   What brought about this
profound change,  and  why?   What is  the
effect of queen number during various parts
of the colony cycle on the ant's ecology, and
possibly on its potential range?  What is the
source of these multiple mated queens? Are
they adopted after mating flights?  If so,
why are they not killed?  Does mating take
place  in the nest?  If so, what is the genetic
importance, and what effect does it have on
the westward spread?  If  mating flights are
unnecessary in polygynous colonies, can the
ant survive in areas where there is no sum-
mer rain, such as California?
    VI.  Finally, the fact that, in comparison
with  those  of Brazil, the fire  ants  in  the
USA  are all much more closely related to
one another because they  are descended
from a single pair or small number of indi-
viduals has received practically no  atten-
tion.   According to kinship selection theory
and plain com mon sense, this situation could
bring about major differences between  the
biology of  the fire ant in the USA and its
biology in  Brazil.   For example,  it might
affect the degree of cooperation  and  thus
success during the founding period, it might
affect the  degree of colony distinctness  and
competition, and  it  might  even affect  the
mode of reproduction.

SUMMARY AND FINAL REMARKS
    In closing, the fire ant is a weed species
whose  continued  existence is  favored by
human ecological meddling. Its  success as  a
weed  is based  on high reproductive rate,
excellent dispersal and colonizing ability,
rapid colony growth, and early reproduction.
What we do not know about its  ecology  can
indeed  hurt  us,  as is becoming clear  with
respect  to  large-scale,  insecticide-based
control programs. Colony life is dominated
by  a complex and subtle  division  of labor
and an intricate set of trophic relationships.
These and  various behavioral  control mech-

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                                          35
 anisms regulate colony  function  to  maxi-
 mize reproductive success.
    Seen from  the  biologist's point of view,

 without the rancor and heat characteristic
 of  the political arena,  the  fire ant repre-
 sents  a wonderful  research  opportunity al-

 most unique in the  history of myremecology.

 The ant's abundance,  ease of maintenance,

 and general habits  make it an outstanding
 subject for  research,  while  our  society's
 relatively high  need for knowledge of this

 ant gives us the opportunity  to  carry  out

 this research. This potential knowledge may

 some day more than repay us for the real
 and imagined damage  and  aggravation  the
 fire ant caused along the way.

    Whatever we, as a society, decide to do
 about  the  fire  ant, whether  it be to fool

 with it or leave it alone, we are obligated to

 do  it intelligently,  with a sound foundation

 of  biological knowledge.  If the decision is

 to "do something" about the  fire ant, even if
 only in certain  situations, we must know a

 great  deal  more of the fire  ant's secrets

 before we can ever  hope for success.
Fletcher, D. J. C., and M.  S. Blum. 1981.
   Pheromonal  control  of  de-alation and
   oogenesis  in  virgin  queen  fire  ants.
   Science 212:73-75.

Morrill, W. L. 1977. Overwinter survival of
   the  red imported  fire ant  in  central
   Georgia. Environ. Entomol. 6:50-52.

Pimm, S. L., and D. P. Bartell. 1980.  Sta-
   tistical model for  predicting range ex-
   pansion of  the red imported fire ant,
   SoZenopsis  invicta, in  Texas.   Environ.
   Entomol.  9:653-658.

Summerlin, J. W., A. C. F. Hung, and S.  B.
   Vinson. 1977.   Residues  in  non-target
   ants, species simplification and recovery
   of populations following  aerial applica-
   tions  of   mirex.    Environ.  Entomol.
   6:193-197.

Vandermeer,  R.  K., B. M. Glancey,  C.  S.
   Lofgren, A. Glover, J.  H. Tumlinson, and
   J. Rocca.  1980.  The  poison  sac of the
   red imported fire ant, Solenopsis invicta,
   queens: source of a pheromone attract-
   ant.   Ann. Entomol. Soc. Amer.  73:609-
   612.

Wilson,  E. O.  1962.   Chemical communi-
   cation among workers  of  the fire ant,
   Solenopsis  saevissima   (Fr. Smith).   I.
   Organization of mass-foraging.   Anim.
   Behaviour 10:134-149.
REFERENCES
Buren, W. F.  1972.  Revisionary studies on
   the taxonomy of the imported fire ants.
   J. Ga. Entomol. Soc. 7:1-27.

Buren, W. F., J. L. Stimac, and F. G.  Max-
   well. 1982.  A model of imported fire ant
   populations: implications  for  a difficult
   problem. Science  :  .

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                  THE STATE PERSPECTIVE OF THE IMPORTED FIRE ANT
                                     Reagan V. Brown
                                       Commissioner
                             Texas Department of Agriculture
   For  many  years, the imported fire ant
was  considered a rural problem.  It repre-
sented a headache for the farmer, rancher,
and rural  landowner, but was of little con-
cern to urban residents,  and  therefore  to
urban legislators.
   Today,  the situation has changed dra-
matically.   No longer  are our  urban parks
and  playgrounds  free  from  this  damaging
and dangerous pest.  The appearance of fire
ant mounds on football fields, in city parks,
and on  urban  lawns  has  brought into sharp
focus the  fact that the fire ant  is a  concern
of all citizens.
   The  imported fire ant now totally infests
several  southern states,  and threatens  to
overrun several others.    Texas,  Alabama,
Arkansas,   Florida, South  Carolina, North
Carolina,  Mississippi, Louisiana, and  Georgia
all report  infestations, and Puerto Rico has
just recently been added to the list.  In the
south a  total of 230 million acres are infest-
ed.  In Texas alone, the fire  ant now infests
45  to 50  million acres,  and  the  number
grows each day.
   The  fire ant is marching like  Sherman's
army throughout the South, and it is safe  to
say that the threat is no longer of  infesta-
tion, but of invasion.
   There  is a very real need  today to ad-
dress the fire ant problem in a calm, ration-
al  manner, especially in light of the  sensa-
tionalism  surrounding the issue.  This con-
ference will do a great deal to fulfill this
need.  But the fact remains  that the fire ant
is  one  of  the  most damaging and  insidious
pests to come down the pike in a long while.
Consider these  facts:
   1.  Each month,  two-and-a-half million
Americans are stung by the imported fire
ant.   Some 4,000 of these victims experi-
ence  allergic   reactions.    In  Texas,  two
deaths have  been  officially attributed  to
fire  ant  stings.   Deaths  also  have been
reported in Georgia, Florida, Alabama, Mis-
sissippi, and North Carolina.
   2.  Productive  farm  and ranch land  is
being abandoned because  of  fire ant  in-
festations. Infested counties in Texas aver-
age 80 to 90 mounds per acre.  However, we
have seen up to 600 mounds per acre in very
severe  cases.   From  a purely  economic
viewpoint, the  question must be raised as to
what effect this will have on property val-
ues in both rural and urban areas.
   3.  While   the   economic   impact   on
stockraisers can be fairly easily determined,
an unknown factor at the present time is the
extent of  damage to wildlife. Fire ants will
viciously  attack new born calves,  but they
                                         36

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                                         37
also  will kill quail, ground  squirrels, young
deer, and even earthworms.
   4. So far, the imported  fire ant has not
moved into the colder states,  nor farther
west than Texas. However,  the fire ant is a
notorious "hitchhiker."  Every  state is vul-
nerable as  long as the possibility exists that
the fire ant could accidentally be introduced
through  interstate movement  of  vehicles
and products.
   5.  Preliminary  studies  show  that fire
ant  infestations  can  definitely   decrease
yields in some crops.   One study documents
a  5.6  bushel-per-acre  decline in soybean
yields in infested fields.  Yield damage also
has been seen in corn crops. The spread of
the fire ant into major citrus and vegetable
producing  areas of the nation—such as  the
Lower Rio Grande Valley of Texas, where
much harvesting is done by hand—could pre-
sent serious  danger to  workers who harvest
these crops.   A point could be reached at
which  it would  not be possible for workers
to even enter the fields.
   6.  Definitive  economic  impact studies
have not been  conducted recently.   How-
ever, in 1977 it was estimated that the nine
infested southern states suffered crop losses
and  pastureland damage of over $50 million.
That amount is certainly greater today.
   The magnitude of the fire ant infestation
in the South  is alarming.  But equally worri-
some  is the speed at which  this pest has
spread.  Texas, one  of the most  seriously
affected southern states, offers a good ex-
ample.  In 1973, 57 of 254 counties in Texas
reported fire ant infestations.  By 1975, the
number rose to 71, and by  1977 the total
stood at 91.   As  of this month, the  list
includes 110 Texas counties,  some in  the
western-most areas of  the state.   Several
scientists at  a  recent  meeting in Texas
pointed out that control pesticides with long
residual qualities,  now  banned, are still in
the soil and are helping  keep down insect
populations.   As  these chemicals degrade,
we  could see  even more  rapid growth in
populations  of several damaging insects, in-
cluding the fire ant.
   The  following  reports from  individual
states give some indication of the scope of
the problem:
   From the Alabama Division of Plant In-
dustry:  At the present  time, only three of
Alabama's  67 counties  remain free of the
fire ant. The greatest number of complaints
come from  forage farmers,  but calls also
are received from nurserymen, homeowners,
school officials, and others.
   The Arkansas State  Plant Board reports
that  population density  has  increased dra-
matically over the past two or three  years
as no control program has been in existence.
   Every land acre in the state of Florida is
infested with the imported fire ant, accord-
ing to the director of the Florida Imported
Fire  Ant Program.   He reports a  sharp
increase in  the number of  fire ant stings
among  workers in  citrus groves, as well as
damage to  young  citrus   trees caused

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                                          38
 by ants girdling the trees.
    Increases in fire ant populations on new-
 ly-developed apartment,  condominium, and
 business sections has  focused the problem in
 many  of South Carolina's urban areas, ac-
 cording to state entomologists.
    North Carolina reports a somewhat less
 severe infestation problem than most other
 southern  states.   Because of  the limited
 problem,  state entomologists report that
 they are in a position to successfully control
 the spread.   Officials, however, underscore
 the continued  need  for a control  material
 that is inexpensive,  effective, and can  be
 applied during  most of the spring,  summer,
 and fall months.
   Mississippi reports that the ant is rapidly
 moving into  northern portions of  the state
 that formerly  were  fire  ant free.   State
 officials report serious problems caused  by
 the fire  ant undermining levees  used for
 flood  control.  In addition, the number  of
 pine  seedlings  destroyed by the ant  is
 increasing.
   In Louisiana, it has become necessary to
 cancel recesses at some schools due to fire
 ant infestations on playgrounds.  Pest con-
 trol officials  report that since June of 1978,
 population density of the imported fire ant
 has increased by 75 percent.
   Officials of the Georgia Department of
 Agriculture indicate that the fire ant, after
being eradicated from much of the  state
with mirex, reappeared after the chemical
was restricted,  and its use banned.
    In my own state, the House Select Com-
 mittee on Fire Ants said, and I quote, "The
 problem  has  passed the  serious level and
 reached the critical stage."   The situation
 was deemed serious enough that the Gover-
 nor  this  spring  released   an  additional
 $500,000  in emergency contingency funds to
 fight  the  fire ant,  an  amount that  was
 matched by the Texas  Department  of Agri-
 culture's own contingency funds.
    As you  can see, the magnitude of the
 problem facing these southern states is im-
 mense.   Most officials concede  that the
 imported fire ant will never be eradicated in
 this country,  but  only  controlled.   Because
 of the threat to human lives and property, I
 cannot emphasize strongly enough the need
 for a  nationwide  mobilization to stave off
 this invasion.  There is virtual  across-the-
 board  agreement  that  the following steps
 must be undertaken if we are to achieve the
 control that is  so desperately needed:
    1.  The U.S.  Environmental  Protection
 Agency  must  make  speedier decisions  in
 granting experimental use permits  for new
 control chemicals, so that effectiveness and
 environmental  safety can be  more rapidly
 determined   for   promising  new  control
 agents.
   2.  In many cases, state funding for fire
 ant research is nearly  as great as federal
 funding levels, and we  feel  this is  inequit-
 able since the fire ant is a national problem.
 We must renew our  commitment to discov-
ering new biological controls,  as  well as

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                                           39
 effective,  safe  chemical controls, and the
 federal government  must  bear a  greater
 share of the load.
    3.  U.S. Department of Agriculture fund-
 ing for fire ant control currently stands at
 $5.9 million, to be divided among nine states
 and one commonwealth.  This amount could
 easily  be utilized  in  Texas  alone.  Federal
 funding levels  for fire ant control should be
 increased  and  maintained  until  effective
 control is achieved.
    4.  Two weeks ago, the Southern Legisla-
 tive  Conference of  State  Legislators  ap-
 proved a resolution urging each member to
 support the allocation of state funds  for
 imported fire ant research and control.  The
 resolution also  supported  several of   the
 needed steps that I detailed previously.  This
 action  should  serve  as  a   model   for
 legislators at the national level.
    5.  Perhaps  most  important,  we  must
 reach a national consensus among all con-
 cerned on how to  best achieve  the goal of
 fire ant control. This includes environmen-
 tal groups,  researchers,  government  agen-
 cies,  and  all  others.   Only through  co-
 operation can  this  be  achieved.  Control of
 the imported fire ant  is in the interest  of,
 and  not contrary to, environmental protec-
 tion.
   I hope that  I have shed some light on the
seriousness of this problem and of the diffi-
culties  facing  those states that must deal
with it.  I  feel  this summit meeting is a
giant step forward in the process of gaining
the consensus and understanding that I men-
tioned, but it is only the beginning.
   The  situation  damands  action.   Let us
work  together to make this conference  a
success  and, ultimately, to achieve victory
in the fight against the imported fire ant.

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THE ENVIRONMENTAL PERSPECTIVE OF THE IMPORTED FIRE ANT

                        Carolyn Carr
                        Vice President
                 Gulf Coast Region, Sierra Club
       (Report not available at time of symposium completion)
                            40

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Panel Reports

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                                PANEL I

SOCIO-ECONOMIC FACTORS RELATING TO THE EPA AND ITS MANAGEMENT
                       J. Charles Headley, Chairman
                          University of Missouri

                    Arnold Aspelin, Reporter, OPP-EPA
                            Washington, D.C.

                           C.T. Adams, USDA
                           Gainesville, Florida

                               Ted Brooks
                        Mississippi State University

                             Ralph E. Brown
                    Florida Department of Agriculture

                            Gerald A. Carlson
                      North Carolina State University

                       Carolyn Carr, Vice President
                   Gulf Coast Region of the Sierra Club
                            Auburn, Alabama

                           Frank James,  M.D.
                           San Antonio, Texas

                             Quentin Jenkins
                        Louisiana State University

                         John Schaub, NRED-ERS
                            Washington, D.C.

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INTRODUCTION
   It is important  to evaluate the socio-
economic aspects of the imported fire ant
(IFA) to assure that the benefits and costs
of alternative  actions that could be  taken
toward  the ant are  considered.  It is also
important to consider the effects of the ant
on people  and their lives such  as people's
perception of  the pest  and the effects it
may have on their health and happiness.
   This  report evaluates the  benefits  of
controlling  the ant, costs of  large  scale
treatment  programs, and the role  of and
need  for education, information,  and  re-
search in support of cost effective manage-
ment of the IF A.

EVALUATION OF BENEFITS AND COSTS
   Benefits of IFA Control on Agricultural
   Sites
   Benefits from IFA treatment vary among
different sites.   Generally, the benefits  of
control  on non-agricultural sites are higher
than on agricultural  sites.  The data  are not
complete enough  to support  the assertion
that  the IFA is truly an economic  pest  in
terms of agricultural losses.  The IFA seems
to be primarily a nuisance and human health
pest  rather than  a pest  that causes signifi-
cant actual losses on large numbers of farms
in the  southeastern United  States.   IFA
control in agriculture, however,  can be ben-
eficial in some situations.  Areas that might
benefit most  from treatment are (1)  live-
stock  production sites,  (2) hay  production
land,  (3) soybeans,  and (4) fruit, vegetable,
and nursery crops.  Studies report losses in
hay yields,  quality of hay, soybean  yields,
and damage to equipment from IFA.  Other
studies report livestock losses  from  IFA
stings.
   Studies  by Lofgren  and  Adams  (1981)
showed an  average decrease of 14.5%  in
soybean yields for  eight paired  fields  with
infestation rates of 49  to 176 mounds per
ha. These losses are primarily due to  har-
vesting difficulties  caused by  the ant.  Lof-
gren and Adams are continuing these studies
in an  attempt to cover more of the infested
area.    At  present one  cannot  generalize
from  these findings as to the significance of
soybean losses across the infested area in
the southeast U.S.
   The IFA  also  causes  discomfort  and
health problems to  humans conducting  agri-
cultural activities.  For example, ants  tend
to accumulate  in  hay  bales left  on  the
ground  and  create problems for workers
cultivating and  harvesting fruit  and vege-
tables.  Nursery workers also have problems.
Additionally, nurseries that have  IFA cannot
ship plants to non-infested areas.
 -  A  detailed analysis was made  of agricul-
tural  benefits and costs of IFA controls for
one county in  Florida  covering the  year
1973.   The county has a broad  range of agri-
                                         41

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                                          42
cultural  and   non-agricultural  activities
and a well-established IF A infestation.  The
analysis, completed as a Master's thesis in
1975  (James  D.  Wilson),  indicated  that
treatment  of  15,931  acres  in  Washington
County, Florida, resulted  in  agricultural
benefits totaling $2,128.  Total operational
and  administrative  costs  for  mirex  treat-
ment in the county  were $11,947; for every
dollar   of  agricultural  benefits received,
$5.61 were spent.  The  agricultural benefit
averaged $0.13  per  treated  acre compared
to the average  treatment cost  of $0.75 per
acre for aerial applications.  It is not known
the extent  to  which  these  results can be
extrapolated to other  counties in Florida or
the total nine-state area  where the IF A is
an agricultural pest.
   In conclusion, given  available data  on
agricultural  losses  and  treatment   costs,
broad-scale  control  programs are not war-
ranted.  However, treatment may  be justi-
fied  where  losses  to crops or  damage to
machinery occurs and/or where  IFA  impair
the effectiveness and safety of agricultural
workers.
   Health Effects of IFA and Its Control
   IFA  causes discomfort, a  certain amount
of serious  reactions and  infections,  and  a
smaller number  of  deaths  due to  stings.
Information on  the  size of  the population
and  the characteristics  of  individuals  at
greatest risk from IFA  is inadequate.  To
determine  an economic  rationale for IFA
control, reliable estimates of the number of
persons at risk due to sensitivity are needed.
   The Florida  study by Wilson (1975) in-
cluded an analysis of non-agricultural bene-
fits of IFA control.   The analysis indicated
that the probability  of  a household  exper-
iencing stings during  a year was 0.76.  The
probability  of  a  household  experiencing
stings  and  incurring  professional medical
costs was  0.048,  and the  probability  of  a
household experiencing stings and  incurring
home medical costs was  0.734.  Professional
medical  costs  averaged  $15.75,  whereas
home medical costs averaged $4.36.  Anoth-
er study (Triplett 1971) reported an average
cost  per  person  for  professional medical
care of $28.50.  Wilson projected total home
and professional medical costs in the  county
studied to be $9,154,  with expected costs of
$0.51 per household for professional medical
care for stings and $2.40 for  home medical
care.
   By far  the most concern for  human
health associated with IFA is with hypersen-
sitivity to stings.   Rhoades et  al.  (1977)
recorded allergy systematic reactions as re-
ported to allergists in Jacksonville, Florida.
They found an  incidence rate of 3.8 per
100,000 population.   Rhoades  et  al. (1977)
believe that this is a minimal estimate since
patients who went to  emergency rooms and
those  who were not  diagnosed  were not

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                                         A3
counted.  While the data on health effects,
including secondary infections, is very epi-
sodal, it is clear that the health effects of
the pests cannot be ignored.
   Individuals who are allergic to the IF A
toxins may incur considerable medical costs.
These costs may include desensitization pro-
grams  and/or  hospitalization.   There  are
also  several   well-documented   cases  of
deaths resulting from IF A stings.
   Further  information on costs and bene-
fits  of control are available  from large
consumer surveys.  In 1980 and  1981, the
American Cyanamid  Corporation conducted
two large telephone  surveys on the willing-
ness of households  to  expend resources to
obtain ant-free conditions.  Approximately
82% of those  who said they "had a fire ant
problem"  indicated  they would  treat the
problem.   Seventy-eight  percent  of those
who would treat would  do so with an insecti-
cide.  The surveys indicated that about one
million households  were  treating for  IF A
with insecticides  in 1981, with the balance
(22%)  using gasoline,  boiling water,  or a
cultural practice.   The   areas  treated  by
farmers were: lawns,  73%;  gardens,  58%;
pastures,  54%; row crops, 19%;  and woods,
4%.  The most frequently used insecticides
were chlordane and diazinon.  Seventy-five
percent said  they would pay at  least  $7.50
for complete control of up to one acre.  The
retail  lawn and garden market price  of Am-
dro* is $7.00 to $15.00 per pound.
   There is considerable concern about pos-
sible  short-term   and  long-term   human
health effects from  insecticides  used  to
control  the IF A.  The short-term problem
centers on poisoning due to direct  contact
with  the  pesticides.   In  1975,  the  EPA
estimated  approximately 200  deaths from
pesticides  in 1975  (EPA 1976).   Work  by
Hayes and Vaughn (1977) suggests that about
50 were deaths in which accident could not
be ruled out while the remainder  were in-
tentional, i.e., murder or suicide.  Data do
not  permit  estimates of  deaths  due  to
chronic disease induced by pesticides.
   The possible long-term problems concern
occupational exposure  of some individuals
and the risk to the general  population from
widespread  use of IF A pesticides.  The ma-
jor pesticides (dieldrin, heptachlor, and mir-
ex),  formerly used  for broadcast or  aerial
application  in IFA control, have been can-
celled due  to possible human health  and
environmental risks.  The compounds were
found to be carcinogenic or teratogenic.
   Little research data are presently avail-
able on possible health effects of  the  two
pesticides  now  being  considered  for  IFA
control.   Amdro, a new compound,  is only
conditionally registered.    Ferriamicide,
which is not registered, is a new formulation
of mirex.  While little is known about ferri-
amicide, mirex was cancelled because of its

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                                         44
teratogenic and carcinogenic properties and
because of the dangers posed by its degra-
dates, which include kepone and photomirex.

EVALUATION OF ALTERNATIVE LARGE-
SCALE TREATMENTS
   The purpose of this section is to identify
possible alternative large-scale IF A treat-
ment programs or scenarios and to consider
their costs  and  operational   feasibilities.
Decisions   must  be made  about  chemical
registration for aerial and/or ground broad-
cast application.   Also, decisions  must  be
made on the extent of financial and institu-
tional support for pesticide application pro-
grams, primarily large-scale  aerial  broad-
cast programs:
   Tables 1 through 4 outline  four alterna-
tive  programs including approximate treat-
ment acreages, treatment costs, and indica-
tions of operational feasibility and limita-
tions.  The particulars presented  in  these
tables should not be taken as projections of
actual outcomes, but rather as indicative of
a possible range of outcomes.   Key aspects
in the  design of  the four  sample programs
are as follows:
   A. Chemicals assumed to  be registered
for use    (aerial,  ground  broadcast,  and
mound-to-mound): Amdro and ferriamicide.
   B. Level   of  involvement/support   by
state/federal government units: (1) state/-
federal eradication, totally funded  and sup-
ported by public funds; (2) federal/state/-
local government support and funding of
aerial suppression program,  with cost shar-
ing in line with traditional formulas; (3)
federal/state subsidization of aerial relief
program with landowners paying a signifi-
cant share of treatment costs, e.g., 1/3 (for
Amdro $1.66 of $5.00 per acre of $0.83 of
$2.50 per acre for ferriamicide); and (4) free
market treatment by landowners, where
they incur all chemical and application
costs.  Government roles in research and
educational/extension.
    Each alternative assumes the availability
of Amdro or ferriamicide for purchase by
landowners in addition to whatever treat-
ment would be provided by the publicly
supported programs.
    For the three state/federal alternatives,
the cost per acre of broadcast treatment
                 o
was estimated as:
                    Amdro  Ferriamicide
Pesticide
Application,
guidance,
overhead

$2.65
$2.35
$5.00
$0.35
$2.15
$2.50
   For the non-subsidized relief approach,
costs per treated acre were estimated as:
                   Amdro  Ferriamicide
   Pesticide
   Application,
   guidance,
   overhead
$6.00
$1.00
$7.00
$1.25

$1.00
$2.25

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                                           45
    Table 5 summarizes the evaluation and
 outlines  the key  aspects  of the  four ap-
 proaches.  The  eradication and suppression
 alternatives are not  considered  prudent or
 advisable, as they would cost more than the
 benefits  derived.   Funds  would be  better
 utilized  in other  pursuits.   The subsidized
 relief  type  program  haspotential in  line
 with the approach now being used in several
 states.  Subsidy  levels could be adjusted to
 influence the scope of the program desired
 and/or availability of matching funds.  The
 non-subsidized   market  approach  appears
 most  feasible and would  offer  maximum
 opportunity to tailor treatment costs to user
 benefits.
    Before  any funds  are  committed,  the
 merits of the alternative approaches must
 be compared to  the other public programs
 with claims on federal funds.  An evaluation
 of  the  merits of large-scale treatment  pro-
 grams relative to  other  non-IFA programs
 has not been made. Also, when considering
 alternative  treatment programs,   decision
 makers should be cognizant of the possibil-
 ity of legal action being brought against the
 use of ferriamicide. Since ferriamicide is a
 formulation of mirex,  environmental organ-
 izations will  probably  challenge  any regi-
 stration of  ferriamicide, even registration
 under  Section  18,  emergency exemptions,
since there may be no documented agricul-
tural emergency.
Data for Estimating Benefits and Costs
   The current  data are limited in  their
usefulness to assess  the  costs and benefits
of the IFA  in agricultural crops, livestock,
property,  forestry,  human health,  recrea-
tion, and  wildlife.  Consequently, the bene-
fits and costs of various IFA control options
cannot be fully evaluated.   The following
information  represents  the  types of  data
that should be developed to estimate the
costs and  benefits associated with the IFA.
A. Costs
   1. Crop production
      a)  Extent  and unit  value of direct
          losses from IFA feeding by  crop
          and level of infestation
      b)  Extent  and unit value  of crop a-
          bandonment as a result of  mounds
          or  incomplete harvesting by  crop
          and level of infestation
      c)   Unit value  of reduced efficiency
          of cultivation and  harvesting, by
          crop and level of infestation, for
          equipment  and  labor,  including
          cost of machine damage and re-
         pair, time to perform  activities,
          wage rates, and quality of  har-
         vested product
   2.  Livestock production
      a)  Number and value of death losses
         by  type  of animal  and level of
         infestation
      b)  Veterinary costs by type of  ani-

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                                          46
          mal, frequency of occurrence, and
          infestation level
       c)  Value of reduced rates of  gain or
          level  of  milk production by type
          of  animal,  frequency  of occur-
          rence, and level of infestation
   3.  Forestry
       a)  Extent and value of losses by tree
          type and level of infestation
       b)  Extent and  cost  of replanting by
          tree type and level of infestation
       c)  Increased labor costs of planting
          and harvesting by  tree type, level
          of infestation, and  frequency  of
          occurrence
   4.  Human health
       a)  Number of deaths  from IF A stings
       b)  Treatment  costs  resulting  from
          IF A stings
       c)  Days and value of work  lost from
          IF A stings
       d)  Proportion of the  population with
          systemic sensitivity
   5.  Recreation and wildlife
       a)  Extent and value  of loss  of visitor
          days by  type  of  recreation  and
          level of infestation
       b)  Number and value of death losses
          by species of  animal  and level of
          infestation
B. Benefits
   1.  Extent and value  of IF A as a predator
       by  crop and infestation level:   in-
       cludes  reduced  management  costs,
       decreased insecticide use and appli-
       cation costs, and reduced crop losses
   2.  Impact of  IFA  on beneficial  insect
       populations and  the  resultant ability
       of  beneficials  to  control economic
       pests by crop and infestation level
   3.  Extent and value of predation on nui-
       sance and injurious pests to  humans
       and wildlife
   Data are  also  needed  to  evaluate the
benefits and costs associated  with  alterna-
tive  levels and methods of control programs.
These information needs follow:
A. Information  on  the  current situation:
   geographical distribution, sites affected,
   intensity of infestation, and effective-
   ness of current control practices
B. Identification and description of controls
C. Effectiveness  of controls  by type and
   level of infestation (include resurgence
   aspect of IFA)
D. Costs associated with controls:
   1.  Direct private costs
   2.  Direct public costs
   3.  Indirect private and public costs as-
       sociated  with reduced predation, re-
       surgence,  human health, and  environ-
       mental effects
E. Benefits associated with controls:
   1.  Value of reduction in crop and live-
       stock losses
   2.  Reductions in crop and  livestock pro-

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                                         47
      duction costs
   3. Value  of reduction  in  human health
      effects
   4. Value of reduction in adverse recrea-
      tional and wildlife effects
   When plans are developed to collect data
for analytical purposes,  consideration must
be given to the quality  of the information
required, the  length of time available  to
collect and analyze the data, and  the cost of
these activities. In the case of IFA control
and the role  of various governmental  units,
there are short and longer  term needs.  De-
cisions  on pesticide  registration  for IFA
control  are short-term, while evaluation  of
the control programs is a long-term need.
Economic Effects of IFA Outside Infected
Areas
   The  IFA is a mobile pest,  and some fear
it  could spread to areas  where  conditions
are suitable  for  establishment.    For ex-
ample, the climatic conditions in California
are believed to be compatible with the IFA.
Given the extensive irrigated production  of
fruits and vegetables in California, the IFA,
if  established, could significantly impact
such labor-intensive crops.  Where the dan-
ger of such an agricultural effect is coupled
with  the  effect  the IFA could  have  on
People as a nuisance and health problem, the
federal  government has some responsibility.
The  appropriate federal role  in  this  case
would be operating a quarantine and inspec-
tion  program  to  prevent  the  interstate
spread of IFA.
   There appear to be no significant nation-
al effects of the IFA  on the price of farm
products.  Therefore, consumer expenditures
for food and fiber probably are not influ-
enced by the presence of IFA.

EDUCATION AND EXTENSION ACTIVITIES
   Although several agencies and  institu-
tions have been involved with IFA informa-
tion, more education is needed.  There is (1)
a  lack  of   reliable  information  on  home-
owners' knowledge  and   perceptions about
IFA control  procedures, and (2) considerable
misconception  about effectiveness of  var-
ious pesticides, human hazards from aerial
applications, and  health  effects  of  IFA
stings.  If properly compiled and presented,
the current information  on the IFA can
decrease the human health and agricultural
problems caused by the IFA.
   New  residents  to IFA-infested  areas,
young  children, campers,  and residents  to
newly IFA-infested areas are logical educa-
tion candidates.    Local  television,  news-
paper articles,  and "welcome wagon" associ-
ations are useful media.  Information on how
to  avoid  ants, how  to  control backyard
mounds, and what  to  do if medical help is
needed  should  be presented.  IFA training
could   be  given  in schools together  with
training  for other  dangerous insects and

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                                          48
 plants.
    Special  care  should be directed toward
 individuals  who  are  hypersensitive  to  IF A
 stings.   Information about various precau-
 tionary  and medical  actions  needs  to be
 made  available through school nurses,  4-H
 clubs,  etc.  Consideration should be given to
 forming national information networks  pre-
 dicting likely victims of serious reactions to
 IF A stings.
    IF A  control  recommendations in urban
 areas for individual homeowners  need  spe-
 cial attention.  Methods of control,  speed of
 action, rates per  mound,  and hazards of
 pesticides need explanation.  A regular ex-
 tension  publication to  be used  regionally
 should be a  top priority extension activity.
 Radio  and television programs for  children
 and parents  of young  children  are needed.
 Automatic telephone messages  for  IF A in-
 formation should  be tried, also.
    Information on IF A should accompany
 IF A bait when  it is made  available through
 state and local  programs. The current Flor-
 ida information  sheet  is  a  good example.
 The state departments of agriculture should
 attempt  to   increase  IF A   information
 through their weekly bulletins.
    Schools,  rights-of-way, parks,  and other
public  places often are treated.   Managers
and users  of these facilities  should have
special  IF A training programs  through uni-
versity  extension offices.  Urban pest con-
 trol information from extension seems lim-
 ited  in  many IFA  areas.    Demonstration
 projects  in  urban areas  would be  useful.
 Others that  should  help with IFA training
 are  state  park, public health, and military
 officials.
    As soon  as  more  research is  available
 concerning seedling  damage  and  soybean
 harvest, the  agricultural extension service
 can expand its IFA control recommendations
 to include crop  land.  This could be done by
 soil type, cropping system, and coincidence
 with  adjacent IFA infestations.  Methods to
 avoid IFA damages  must be  included, such
 as changing type of hay-handling equipment.
   Information  directed at  farm  workers
 also  is  needed.   Fruit workers,  hay har-
 vesters,  etc., and their employers can  be
 shown how to avoid  stings.   Farmers need
 information on the effect  of IFA  stings  on
 the availability and productivity of  labor.

GENERAL CONCLUSIONS
   Federally-supported programs aimed  at
eradication or preventing the spread of IFA
have  not been successful.  The current data
are not complete enough to support general-
izations  about the importance of IFA as  an
economic pest across the currently-infested,
nine-state  region.  Therefore, due to uncer-
tainty of success  and the widespread eco-
nomic need,  a rationale for future large-
scale  control programs to eradicate or pre-

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                                          49
 vent  the spread of IF A cannot be defended.
 Funding as well as legal  and technical con-
 straints work against commitment to such
 efforts. A more prudent  course would seem
 to  be to  pursue smaller efforts  to relieve
 the pressure of  the pest  in localities where
 it  is  most critical.  Through the use of
 market alternatives, public and private land
 managers  can  decide   to  apply  controls
 where benefits appear to  justify the costs.
    The appropriate   role  of government,
 especially federal,  is to conduct research to
 provide pest  management information,  to
 operate inspection  and quarantine programs,
 to  attempt  to  protect  areas  not already
 infested, and to see that  public-owned lands
 are managed properly with respect to IF A.

 RECOMMENDATIONS
 Federal funding
 1.  The imported status  of  the IF A should
    not be  considered justification  for fur-
    ther federal involvement in  control  or
    eradication programs.   However, federal
    support of and  involvement in research
    related to IF A should continue.
 2.  Preventing the  spread of the IFA should
    not be considered justification for fund-
    ing federal control programs. Operating
    inspection  and  quarantine programs  to
    protect uninfested areas is justified.
3« Treatment costs should  be borne by  the
   direct beneficiaries such as farmers and
    property owners.
 Data for estimating costs and benefits
 1.  Immediately  begin collecting informa-
    tion  on damages  and benefits of  IFA
    control, relying principally  on the  in-
    formed judgment of experts in the field.
    These experts should draw  on available
    research information,  but rely heavily on
    their own field experience.   Develop a
    structural  process for  collecting  and
    evaluating  the  expert judgments.  One
    such  method  is a  delphi-type approach.
    This should be a joint federal/state acti-
    vity.
2.  Utilize the data to assess the  economic
    and social implications  of  alternative
    control options following accepted anal-
    ytical procedures.
3.  Analyze the strengths and weaknesses of
    the data and  develop longer  term  re-
    search, data  collection, and monitoring
    plans to improve the data.  Initial atten-
    tion should focus on data items that are
    most critical and least reliable. A work-
    shop  could be  held to  determine  and
    establish research,  survey, and monitor-
    ing priorities.
Education, training, and extension
1.  Devote new resources to IFA informa-
   tion and training activities.  This should
    be the lead responsibility of the Cooper-
   ative  Extension Service, U.S.D.A., public
   schools, and other agencies.

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                                          50
 Research in IF A and its management
 1. Research must  be done on  the percep-
    tions of homeowners, farmers,  and other
    groups as to  (1) the IF A as a pest, (2)
    pesticides, (3) pesticide hazards,  and (4)
    willingness to contribute to IFA control.
 2. Conduct  a detailed epidemiological study
    in IFA-infested areas to estimate the
    size  of  the  human population at  risk
    from IFA stings, the frequency  of  health
    effects, and their significance.
 3. Better coordinate  and target  research
    efforts on the biology and control  meth-
    ods of the IFA.
 IFA management on federal/state lands
 1.  Federal/state  agencies responsible for
    managing lands  subject to  IFA infest-
    ation  should  develop IFA  management
    programs that are consistent with eco-
    nomic thresholds.
 2.  Agencies  should demonstrate IFA  man-
    agement practices that can be  emulated
    by private land managers on similar type
    sites.
 3.  State/federal   management  demonstra-
    tion projects should be  coordinated with
    research and extension programs.
 REFERENCES
 Hayes, W.J. and W.K. Vaughn.  1977.  Mor-
    tality  from  pesticides  in  the  United
    States in 1973  and  1974.   Toxicology
    Appl. Pharmacology 42:235-252.
 Lofgren,  C.S. and C.T. Adams.  1981.  Re-
    duced yield of soybeans in fields infested
    with red imported fire  ant, Solenopsis
    invicta Buren.   The  Florida Entomolo-
    gist. 64:199-202.
 Rhoades, R.B. et al.  1977.  Hypersensitivity
    to  the imported  fire ant in Florida:  A
    report of 104 cases.  J. Fla. Med. Assoc.
    64:247-254.
 Triplett,  R.F.   1971.  Statement:  Medical
    Significance  of  the Imported Fire  Ant,
    and Allied  Chemical Corp.: A  Health
    Impact, in memorandum of Allied Chem-
    ical in support of  opposition to cancella-
    tion of mirex registration.
Environmental  Protection Agency.    1976.
    National  Study  of  Hospital Admitted
    Pesticide   Poisonings,   Epidemicologic
    Studies Programs.   Office  of Pesticide
    Programs, Washington, B.C.
Wilson, James D.   1975.  Mirex:  decision
    making problems in pesticide programs.
    Unpublished M.S.  thesis, Univ. of  Flor-
   ida.
FOOTNOTES
1
 In addition  to other currently registered
 pesticides.
 Costs were  calculated  using  1982 prices,
 even though costs in future years would be
 higher due to inflation.

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                                   TABLE 1
PROGRAM:
Aerial eradication
PROGRAM DESCRIPTION: 1.  Federal/state financed program to eradicate IF A
                          2.  Three treatments over about 18 months
                          3.  All infested acreage treated
ACRES TREATED:
1.  Slow approach

    1st year           7 million
    2nd year         14 million
    3rd year          21 million
    4-33rd years      21 million/year

    Total acres = 230 million x 3 = 690 million

2.  Faster approach (3x the slow approach)

    11 years total
    21-63 million acre applications per year
TREATMENT COSTS:      1.  Slow approach       Amdro
                          2.
                              1st year
                              2nd year
                              3rd year
                              4-33 years

                              Total

                              Cost/acre
                     $35.00 million
                      70.00 million
                     105.00 million
                     105.00 million
                        $5.00
  Ferriamicide

$17.5 million
 35.0 million
      million
      million
52,
52,
                     $  3.45 billion     $1.725  billion
    $2.50
    Faster Approach
    Same total  as  above,  but increases sooner,  thus
    saving costs of inflation.
FEASIBILITY ASPECTS/LIMITATIONS:
                          1.   Legal problems  preventing complete  area  coverage
                              essential for eradication.

                          2.   Funding limitations—other claims on funds are likely
                              to have higher social priorities.

                          3.   Speculative nature of the biological success.

                          4.   Program  management,  logistical and quality control
                              problems due to program size.
                                  50.1

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                                  TABLE 2
PROGRAM:
                          Aerial suppression
PROGRAM DESCRIPTION:  1.   Federal/state/local cooperative financing

                              a.
                                   One-third
                                   Fed
                                   State
                                   Local
                                                  33%
                                                  33%
                                                  33%
                              b.
                                   Fed matching
                                   Fed            50%
                                   State/local     50%
                          2.   Suppression  to  lower populations in large scale
                              areas.
                              Large area treatments are designed to  decrease
                              resurgence.   States  likely  to  take  initiative on
                              general areas and number of acres to be treated.

                          3.   Open  market  sales  of  chemical  for  ground
                              broadcast and mound-to-mound treatment.
ACRES TREATED:
                              Principal sites
                              Agriculture;   Pastures,   hayland,   f encerows,
                              farmsteads, hand labor crops and generally where
                              problems are  most severe
                              (Some row crops)
                              N on-agriculture;  Lawns,  campgrounds,  school
                              yards,  other  public   outdoor  meeting places,
                              cemeteries, etc.
                              Acres
                              10-30  million/yr., depending
                              state/local interest
                                                           on  financing  and
TREATMENT COSTS:
                          Amdro
                          Ferriamicide
$50-75 million/yr.
($5.00/acre)

$25-75 million/yr.
($2.50/acre)
FEASIBILITY ASPECTS/LIMITATIONS:

                          1.  Funding limitations could be quite significant.

                          2.  Some  legal  problems,  but  less  severe  than
                              eradication.
                                   50.2

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                                  TABLES
PROGRAM:
Aerial relief (subsidized)
PROGRAM DESCRIPTION:  1.
    Individual landowner pays one third of total
    cost of treatment ($1.66/acre for Amdro and
    $0.83/acre for Ferriamicide)
    Federal/state pay remaining 2/3 of cost

    Temporary  relief to  individual  property owners
    with more rapid resurgence than with large scale
    suppression program.  Treatment lots would range
    in size from 40 acre minimum

    Open  market  sales  of  chemicals  for ground
    broadcast and mound-to mound applications
ACRES TREATED:
1.   Principal sites

    Agriculture; Pasture,  hay,  intensive labor crops
    and especially farmsteads.
    Non-agriculture;    Lawns,    school    grounds,
    campgrounds and other public places
                          2.  Acres/yr.:
                          Amdro    Ferriamicide
                        3-5 million   5-10 million
ANNUAL TREATMENT COST: Amdro
                              Landowners
                              State/Fed.
                              Total

                             Ferriamicide
                              Landowners
                              State/Fed.
                              Total
                        $  5-8.3 million
                        10-16.7 million
                        15-25.0 million
                        $  4.1-8.30 million
                        8.4-16.75 million
                        12.5-25.00 million
FEASIBILITY ASPECTS/LIMITATIONS:
                              1. Operational and legal problems do not
                                 appear to be critical.

                              2. Dependent  upon availability of public funds
                                 which may  have higher priority uses.
                                   50.3

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                                 TABLE 4


PROGRAM:               Landowner Relief (no subsidy)


PROGRAM DESCRIPTION:  1.   Individual landowner pays total cost of treatment
                              ($6.00/acre for Amdro and $2.25 for Ferriami-
                              cide).

                          2.   Temporary relief  to  individual property owners
                              with more rapid resurgence than with large scale
                              suppression program.

                          3.   Open market sales of  chemical  for aerial and
                              ground    broadcast    and    mound-to-mound
                              applications.


ACRES TREATED:         1.   Principal sites

                              Agriculture:  Pasture,  hay, intensive labor  crops
                              and especially farmsteads.
                              Non-agriculture:    Lawns,    school    grounds,
                              campgrounds and other public places.

                          2.   Acres/yr.:             Amdro    Ferriamicide
                                                 2-4 million    4-8 million
ANNUAL TREATMENT COST:  Amdro
                              Landowners         $12-24 million/yr.
                             Ferriamicide
                              Landowners         $9-18 million/yr.


FEASIBILITY ASPECTS/LIMITATIONS:

                              1.  Operational and legal problems do not appear
                                 to be critical.

                              2.  Program  effectiveness limited  where  land-
                                 owners lack pest management information for
                                 IF A control.
                                  50.4

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     Table 5. Summary of key findings on four sample alternative imported fire ant control program approaches.
     Program Approach
   Obj ective/scope
     Cost
        Evaluation
     1. Eradication
Complete elimination of
IFA from 230 mil. acres,
over 11-33 yr. period
Amdro
a) $35-315 mil./yr
b) $3.45 billion total

Ferriamicide
a) $17.5-157.5 mil./yr
b) $1.72 billion total
                                                                                       Definitely not prudent due to lack of
                                                                                       feasibility and adequate resources;
                                                                                       severe legal problems. (e.g.
                                                                                       environmental groups and non-
                                                                                       cooperative landowners)
     2. Suppression
        (Large area)
Ul
o
     3. Subsidized
        relief
Sustained control with
minimum reinfestation on
priority land areas
(10-30 million acres
treated/yr.)
Temporary relief to
owners at one third
treatment cost as
requested by owners;
3-10 million acres/yr.,
lawn, school, recrea-
tional, farmstead and
priority ag. lands
Amdro
$50-75 million/yr.

Ferriamicide
$25-75 mil./yr.
Not adviseable, given the level of
benefits to be achieved relative to
costs; significant legal and funding
problems for full scale program.
Amdro
Landowners $5-8.3 mil./yr.
Government $10-16.7 mil./yr.
Total $15-25 mil./yr.

Ferriamicide
Landowners $4.1-8.3 mil./yr.
Government $8.4-16.7 mil./yr.
Total $12.5-25.0 mil./yr.
                                                                                       Feasible; scope depends upon
                                                                                       availability of funding and level
                                                                                       of subsidy per acre treated.
      4.  Non-subsidized
         relief
Temporary relief at
full market price
to landowner
a) Amdro; 2-3 mil. acres
b) Ferriamieide; 4-8 mil.
   acres
Amdro
$12-24 mil./yr.

Ferriamicide
$9-18  mil./yr.
Market solution feasible provided no
government subsidies or interference
in market; costs to be incurred in line
with benefits.

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                PANELD

THE THEORY OF POPULATION DYNAMICS
        Dean L. Haynes, Chairman
        Michigan State University

  Daniel P. Wojcik, Reporter, USDA-ARS
           Gainesville. Florida

              John C. Allen
          University of Florida

         Robert Campbell. USFS
            Corvallis, Oregon

            C. Ronald Carroll
            Baylor University

              Ting H. Hsiao
          Utah State University

              Jesse Logan
        Colorado State University

              Ron Stinner
     North Carolina  State University

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INTRODUCTION
   When studying a group of insects, we are
often overly  impressed by  their  presence
and number.  When numbers  are high, eco-
nomic entomologists usually locate  the point
of highest  density and count the individuals.
From this estimate, the "outbreak" is char-
acterized and control recommendations are
presented,  with the underlying belief that if
sprays are applied at points of highest den-
sity, we will  get the most kill for  control
cost and  therefore the most benefit.  The
complex interactions of a pest population
with  its  biotic  and  abiotic  environments
renders these  assumptions and approaches  to
a useless leftover  from the chlorinated hy-
drocarbon  era.   The lack of understanding
about the interaction of individuals within a
Population leads  to  many,  often  counter-
intuitive,  outcomes.   For example, every
individual will die from natural causes with-
out human-imposed controls.  Thus, killing a
Pest with  a pesticide  usually brings about
damage  control through population  reduc-
tion, but not  population control.   This  fact
appears  trivial, but  perhaps is   the most
significant point in population dynamics.

THE THEORY OF
POPULATION DYNAMICS
    When  considering the applied  and theo-
retical  aspects  of insect  populations,  the
Organizational levels where interactions oc-
cur should be considered.   Basically there
are four  levels of generalized pest insect
groupings: subindividual, individual, popula-
tion, and community. Difficulty raises when
observations are made at one level and the
implications are  projected  to  a  different
level.    The  key  to  understanding most
"single-organism"  populations is the popula-
tion; therefore, individuals must be counted.
This  simplistic  idea  becomes a complex
issue  with social  insects or what  might be
considered as "multi-organism" populations.
   For  the purpose of this  report, we  can
define "population dynamics" as a discipline
that studies the factors producing change  in
the number and quality of individuals.   The
term  "population" as  it relates to insects  is
ill-defined and takes on meaning  only from
the context in which it is used. As such, one
ecological definition might be: a  population
is a group of  individuals sharing a common
gene  pool.  Unfortunately,  the operational
definition is usually:  a population is a group
of individuals occupying an  area defined by
our concern for considering it as a popula-
tion.
   Thus,  a crop pest becomes defined as a
population with little concern for its  linkage
with other individuals outside the crop. This
operational differential may  be a philosophi-
cal side effect  of using pesticides.  Pesti-
cides applied to the crop kill a large number
of insects present or soon to arrive.  Defin-
ing the population as  individuals  living  or
dead  in the crop  results in  high kill statis-
                                           51

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                                           52
 tics.  If 1% of a population resides in a crop
 and 99% are killed, it is not very impressive
 to  state  that  slightly less  than 1%  of the
 population was destroyed.
    In  a  community,  groups of individuals
 live together in some sort of natural order.
 The temporal and spatial aspects of a com-
 munity do  not  need  to  coincide  with  a
 specific population.  Communities are com-
 plex biological, social, and ecological webs.
 Managing such structures could  be the most
 important, and largely untapped, non-chemi-
 cal control method for any species.  Thus,
 community  structural modification research
 should be a  high priority.
    Adding the word dynamics to population
 implies a change over time.  To understand
 this, it is essential to realize that a popula-
 tion is distributed over time and space.  The
 spatial distribution  is normally  used  during
 pest surveys, with results expressed as pests
 per sample, pests per field,  etc.  The tempo-
 ral aspects  such as age structure and popu-
 lation  maturity and distribution, are seldom
 addressed even though they are  equally im-
 portant.  Both spatial and temporal aspects
 of a population interact in  a way that ap-
 pears  to  be opposite  or  in conflict with
simple intuition.
   For example,  Figure 1 is a typical prob-
lem associated with sampling insect num-
 bers to compare  spatial differences.   The
population remains relatively constant until
 March,  when  it  reproduces rapidly  until
 May.   Natural mortality causes a decline
 until November.   Sampling  this population
 would result in densities varying from 10 to
 60  on this theoretical curve.  The significant
 parameter represented by this graph is not
 the six-fold difference in density,  but the
 generation index of I equal to one where I =
 (density March 1, year 1) f (density March
        Reproduction P«rhd Mortality Period
  C

  k.  O-
  C
  a  o
  0  
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                                            53
  gy has analyzed factors that limit or control
  Population numbers, and the relative impor-
  tance of abiotic  and biotic components  of
  the habitat have been argued.  Only recently
  have individual populations and community
  structure been  linked in highly interdepen-
  dent  models  representing  natural systems.
  Linkage between  abiotic  factors and the
  biotic components of the  ecosystem can be
  direct and  indirect,  with  or  without  time
  delays.  Since these  linkages and interrela-
  tionships are  often complex, a sound theo-
  retical framework is helpful for interpreting
  the effects that management practices may
  have  on population performance and com-
  munity structure.

 DIFFERENCES IN PESTS
    In  American agriculture  there appears to
 be four classifications of  "emergency  pest
 Problem," each  requiring  a different  pest
 management response:
    1.  Exotic pests:  These are newly-intro-
 duced pests whose  populations  rapidly ex-
 Pand to high numbers before slowly adapting
 to  the new  environment.   Insects in  this
 category are cereal leaf beetle, gypsy moth,
 imported fire  ant  (IFA),  Japanese beetle,
 winter  moth,  European pine sawfly,  Essex
skipper,  European  skipper  (McNeil 1975),
and alfalfa weevil.
   2.  Native pests with cyclic outbreaks:
Because  they are so closely tied  with  the
  environment, these pests go through perio-
  dic outbreaks.  Pests in this category would
  include spruce budworm, grasshopper, range
  caterpillar,  hemlock  looper,  bark  beetle,
  etc.
     3.  Native species with expanded range:
  This pest species exists in limited geograph-
  ic areas or environmental habits and adapts
  to new hosts or climate conditions.  Insects
  such  as the Colorado  potato beetle,  bean
  leaf beetle (Dietz et al.  1976), apple mag-
  got, boll weevil, and corn rootworm belong
  in this  category.   Included  could  be pests
  developing  additional  generations in  re-
 sponse to agricultural production practices,
 or the  release  of resistant  varieties (e.g.,
 Hessian fly). Pests developing resistance to
 chemicals also could fall with this category.
    4.  Induced outbreak:  This category in-
 cludes  most secondary  pest insects  that
 build up in pesticide-impacted environments
 when the  pesticide is not directly applied
 for  their control.   The category would in-
 clude  such  pest species  as  spider mites,
 aphids, and numerous lepidopteran pests.
   The response  by governments and similar
 institutions to pest outbreaks needs  to care-
 fully  consider  the  unique population char-
 acteristics  associated with  each category.
 An effective management response  may be
very  different for  each  situation, and  a
single control option  may  have very differ-
ent outcomes in different classifications.

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                                          54
ECOLOGICAL PHASES
OF INTRODUCED PESTS
   In this section, we will track the ecologi-
cal progression of  an  introduced  (exotic)
pest as it adapts to its new environment.
   During  a  new introduction  phase,  the
insect rarely  is adapted to or  closely cou-
pled with  the  ecosystem.  At this time, the
abiotic environment  exerts several pressures
on the insect  population. It determines the
physiological  limits  for  colonization  and
whether  the  insect  will survive.    Under-
standing the  physiological  limits will help
determine how successfully the species  will
colonize.  Knowing how climate affects sur-
vival  and movement  will help determine how
effective  a pest the insect might become.
Also,  understanding  the abiotic effects  on
the population will aid in predicting whether
the new introduction or indigenous  species,
occupying the same  niche,  will be favored in
a  competitive interaction.  These  predic-
tions  will be  useful when  evaluating man-
agement  tactics.    For example, a broad
spectrum biocide that disrupts existing com-
munities could  lead to a  more  successful
establishment of an introduced species.
   After  the new  introduction phase,  in-
sects go through a  physiological adaptation
stage.  Life  table  analysis of this phase
could indicate windows of vulnerability in
the pest's  life system,  such  as periods of
stress.   Exploiting  these  vulnerable times
could  result  in   successful  management
strategies   (i.e.   disrupting  overwintering
sites).    Included  in  this  phase is genetic
adaptation.     During  colonization,   insect
pests are subjected to new selective pres-
sures as a  consequence of  changes  in  the
abiotic  and biotic  components of  the envi-
ronment.  Populations  that  succeed  in sur-
viving  the genetic selection may  have ac-
quired a radically  altered,  balanced, genetic
system.   Such genetic evolution is observ-
able in  terms of  morphology,  physiology,
behavior, and life  history traits.  The alter-
ations can be so drastic that the introduced
population can be considered  to be a new
race or even a new species, complete with
pre- and post-mating isolating mechanisms.
In terms of  pest control, this means that an
introduced species has, in  its  new environ-
ment, the potential to  evolve in an unfore-
seen manner (Templeton 1979).
   The  final phase of colonization  is  the
successful physiological adaptation  of  the
insect.  At  this time both  competitive  and
predator/parasite  relationships are  impor-
tant, which  typically results in the  pest sta-
tus of  the introduction being less  than the
previous stage.  Again, abiotic factors may
alter competitive  relationships between the
pest and its  natural enemies.
   By  knowing the  effects that  weather,
community  structures,  and their  interac-
tions have on pest populations, it is possible

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                                          55
to predict  when and where  pest populations
will  occur.   This information also can  be
used to avoid control tactics that adversely
disrupt  the system.   Humans can greatly
impact the natural evolution and adaptation
of exotic species to its new environment  by
stopping and, in  some cases,  reversing this
natural progression.

THE WORLD: A BUG'S POINT OF VIEW
   Elephants and  hippos do not get caught
>n water surface tension.  Insects  do.  Un-
derstanding the needs  and dynamics of  a
Population  requires that we imagine things
in the way that  a species  must see them.
The  microclimate experienced by a particu-
lar species is not necessarily that  reported
by the U.S. Weather Service or measured in
* weather  shelter. Often that species has
evolved over millions of years to become
adapted to  a particular environmental niche.
The  fact that is becomes a pest may simply
be a consequence of  our inadvertently ex-
panding its  niche  space a million-fold or  so
with  bulldozers and tractors  or  accidental
movement.   When this happens, we might
consider possible ways to shrink the micro-
climate niche  space.   If this can be done
While still  achieving system goals,  then the
Pest  may  be  reduced to  non-pest  levels.
Understanding the microclimate of the pest
could lead  to the development of interesting
management options.   The literature is  re-
plete with such examples.

OPPORTUNITY IN A CRISIS
   A unique  opportunity exists in social
insects to research the effects of individual
quality on population dynamics.  By defining
a colony of social insects as  an "individual,"
the individual quality and its effects on the
population  of such  individuals  becomes
easier to research and model. Model resolu-
tion  increases. In fact, for a community of
ant  species,  many  levels can be identified
and  measured fairly easily.   Levels start
with a species; within a species  there is an
age  of  nest;  within that  level  there  is  a
distribution  of ant  types; and  within  that
level there  is an  age  distribution.   This
complexity  is measurable for most insect
populations  only  with enormous resources.
For ants, however, the within-nest dynamics
can  be measured and  studied fairly  easily;
the direct effects of changes of  within-nest
distributions   (age and type) can also  be
modeled.  Such models will help  integrate a
research program much more than is usually
possible.  With increasing complexity models
become more  realistic, which increases the
level of understanding of the population and
its interactions.   This is  particularly  true
when measuring  abiotic  stress  on  within-
nest   dynamics.    Models  that   effectively
incorporate  abiotic  stress are  difficult to
develop for non-social pest populations.

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                                          56
POPULATION ANALYSIS
    Measuring an Abstraction—Determine
    Sampling Attributes
    All  populations  share  certain  life pro-
cesses.   For example, the  development rate
of  all   insects  is  temperature-dependent.
Thus, both  physiological and  chronological
time scales should be used when measuring
life processes.   Many processes that occur
(e.g.,  reproduction,  mortality,  movement)
are related  to  the density of  the  target
species  and/or other species.
    An  important  concern  in  dealing  with
social  insects  is  that different  processes
affect the individual and the colony  differ-
ently.    Understanding the individuals'  dy-
namics  does not necessarily imply  a  knowl-
edge  of colony dynamics  and vice  versa.
Because of  this hierarchy,  it is imperative
that processes be examined at the appropri-
ate level.  Thus, if one is concerned  with
managing a  social pest and  the target is the
colony,   colony  dynamics  should be most
closely  examined.   Given  this  background,
the major sampling considerations are:
   (a) selecting  the  sampling entity (indi-
      vidual, cluster, colony),
   (b) selecting  the sample  unit (square me-
      ter, soil type, habitat, etc.),
   (c) selecting  the  spatial  and temporal
      sampling intervals,
   (d) determining  the  type  of  distribu-
      tion^) observed and any changes
       associated with other population  and
       habitat characters, and
    (e) calculating the sampling schemes for
       various specific objectives.
    All sampling  plans  must  provide  error
 estimates and make variance partitioning
 possible.   The necessary data to establish
 these sampling attributes can come  from
 early phases  of  concurrent research that
 includes changes in (1) the pest:  numbers of
 individuals and individual attributes, and (2)
 the  environment:   physical  and  other  or-
 ganisms (plants, competitors, enemies, and
 commensals).  In social insects, where the
 unit of study may not be the individual, nest
 or colony characters have to be measured to
 give  the  colony  some specifically identifi-
 able states (i.e.,  all colonies are not equal).
 These studies  should be  conducted exten-
 sively (coarser sampling  over  wide areas)
 and intensively (including the extreme situa-
 tions).
   Population  behavior   of  new   invaders,
 such  as the  IF A,  may change dramatically
 through time.   Inferences drawn from the
 study of invading populations along the ad-
 vancing  front  of an infestation  must  be
 interpreted cautiously.  For example, popu-
lations of the sea lamprey virtually exploded
when the  species reached  the Great Lakes.
Despite aggressive control efforts,  preda-
tion  on lake  trout devastated that  fishery.
Now,  however, lamprey predation is scarce-

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                                          57
 ly a factor in the booming sport fishery for   aspects that have  immediate  management
 the several  salmonid  species  introduced   applications, or (2) continuing, ad infinitum,
 from  the Pacific.   For this reason,  it  is   studies  of relationships having  no known
 particularly important to encourage studies   potential for management.
 explicitly designed  to detect and  interpret
 long-term changes  in  population  behavior.   ANTS AND WHAT TO LOOK FOR—
 Specifically, some  areas should be reserved   A PARTIAL LIST
 for long-range (perhaps 20 to 30 year) stud-      As in all other cases, the attributes of a
 ies on the population dynamics of the IF A.      system are determined by the questions and
    From  this work,  correlations  can be   hypotheses guiding the study.  The following
 found  between the pest and its environment,   example concerns the community dynamics
 Typically, these become the  basis  for  gen-   of  ants.  Since  the  level of study has been
 Bating hypotheses  about cause  and effect   defined  at  the  community  level, measure-
 relationships.  These hypotheses need test-   ments are restricted to processes that  feed
 lng. As correlations are developed, empha-   into   determining  community   dynamics.
 sis should shift toward experimental  studies   Thus,  many features  may be excluded  en-
 designed  to test  these hypotheses,  rather   tirely  and treated as a "black box."  For
 than to assume their  validity.  Initial  re-   example, for some  purposes,  the  mech-
 search should concern hypotheses  that ap-   anisms of pheromone production and distri-
 Pear most  crucial   to  conceptualizing the   bution within  a  nest may be ignored; inte-
 Pest system. Since more than two alternate  gration of nest activities becomes a product
 hypotheses may explain any single  correla-  of a "black box"  hormonal  system.  How-
 tion, the  researcher should  consider  all hy-  ever, the decision  to exclude the mechanics
 Potheses and design research to  different!-  of a process has  to be  chosen carefully.  For
 ftte among them.  Once a given hypothesis is   example, ignorance concerning the function-
 confirmed,  the general  conceptualization   al details of mammalian  hormones  may be
 should  be  updated.                            acceptable when studying the  interactions
    At  any time, both  the scientist and the   of ungulates, but  it  would  be  essential to
granting and/or regulatory  agency  can use   rodent  interactions  where  adrenal gland
this construction when making judgments on   weight and activity  relates to  behavioral
current research or management requests,   dominance.  The  point  is to be cognizant of
However,  both the  researcher and  involved   the  role of  hormones/pheromones  in  ant
agencies should avoid (1) studying only those   community  dynamics  and   to   carefully

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                                          58
choose the level of measurement that meets
the requirements of the guiding hypotheses
and questions.
   Some examples and rationales for select-
ing sampling  attributes of community  dy-
namics  of ants  include the following, very
incomplete, variables.
   1. Species-specific  foraging  behavior:
Shifts in the time or location  of foraging in
the  presence  or absence  of  other species
(e.g., McNeil et al. 1978) may indicate  im-
portant  competitive interactions and could,
under some circumstances,  feed  into  the
community structure.
   2. Spatial  distribution of nests: For this
study, movement  of  workers of  the  same
species  from nest to  nest  validates the  use
of the nest  as the sampling attribute.  The
distribution of nests of  each  species  and
their abundance through space  and time is
the  appropriate  sampling  unit  to measure
the  outcome  of  community  interactions.
The  distribution of foraging workers around
each  nest may  be  the  more  appropriate
sampling unit  for measuring the interactive
mechanisms of community change.
   3. The  dynamics  of  the  community:
Change,  resistance  to change, and rates of
return to the  original community composi-
tion  are the focus.  Therefore, experimen-
tally, nest distribution  is appropriate.   For
meaningful results, conditions  must be spec-
ified  (e.g.,  which environment, over  what
time course, the initial set  of  populations,
etc.).

SOCIAL INSECTS:
PROBLEM OF DEFINITION AND BIOLOGY
   Relative Time as a Problem
   and Opportunity
   For most pests in annual cropping sys-
tems, the periodicity of the  habitat is long
relative to the generation time  of the pest.
With many species, the  reverse is true. The
lifespan  of  a  particular crop  is  generally
shorter  than  the  generation time  of  the
resident social insect colony.  Short-genera-
tion  pests that spend much  or  all of their
lives in a single environmental patch should
follow the environment  closely (i.e., become
specialized  for   particular   field  types).
Long-generation pests  and  pests  with low
dispersal thresholds  should be relative field
generalists.  Thus, habitat manipulation as a
control procedure  for long-generation pests
may  have limited  success unless the  alter-
nating  habitats (in  time and  space)  are
chosen on the basis of knowledge concerning
environmental  determinants  of population
dynamics.
   Population Processes
   Birth-death processes in  social  insects
are similar  to other organisms, but  some
important differences exist.  Obviously, the
addition  of  sterile workers is simply indi-
vidual  growth of the colony; the colony is

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                                           59
 the organism from the perspective of popu-
 lation  dynamics.  As the  colony adds  or
 subtracts  workers  and  adjusts  the  caste
 composition,  the colony  changes its  ability
 to  meet  the various life  contingencies  of
 reproduction  (new sexuals leaving the colo-
 ny), competition, nest repair, etc.  That  is,
 the colony has various age  or stage-specific
 parameters.   In cases where  queen substitu-
 tion occurs,  the  colony is,  in principle, im-
 mortal.    Concepts,   such  as  reproductive
 value, become stage-specific  properties, and
 'life" expectancies become the set of tran-
 sitional  probabilities  of  death  associated
 with each stage.   The possibility of polygyny
 (multiple queens) occurring in social species
 means that fecundity  will be  highly variable
 within a species; it then  becomes necessary
 to  treat variance as a parameter in  a life
 system  model.   Death of  queens in  poly-
 gynous  colonies is treated  as an effect on
 reproductive   value.   This  explanation  of
 birth-death processes illustrates the equiva-
 lent processes in  social and solitary species.
 These processes,  however, may be difficult
 to measure.
    The  colony is a  responsive  homeostatic
system with many paths for feedback loops
and mechanisms  for  controlling flow rates
^ong the loops.  For example, a colony has
four levels of  buffering against the morbidi-
ty effects of a variable food supply.
    1.  The  colony can store  food in the nest;
 therefore, foraging and harvesting rates are
 not  limited by  the  immediate metabolic
 needs of the colony.   Furthermore, satura-
 tion curves for foraging behavior may not be
 closely  correlated  to colony  biomass  but
 may be limited by  environmental, temporal,
 and spatial patterns of food availability.
   2.  The ability to change foraging behav-
 ior relates to the abundance and distribution
 of food  outside the nest.  For example, an
 ant colony may forage by using a few well-
 defined  trails  when food is predictable and
 clumped.  When food  is unpredictable and
 dispersed,  the colony may switch to diffused
 foraging behavior without defined trails.
   3.  Larval  secretions may  be  used to
 feed  other larvae  and workers, which dis-
 tributes  the food within  the colony to pre-
 vent local shortages among some larvae.
   4.  Larvae may  be cannibalized (actually
 a form of  colony  catabolism)  as food  for
 other  larvae.  There  is considerable  fine
 tuning in this behavior. For example,  since
 eggs have received little  colony investment,
 they are the first stages to be used  as  food.
 Sexual larvae  are  fed preferentially,  thus
 maintaining reproductive  success.
   Relatively  little  seems  to be known
 about the population dynamics  of social in-
sects.  Even age at death, a straightforward
attribute of individual insects, may be diffi-
cult  to define  for  a colony or  nest.  While
the members of  this panel had relatively

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                                          60
little experience  dealing  analytically  with
such  unique attributes,  they judged  that
current analytical methods  can easily  be
modified to incorporate  these  unique  fea-
tures.

GENETIC CONCERNS:
A CASE OF NEGLECT
   Problem or Opportunity
   Genetic systems of social and non-social
insects are similar in some respects, but
different in others.   In  non-social insects,
bisexual reproduction  of diploids maximizes
genetic exchange  and  thus maintains a high
level of genetic heterogeneity  in the spe-
cies. In social Hymenoptera, males develop
from fertilized eggs  and are  haploid; the
females, from  fertilized  eggs,  are diploid.
This  genetic  system  is  known as haplo-
diploidy (Wilson  1971, Crozier  1977).   A
connection between  haplodiploidy  and the
frequent occurrence  of  sociality in insects
has  been  suggested by several  researchers.
This system allows considerable inbreeding
and  thus maintains a  high degree of homo-
geneity among social  insects.  Recent bio-
chemical evidence from  gel  electrophoresis
of isozymes reveals that the average heter-
ozygosity  of  social insects  is  considerably
lower  than  that  of   non-social  insects
(Crozier 1977, Ayala 1982).  Such low genet-
ic variability in social insects confirms that
there are  specific differences  between  the
genetic systems of  social  and non-social
insects.
   The development of social systems in-
volves many changes in the characteristics
of social species that are  not  found in non-
social insects.  Many behavioral and ecologi-
cal interactions that are integral parts of a
social system have no parallel in non-social
insects.  Regarding the reproductive poten-
tial, social  insects are often thought of as
having unusually high fecundity.  The task of
reproduction in social insects, however,  is
carried out by  one or a few reproductives;  in
non-social insects,  all females contribute to
the  reproductive  task.   When comparing
populations, the reproductive  potential of
the  two insect.systems is probably similar.
A special  feature  of  social insects  is that
the  reproductives are protected in the nest
and are seldom  subjected to  adverse  envi-
ronmental conditions.  Since  most of  these
species have a long generation time, they
are  less affected by natural selection pres-
sures.  This may be one of the reasons why
social insects  appear to develop resistance
to insecticides at  a much slower  rate than
non-social insects.
    Community Analysis
    Performance of a population depends  on
 the combined  effect of the individual attri-
 butes of the population plus the total  inter-
 actions of other populations  occupying the
 same geographic  region.   Analysis  of  the

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                                         61
nature of the interactions between popula-
tions, and the results  of  these interactions
in terms of  stability, persistence, and domi-
nance, is the topic  of  community  ecology.
Community  ecology, therefore, can be used
in understanding  the  effects of  complex
interactions  (i.e., competition  and preda-
tion)  on the abundance of particular pest
populations.
   For  an introduced  pest, which  progres-
sively becomes more adapted  to new ecolo-
gical  associations,  particular community-
level  associations may be more important
during certain phases of adaptation than at
other times.  For example, during the early
stages of colonization, competition  with na-
tive species  occupying  a similar niche would
be the most  important community-level as-
sociation.  In later phases of  adaptation,
relationships with natural  enemies would be-
°o ne important.

A C VSE FOR MODELING
    •ur understanding of the actual popula-
tion  dynamics of organisms can be greatly
enhanced by considering the diversity  of
behavior of  population models.  Even very
simple models of a single species can exhibit
a vast array of possible behaviors. This type
°f complexity can usually  be obtained  by
varying the "constants" in the  model, which
18  analogous  to  making them functions  of
tirne or  space in  a  very  general sense (to
what  actually  happens in the  real, "non-
constant" world).  That very simple models
of one or two  species exhibit  complex be-
havior when subjected to this type of anal-
ysis is encouraging to the  population biolo-
gist.  It implies  two things: (1) predicting
complex behavior of the real world is within
the scope of relatively simple models, and
(2) real world complexity can be reduced to
simple components.
   Simplistic   population   models  showing
that a wide array of behavior is possible also
says something to humans  about population
management—ecological  communities  will
not have simple responses  to simple inputs.
Surprises  will  be  the  order  of  the  day.
There  are no simple rules—just exceptions.
Good  management is possible, but it must be
long-range  and   founded   on  knowledge.
Given the complexity of the simplest ecolo-
gical  community,  ill-considered,   forceful,
management attempts will simply produce
large  perturbations with  uncertain  conse-
quences. The worst enemy is ourselves—our
haste for a  quick,  simple solution,  rather
than  a desire  to understand  the problem
(Stinner 1982).

HIGHER ORDERS OF INTERACTION
   The environment largely determines how
a community will  move through  time and
space. By varying the "constants" in simple
models, very complex behavior can be ob-

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                                          62
tained.   Therefore,  when these "constants"
in a community are actually  environmental
functions, the environment  drives the com-
munity dynamics.  Even the  most gross level
of dynamics (e.g., establishment  of a new
species) is obviously a function of tempera-
ture,  rainfall  patterns, etc.  Therefore, it
should not  be  surprising that even  simple
species  interaction  models  display remark-
ably different behaviors in response to only
one variable, like  temperature.  As temper-
ature changes, a pest and its natural enemy
may  change   in  their  interaction  from
damped  cycles to constant  cycles  to  in-
creasing cycles to chaotic  behavior.   This
change  in behavior could  occur  over  the
course of an annual cycle or over the spe-
cies' geographic range  in response to tem-
perature.  We must understand that simplis-
tic thinking about  biological responses  to
environmental influences is not  likely to be
correct.   The rich diversity of  possibilities
will not be predictable.
   In agricultural systems,  perhaps exclud-
ing tree crops and  permanent pastures, com-
munities of  pests are unlikely to be at near-
equilibrium  conditions.  Under these condi-
tions, much community  ecology  theory is
inapplicable.  The appropriate development
of a  theoretical  basis for an  agricultural
community ecology should consider the fol-
lowing:
   1. Perturbation analysis with an empha-
sis on resistance and resilience.
    2.  Methods of analysis, e.g., loop analy-
sis as developed by R. Levins, appropriate to
complex systems  where  many interactions
can be expressed only in qualitative form.
    3.  The relationship between changes in
the connections between species and  what
happens  to  the form  of  stability.   This
requires  an analysis of the hierarchical pat-
tern of species links within the community.
It is important to identify subsets that are
connected  to the rest of the community by
single links.
    4.  The relationship of resource utiliza-
tion  curves  as a  function  of  community
composition  and local habitat.   In  other
words, in which habitat and for which per-
mutation of species  mixtures  do we find
minimum and maximum overlaps in species
resource utilization curves.
   The goal is to  develop procedures  and
generalizations such  that community level
management can  systematically  and  pre-
dictably  determine the probability of inva-
sion by a new  species.  With regard to the
IF A, it is frequently asserted that no natural
enemies  or  important competitors  exist.
Since the IF A is abundant and expanding its
range, the  IFA seems to  be  independent of
competition and predation from other spe-
cies.  However, this assumption ignores the
reality of  considerable  local variation  in
nest density  and colony abundance.   When

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                                          63
the IF A is abundant it is said to lack com-
petitors  and  predators,  but  when  it  is
scarce,  the IF A is  said  to be in  a "poor
habitat."   Thus,  the  possibility  of biotic
controls on IF A population dynamics is se-
roantically excluded.   Clearly, the proper
natural laboratory for  the study of the popu-
lation dynamics and community ecology of a
Pest is across  an array of habitats where the
proportional representation of the  pest in
the community ranges from "frequently ab-
sent" to "usually abundant."

CONCLUSIONS
   Research and Resources
   As  applied biologists,   we often have
heard: "The problem is here now!  We must
do  something!   We   cannot  wait  for  re-
search."   If this policy of ignorance were
only words  and  not subsequent budget  ad-
justment,  there would  be more hope. There
^e at least two ways to manage crisis:  one
is  to prepare  a program of action in ignor-
ance, and the  other is  to prepare a program
where at  least one outcome is a significant
increase  in  our understanding  of  the prob-
lem.  Research does not have  to be  consid-
ered as a noble  human endeavor conducted
outside  of immediate  need or, conversely,
conducted solely for the purpose of immedi-
ate application.   Both approaches perpetu-
ate our initial ignorance for future  consid-
epation.   Neither  has  a high  probability of
success.  Our lack of basic understanding of
IFA population dynamics  after  more than
two decades  of  government response is  a
specific case in point.  The policy, "the only
good insect is a dead insect," has not worked
and cannot be expected to work.  It should
be  a given policy  that, in any control re-
sponse  (eradication, containment, manage-
ment),  failure is  possible.   Thus,  modest
funds should be provided for long-term study
of the population dynamics of the species at
the onset (or certainly within six months) of
eradication attempts.
    Historically,  there  has  been  a  strong
reluctance  to provide  these funds since it
admits  potential  failure of the present pro-
gram.   If it was a  general policy  to  provide
research funds,  then the political problems
associated  with an admission of  potential
failure  are avoided. All efforts at challeng-
ing a newly invading species should  include
an  initial  conceptualization of the  popula-
tion dynamics of the species. This construct
must  be flexible and should be  updated as
new information is  obtained.
    To  blame  institutional response  totally
for perpetuating biological ignorance of in-
vading pests would be a gross oversimplifi-
cation of the problem.  Clearly institutional
inertia  and political expediency  are domi-
nant factors in resource allocations for pro-
gram  development.  However,  the lack of
resources for basic population research can-

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                                          64
not be strongly implicated in closing minds
or the  inability to conceptually interpret
existing  information and theory related to
other animal populations.
   Economic entomologists and pest control
specialists in particular dwell on the unique-
ness of  each pest subdivided into each crop.
If, on the other hand, biologists were looking
for theoretical  bases  for examining appar-
ently dissimilar events,  a great deal of in-
formation could be brought to bear on par-
ticular problems.  The case in point is that
IF A  research  should  look for  population
principles in other pest species instead of
treating IFA characteristics as if they were
unique.
   Single Factor Control
   In given pest situations we tend to at-
tack the pest directly with mortality agents
whose action is  often non-specific.  Natural
enemies,  competitors,  and disease  agents
may be  exerting a very high, and continuing,
mortality on the pest despite  its pest status.
If this complex is disrupted, the pest, usual-
ly having a high reproductive potential, is
released from  much of its mortality pres-
sure.  The result is the often  observed pest
resurgence  phenomenon; in  addition,  new
pests can be  created by indiscriminately
removing their  mortality  agents.    Thus,
knocking out a section  of a community with-
out  being sure of  what  will  happen  can
produce undesirable surprises.
    Community Structure
    We  must understand and  manage at the
 community level.  We are part of the  com-
 munity  that  we  seek to manage, and  we
 cannot escape its feedback if we completely
 ignore its structure  and proceed in heavy-
 handed ignorance.  The scientist needs time
 and support to  obtain the basic  knowledge
 necessary  for any intelligent  management
 program.   Large-scale programs covering
 millions  of acres should never be undertaken
 until a  high level of understanding of the
 system.has been  obtained.  In fact, in many
 situations, once that level of understanding
 is obtained, we  will probably have resolved
 the  system into  several  sub-systems  each
 requiring a somewhat different program of
 management.   There  are  few  simple  solu-
 tions to managing community  ecosystems.
 If we apply the  intelligence we have to the
 management of  ecosystems,  we  probably
 can  be successful in  many cases.  If we do
 not apply that intelligence, it is most likely
 that the ecosystems we seek to manage will
 control us.
   Genetic Analysis
   Genetic analysis  of insect  populations,
especially pest species, has been a neglected
field of  research.  Extensive research  data
will be needed before any generalization can
be made about the genetic systems of pest
species.  Since population  is the basic unit
of ecology and evolution, the study of gene-

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                                         65
tic variation should be focused at the popu-
lation level to  determine the genetic com-
ponents that influence population processes.
Many fruitful approaches are available for
genetic analysis of  social  and non-social
insects.  Techniques  such as chromosomal
karyotype  analysis,  gel electrophoresis  of
isozymes, and DNA sequence should be rou-
tinely used for genetic  studies.  In addition,
various ecological, physiological, and beha-
vioral traits  of pest species should be moni-
tored  to  determine  population  variations.
Traditional  crossbreeding  experiments will
also  be needed to define  genetic mecha-
nisms  of inheritance.   Since most of these
studies require a long time,  adequate dura-
tion  of time and financial support must  be
available for such research programs.
   Evidence of high genetic variability in
insects reflects the tremendous evolutionary
Potential  of pest species;  control  programs
should be designed with this in mind.  Pro-
bably  no  single  perfect  control method
exists against an insect pest  since the insect
is likely  to evolve  resistance.    However,
evolutionary theory predicts that an  insect
Pest is  far less likely to evolve resistance to
a control  program where many  strategies
a?e  used.   In  general,  therefore,  a  control
Program  that  incorporates multiple  ap-
proaches  is  the best type  of program.  In
°rder  to  employ multiple-approach  control
strategy,  basic knowledge  of  the ecology
and  genetics  of  pests  and related species
must be available, and only through applica-
tion of such  knowledge can the control op-
tions that exist and their respective risks be
dealt with.  Therefore, for the development
of a long-term control program, there is an
immediate and  critical  need  to increase
basic research on the ecology and genetics
of pests and related species.

RECOMMENDATIONS
1.  Funds should  be  provided  for  long-term
    study of the population dynamics of the
    pest species at the onset of any eradica-
    tion trials for any pest.
2.  Research on the  IF A should examine the
    population  dynamics   of   other  pest
    species and compare them  to the IF A.
3.  Single-factor  control  should  not be a
    priority  in  control  strategies,  rather
    emphasis   should  be  placed  on  multi-
    factor management strategies.
4.  A conceptual  framework for dealing with
    the population  dynamics  of  the  IF A
    needs to be developed.
5.  Modern  experimental  design,  analytic,
    and measurement tools should  be used to
    study the  population  dynamics  of  the
    IF A.
6.  A workshop of researchers studying pop-
    ulation dynamics of the IFA and of other
    species should be held  to pool  knowledge
    and develop a sound system  for studying

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                                         66
   the population dynamics of the IF A.
REFERENCES CITED

Ayala, F. J.  1982.  The genetic structure of
   species,  pp. 60-82 in Milkman, R.  (ed.),
   Perspectives on Evolution.  Sinauer As-
   sociates, Inc., Publ.  Sunderland, MA.

Crozier, R. H.  1977. Evolutionary genetics
   of the Hymenoptera.  Ann. Rev. Ento-
   mol. 22:263-288.

Dietz, L. L.,  J. W. Van  Duyn, J. R. Bradley,
   Jr., R. L.  Rabb, W. M. Brooks, and R. E.
   Stinner.   1976.  A guide to the identifi-
   cation and biology of soybean arthropods
   in North Carolina.   N.C.  Agr.  Exp.  Stn.
   Tech. Bull. 238.  264  pp.

McNeil, J.  N., J. Delisle, and R. J. Finne-
   gan.  1978.  Seasonal predatory activity
   of the introduced redwood ant, Formica
   lugubris (Hymenoptera:  Formicidae) at
   Valcartier, Quebec, in 1976. Can. Ento-
   mol. 110:85-90.

McNeil, J.  N., R. M. Duchesne, and A. Co-
   meau.  1975.  Known distribution of the
   European  skipper,  Thymelicus  imeola
   (Lepidoptera:  Hesperiidae), in  Quebec.
   Can. Entomol.  107:1221-1225.

Stinner, R. E. 1982.  La lutte integree—une
   perspective.  Phytoprotection (in press).

Templeton, A. R.  1979.  Genetics of colon-
   ization and establishment of exotic spe-
   cies,   pp. 41-49 in Hoy,  M.  A.,  and
   McKelvey, J.  J. (eds.), Genetics in Rela-
   tion to Insect  Management.  Rockefeller
   Foundation.

Wilson, E. O.  1971. The Insect Societies.
   Belknap Press of Harvard  Univ. Press,
   Cambridge, MA.  548 pp.

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                      PANELm

POPULATION DYNAMICS OF THE IMPORTED FIRE ANT
             Fowden G. Maxwell, Chairman
                Texas A &. M University

           W.A. Banks, Reporter, USDA-ARS
                 Gulf port, Mississippi

                     J.L. Bagent
              Louisiana State University

                      W.L. Buren
                 University of Florida

                    Oscar Franke
                Texas Tech University

                    Steven Risen
                  Cornell University

                    Ann Sorenson
                Texas A &. M University

                    W.L. Sterling
                Texas A &. M University

                   Jerry L. Stimac
                 University of Florida

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 INTRODUCTION
    The  imported fire ants, Solenopsis rich-
 teri Forel and Solenopsis invicta Buren were
 introduced into the  United States in  the
 early  1900's and late 1930's, respectively, at
 the port of Mobile,  Alabama.  The spread of
 these  ants,  primarily S. invicta, from this
 area  was  dramatic.   Surveys conducted  by
 the U.S.  Department of Agriculture in  the
 late 1940's and early  1950's  revealed that
 IFA were present from  Miami, Florida,  to
 San Antonio,  Texas,  and  as far  north  as
 Memphis,  Tennessee,  and  eastern  North
 Carolina.  Today it  is found on  about 240
 million acres in ten states; within this geo-
 graphic area, mound densities range upward
 to  600 per acre.  S. invicta, the red IFA,
 occupies  over  95%  of  the  infested  area,
 while  S.   richteri,  the  black IFA,  infests
 northern Mississippi  and Alabama.
    IFA are found in many habitats,  but tend
 to  favor  open  or sparsely-forested areas.
 Levels of infestation vary widely within the
 habitat types.   However, the  factors influ-
 encing these levels are not clearly defined.

 EXTRINSIC FACTORS
    Abiotic
    The role of  abiotic factors,  especially
 temperature and humidity,  on the distribu-
 tion and abundance of IFA are being investi-
gated.  Because the IFA prefer high relative
 humidities and  moderate temperatures, they
 probably will  not  spread further  north, al-
 though they may be able to  survive in pro-
 tected areas if accidentally introduced.
    Natural spread of S.  invicta through the
 desert southwest  will be very slow  if it
 occurs.    However,  based on comparisons
 with closely  related  Solenopsis species, S.
 invicta probably can establish and  survive in
 the southwest  and along the west  coast.
 Artificial  introduction by human  activities
 may greatly hasten spread through  this area.
    The  effect of  moisture (mode, amount,
 and timing) on reproductive potential is un-
 clear.  Variability in this factor may strong-
 ly influence the ability of the  ant to produce
 mating  flights and colonize  the southwest
 and far west.
    Biotic
    Despite intensive searches, no  effective
 parasites or pathogens on the  IFA have been
 found  in the  U.S.    Predators have  been
 found, but  their role in regulating IFA popu-
 lations has not been  studied  in depth.  S.
 invicta queens are attacked and killed by a
 variety  of  predators  from the time  they
 take flight  until  they successfully  establish
 a  colony.    Neivamyrmex opacithorax has
 been reported to prey on larvae of S.  rich-
 ten'  Also  the thief ant, Solenopsis moles-
 ta, has been  found living in  the nests and
preying on the eggs and young  larvae of both
IFA species.   In southern Mississippi, the
ant, Paratrechina melanderi, has been found
                                          67

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                                         68
preying on S. invicta eggs.
   The IF A in South America are beset by a
number of diseases,  parasites, and competi-
tors.   Thus  far,  none of  these  have been
shown  to  influence population density; how-
ever,  this may  reflect a  lack  of detailed
studies that could be alleviated if long term
research in  South America were performed
by competent scientists  provided with ade-
quate technical support.
   Although no definitive  studies have been
conducted on habitats prior to and  as  the
IF A colonizes an area, observations indicate
that the IFA populates new areas with 15 to
40 mounds per acre.  In areas where control
measures  have been applied or other ecolog-
ical  disturbances  have  occurred, a large
number (100+ per acre)  of  small colonies
may establish a year or two later.  In time
the number of colonies decreases to  predis-
turbance  levels  or higher.  These temporal
changes in IFA  populations may be  due to
intraspecific competition  among S.   invicta
colonies  and   interspecific   competition
among S. invicta  and  other  ant species.
Such   inter- and  intraspecific  competition
needs  to be studied.
    S.  invicta is an efficient colonizing spe-
cies with a high reproductive  capacity  and
excellent dispersal and habitat-finding abili-
ties.   This  opportunistic  species thrives in
areas  where lands  are   disturbed  by  any
means (e.g. flooding, cultivation, and insect-
icide  applications).   In  addition,  once the
IFA successfully colonize an area,  there are
no known competitors that can displace the
IFA.  Therefore, any management strategy
should be directed at imposing mortality on
IFA queens at rates that are discriminantly
higher than mortality imposed on other ant
species.  Control tactics imposing indiscrim-
inant   mortality on all  ants  may strongly
select for proliferation of the IFA.

INTRINSIC FACTORS
   Reproductive Potential
   One of the primary reasons for the suc-
cess  of  the  IFA in the United  States  has
been  their reproductive potential.  The num-
ber of reproductives, frequency of flights,
and climatic conditions are major factors in
determining  distribution and rate  of spread.
Most  IFA mating flights occur during late
spring and summer, but they  may fly any-
time  during  the year.   Studies have shown
that  flight range  depends on wind speed,
rainfall, and temperature.  Most queens land
within a few  miles from  the source,  but
distances up to 12 miles have been docu-
mented, and it is suspected that the range
may  be  much  greater.  Rate  of spread has
not yet been accurately ascertained.
    An IFA colony may produce three to five
thousand queens per  year.   Winged (alate)
forms were  trapped leaving mounds in four
habitats  in  north  Florida,  and it  was esti-

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                                          69
 mated that  an average of almost 100 thou-
 sand alate queens flew from the mounds in
 one acre during one year.  Most queens die
 during and after their  mating flight; how-
 ever,  only a few queens need to survive to
 start new colonies.  For example, if an acre
 is infested with 30 mounds, only 30 or 0.03%
 of 100,000 queens need to survive to replace
 the  original population.   Within the indi-
 vidual colony,  large numbers of worker ants
 can  be produced.   Recent  observations on
 colony growth  within the laboratory indicate
 that most colonies one year or older contain
 at least 100 to 200 thousand workers.
   Nest Site Selection
   Newly-mated queens may select poten-
 tial  nesting  sites  during flight  and  after
 landing.  Selection  appears to be based on
 surface properties (e.g., moisture, soil type,
 topography, and reflectance).  This behavior
 results in colonies being established in road-
 sides,  playgrounds,  shopping  malls, housing
 developments,  lawns,  pastures,  and  some
 croplands. Heavily shaded areas (e.g., for-
 ests) are rarely infested.
   Generation  Time
   Mean  generation  time is partly  influ-
 enced  by the  time of year  the colony  is
 founded.  However, 6- to 12-month old colo-
 nies  can  develop  reproductive  forms and
stage mating swarms.  With respect to mean
generation times, no  life  tables  (birth and
death  rates,  age specific mortality)  have
 been  prepared for  any IF A  species on  any
 part of their geographic range.  These data
 are fundamentally important  for sound man-
 agement decisions.
    Genetics
    No studies have  been conducted on  the
 genetic diversity of  S.  invicta populations.
 If the original IF A  inoculum  into the U.S.
 was very small, there may be significantly
 less genetic diversity in the U.S. than in  the
 South American population.   The diversity
 of the U.S.  population could affect the rate
 of  spread  of IF A to new  habitats and  the
 rate  of evolution of resistance to  various
 control measures.
    Development
    The ontogenetic  development of individ-
 ual ants has received some attention in the
 laboratory,  as  has  the influence  of some
 abiotic and  biotic factors on the rate  of
 development.  The underlying principles of
 colony foundation, growth, and development
 are broadly known, but the role of ecologi-
 cal factors  on the rate (i.e.,  the dynamics)
 of the process needs to be quantified.
   Feeding Behavior
   Because  the IF A  can exploit many dif-
 ferent food  sources,  there are no  known
limits  to  its  distribution based on feeding
behavior.   IFA colonies can survive consid-
erable worker mortality because, under con-
ditions of  stress, feeding  behavior  is  di-
rected towards maintaining the queen.  The

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                                         70
present understanding of the  dynamics of
food distribution within the colony may re-
sult  in the design of more  effective bait
formulations.  Temporal changes in feeding
preferences can affect  management strate-
gies where baits are used.
   Endocrine Systems
   Understanding the IFA endocrine system
may  lead  to  control tactics  that affect
colony integration  and  development.  The
endocrine system  of  IFA has been studied
mainly from the standpoint of  caste deter-
mination.   Juvenile hormones play a major
role  in this.  Juvenile  hormone analogues
that  can severely disrupt the  reproductive
processes   of  IFA are  being  extensively
studied as potential control agents.
   Pheromones
   Queen  pheromones   help  regulate  the
social organization of the nest and influence
reproductive potential.   The queen attrac-
tant/recognition pheromone ensures that the
queen is fed, groomed, and protected by her
workers. This same pheromone is applied to
eggs as they  are  laid,  causing workers to
care for the eggs.  Queen pheromones regu-
late  reproduction  by  (1)  producing  new
queens (caste determination), (2) suppressing
egg laying by  virgin queens in  the  parental
nest,  and  (3)  causing workers  to  execute
queens. These regulatory queen pheromones
have   considerable  potential   as  control
agents. Several components of the attrac-
tant/recognition   pheromone   have   been
chemically identified, and synthetic mater-
ials are  currently being evaluated for  bio-
logical activity.
   The IFA also produce a brood pheromone
and a trail pheromone.  The brood phero-
mone elicits  tending behavior by the work-
ers to the larvae.   The  trail pheromone
directs  workers  to  newly-discovered  food
sources;  some of  its chemical components
have been  identified.  These may be used to
enhance  the  attractiveness of baits.   The
special advantages of  using  pheromones in
control  programs  are  that  these naturally
occurring compounds are highly specific to
the IFA and should be environmentally safe.

BENEFICIAL AND DETRIMENTAL
ASPECTS
   Cotton
   In the cotton agroecosystem,  the IFA is
both detrimental and beneficial.   Negative
effects  occur from  IFA stings to workers
when hoeing,  harvesting, or repairing equip-
ment.  The IFA is beneficial  in controlling
cotton pests, such as  boll weevils.  When
four IFA's are found per ten plant terminals,
boll weevils will be controlled 90% of the
time.   IFA are also  considered to be a key
predator  of Heliothis  species, such as the
bollworm and the  tobacco budworm.  How-
ever,  many natural  entomophages feed on
these Heliothis species, so if  the IFA  were

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                                         71
removed,  other  entomophages  may  still
maintain  these pests  below economically
damaging levels.
    Mound  sampling is not  an effective way
to  assess  IF A density in  a cotton  field.
During the early part of the growing season
it may be difficult to find mounds in a  field.
A "beat  bucket" sampler on  plant terminals
precisely determines  the abundance of for-
aging worker ants and is useful when making
management decisions  for pests of cotton
such as the boll weevil.
    The IFA colonize cotton fields early  in
the growing season primarily in  response  to
aphids as  a source  of honeydew.   After
colonization, the IFA tend to aggregate  in
the  field  primarily  in  response  to  aphid
aggregation.  The dispersion  of worker ants
in the cotton field  is best described  by a
negative binomial distribution.
    The  IFA may kill other  entomophagous
arthropods.  They  have been observed con-
suming parasites of aphids and boll weevils.
Although  the IFA  generally  are thought  to
be  effective predators  on  entomophagous
species, other data indicate  that they  only
minimally  impact  the  abundance of  most
entomophages.
   Sugarcane
    Although the IFA is generally an excel-
lent predator  of  the  sugarcane  borer  in
sugarcane  fields,   at  harvest  time   IFA
mounds may damage equipment and the ants
 may sting workers.  Some sugarcane farmers
 would prefer to live without the IFA simply
 because of  its  sting.   However, it is well
 documented that  the  IFA saves the sugar-
 cane  farmer an  average  of one  to two
 insecticide applications per season by feed-
 ing on the sugarcane borer.
    Sweet Potatoes
    The IFA tend  to infest entire fields  of
 sweet potatoes, but  greater  numbers are
 found around the  periphery  of  the fields.
 Since all sweet  potatoes must be harvested
 by hand,  even in  highly mechanized farms,
 IFA create problems with the laborers in the
 harvesting process.
    IFA prey on the egg and larvae of the
 banded cucumber beetle and the sweet pota-
 to  weevil.   When  IFA are controlled, both
 insects and their damage increase in sweet
 potato fields.  In fact, the statewide  prob-
 lem with these two pests increased immedi-
 ately  after  large  scale  control measures
 were initiated for  the  IFA.  More research,
 however,  is  needed  to  determine  if  this
 resurgence is due partly to the reduction of
 predators other than the IFA.
   Soybeans
   The IFA is considered to be  a nuisance
pest on soybeans,  grain sorghum, and corn
and may  be of economic significance where
ants are  very abundant or where seed has
not been well covered at planting.  Defini-
tive economic assessments of losses in these

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                                          72
 crops is generally not available and there is
 a need for additional unbiased research on
 the impact of IF A on these crops.
    In soybean  fields,  IFA  interfere  with
 harvest  and  feed  on germinating  soybean
 seed.    Large  IFA  mounds,  particularly
 around the borders of soybean fields, fre-
 quently clog the cutter blade of  combines.
 Thus,  a  problem  is posed  to the  person
 removing the ants, dirt, and debris by hand.
    IFA prey on  several pests and serve as an
 important  predator on many detrimental in-
 sects  in  soybean  fields.    Three-cornered
 alfalfa hoppers,  stink bugs, and several lepi-
 dopterous soybean pests are  reduced by IFA
 predation.  Research in Louisiana has shown
 that  insecticides that reduce  IFA numbers
 actually increase  the  number  of  three-
 cornered alfalfa hoppers.  No  insecticides
 at this time give better than 60% control of
 this pest—the  same control provided by IFA.
    Forest
    The Nantucket pine tip moth larvae  are
 significantly reduced by the IFA.  This pine
 pest infests pine branch tips, causing addi-
 tional branching rather than the more pre-
 ferred erect growth.  The IFA has also been
 observed feeding on bark beetles in pine
 forests.
    Pastures and Hay Fields
    The IFA pose a problem with equipment
in cutting hay and with bush-hogging  opera-
tions of pastures. Large IFA mounds require
 that  tractors be  run at  considerably less
 than maximum efficiency.  Sickle blades and
 bush-hog blades  are often broken as a result
 of the mounds.  In addition, the small hay
 bales (60  to  100 pounds), if left on the
 ground overnight,  attract large numbers  of
 IFA, making it extremely uncomfortable for
 laborers to haul the hay.  In general, IFA are
 considered a  significant  nuisance in  and
 around hay fields  and to a lesser degree  in
 pastures.
    The IFA, however, serves as an excellent
 predator  of ticks, horn  flies,  and  stable
 flies.  In  many areas, the IFA have reduced
 lone  star tick populations  so well  that the
 tick  is no longer  considered  economically
 important.  IFA  also reduces horn fly popu-
 lations, but not  as dramatically.  Although
 leaf hopper numbers are reduced by IFA pre-
 dation, it is  not  known how  much  actual
 damage the leafhopper does to pastures.
    Wildlife
    IFA may kill young quail,  rabbits,  and
 other  forms of  wildlife,  especially those
 that nest on the ground,  and therefore, are
 more vulnerable  during  the early  hours of
 life.   The IFA probably are one  of many
 native predators of these animals, as studies
 have  not  demonstrated reduced abundances
 of these animals due to IFA predation.
    Song  birds, field  mice, etc.,  might be
 detrimentally affected by  large numbers of
IFA,  but  no studies  document  this  effect.

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                                          73
 Although the Louisiana Department of Wild-
 life has documented  cases  of both young
 quail and newly born rabbits being killed by
 IF A,  they have also shown that quail num-
 bers  in the  primary  sugarcane  producing
 parishes are greater now than they were in
 the late 1950's and early 1960's. In addition,
 rabbits are as abundant as they were before
 the IFA  colonized the  Florida  Parish  of
 Louisiana.

 RESEARCH NEEDS
    There are  legitimate research needs for
 short-term  chemical solutions  to the IFA
 problem in  particular  areas  and for long-
 term  ecological  management  of  IFA  over
 the entire  area  of  its  distribution.   We
 address  here  the  biological  information
 necessary for  long-term  IFA  management.
 It  is  important  to recognize  that undue
 emphasis  on short-term chemical solutions
 has two important  negative  consequences.
 First, the distribution of available funds will
 be   disproportionately  directed   towards
 short-term  solutions.    Second,  long-term
IFA management can be more difficult due
 to adverse ecological consequences from  an
over-emphasis on chemical solutions.

RECOMMENDATIONS
 1.  Research the basic population dynamics
    of  the IFA and related  ant species  in
    disturbed and  non-disturbed habitats  in
    the South American homeland and in the
    United States.
 2.  Develop life  tables for IFA colonies in
    South and North America.
 3.  Assess potential biocontrol agents (para-
    sites, predators, pathogens, and competi-
    tors) in Brazil and the United States.
 4.  Study  the factors  influencing  mating
    flights and colony founding, particularly
    (a) abiotic factors influencing flight ini-
    tiation, mating, and dispersal; (b) intrin-
    sic  factors  influencing   readiness  to
    swarm; and (c) factors  influencing nest
    site selection.
 5.  Investigate interspecific competition be-
    tween  IFA and other ants in vari-ous
    South   and North  American  habitats.
    Also study interspecific competition in
    and on  IFA  populations  found on the
    periphery of infested areas.
6.  Investigate  intraspecific   competition
    among IFA colonies and the role it plays
    in determining population densities.
7.  Investigate the  intrinsic  factors  in-
    fluencing the  production  of  males and
    virgin queens.
8.  Continue  researching  the  endocrine and
    exocrine systems  (hormones and  phero-
    mones);  determine how these  regulate
    reproduction.
9.  Chemically identify   pheromones,  and
    evaluate   their  potential   as   control
    agents.

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                                         74
10. Analyze  the  genetic  diversity  (heter-
   ozygosity) of IFA in its South American
   homeland and in the U.S.
11. Evaluate the impact of the IFA on pests
   and beneficial  arthropods in forest  and
   agricultural ecosystems.
12. Determine  how IFA populations effect
   wildlife and domestic animals.

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           PANEL IV

ENVIRONMENTAL TOXICOLOGY
  Robert L. Metcalf, Chairman
      University of Illinois

David J. Severn, Reporter,  EPA
       Washington, D.C.

         Earl L. Alley
   Mississippi State University

         Murray Blum
     University of Georgia

       Maureen K. Hinkle
    National Audubon Society

       Herbert N. Nigg
             IFAS

       William H. Schmid
           Allergist

          John Wood
            APHIS

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INTRODUCTION                             formation that  results from IFA stings and
   Repeated failures of massive eradication    the  hypersensitivity  and allergic reactions
programs for the imported  fire  ant  (IFA)    that are experienced by perhaps one percent
have  focused attention on the benefits and    of those who are stung.  In some cases, this
risks  of the eradication process.   The envi-    allergic  reaction is so severe  as to require
ronmental toxicology of the ecosystem com-    hospitalization and/or  expensive  desensiti-
plex  where humans and  the IFA  compete    zation treatments.   Thus  the presence of
directly  with one another comprises a large    trillions  of IFA  workers from  an estimated
part of the benefit/risk equation.  The two    10 billion nests  over the infested area rep-
major components are the toxicological and    resents a readily defined and unforgettable
human health hazards resulting from infes-    experience  in  environmental biochemical
tation by the stinging IFA and the destruc-    toxicology. In appended reports,  the panel
tion  of  wildlife  and  the  pollution of the    has  summarized knowledge about  the  fire
human environment resulting from the wide-    ant venom—its generic composition and evo-
spread use of persistent organochlorine in-    lution  (Blum  1982,  Appendix A)—and  has
secticides. The Panel examined these issues    placed in perspective the medical aspects of
in some detail  and has summarized these    the consequences of IFA attacks on humans
discussions in a  series of reports (Appen-    (Schmid  1982, Appendix B).  These apprai-
dices A through H).                           sals  together with  detailed analyses from
                                             Panel I and other components of this Sympo-
IFA VENOM AND HUMAN HEALTH           sium should make it possible to characterize
   The presence of IFA infestations over  a    the human risk element of IFA infestations.
10-state area of the  eastern and southern      The  Panel believes that a better assess-
U.S.,  about 240 million acres (97 million ha),    ment of  the actual  impact of fire ant stings
has brought  Solenopsis invicta into  direct    is essential to the long term management of
conflict with an estimated 40 million inhabi-    the fire  ant  problem.  Such an assessment
tants. This conflict has excruciating reality   should include (1) epidemiological studies of
to urban and rural dwellers  because of the   IFA morbidity and correlations between IFA
aggressive stinging  behavior  of  IFA.   The    densities  and incidence  of morbidity, (2)
IFA venom contains a unique series of dial-    toxicological  studies on IFA venom (especi-
kylpiperidine alkaloids together  with reac-    ally  the  diakylpiperidine alkaloids), and (3)
tive protein  constituents that  collectively   research on the natural products of the IFA
are responsible for the urticaria and pustule   and their potential role as  population regu-
                                           75

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                                          76
lators.

INSECTICIDES FOR IFA CONTROL
   Environmental toxicology has been  cen-
trally  involved in  the  IFA "problem"  ever
since organized attempts were first made to
control its spread by  the use of insecticidal
chemicals (about  30 years).  The insecticides
chosen  for control  and  later  eradication
efforts were the  hexachlorocyclopentadiene
adducts chlordane, dieldrin, heptachlor, and
mirex.  These insecticides can be collective-
ly described as extremely persistent in the
environment, broad spectrum  in their toxic
action, highly bioaccumillative  with  long
residence  times   in  human  and   animal
tissues, and  generally hazardous to  a  wide
variety of terrestrial and aquatic wildlife.
These  insecticides have also been shown in a
variety of animal experiments to be  chemi-
cal  carcinogens.    The extensive usage  of
chlordane, heptachlor, and  dieldrin for IFA
control from  1957 to  1962 on millions  of
acres,  produced countless problems in envi-
ronmental toxicology relating to bioaccumu-
lation  in  human  tissues, severe  damage  to
wildlife, and threats to human health.
   The introduction of mirex baits  for IFA
control in 1962 represented a step forward
entom©logically,   in  that  control   efforts
were  more  selective for  the  target  pest
(IFA)   and  dosages  were   dramatically
reduced from  about  2 pounds  AI  (active
ingredient) per acre for heptachlor and diel-
drin, to 1.7 grams and later to 0.4 grams of
mirex  per acre.  At first,  mirex was touted
as  being  the  perfect  insecticide.   While
heptachlor and dieldrin primarily killed ants
after they left the mound, mirex, a delayed
stomach poison, allowed foraging workers to
carry the  poison back to the nests where it
was transferred to the queen and nestmates.
    Mirex, however, proved to be even more
environmentally  recalcitrant   than  chlor-
dane, heptachlor, and dieldrin.  Even small
dosages caused serious problems in environ-
mental toxicology of field, stream, wildlife
areas,  estuaries, and the  human ecosystem.
Mirex  is one  of the most  stable xenobiotics
known. It dissolves in water to about 20 ppb
(parts  per billion) and has  an octanol/HgO
partition coefficient of about 10,000.  Resi-
dues of mirex were found  in snails, crayfish,
fish, birds, turtles, vertebrates,  and humans.
It  accumulated  in the brain,  muscle, liver,
skin, and  tissue of mammals; was resistant
to  metabolic   attack;  was   not  readily
excreted;  biomagnified; leached  into  soil;
attacked non-target insects; and persisted in
the environment.  The Panel has endeavored
to  place  these  toxicological   effects and
their ensuing political and sociological con-
sequences in  perspective  in  the  appended
papers (Metcalf  1982,  Appendix  C;  Hinkle
1982, Appendix D).
   In  1973,  EPA  prohibited   mirex  from

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                                           77
being sprayed in coastal counties or broad-
cast on aquatic and heavily-forested areas.
In 1977, mirex was phased out of use as an
insecticide;  Mississippi  was  permitted  to
apply mirex on mounds and ground broad-
cast.  The  pesticide registration of mirex
was cancelled on June 30, 1978.
    Once  the environmental  toxicology  of
mirex  baits  for IF A  was  recognized, more
rational  methods  for  insecticide use were
explored.   Significant progress was  made in
understanding the environmental degrada-
tion of mirex and  characterizing  the lexico-
logical  properties of the  degradation  pro-
ducts.  From this  information a new formu-
lation, ferriamicide,  was  developed (Alley
1982, Appendix  E).  Ferriamicide incorpor-
ated mirex (0.05%), ferrous chloride  hexahy-
drate (0.2960, and soybean oil (8%) to pro-
mote more rapid photolysis and faster envi-
ronmental degradation.
   Field degradation  studies showed  that
after three years, only 20% mirex was found
in plots treated with a 300-fold  application
of ferriamicide. The added amine and fer-
rous chloride components  were  shown  to
reduce the half life of mirex from 12 years
to  about  0.15  years.    Such accelerated
degradation was felt to result in decreased
problems with bi©accumulation and biomag-
nification.
   The  use of ferriamicide, however,  also
posed problems in  environmental  toxicology.
Its principal environmental degradation pro-
duct is photomirex—a highly toxic and car-
cinogenic product.  The State of Mississippi
was granted temporary registration by EPA
to use ferriamicide as a mound treatment
until July 30, 1978.  Before a renewal was
submitted, chlordecone (Kepone) was  found
in shelf  samples of  ferriamicide (Metcalf
1982, Appendix C).  Chlordecone,  an ana-
logue of  mirex, had been shown through the
Hopewell,  Virginia,  episode  to be highly
toxic to  humans  and animals as a delayed
neurotoxin, an estrogen, and a carcinogen.

PESTICIDE REGISTRATION
   The responsibility for pesticide registra-
tion  rests with the EPA whose  registration
guidelines require that extensive toxicologi-
cal and environmental studies be conducted
before   registration   can   be   granted.
Detailed  evaluations  of these  studies  are
made by  scientists in the Office of Pesticide
Programs (a division  of  EPA).    Although
under the Federal Insecticide, Fungicide and
Rodenticide Act  (FIFRA),  registrants must
demonstrate  the  safety of their products,
ultimately, EPA bears the  burden of deter-
mining the safety of a pesticide.
   EPA  also conducts risk assessments  to
determine the  likely  risks  of pesticide use.
In addition to the toxicology of the pesti-
cide, these assessments consider human and
environmental  exposure,   i.e.  actual  use

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                                            78
 practices, human activities at treated sites,
 and possible  absorption of residues.  These
 requirements are discussed in more detail by
 Severn (1982, Appendix F).
    Little information  has been available on
 the exposure of applicators  or the general
 public  to pesticides  for IF A control. While
 methods  to  measure direct  exposure from
 other types of pesticide use have been avail-
 able, field measurements of exposure to bait
 formulations  has not  been conducted.   As
 more chemicals come before EPA for regis-
 tration for IFA control, such measurements
 will need to be  conducted (Nigg 1982,
 Appendix G).

 DEVELOPMENT OF NEW INSECTICIDES
    The Panel has surveyed the range of
 insecticides  currently  registered   for  IFA
 control as well as those  under immediate
 development.   The  Agricultural  Chemical
 Industry responded  wholeheartedly  to  our
 request for  information on  the  range of
 properties, uses,  and performance  that  we
judged as  esssential to evaluate the  environ-
 mental toxicology of each insecicide, i.e.:
    1) chemical name and structure,
    2) chemical and physical properties, in-
      cluding melting point, vapor pressure,
      water   solubility,  and  octanol/H0O
                                       It
      partition coefficient,
   3) metabolic  and environmental degra-
      dative fate and pathways, soil persis-
        tence, etc.,
    4)  acute and chronic toxicity,
    5)  possible  mutagenicity,  carcinogeni-
        city, teratogenicity,
    6)  wildlife toxicity and hazard,
    7)  use patterns, and
    8)  proposed label directions.
    This  information  is  appended in  data
 sheets dealing with (a) mound  drenches, (b)
 bait toxicants, and (c) insect growth regula-
 tors.   The  properties,  toxicological evalua-
 tions, and uses of all the chemicals studied
 by the Panel are summarized and  presented
 in Appendix I.
    As  a  result of this  approach and  thanks
 to  the  excellent cooperation of Drs.   Clif-
 ford  Lofgren,  D.  F. Williams and  W. A.
 Banks  of the  USDA, we can  report  that
 there is a considerable array of insecticides
 that probably can be recommended and uti-
 lized with  some confidence in direct ap-
 plication  to IFA mounds by  homeowners,
 licensed pest control operators, and local,
 state, and federal authorities.
    Bait Toxicants
    Several   new  insecticides  have  either
 conditional or pending registration with EPA
 as ingredients of IFA baits.   These promise
 effective IFA  control  at dosages ranging
from  1  to 10 grams per acre, are  generally
biodegradable,  have  favorable  selectivity,
and low hazards to wildlife.   It  seems prob-
able that  they  will be used in a variety of

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                                           79
 IPM efforts (see Appendix I, bait toxicants).
     Insect Growth Regulators
     Four "insect growth  regulators"  (IGR)
 are under development for IF A control (see
 Appendix  I,   insect  growth  regulators).
 These offer considerable promise for oblit-
 erating  colonies by affecting development
 and reproduction.  These IGR's are of very
 low  toxicity to humans  and other verte-
 brates and are effective at  2 to 20 grams
 per acre in bait formulations.  These  new
 chemicals offer opportunities for new and
 innovative  IF A control  by  householders,
 PCO's, and governmental agencies.
    In using these  new  chemicals for  IFA
 management,  consideration  needs  to  be
 given to the range of  use:  direct  mound
 treatments,  broadcast (ground) bait treat-
 ments,  and  aerial  bait  applications.   The
 array of chemicals now registered or pend-
 ing  registration  for  IFA management  per-
 mits a  significant choice  of alternatives.
 However, these  chemicals  must  be  evalu-
 ated carefully for their capacity to adverse-
 ly affect  the  environment  and population
 dynamics of target,  non-target, and other
 invertebrates in  the IFA ecosystem.  Their
 cost effectiveness and potential for  resur-
gence by IFA also must be evaluated.
   More   than  20  years  of  study  in  the
"school of hard knocks" have been expended
in  learning  about the environmental toxi-
cology of  mirex and its distribution through-
 out the human environment.  The magnitude
 of  the  IFA problem  and  the need  for
 developing more optimal insecticidal strate-
 gies for  its control and  management dic-
 tates that  this rate  of  accumulation  of
 knowledge about environmental  toxicology
 is  woefully  inadequate to  deal with  the
 development of bait programs incorporating
 entirely new types of toxicants and insect
 growth regulators.   Modern systems  analysis
 and computer  technology  have the  simula-
 tive  capacity to incorporate  such  param-
 eters  as  IFA density,  rate  of application,
 rate of effectiveness, effects  of competing
 organisms,  chemical   properties such   as
 water solubility,  partition  coefficient, rates
 of  photolysis, and  biodegradability, bioac-
 cumulation potential, etc. into predictive
 models that  will avoid  environmental mis-
 takes  or  irretrievable  environmental dam-
 age.   Greater emphasis and  research needs
 to be directed into the development of com-
 puter simulations for IFA management.

 CONCLUSION
   The historical evidence shows that sim-
 plistic control and widescale  eradication
 programs  for the IFA  are ineffective.   It
seems that the best strategy is to develop a
 variety of compounds.  Several  improved
toxicants  for bait  formulations now  have
either conditional registration  or are pend-
ing registration.  These substances promise

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                                          80
effective IF A  control  with low hazard  to
wildlife.  Additionally, four insect growth
regulators are  being  developed for possible
use on IF A.  Perhaps these compounds can
be incorporated into an integrated plan  to
manage the  IF A.

RECOMMENDATIONS
1. An epidemiological study should be con-
   ducted of IF A morbidity in  typical rural
   and  urban  situations.   (A preliminary
   discussion  with epidemiologists at the
   Center for Disease Control  has indicated
   that a study is  feasible.)   Such  a  study
   could lead  to  the  development  of  an
   action threshold for initiating commun-
   ity or areawide control programs.
2. A reliable correlation should be estab-
   lished between  IFA densities  and inci-
   dence of morbidity in a variety of eco-
   logical situations.  There is still a  great
   deal of uncertainty about the pharmaco-
   logical and  physiological effects of IFA
   effects and IFA  stings.
3. Toxicological  studies  should be under-
   taken on the properties of the dialkylpip-
   eridine alkaloids in IFA venom.
4. Research should  be  conducted  on the
   chemistry of  IFA natural  products and
   their potential role as population regula-
   tors.   Toxicological studies  on  these
   compounds should  be implemented simul-
    taneously.
 5.  The  cost effectiveness,  environmental
    impact, and potential for IFA resurgence
    under the various control options should
    be  considered.   Using  all   chemicals
    against the IFA may have extrinsic and
    intrinsic effects on other ant species and
    on a variety of non-target species in the
    treatment area.
6.  New insecticides and insect growth regu-
    lators should be evaluated for their cap-
    acity  to  adversely  affect the environ-
    mental toxicology and population dynam-
    ics  of the complex  of  target and  non-
    target  insects  and  other vertebrates.
    Particular attention  should be  given to
    the potential for IFA  resurgence
7.  Computer simulations need to be devel-
    oped for IFA pest management methods
    (Wood  1982,  Appendix H).   Realistic
    models dealing  with the  environmental
    toxicology of IFA abatement procedures
    can be expanded into  overall IFA mange-
    ment and decision-making models by in-
   corporating such key features and tech-
   nologies as:
   a) new pesticide formulation effective-
      ness,
   b) local area applications mapping,
   c) local area environmental effects,
   d) site specific and aggregated applica-
      tion costs,
   e) aggregate area benefit assessments,

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                                        81
f) interactive information and situation
   displays, and
g) distributed    information    system
   demonstrations.

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                       PANEL V

MANAGEMENT OF ESTABLISHED VS. INTRODUCED PESTS
              Harold T. Reynolds, Chairman
            University of California, Riverside

                Roy Clark, Reporter, EPA
                    Atlanta, Georgia

                    Gordon Frankie
            University of California, Berkeley

                    Frank E. Gilstrap
                 Texas A &.  M University

                   Phillip J. Mammon
                 Texas A &.  M University

                     Marcos Kogan
                  University of Rlinois

                    Edward H. Smith
                   Cornell University

             Donald E. Weidhaas, USDA-ARS
                  Gainesville, Florida

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INTRODUCTION
    There are literally thousands of exotic
pest species that could thrive in the United
States.  Likewise, many species already ex-
isting  in this  country could  extend their
range  if transported into areas with com-
patible environmental parameters.  Typical
examples  of such  introductions  are  the
movement of the pink bollworm  into  Ari-
zona and California cotton production areas,
the anticipated  westward movement of  the
IF A, and the gypsy moth.  Introductions of
fruit fly species from foreign sources can be
expected to occur  periodically.  These  ex-
amples typify introductions that can be  ex-
pected to occur with a host of species with
potentially   serious   problems   resulting.
Authorities  must remain alert  to such  po-
tential introductions  and  prevent  them if
possible.  The rapid transportation provided
by jet  aircraft and the enormous numbers of
people  travelling  have vastly complicated
existing quarantine  systems.   Quarantines
are the first line  of  defense  against intro-
duction, and their degree of  effectiveness
should    be  continually   evaluated  and
strengthened.
   The importance  of early detection  of
introduced  pest  populations cannot be over-
emphasized.  Detection before such  popula-
tions adapt  to  their new  environment  or
prior   to  population  explosion  makes   the
problem of coping with them much simpler.
Eradication, for example, may be feasible if
detection is early, but eradication  may be
impossible at a later time.  Improved detec-
tion methods  should  be sought continually
and adopted when appropriate.  Survey and
monitoring techniques should be simple,  re-
latively  inexpensive,  and  effective.  Pro-
grams to provide early detection are operat-
ing; however, their effectiveness is less than
desirable   and  enhancement  is  clearly
needed.
[Appendices M  through P  provide detailed
information on the concept and practice of
eradication and prerequisites (Appendix M:
Smith);  biological  control, an historic over-
view and  as it is applied to the IF A  (Appen-
dix N:  Gilstrap);  examples of  eradication
programs and  the population dynamics of
introduced species (Appendix O:  Kogan); and
the special problems of introduced species
in urban environments (Appendix P:  Frankie
et al.)J

INTRODUCED PESTS IN ESTABLISHED
ECOSYSTEMS
   Despite  the  large  numbers of potential
pests confiscated at quarantine  points, pest
species  continue to invade and  become es-
tablished  in  the  U.S.   Often  these  pests
cause major losses to  agricultural  produc-
tion.   They also  can detrimentally affect
environmental  quality,  human  health, and
the aesthetic value of plants.  Losses from
                                           82

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                                           83
 these pests are sometimes catastrophic, and
 yet attempts to cope with such acute prob-
 lems  frequently  result in ecological upsets
 and associated problems.
   Human  commerce  has  magnified  the
 flow of arthropods across geographic barri-
 ers.   Although measurement of the rates of
 movement in terms of numbers of species
 and  of  individuals per species is  difficult,
 APHIS  reports on interceptions may be  a
 valuable data base for an analysis of these
 events.  (For example, in a one-year period
 (1978 to  1979),  14,002  insect plant pests
 were  intercepted  at  quarantine  points.)
 Some species that cross geographic barriers
 successfully  establish  themselves  in  a  re-
 gion.    Many  more species do not  succeed
 probably due  to hazards in the new region,
such as (1) the absence of adequate  hosts,
(2) inhospitable climatic conditions, (3) pre-
dation by general native predators, and (4)
genetic degeneration due to excessive in-
breeding because of the narrow gene pool of
the few colonizers.
   Agricultural Environments
   Many introduced pests have been detect-
ed approximately  10  to  15 years after  the
presumed date of immigration.  After this
initial,  latent  phase,  the pest  population,
free of effective natural enemies and better
adapted  to the new environmental condi-
tions, explodes.  It is in the beginning of  the
explosive  phase that the  pest most  often is
detected  and control actions are contem-
plated.   During  the explosive phase, IPM
programs in agricultural ecosystems are dis-
rupted,    because  researchers,   extension
specialists,  the pesticide industry, and pro-
ducers  must  redirect  their  efforts,  thus
hindering long-term programs (see Appendix
N).
    Many introduced species that go through
this explosive phase are extremely difficult
to eradicate.  They expand their geographic
range and, after a time,  stabilize and are
increasingly  affected  by  the   regulating
forces of the new environment.  Sometimes
the  stabilized population  exceeds tolerable
levels.  Such introduced pests often become
key  pests of a crop,  either as an additional
key pest, by replacing previously-established
key  pests, or by assuming  key pest status if
the  crop was  previously free of key pests.
This status  means  that inadequate  popula-
tion regulation exists and control procedures
must be applied on  a  recurrent basis. Often
this  disrupts  other  pest  populations  that
were previously under  dynamic equilibrium
and kept in  check by natural enemies.  The
boll  weevil  in  cotton is a classic example
and  dramatically illustrates this  phenome-
non.  Among the many consequences of the
boll  weevil  invasion many  years ago  has
been  the  rise  of Heliothis to its  current
position of prominence in cotton ecosystems
throughout the cotton belt, largely because

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                                           84
 attempts to control the boll weevil,  mainly
 with insecticides,  have so  destroyed  the
 natural biotic  components in the cotton en-
 vironment that Heliothis populations are re-
 leased from effective population regulation.
    Public awareness  of newly-introduced
 pests  usually  occurs during the  explosive
 phase of establishment.  The  public  often
 overreacts, even  panics, and pressures  au-
 thorities  to  "act."   If  the energies of  the
 public outcry  are directed  correctly, they
 may  help generate the necessary funds  to
 support  the coordinated  efforts  that are
 required  to  eradicate,  contain, or manage
 the pest, e.g.  the imported  crucifer weevil
 in Illinois.
   The examples  of the European  corn bor-
 er, cereal leaf beetle, and several  other
 introduced agricultural pests suggest that it
 is virtually impossible to detect these pests
 during  the  early  phase of establishment.
 Quite possibly, this difficulty is one of the
 reasons why the  eradication programs for
 these pests failed.
   Urban Environments
   In contrast  to  agricultural environments,
new  pests introduced  into  urban environ-
ments often exploit previously  unoccupied
niches, mostly  because so many actual and
potential  niches are  extant  in urban areas.
This  in  turn  is related to the urbanization
process, which  includes the introduction of a
wide variety of exotic plant species and the
 establishment  of  new  structures  and  the
 renovation  of old  ones.   Thus,  one  may
 expect most newly-introduced species to oc-
 cur  in urban environments.  In some cases,
 these pests establish in  indoor habitats that
 are  geographically  far  beyond  their  usual
 physiological limits (e.g.,  pests  that invade
 indoor habitats in cold climates).
   Because  many  species introduced  into
 the  urban   environment  cause  aesthetic
 rather  than economic  loss,  they  may be
 assimilated with little  overall  impact on
 urbanites (witness the introduction of a new
 domiciliary cockroach species or a new a-
 phid species on an  ornamental plant—organ-
 isms that are already represented in  most
 urban areas).  On the other hand,  when the
 introduced species  are considered to be of
 economic or public health importance, the
 impact  may be substantial, especially  from
 a social standpoint.
   Frankie  et  al.  (Appendix O) postulates
 that urban centers are and will  remain the
 areas of first discovery  for most exotic
 pests, mainly because urban  areas are the
 major points of entry for  goods  and people
 by air or sea.  Once new pests are estab-
lished,  people  may exacerbate  their  pest
problems through their everyday activities,
for example, through their intra- and inter-
city  movements  where they unknowingly
transport pests to uninfested areas (i.e. gyp-
sy moths,  IF A,  bark beetles,  Dutch  FJm

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                                           85
 disease, Japanese  beetles).   In fact,  such
 activity could be the route of first introduc-
 tion. Once arrived, pests may interact with
 people  and essentially become more of  a
 "people  problem"  than  a strict  biological
 problem due to the way people perceive  and
 respond  to these pests.
    People can further increase their  pest
 problems when they muster enough political
 power to determine or greatly influence the
 type of control programs to be used against
 the  pests.  Often  these  are not the most
 effective programs and thus  represent com-
 promises that are strongly tempered by
 social and political considerations.   Results
 usually  are unnecessarily  expensive  and  en-
 vironmentally detrimental.  Some urbanites
 cooperate  in  management  programs,   but
 many are apathetic. This may be related to
 the aesthetic  nature of the  problem rather
 than to economic or public health concerns.
   Other Environments
   Newly-introduced pests can economical-
ly impact animal production.  In the 1880's,
the horn fly spread throughout the  country;
control  costs  and  economic losses  due to
reduced  animal production were great.  The
screw worm, native  to  the  southwest U.S.
and  introduced into southeast U.S. in  the
1930's, annually caused losses and  control
costs in  the millions of dollars, until it was
essentially eliminated.  The face fly, anoth-
er economically important introduction, also
affected animal production.  These types of
introductions  have impact  because of  the
insect itself.  Introductions of diseases pre-
sent a different problem. For example, the
mosquito,  Aedes  aegypti, although a  very
old introduction, exists  and is a potential
vector of  dengue fever which is currently
present in the Caribbean area and Mexico.
Other diseases of humans and animals could
be introduced because the vectors of  these
diseases are present in the U.S.

MANAGEMENT METHODS FOR
INTRODUCED PESTS
   Research Needs
   There  is an historic and substantial gap
between the "action" of regulatory agencies
charged  with conducting  eradication  pro-
grams and research scientists who have gen-
erated the information and  technology used
for various control tactics.  This point was
made extremely  well by  W. L. Brown, Jr.,
who over 20 years ago reviewed four,  area-
wide,  mass  insect control  programs,  of
which one  was the IF A.   Brown  (1961) was
highly critical of the programs because  re-
search was not integrally involved.
   Every  mass control campaign  should
   have an adequate research program
   functioning as far  ahead as possible
   before control operations get under-
   way.   The control work  should  be
   guided by  the  research  and not the
   reverse, and every campaign  should
   be reevaluated frequently to see if a
   need for it continues.

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                                           86
   The  newly-detected,  introduced  pest
presents a rather unique  set  of problems.
Not  only must decisions  be made quickly
regarding tactics and scope of the program,
but  these decisions  are  usually based  on
limited biological information and  no cer-
tainty of the pest's rate  of success or distri-
butional increase  in  the new  environment.
Furthermore,  recent decisions,  made  by a
small group of state and/or federal regula-
tory personnel, have often opted for eradi-
cation via pesticide  application.  Eradica-
tion  programs are not always successful, and
when they are not,  research to develop or
implement alternative courses  of action is
generally inadequately organized  or funded.
This delay in research activity is unneces-
sary and unwise,  as area-wide programs are
increasingly subject to public focus and par-
ticipation. Such public focus should be used
to initiate research into  short and long term
needs  and studies on alternative manage-
ment tactics.
   The  short-term   management research
needs could include  advice from a panel of
appropriate  scientists  regarding  pesticide
options,  formulations, modes and rates of
application, and,  perhaps most importantly,
obtaining and interpreting  efficacy   data.
The  short-term research  panel  would also
promote collection and interpretation of lit-
erature; considerations regarding best meth-
ods and materials for detection; and sugges-
tions  for  kinds of approaches  to, and  suit-
able scientists for, pressing research needs.
Short-term management research should al-
so continually evaluate  program  objectives
and actions.   The formal incorporation  of
research in an  advisory  role to  eradication
programs  (1) would be  relatively inexpen-
sive,  (2) would allow early development  of
research needs on a commodity and area-
wide  basis, (3)  should substantially improve
prospects  for successful eradication,  and (4)
would assure the affected public of  an or-
ganized transition  into  other  management
tactics.
   Given   that  an  eradication  program
evolves into  one only of  containment, the
original short-term advisory  panel  should
become involved  in developing the probable
changes in longer-term  tactics  for regular
commodity protection (e.g., changes  in rec-
ommendations  for  IPM)  and   production.
These changes would minimize the immedi-
ate impact of the pest on affected crops and
existing IPM programs.   The  panel  should
recommend and promote new research needs
where required to  develop  potential  crop
protection options.
   Biological Control
   Classical biological control is more like-
ly to  succeed for introduced pests, and can
permanently regulate populations. Because
of this,  preliminary studies  on biological
control, possibly  funded by the  eradication

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                                           87
program, should be initiated at an early date
and should be evaluated in the event eradi-
cation cannot be undertaken or fails.  These
studies should be separate from objectives
of the short-term research panel and should
function  concurrent  with early eradication
attempts. The research panel  should include
a  taxonomist of   parasitic  Hymenoptera
and/or  Diptera  as appropriate, an  insect
pathologist, a quantitative ecologist, and a
specialist with formal training  and experi-
ence in classical biological control.  Initially
the panel would  evaluate the prospects for
successful biological  control,  including (1)
known  natural enemies and their  biologies
and distribution, (2) probable host plants and
any  existing  host-plant  resistance of the
pest in  the  aboriginal home, (3) potential
foreign exploration problems and needs, and
(4)  the  ecosystem of the pest in the abori-
ginal home.
   The  panel's role  and  activities  would
increase if  the eradication program looked
like it was failing.  Foreign studies  would be
initiated to begin collecting and testing the
pest's natural enemies.  If the eradication
definitely was not working,  funding would
shift  to biological control and  eradication
tactics  towards containment  using control
methods  compatible  with establishing  new
natural enemies.
   Eradication
   The   term  "eradication"  as  used   here
means to eliminate a pest population from a
specified area.   Presumably,  having elimi-
nated  the pest  population,  the area would
remain free of the  pest until reentry  by
mobility  of  the  species  or  introduction
through human activity.  Ecologically, erad-
ication involves removing a species from a
niche.    This  action sometimes  opens  the
niche to one or more other species that may
be economically significant.  As eradication
is normally directed  against  newly-intro-
duced  species, the  steps involved in  pest
establishment and stabilization are of parti-
cular interest. The population dynamics of
newly-introduced  species   usually  reflect
three phases:  (Phase 1) establishment in the
niche,  (Phase 2)  rapid population growth,
and (Phase 3)  stabilization from the actions
of biological constraints.
   During phase 1,  pests are most  vulner-
able to eradication efforts; therefore, early
detection is necessary.  Once the introduced
pest advances to phases 2 and 3, its unique-
ness and vulnerability changes and becomes
similar1 to  the problem posed by indigenous
pests.
   Biology, economics, and  politics influ-
ence eradication.  The political factors  are
particularly complex because they  involve
different  constituencies  and political  enti-
ties  and agencies having conflicting objec-
tives and  needs.    The  case  histories  of
eradication programs are  widely variable,

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                                          88
panging from  highly  effective programs to
abject failures.  Based on experience  ac-
quired over a period dating from the earliest
eradication programs in the late 1800's,  a
list of prerequisites needed for programs to
have  a reasonable probability for  success
can be drawn.  This list includes the follow-
ing:
   1.  High socioeconomic importance  of
   the pest.  The eradication strategy gen-
   erally,  but not  always, involves a com-
   prehensive research program to  develop
   the needed technology.  This  phase is
   followed by a  complex  phase involving
   extensive control programs.  Such  major
   effort should be reserved for insect pests
   of high  socioeconomic importance.
   2.  Specific advantages of  eradication
   over suppression.  Unless there is a clear
   advantage  to  eradication over  suppres-
   sion, eradication is not justified assum-
   ing effective  technology  and  modest
   economic and  environmental costs  for
   suppression  programs.   Recent advances
   in controlling cotton pests, for example,
   requires a  reassessment of the eradica-
   tion option.
   3.  Effective monitoring technology.  Ef-
   fective  technology for monitoring pest
   populations  must be available.  Without
   such technology, it is  impossible  to  de-
   termine the area infested by the pest or
   the results  of  treatment.  Recent  ad-
vances  in  pheromone  chemistry  and
technology offer promise here.
4. Effective  control  technology.    In
most  cases, eradication efforts will in-
volve a combination of measures.  The
potential  effectiveness of the total ef-
fort must be demonstrated before under-
taking eradication, particularly in large
expensive programs.   This poses special
problems  because of the difficulty  of
interpolating  from   small,  preliminary
tests  to large area tests.  The paucity of
data on effectiveness of IF A treatments,
for example,  was a  problem of  early
eradication efforts.
5. Environmentally    acceptable    pro-
grams.  The impact  of control programs
on the  environment  must be  assessed
before launching  eradication programs.
This poses a difficult problem because of
the time element involved  in  making
preliminary determinations.
6. Favorable  logistical odds.   Large-
scale  application programs  should  be
simple or the element of human error is
likely to  cause serious setbacks.   The
accuracy  of aerial  application  or the
thoroughness of scouting for infested ar-
eas are  the kinds of operations alluded to
here.  The likelihood  of failure increases
as the  size of  the  infested area in-
creases.   Similarly,  the longer the  pest
has been established, the better it adapts

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                                         89
 to its environment.
 7.  Adequate  funding  to  sustain  pro-
 grams.  Realistic  estimates of costs of-
 ten  have  not  been  established  before
 programs are begun.  Undertaking pro-
 grams that have open-ended budgets will
 likely place the program in jeopardy  as
 funding may be  dropped  or  credibility
 may be lost because  of  excessive costs.
 The  WHO program on  malaria eradica-
 tion illustrates the impact of inadequate
 funding, although  other  major  flaws ex-
 isted in the overall design.
 8.  Adequate administrative resources  to
 sustain programs.  A high level of admin-
 istrative competence  is required to coor-
 dinate  an  eradication  program.   This
 essential  input is more  difficult  to pro-
 vide when programs extend across state
 and national  boundaries.   Good science
 and sound scientific advice should  be the
 foundation  for  administrative  decisions
 early in the planning period.
 9.  Favorable socioecological conditions.
 The success of eradication programs may
 depend on  the  cooperation and  active
 participation  of  area residents.    It  is
 essential that a high level of public sup-
 port is assured so that  regulatory author-
 ity can be invoked  to take required mea-
 sures with minimal  impediments.
 10. Favorable  cost/benefit  relationships.
The great appeal  to eradication  pro-
    grams is that through the initial "capital
    investment" phase the pests will be elim-
    inated  thereby avoiding  the recurring
    costs of control programs.  These cost/-
    benefit relationships must be calculated
    realistically to avoid disillusionment.
    No list of prerequisites can assure suc-
 cess  of eradication programs.   An element
 of risk will always  remain.   Eradication
 should be a viable option subject to rigorous
 assessments to  determine its  appropriate-
 ness.   The  ten  points  listed above  should
 help  in putting this decision-making process
 on a  scientific basis and in improving biolo-
 gical, social, environmental, and economical
 acceptance.

 RECOMMENDATIONS
 1.  Each new eradication program should in-
    clude concurrent research to identify the
    pest's probable aboriginal home; the ex-
    isting biological restraints, particularly
    the existence and taxonomy of potential
    natural enemies; the known host plants;
    and the political mechanisms needed in
    the foreign country  to implement pro-
    grams.
2.  The program  ideally should consist of a
    taxonomist specialized in the  pest group,
    a  taxonomist  of parasitic Hymenoptera
    and/or Diptera as appropriate, an insect
    pathologist, a  quantitative ecologist, and
   a specialist with formal training in biolo-

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                                           90
   gical control.
3.  The following considerations  should  be
   made to guide decisions on  large eradi-
   cation programs:
   Assess  and demonstrate the  effective-
       ness of eradication tactics;
   Assess the socioeconomic importance of
       the pest;
   Evaluate  the  advantages of eradication
       over other control strategies;
   Determine the  availability  of  effective
       monitoring systems;
   Develop concurrently  effective control
       technologies;
   Assess  environmental  acceptability  of
       the program;
   Assess  the availability of  favorable  lo-
       gistical odds;
   Assure  availability  of  adequate funding
       to sustain  such programs;
   Assure  availability  of  adequate admini-
       strative resources to sustain the pro-
       gram;
   Assure adequate communication with  the
       public affected by the program;
   Evaluate  the probability of a  favorable
       cost/benefit relation of the program.
4. The effectiveness of existing quarantine
   and inspection  procedures  (international
   and  between  states)   that  deal  with
   movement of travelers and products be
   evaluated.    Effectiveness  needs  to be
   enhanced  wherever possible,  including
   new educational  materials  that notify
   departing  travelers of  kinds of  items
   restricted  on re-entry and the  rationale
   behind such restrictions.
5.  Appropriate educational materials should
   be  prepared  for  informing   the  public,
   particularly  in  the vicinity  of ports of
   exit and entry,  about  the identification,
   biology  and  importance  of introduced
   pests.  This information should be avail-
   able to urban and non-urban residents.
6.  Aggressive efforts should be  made by
   responsible and  informed officers to pre-
   pare and deliver  education  materials to
   the public and public officials explaining
   the importance of introduced pests and
   why efforts to manage them, although an
   inconvenience, are imperative.
7.  Students should be given  information on
   the importance of introduced pest  prob-
   lems and in the philosophies, methodolo-
   gies, and  need for  eradication  as one
   option to cope with such problems.

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               PANEL VI

    IFA MANAGEMENT STRATEGIES
       Richard J. Saner, Chairman
        University of Minnesota

Homer L. Collins, Reporter, USDA-APHIS
          Gulfport, Mississippi

          George Allen, USD A
           Washington, D.C,

           Doug Campt, EPA
           Washington, D.C.

           T. Don Canerday
         University of Georgia

         George Larocca, EPA
           Washington, D.C.

     Clifford Lofgren, USDA-ARS
          Gainesville, Florida

             Gene Reagan
       Louisiana State University

           D.L. Shankland
         University of Florida

             Mark Trostle
   Texas Department of Agriculture

         Walter R. Tschinkel
       Florida State University

             S.B. Vinson
       Texas A &. M  University

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INTRODUCTION
    Evidence shows that the red  imported
fire ant, Solenopsis invicta, cannot !>e eradi-
cated from the U*S.; therefore, there will be
a  continuing need  for programs to manage
this pest.   The  actual  pest  status  of  the
imported fire ant (IFA) is yet undetermined;
however, the fact that it is a pest is irrefut-
able, although much more needs to be known
about its public health,  economic, and nui-
sance impact in various  environments.  The
IFA is a human or  "people" pest  of major
medical  importance. Surveys show that  25
to  30%  of  the persons  living  in infested
areas are  stung at least once each year
(Clemmer  and Serfling   1975,  Adams and
Lofgren  1981,  Yeager  1978).   Less well-
defined data suggest that up to 1% of  the
persons stung may require medical consulta-
tions (Lofgren and  Adams 1982).  A survey
by  physicians in Jacksonville, Florida, esti-
mated  that  3.8  new  persons per  100,000
population  develop  a hypersensitivity reac-
tion each year  (Rhoades et al.  1977). This
figure translates to about 1,500 new cases
per year over  the  IFA-infested area.   Its
importance as a pest of  pastures, livestock,
and  crops  is less  defined.   Although the
possibility of crop losses  exists, especially in
soybeans, the IFA has been shown to be a
beneficial predator  in several  agricultural
ecosystems (Oliver et al.  1979).
   The  problem of  controlling  the  IFA  is
 particularly difficult because  the ant occu-
 pies  a wide range of  habitats and is an
 extremely effective colonizing species.  Pri-
 mary  objectives  of  any management  pro-
 gram  for IFA are to maintain  the species at
 a density level low enough  to  reduce its (1)
 public health impact by minimizing  contact
 with   humans and (2)  impact on  farming
 operations  and  crop  production.  Fulfilling
 these  objectives  requires strong suppression
 of IFA in areas where there is a high proba-
 bility  of  human-ant  contact  and mainten-
 ance  of IFA populations in other areas at
 levels that do not cause nuisance  or  eco-
 nomic problems.
    As the  only  available tactic for strong
 temporary  suppression  of   IFA, chemical
 controls (see Appendix  K)  will have to be
 used  periodically (usually once  a  year) to
 eliminate new or re-infestations. Biological
 or cultural  controls are  desirable; however,
 no biocontrol techniques are  available  and
 probably will not be for  at least five to ten
 years.    Emphasis  needs to  be placed on
 research to discover biological and other
 non-chemical approaches to control.  The
 most  desirable long-range strategy  for  any
IFA management program should be a com-
bination of chemical and non-chemical con-
trols  where  IFA  cannot be tolerated and
biological controls or integrated pest man-
     i
agement where low-level populations can be
tolerated.
                                            91

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                                          92
   In some habitats the IF A is a key bene-
ficial insect.  In Louisiana sugarcane fields,
the IF A is the most important  beneficial of
the biological control  component which re-
duces  sugarcane  borer populations by  25%
(Reagan  1982).   It is also an important
predator in Louisiana  soybean fields (Stam
1978).  The IF A has drastically reduced tick
populations in Louisiana and has been asso-
ciated with a decline  in  tularemia rij
(Burns and  Melancon 1977, Oliver  et  al.
1979). The IFA also preys on horn flies and
other pests  in pastures (Howard and Oliver
1978 &  1979).  However,  the IFA also tend
disease-carrying aphids and kill ground-nest-
ing bees (Vinson, unpublished).

CURRENT TECHNOLOGY USE IN
VARIOUS HABITATS

    The IFA occupies a variety of habitats in
urban, suburban,  and rural situations.  The
pest status  of the  IFA  in  each of these
habitats  differs  because  the   ant   causes
varying types and degrees of problems and,
in a few  cases,  is beneficial.   Because of
these disparities, certain  questions must be
considered for each habitat where control is
needed:
    1. What is the nature and magnitude of
the problem?
    2. What measures are available to solve
      the problem?
   3.  Who  makes  the  decision  to   take
       action  and  what  action  should be
       taken?
   4.  Who implements the action?
   These questions imply that the decision-
maker will bear the cost of the action.
   Homes: Urban and Rural
   Generally,  the problem in this habitat is
human exposure,  especially that of  small
children and hypersensitive individuals,  but
it  may also  include aesthetic appearance of
lawn  and garden.  The  tolerance for either
problem is likely  to be very low, with treat-
ment costs  probably not a determining fac-
tor.
   Several pesticides are labeled for home-
owner use as mound drenches; one is labeled
as a bait for mound or  broadcast treatment
(see  Appendix K).  In addition, homeowners
can drench  mounds with hot water  if only a
few to several mounds are to be  controlled;
however, this method is minimally effective
and requires multiple applications.
   Ultimately, the decision to treat  rests
with the homeowner or occupant, if a lessee
or renter  has  authority to make such deci-
sions  for the  owner.   If control action is
decided on,  the responsible person  has  the
freedom,  because  of  the availability of
materials registered for home use, to imple-
ment the  action  or to  hire a  pest control
operator or  other agent.  In some instances,
government  control programs are necessary

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                                           93
 to  give relief  to homeowners on  limited
 incomes.
    Public and Private Lands
    Because the accessibility and activities
 in these areas makes contact with the IFA
 highly probable, human exposure is generally
 the  main problem  and, perhaps, aesthetics.
 Sites of concern include school grounds, play
 grounds, parks, cemeteries, median strips or
 borders of streets and roads, municipal golf
 courses, power line rights-of-way and ease-
 ments, grounds of municipal facilities of one
 type or another, rest areas, levees, etc.  In
 the  case of levees,  tunneling  by the IFA
 could cause water seepage.  In contrast to
 homesites, public exposure includes children
 in  schools, citizens  utilizing  recreational
 and  other  areas, and employees of  various
 organizations  having stewardship over the
 land.   Questions  of  legal  liability  of  the
 respective controlling authority for harm to
 persons by IFA stings may arise and could be
 a factor in determining tolerance levels.
   All of  the  EPA-approved control mea-
sures available to the  homeowner are avail-
able  for public  lands.   If  large  areas  are
involved (more than a few acres),  individual
mound  treatments  with  drenches are im-
practical; however, baits may be used either
as individual mound treatments or broadcast
with ground or aerial equipment.
   In every case cited above, some identifi-
able  agent has stewardship  and  authority
over  the land concerned.   School boards,
park  boards, county  boards,  city  councils,
for example,  generally  make decisions  on
the management of  the land within their
commission—including  pest   control  deci-
sions.  Decisions  may be based on  concerns
of the patrons; therefore, the tolerance for
IFA may vary with each case.  There may,
for example, be a much lower tolerance set
for IFA on school playgrounds than for IFA
in median strips.  Legal liability  may  be
another  factor affecting  tolerance  levels.
In any event, the  decision to take action will
be jointly considered by the legally-account-
able authorities,  if not also by the patrons.
The decision may be tempered by the avail-
ability of funds to  support the action (e.g.,
the tolerance threshold may be partly deter-
mined by the cost  of treatments).  This is
more  likely to be an issue on public lands
than on homesites.
   Depending  on  fiscal, manpower,  and
equipment   resources    of   the   agency
concerned, a control measure  may be imple-
mented  by  the  agency, or  contracted
through commercial operators. Private golf
courses constitute a special case.  Usually,
however,  golf courses   have professional
managers authorized  to  take  the necessary
action to control IFA,  or at least  to seek
approval to do  so from the governing board
or other governing body  of the course.  IFA
management falls  under  the course pest

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                                           94
 management  program  which usually  exists
 at   some  level  of  dependency   on  the
 resources  and standards of  the  particular
 course.    Managers  generally  have  ready
 access  to  current  pest  control information
 through university  extension,  USDA,  or
 research sources or  from commercial con-
 sultants or industry.
    Agricultural Environments
    The most  significant problem when IFA
 inhabit  agricultural  environments  involves
 human  exposure—the nuisance, discomfort,
 and potential health hazard associated with
 the ants and their sting. Potential problems
 exist with  damage  to harvesting equipment
 by  IFA  mounds and the impact  on  crop
 yields.  Some data reveal  that stands and
 yield of  soybeans  may  be  substantially
 reduced by IFA (Lofgren and  Adams  1981,
 Adams  and  Lofgren 1982,  Apperson and
 Powell  1982).   Conversely, the literature
 reports  that IFA are good predators, especi-
 ally against the sugarcane borer (Reagan et
 al. 1982).
   Currently, few alternatives are available
 to control IFA in agricultural environments.
 Amdro* bait is registered for application to
 pastures, range grass, lawns, turf, and non-
 agricultural lands, and may  be available for
 cropland in 1983.   On small acreage  or in
light infestations, Amdro can be applied to
individual mounds.  Another option includes
broadcast  treatment with   ground  equip-
 ment—a procedure  more adapted  to  inter-
 mediate-size parcels of land.  Aerial  appli-
 cation is perhaps best suited for large acre-
 ages. For long-term control, yearly applica-
 tions may be  required.  Some  mechanical
 options,  such as mound leveling in the win-
 ter, provide limited  mound  reduction  and
 ant suppression.
    The  landowner/attendant  should be  the
 primary  person in assessing  the problem  and
 selecting a  course of action.  This does not
 assume that various  governmental units may
 or may not take the responsibility for area
 suppression programs when acceptable man-
 agement tools and technology are available.
   Regulatory Control/Quarantine
   Artificial spread or  movement of  the
 IFA  into non-infested areas  of the  U.S.
 through interstate shipment of items such as
 grass sod and nursery plants  is  well docu-
 mented.   Federal  Quarantine  301-81,  in-
 voked May 6, 1958, was designed to prevent
 this  occurrence.  Initially dieldrin and hep-
 tachlor were used as insecticidal treatments
 to certify movement of regulated articles.
 Use  of  these  products  was  discontinued
 February 13, 1970, in preference to  chlor-
 dane.  Chlordane was used  until December
 31,  1979, when the final  cancellation order
concerning use of chlorinated hydrocarbon
insecticides  for IFA quarantine treatments
became  effective.    Currently  available
chemicals do not fulfill all of the necessary

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                                          95
requirements  for good quarantine  treat-
ments.
   Dursban Fa-5 is registered to treat pot-
ting soils where plants are grown.  However,
due to phytotoxicity problems,  Dow Chemi-
cal (the registrant) voluntarily withdrew this
product from  the market.   Dursban 4E and
2E are  registered as a root-dip treatment
for balled and  burlapped  plants,  but  this
procedure  is highly  disfavored  by growers
due to the cost and labor required for imple-
mentation.  Currently,  no  chemical treat-
ments are registered to treat grass sod.
   Statutory authority  promulgated under
two Acts of Congress (Plant Quarantine Act
of August 20,  1912, and Organic Act of the
Department of  Agriculture  September 21,
1944) designate  the U.S.  Department  of
Agriculture, Animal and  Plant Health In-
spection  Service,  Plant   Protection  and
Quarantine as the responsible  organization
to issue regulations governing movement of
articles capable of spreading the IF A.
   Growers implement  USDA/APHIS/PPQ-
approved treatments as specified in admini-
stratively approved  control manuals (805-
25.000).  These treatments are supervised by
federal  (or in  some cases state) quarantine
inspectors.
   Other
   In addition  to the above problems,  IFA
increasingly are  reported as damaging air
conditioners, water well relays,  ground elec-
tric transformers, telephone junction boxes,
airport lights,  and underground sprinklers.
This has caused inconveniences and econom-
ic losses to various commercial businesses.
At this time, other  than  heptachlor  5%
granular  for   IFA in  telephone  junction
boxes, there are no controls specifically for
this situation other than to use the chemi-
cals available  for control  in the habitats
where these types of equipment are found.
Research is needed on why electrical wiring,
relays,  and related equipment attracts IFA
and  causes them  to  feed  on and  damage
these items.

CURRENT TECHNOLOGY AND GAPS IN
CURRENT RESEARCH
   Existing, But Unavailable Tools
   Several chemicals presently exist but are
not available, at least for some uses, as IFA
control tools for the following reasons:
   Amdro is  presently registered for use in
pastures,  rangeland,  and   non-agricultural
areas.   American  Cyanamid, the registrant,
has requested EPA approval for use of this
product on all croplands.   Data supporting
use of this expanded label has been submit-
ted to  EPA (May 1982).  The EPA is present-
ly evaluating this data.
   Mirex was previously used in IFA control
programs.  When  problems  of persistence,
bioaccum ulation,   and alleged  carcinogeni-
city  surfaced,  EPA cancelled  all registra-

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                                          96
tions effective June 30, 1978.
   Ferriamicide is presently under consider-
ation  by the EPA for registration for IFA
control.   Questions  concerning the human
and environmental impact of this compound
have been addressed under Panel IV of this
symposium.   Final determination on regis-
tration will be made by the EPA.
   Chlordane  was previously  used  in IFA
control  programs  and in regulatory  treat-
ments.  Studies alleging that chlordane was
a  carcinogen  resulted in cancellation of
most  uses  by the EPA  on March 6,  1978.
Use of chlordane for regulatory treatments
was phased out December 31, 1979.
   Dursban  (chlorphyrifos)  was  previously
registered as a quarantine treatment to nur-
sery potting media and  bench  soils.   How-
ever,  phytotoxicity problems resulted in vol-
untary withdrawal by  Dow Chemical  Com-
pany pending further research  to develop a
dose rate that would  alleviate phytotoxicity.
   Lindane is currently  under  investigation
for broad spectrum  quarantine  treatment.
Preliminary data  indicate that  it  will be
satisfactory as a potting soil  and root dip
treatment.  Results  on grass, sod and  field-
grown ornamentals are incomplete.
   Aldrin, which is presently registered for
termite control, can  be  used as  a root dip
treatment for IFA control; however, no pro-
ducts are  presently  labeled for  this use.
When aldrin/dieldrin was cancelled in 1974,
one of the exempted uses was the dipping of
roots and tops of non-food plants.   USDA
indicates that  this procedure  (root dip) is
not widely accepted by growers due to  the
cost and labor required for implementation.
   Pesticides  registered for other uses  are
presently  pending  EPA  approval for  IFA
control.    These  chemicals  are  targeted
mainly for  individual mound treatments  and
are to be used primarily on non-agricultural
lands by professionals and homeowners.  The
present group includes:  methyl chloroform
(1,1,1-trichloroethane),  Imidan, Resmethrin,
rotenone, lindane and Methylenebis (thiocy-
anate).
   Current technology
       1. Chemical Control
       Bait  Toxicants:   The  USDA   has
   screened approximately 7,500 chemicals
   and  formulations as toxic  bait for  the
   IFA (Williamson 1982).  These tests  are
   designed to select chemicals that have a
   delayed toxic reaction, i.e., allow worker
   ants to distribute the bait to other work-
   ers and the queen.   Only two compounds
   have been  registered by EPA, but regis-
   tration  of  the most effective chemical
   (mirex)  was  withdrawn  in December,
   1977.   In  August of  1980,  Amdro   was
   conditionally registered for  public use by
   EPA for mound or  broadcast application
   to  non-agricultural  lands,  lawns,  turf,
   pastures,  and  range  grass.    Another

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                                        97
 active toxicant is being developed by the
 Eli  Lilly Company and may have  condi-
 tional registration in 1983. A third com-
 pound that acts as a toxicant  and  repro-
 ductive inhibitor is  being developed  by
 Merck and Company and  is undergoing
 field tests under an EUP.
    Evaluation of insecticides  for use  as
 mound drenches or fumigants to control
 IF A colonies  has accelerated during the
 past few years.  Several chemicals have
 been registered for this  purpose  (diazi-
 non,   chlorpyrifos,  carbaryl,  acephate,
 bendiocarb,  pyrethrins  I  and n, and
 methyl  bromide)  and others  are  being
 tested.    The  problems  with  mound
 drenches are (1) the difficulty in locating
 small or hidden mounds,  (2) the need for
 multiple applications, and (3) the  neces-
 sity of applying the drench when the ants
 are  most susceptible.  In addition, this
 method of fire ant control is applicable
 only to very limited areas, urban proper-
 ties, and homesites.   Research on the
 factors and/or procedures needed  to en-
 hance this method of control are needed.
   Insect Growth Regulators:  Research
 on insect  growth regulators  (IGR) has
 been conducted at Texas  A&M Univer-
sity and the USDA (Banks  1982).   Most
interest has been expressed in the  juve-
nile  hormone  mimics,  although   some
research has been  conducted  on an ex-
 perimental  chitin-inhibitor.    Juvenile
 hormone mimics stop  development  of
 immature stages or induce caste shifts
 that  result in  the development of large
 numbers of abnormal sexuals.
    A bait containing one of these com-
 pounds (Stauffer MV-678) has  been field
 tested in a soybean oil,  pregel, defatted
 corn-grit bait  similar to  Amdro.   High
 concentrations  of the  compound were
 used  to completely flood the crops of the
 ants.   With this approach, a one-time
 feeding  produced effects on the  colony
 that  lasted up to a year; with MV-678,
 75% of treated laboratory colonies died.
 A field  test with a bait  application  of
 MV-678  at four grams per acre was con-
 ducted at Ft. Stewart, Georgia.   Appli-
 cations  were made  in  the fall and the
 spring.   Three months after the  second
 application,  75  to 80%  of the colonies
 were  dead,  and  almost  all  remaining
 colonies were without brood.
   Two  other  insect growth regulators
 (MAAG  agrochemical   R013-5223  and
 Montedison   JH  286) are being  field
 tested.   Problems may  result from the
 need for several applications to provide
 adequate  control and a  lack of specifi-
 city to IF A.
   Behavioral  Chemicals:   Behavioral
 chemicals (pheromones)  are  a fruitful
area  of  research since  a complex of

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                                        98
 pheromones  regulate  colony  activity.
 Behavioral chemicals offer unique oppor-
 tunities to disrupt the IFA's social organ-
 ization or affect their behavior in ways
 that could lead to their demise. Behav-
 ioral chemicals are  important in colony
 recognition, colony founding, egg laying,
 queen recognition,  queen acceptance or
 tolerance, brood  care, food and  nest
 location, and caste control.  Five phero-
 mones  are under  study or  have been
 isolated  and identified (a brood  phero-
 mone, trail and recruitment pheromone,
 feeding stimulant,  a  queen  recognition
 pheromone, and a queen dealation-inhibi-
 tion  pheromone).    The  trail, queen,
 brood, and recognition pheromones could
 be used to make toxic baits more attrac-
 tive and specific.
    Delivery Systems  (Formulations  and
 Application  Methods):    Methods  for
 formulating baits for IFA were described
 several years ago and are extremely ef-
 ficient.   However,  they must  be  made
 more specific to the  IFA.  One approach,
other  than behavioral chemicals, is  a
 bait that  would allow  the  use of  more
rapidly acting  chemicals.   Research is
needed (1) to identify other food materi-
als   (proteins   or  carbohydrates)   that
would  deliver more  specific distribution
of bait and toxicant within the colony,
and (2) to discover if bait attractiveness
 is influenced by  the time of  year and
 changing food preferences of the IFA.
    Methods for applying baits and other
 agents  in  large  plot  tests  have  been
 studied  by  APHIS personnel.   Although
 delivery systems  for granular  baits are
 available for  ground and aerial applica-
 tion,  the technology needs to be further
 developed for more efficient and effec-
 tive application.   If  biological control
 agents are  found, specific delivery sys-
 tems  will  have  to  be  developed  to
 disperse these  agents  in  the  environ-
 ment.
   2. Biological Control
   Pathogens:   The search for  potential
IFA  pathogens  was accelerated by the
discovery in the early 1970's of a proto-
zoan  infection  in fire  ants in Brazil.
This organism was found in up to 25% of
the colonies examined, although the de-
gree  of  infection varied considerably.
One  other microsporidian has  been de-
tected.   Little  is known about the epi-
zootiology of  either of  these organisms.
At least one bacterial pathogen and one
virus  have  been found  in Solenopsis in
Brazil.  Because no research station has
been  established in South America, the
full potential of pathogens for IFA con-
trol  cannot  be assessed  at  this  time.
Research on pathogens of the native fire
ant,  S.   geminata, is  being  used  to

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                                        99
develop  methods  and  procedures  for
working with diseases of ants.
   Parasites:   The  most highly studied
parasite  of the fire ants is the worker-
less social ant, Solenopsis daguerri.  This
ant has been found attacking colonies of
S. richteri, but not S. tnvicta. Research-
ers who have worked with this social
parasite  conclude that it would not  be
useful for  controlling  or reducing IFA
populations in the U.S.  This is  based on
the limited  distribution of the  parasites
in South America  and the difficulty in
transporting the  parasites from one site
to another.  Species of two other groups
of parasitic  insects, chalcid  wasps  and
phorid flies,  are  associated  with fire
ants.  Non-specific parasites such as the
nematode, Neoplectana carpocapsoe, are
under study for  treatment of  individual
colonies.  An  up-to-date review of the
status of biological control  of IFA is
presented by Jouvenaz et al.  (1981).
   3. Procurement, Screening and
   Evaluation
   Developing biological control agents
is a  difficult  and time-consuming pro-
cess.  This is particularly true of patho-
gens.   The biggest drawback to progress
in this  field has  been  the  lack  of a
research station  in  Brazil from  which
researchers could  search for  biological
control agents.   Up to this time, knowl-
edge has been gained through short-term
trips that have lasted  from  two to six
weeks, which does not  provide time for
intensive survey  of  any particular  area
and certainly has not  allowed time  to
determine  the  potential  usefulness  of
any of the  organisms   that  have  been
detected thus far. Once money is avail-
able to  establish  a biological control
station in South America, then the pro-
cess  of   procurement,  screening,  and
evaluation of potential agents  can pro-
ceed.    Provisions,  however,  must  be
made   for backup resources  within the
U.S. for basic research on the organisms
that are found and for  evaluating any
potential  detrimental  effects  of  these
organisms to our native fauna and flora.
Physical and Cultural Control
    1.   Tillage and Cultivation Practices
   It  has been thought that  tillage  or
cultivation deterred the establishment of
IFA colonies. More recent observations,
however,  question  this  conclusion, par-
ticularly where  these  disturbances are
discontinued.  For  example, IFA  com-
monly  are  found in soybean  fields  at
densities  of 30 to 40  mounds  per  acre
(Lofgren and Adams 1981).  Studies  in
sugarcane have demonstrated higher ant
populations  where fields that had a dense
growth of broadleaved weeds shading the
roads were  cultivated four times rather

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                                       100
than  the  minimum  two  times  (White
1980).  However, thorough weed suppres-
sion in sugarcane possibly  restricts gen-
eral insect populations (potential  IF A
food supply) and results in up  to a 50%
seasonal  abundance of IF A  mounds (Rea-
gan  1982).   The   use  of hay-stacking
equipment  is a cultural practice  change
that, in  effect, reduces the  pest status
of the IF A by reducing worker exposure
in hay harvesting operations.
   2. Other Mechanical Disturbances
   The  idea  that  IF A  colonies can be
destroyed  simply   by  digging  up  or
disrupting mounds  has been  disputed in
extensive  research  by  Blust  et   al.
(1982). In pastures, dragging  or knocking
down the tumulus  of the mounds during
the winter  resulted in greater than 50%
season-long control, but only when the
dragging  was conducted just prior to the
occurrence  of freezing  temperatures.
Dragging at other times seems to result
only in   reducing mound size  and  thus
reduces   interference  with  haymowing
equipment (Blust et al. 1982).
   3. Flooding and  Control Burns
   Flooding does not destroy or kill IF A
colonies.    No information is available,
however, on the effects of flooding for
varying periods of time  on the density of
IF A colonies.
   Controlled burns have not  been shown
   to  negatively  affect  IFA  populations.
   Recent  studies by the  USDA in sugar-
   cane fields near Lake Okeechobee, Flor-
   ida,  have shown  that  burns at harvest
   time  may  have  more  effect  on other
   species  of  ants than on IFA.  The  IFA
   apparently  escape  the fire by  moving
   deep into their mounds.
   Pest Management—Research Needs
   Ultimately, a pest management  program
needs to be developed for  the  IFA.  Such a
program must  be based on  sound, biological
and ecological knowledge of the ant as  well
as sound,  economic  and  sociological infor-
mation.    Economic thresholds,   nuisance
thresholds,  cost/benefit  ratios,  beneficial
effects,   and   environmental   and  other
external costs must all  be accounted  for.
At  present, very little of the  information
and technology needed for a pest  manage-
ment program (as  opposed to single control
efforts) are available.  A pest  management
program on the scale needed  for the  IFA
would  require an institutional framework
capable  of   integrating   information  and
making decisions.   Such a framework  also
would aid in allocating funds into  necessary
research.
   Figure 1 is a prototype management sup-
port system.   Data from  the ecosystem,
obtained via  monitoring,  are  recorded and
evaluated such that decisions  can  be made
in designing management systems.  As man-

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                                           101
 agement schemes  are  implemented in eco-
 systems, they are monitored, and the sup-
 port cycle continues.   In such  a system,
 communications are vital:  the  public needs
 to be  informed; staff must  know what  is
 going on and must  have input into decisions;
 and peer review of research  must be main-
 tained.  Figure 1 shows a two-way link with
 the decision/evaluation system and the com-
 munication system.
 DELIVERY.
  SYSTEM
•*• ECOSYSTEM
.MONITORING
   SYSTEM
MANAGEMENT
SYSTEM "*~~
DECI
	 EVALL
SYS
SION/
IATION •*—
TEM
RECORDING
SYSTEM
             COMMUNICATION
                 SYSTEM
            Public   Staff
              1
             Peer
Figure 1. A management support system for an ecosystem or
       research site.
    The  implementation  of effective  pest
 management practices depends on the sup-
 Port  and development  of basic research to
 Provide  the necessary tools.  Knowledge of
 the ecology and population dynamics of the
     and its  impact on the environment is
     vital to developing effective pest man-
 agement programs.  In addition,  methods of
 survey,  detection,  and  control  (including
non-chemical, cultural,  mechanical,  physi-
cal, and biological) must be  developed.  Re-
search is also needed on specific solutions to
specific problems  caused by the IF A; these
solutions may not necessarily  involve con-
trol.
       1. Economics
       The  economic  impact of IFA  as a
   human and  animal pest  is  difficult to
   assess.    Before  any pest  management
   system can be  effectively implemented,
   a  cost-benefit  analysis  must be  made.
   The economic losses need to be balanced
   against  the  economic benefits provided
   by  the IFA.  Will  control lead to other
   pest outbreaks? If the IFA  is eliminated
   from   an  area,   repopulation   usually
   occurs within one  year.  Is  this due to a
   void left  by  the IFA's removal,  and can
   this void be filled  with another non-pest
   species  of ant that  would  provide the
   beneficial effects of the IFA?
       The  human  health problem  needs to
   be  more  clearly defined.  More accurate
   data are  needed on the number of people
   stung,  the number that develop hyper-
   sensitivity,   and  the   economic   and
   psychological effects of these attacks
   (Adams and  Lofgren  1981,  Lofgren and
   Adams 1982,  Clemmer and Serfling 1975,
   Rhoades  et al.  1977).  The factors in the
   venom that cause the anaphylactic reac-
   tion must be  identified so that measures

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 can be developed for people whose lives
 are threatened.
    2.  Ecology and Population Dynamics
    Our   present   knowledge   of  IF A
 ecology and  population dynamics is rudi-
 mentary,  at  best, and filled with  major
 gaps.  Little information exists on age-
 specific  mortality,  development  rates,
 colony growth rates under various condi-
 tions,  reproduction,  limits  to  growth,
 factors controlling  growth,  and  many
 other subjects.  There is little quantita-
 tive  information   on  trophic  relations
 with respect  to growth and reproduction,
 and on the limitations food imposes  on
 growth and reproduction.  Interaction of
 the colony with the environment  is also
 poorly described, and the effects of sea-
 son, temperature,  and rainfall are under-
 stood only generally.   For this and other
 reasons, estimates of the potential range
 of the IF A are mere guesses.
    There  is even less information on the
 population dynamics of colonies.   No
 information  exists on  the life span  of
 colonies under  various conditions  nor  on
 the   age-specific   mortality    among
 colonies  throughout  the  colony  cycle.
 Such  information  is essential  to  under-
 stand the vulnerable phases  of the life
 cycle at which pressure might be applied
most effectively.  Also along these lines,
only  very  general,   non-quantitative
 information is available on  the process
 of colonization of a new habitat, be it on
 the spreading margin  of the IF A range,
 or in long-occupied  areas.   What  site
 preferences are involved in colonization?
 How do  physical and  biological factors
 affect success?  What is the nature of
 inter-colony relationships as the colonies
 increase  in size?  The role of territorial
 behavior?  And so on, for a  long  list of
 unanswered questions.
    Finally, at the level of the relation-
 ships of IF A colonies to other plants and
 animals  in  the  community, we  have
 another knowledge vacuum.   Because it
 seems so important to IFA success, the
 relationship of IFA to other ants greatly
 demands  study. It is becoming apparent
 that other ants may become key consid-
 erations  in any management attempts.
 Information of  IFA exploitation of  the
 community, both  plant and animal,  and
 its impact upon that community is also
 largely unavailable.
    3.  Biology
    Social   biology  of   the   IFA  has
 received  some attention, but  much  re-
 mains  arcane.   While the role of  the
queen  is  generally obvious at  a  crude
level,  many questions  of  queen function
and queen number remain unanswered.
Why  are   there   sometimes  multiple
queens, how do they affect colony func-

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tion, queen replacement, colony growth
and reproduction?
   A thorough understanding of the ant's
feeding behavior and social interactions
is needed.  Research on foraging strate-
gies  of workers,  recruitment  to  food,
natural  attractants   and   repellents,
changes in food preference,  distribution
of food within  the  nest, and  the  influ-
ence of foods or bait type on the distri-
bution  of control agents are needed to
develop more effective, species-specific,
safer baits.
   Development times,  conditions that
trigger the production  of  reproductive
forms,  age of the colonies, the life span
of the  various castes, as well as colonies,
and queen  replacement, colony recogni-
tion, social communication (apart from
the behavioral chemicals), are but  a few
of the  biological factors that  need to be
investigated  for effective  management
of this  insect.
   4.  Physiology
   The endocrine system regulates many
behaviors and functions of the ant colony
yet there  is little knowledge  concerning
this important  system.  Research on  en-
docrine glands  is needed  if  we are  to
understand IFA reproduction  and devel-
opment, queen tolerance, the  problem of
single  vs.   multiple queen colonies, con-
trol  of  mating,  caste  determination,
gene expression, and others.
   The nutrition,  digestion,  and absorp-
tion of foods is important to the success
of the  colony. Very little is known about
essential nutrients for colony growth and
about  IFA  enzyme   systems and their
specificity.  Studies  in these areas could
lead to new  control methods because
growth, development, reproduction, and
competition  are  readily influenced  by
colony nutrition.
   A  study  of  the biochemical  transfor-
mations which the  IFA is  capable  of
could  be  useful because compounds not
metabolized by the  ant  can be used  to
design control methods based on analogs
of  metabolizable compounds,  such  as
hormones or the more degradable toxi-
cants.   The biosynthetic pathways for
the pheromones,  venom alkaloids, and
other chemicals utilized by the ants  need
investigation.
   The flight muscles of the queen are
extremely important  because  they are
used in the mating flight and dispersal of
the queens  and  provide food  for the
larvae  during colony founding.   Interfer-
ence with colony  founding might be pos-
sible if this process  were better  under-
stood.
   Mating and  colony foundation may  be
vulnerable points in the IFA's life cycle,
but the physiological details are virtually

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                                       104
unknown.    What triggers the  mating
flight?  Are pheromones involved?   How
is  wing casting initiated?  How far  do
the sexuals fly?   How  does  the queen
select sites for colony foundation?
   5. Control Tactics and Management
   Strategies
   Chemical Control:  In addition  to a
search  for slow-acting  compounds  that
kill,  bioassays  to detect compounds that
interfere  with  other biological processes
need  to  be  developed.   These  could
include spermaticides,  reproductive  in-
hibitors,  or  muscle  inhibitors.   Tech-
niques  for field  evaluation  of control
tactics must be  improved so  that the
effectiveness of compounds  for control
can be evaluated.
   Insect   growth   regulators    show
promise,  but more research is needed on
their metabolic  breakdown, distribution,
and  persistence.   Also, field tests should
be extended to  determine the best way
to utilize the insect growth regulators
for  IF A  control, keeping in mind  that
these materials  will not be  specific  to
IF A.  Along this line, behavioral chemi-
 cals  offer great promise as they  may
 provide specificity for baits,  lead to new
 baits, and interfere with the social or-
 ganization of the colony.
    Behavioral  chemicals  may  lead  to
 new  delivery systems that might be use-
ful for introduction of a pathogen. Path-
ogens will probably require delivery sys-
tems quite different from those for toxi-
cants.
   Biological Control:  Pathogens, para-
sites, and predators may have  potential
for controlling or  managing   the  IF A;
however, no effective biological control
agents  have been  found.   Part  of the
difficulty is the lack of research, study
facilities,  and financial support  in the
IFA's  homeland  where  such  biological
control  agents  would  most  likely be
found.  An IF A research station needs to
be developed in South America.
    Genetic Control:  Because the  IF A
has a  haplo-diploid sex-determining sys-
tem, development of a sterile  male con-
trol  tactic may  be  possible.    Also,
because the  IF A  mate  only   once,  an
artificial mating technique that has been
developed may prove useful in  a manage-
ment  program.  Genetics is also impor-
tant  in other ways such  as   biological
control and taxonomy.
    Physical   and   Cultural    Control:
 Research is needed on interrelationships
 of IF A to the conditions created by dif-
 ferent types  of land management (i.e.,
 various types of plows and cultivators,
 frequency  of  cultivation  and tilling  in
 annual crops, and the  time  of  year of
 cultivation).   Trends  toward  no-tillage

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                                           105
    crop  production  additionally  support
    these needs.   However, more  detailed
    population  dynamics  studies   on  IFA
    interaction with other species in these
    various  habitats under cultural  changes
    is an essential component  to  answering
    these needs.  The  potential interactions
    of  the  IFA  with weeds  and associated
    fauna are additional areas for study.  In
    most annual  crops,  however, the  pest
    status of the IFA remains undetermined.
       The  potential  for  making  valuable
    contributions  and increasing the impact
    of control tactics in this important  area
    depends  heavily   on the  quality  and
    extent of population dynamics research.
    Only when  the  ecology of IFA  at  both
    the mound and community levels is  bet-
    ter understood are we likely to realize
    applied advances in physical and  cultural
    controls.  Because  these types of control
    tactics  often have  some of the greatest
    long-term impact  on pest populations,
    this research merits some of the highest
    priority.  Relating  this research to  eco-
    logical studies also will help clarify the
    true  pest status  of the IFA as it inter-
    acts  with more  traditional pests in  pro-
    duction agriculture.

SPECIAL ORGANIZATIONAL ISSUES &
AGENCY RESPONSIBILITIES
    Due to the establishment of the IFA in a
variety of habitats, the responsibilities for
its management reside with different organ-
izations  ranging from  the  home owner  to
federal agencies.  Because of this situation,
the responsibilities of the organizations con-
cerned with IFA  research,  education, and
management must  be defined, and a mech-
anism  to  provide  effective,  safe, and  eco-
nomically  feasible  management  programs
must be established. The mechanism should
provide short  and long-range  planning  to
address the needs  for  research, education,
operations, and regulatory agencies.
   Research
   USDA/ARS  and  the  SAES's   of  the
affected  states  conduct   IFA  research.
Yearly meetings of an IFA working group
help coordinate the research  activities  of
the USDA/ARS and SAES's.  Congress has
authorized  the  ARS to conduct  mission-
oriented  research  on   the  IFA  to  support
federal and  state-controlled programs.  This
research  includes  developing chemical and
biological methods to control the IFA.   In
addition, the research provides information
and control  techniques for the general  pub-
lic.
   The SAES's are  mandated by their legis-
latures to conduct  research and  to  develop
IFA  management   strategies to meet the
needs of the  public.   This research varies
from  state  to state, and  cooperative  pro-
grams are encouraged to effectively utilize

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                                           106
 human and financial resources and data ex-
 change.  Basic and  applied research on IFA
 biology, behavior, population dynamics, sys-
 tems  ecology,  and  control  strategies  are
 being conducted.   Unfortunately,  little  or
 nothing has been  done to  determine  pest
 status  and  economic thresholds  for  this
 insect.
    Education
    The IFA has become a volatile emotional
 and political issue debated  in public and
 private,  frequently on the  basis  of  gross
 ignorance  or   misconceptions  about   the
 insect and the problems it poses.  The insect
 has not escaped the attention of any  seg-
 ment  of  the population  within its present
 range, and is an issue  even  well  outside of
 its range.  There is an important need for an
 educational program, organized and promul-
 gated  by  a responsible  and authoritative
 agency,  to  ensure  that those who  need or
 desire accurate  information  about  the IFA
 can obtain it easily. The program should be
structured so as  to  reach specific audience
groups with information appropriate to their
respective needs.  Among the more impor-
tant of  these  groups  are lay citizens in
urban  and agricultural areas;  members of
the news media; special  interest and  civic
groups, such as  those concerned with envi-
ronmental quality or  gardening;  state  and
federal legislators;  appropriate administra-
tors at all levels  of federal, state, and local
government; and members  of  pest  or  agri-
culture-related  businesses.    Each  group
needs  information  relevant to  the fulfill-
ment of their role in society be it as public
officials involved in  making decisions  rele-
vant to IFA or as private citizens exposed to
IFA.
   Reliable, objective,  and unsensational-
ized information on the nature of the prob-
lem  posed by IFA is  of greatest immediate
need because this is the issue  around which
most public and  private  debate revolves.
The  medical problem  should be  defined  on
the IFA as a nuisance to the average human
and as a hazard to sensitive individuals.  The
problem  in terms of  the numbers  of  sting
victims and deaths due to stings, the  rela-
tive  hazard in various situations (e.g., urban,
rural)  and  the  availability of  preventive
medical treatment  for the  overly sensitive
should  be  fully   explained.    Livestock,
poultry,  and agricultural production prob-
lems also should be  explored in  depth.  In all
cases,  it will be important  to  differentiate
between perceived problems, based on opin-
ion or unsubstantiated anecdotal evidence,
and demonstrable effects resulting in medi-
cal, economic, or ecological harm or bene-
fit.
   The public needs information to  be able
to accurately assess any IFA problem  they
may   face  to  determine  whether  or not
remedial action is necessary, and if neces-

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                                           107
 sary  what action would be most beneficial
 (chemical or  nonchemical).    To  broaden
 their understanding of the IF A, the public
 also  should be educated on  the biological
 role of the IFA in the environment.
    These educational needs  are  admirably
 suited to the missions and capabilities of the
 Extension Service  of  the  USDA  and  the
 cooperative   extension   services   of   the
 affected states.  Information  should be col-
 lected and collated at the  federal level by
 the Extension Service and should be dissemi-
 nated through  the  cooperative  extension
 services   for  adaptation  and  use  in  their
 respective extension programs.  In addition,
 it will be equally  or more  important  for
 Extension  to  be actively  involved in  the
 educational phases and information dissemi-
 nation of new  technology as it is developed
 by research.
   Role of APHIS in IFA Program
   The Animal and Plant Health Inspection
 Service (APHIS), as mandated by Congress
 under three plant pest acts,  is responsible
 within the USDA for survey, regulatory, and
 control activities of  the IFA.  Due to  the
anticipated cancellation of mirex and chlor-
 dane, an  ARS/APHIS Working  Group  was
formed in 1977 to study future control tech-
nology, including chemicals,  that could be
used by APHIS and  its cooperators in future
IFA programs.  The Working Group consists
of three  scientists from each  of  the  two
services  who  carefully  review  research
needs and the  research and methods devel-
opment efforts that jointly affect the ARS
and APHIS.
   Soon  after creation  of  the  Working
Group, it became apparent that  there  was a
need  to  involve other services  from within
the USDA, the states,  the  EPA, and  the
chemical  industry  to  expedite  urgently
needed  "tools"  to regulate and  control  the
pest.  Consequently, the Working Group has
guided progress to date with invited  input
from   the  states,   EPA,   and  chemical
industry.  This  procedure could be developed
into a permanent policy and decision-making
mechanism  to  plan  all  future  programs
involving the IFA.
   It  is  anticipated  that the  APHIS will
continue to carry out its mandated charter
of IFA survey and regulatory responsibilities
in  conjunction   with   its   cooperators.
Involvement of APHIS in future IFA control
programs will  depend on  its congressional
mandate. It should be noted that Panel I of
this Symposium concluded that  a rationale
does not exist  for large-scale IFA eradica-
tion or  control programs.   Such federally-
supported programs have not  been success-
ful in eradicating the pest nor in keeping it
from  being widespread  in the southeastern
United States.  This suggests that the role
of APHIS  in IFA programs  should be the
same  as  for   any  other  established   pest

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                                           108
species.
   Regulatory
   As  mandated  by  Congress  under  the
Federal Insecticide, Fungicide and Rodenti-
cide Act (FIFRA), the EPA is responsible for
pesticide registration.  To adequately evalu-
ate the environmental  impact of  potential
IFA  controls (chemical  or biological),  the
EPA needs specific data demonstrating the
safety  and utility of the  controls.  These
data generally include  product  chemistry,
toxicology,  environmental chemistry,  eco-
logical  effects,  and  efficacy  information.
The  extent and  volume of specific tests
needed for IFA control primarily depend on
(1)  target  sites,  i.e., agricultural vs.  non-
agricultural, rural vs. urban; (2) use patterns
including rates and methods of  application,
i.e.,  aerial, ground broadcast, mound treat-
ment, quarantine; (3) user groups, i.e., agri-
cultural, commercial, PCO, homeowners; (4)
size  of treatment area; and (5)  pesticide
classification  of  the compound (biological,
biorational, conventional pesticide).
   Early access  to  the above  information
would enable EPA to (1) evaluate  the exist-
ing data base  on old and  new IFA control
agents and (2)  identify  data gaps, research
needs and/or environmental  problems early
in the  planning activity.  This would  then
enable EPA to provide  an appropriate  and
timely decision on an IFA pesticide—approv-
ing or denying registration, requiring further
studies, or waiving additional data.  In add-
ition, EPA's regulatory  responsibilities can
better serve future IFA  control programs if
it can participate in the preliminary deliber-
ations   concerning   future   management
strategies.

RECOMMENDATIONS
1. Determining the pest status and develop-
   ing economic thresholds for the IFA in
   various  ecosystems  should  receive the
   highest priority for additional research.
   Furthermore,     pest     management
   strategies should  be  developed  for the
   IFA.   However,  because  most of the
   tactics needed for such an IPM program
   have  not yet been developed,  additional
   funding should go to basic  and applied
   research.   The  information  from this
   research would enhance the development
   of practical  and effective pest manage-
   ment strategies for the IFA by providing
   a better  understanding of the biology and
   ecology  of  the  ant  in  each  of its
   habitats.
2. The  research should  include  investiga-
   tions for effective and economical alter-
   native chemicals as well as non-chemical
   methods.    The  latter efforts  should
   emphasize biological  and  non-chemical
   alternative control measures suitable for
   homeowner use.
3. To provide  responsible agencies with a

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                                          109
    clearer definition of  the  existence and
    scope of the problem, an  unbiased third
    party should conduct a thorough scienti-
    fic survey on the economic and human
    health importance of the IF A.  To assist
    this third party,  a small resource panel
    could  be  formed, consisting of  an eco-
    nomist, one or two representatives from
    SAES, and a representative from each  of
    EPA, APHIS, ARS, a state  department  of
    agriculture, and a public health agency.
4.  An educational program  should be organ-
    ized and  promulgated  by  a responsible
    and authoritative agency to ensure easy
    access to accurate and  useful informa-
    tion on the IF A.  The program should
    reach specific  audience groups with in-
    formation appropriate  to  their  respec-
    tive needs.  The agencies to fulfill these
    educational  needs are the Extension Ser-
    vice of USDA and the cooperative exten-
    sion services of the affected states.
5.  Chlordane  should be  re-registered  for
    quarantine treatment  use  only,  until  a
    suitable and satisfactory  alternative  is
    found.
8.  A  comprehensive research planning  and
   action program should be developed  and
   implemented through  existing or new
    mechanisms of  the  Southern  Regional
   Association  of State Agricultural Experi-
   ment  Stations.    Existing  mechanisms
   provide for  strong interaction between
    all interested state and federal agencies.
7.  An  Inter Agency Task  Force should be
    established   to   mobilize   available
    resources to develop a comprehensive 5-
    year program to include research, educa-
    tion, and  action  activities to develop
    management strategies for the IF A.  Key
    agencies  should include  APHIS,  ARS,
    CSRS, Extension and ERS of  USDA;  the
    EPA; the  state agricultural experiment
    stations, cooperative extension services,
    and state  departments of agriculture in
    affected states; and various  state  uni-
    versities.  Other agencies with an inter-
    est  in the  IF A include DOD  and NIH.
    The NSF should be encouraged to support
    research on other ant species to provide
    basic knowledge that could contribute to
    the  development  of  IF A  management
    programs.

REFERENCES
Adams, C. T. and C. S. Lofgren.  1981.  Red
   imported fire ants  (Hymenoptera:  For-
    micidae): frequency of sting attacks on
    residents of Sumter County, Georgia. J.
    Med. Entomol.  18:378-382.
Adams, C. T.  and C.  S.  Lofgren.   1982.
   Impact  of   the  red  imported  fire  ant,
   SoZenopsis  invicta  on  the growth  and
   yield of soybeans.    Florida  Entomol.
   (Submitted for pub.).
Apperdon, C.  S. and  E. E. Powell.  1982.
   Correlation of the red imported fire ant,
   Solenopsis  invicta Buren,  with reduced
   soybean  yields in  North Carolina.   J.
   Econ. Entomol. (Accepted for pub.).

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                                            110
 Banks, W.  A.   1982.  The effects of insect
    growth  regulators and their potential as
    control agents  for  imported fire ants.
    Florida Entomol. (Accepted for pub.).

 Blust, W. E., B. H.  Wilson, K. L. Koonce, B.
    D. Nelson and J. E.  Sedberry, Jr.   1982.
    The  red  imported  fire ant,  Solenopsis
    invicta   Buren:   cultural  control  and
    effect on hay meadows.  L.S.U. Ag. Exp.
    Stn. Bull. No. 738. 27 pp.

 Burns,  E.  C. and D. G.  Melancon.    1977.
    Effect of imported  fire ant (Hymenop-
    tera:  Formicidae) invasion on lone star
    tick   (Acarina:   Ixodidae)  populations.
    Iowa Med. Entomol.  14:247-9.

 Clemmer,  D. L. and R. E.  Serfling.   1975.
    The imported fire ant: dimensions  of the
    urban problem.   South Med. J.  68:1133-
    38.

 Howard, F.  W.  and A. D. Oliver.   1978.
    Arthropod populations in permanent pas-
    tures treated and  untreated with  mirex
    for   red  imported  fire  ant  control.
    Environ. Entomol.  7:901-3.

 Howard, F.  W. and A. D.  Oliver.   1979.
    Field observations of ants (Hymenoptera:
    Formicidae)   associated   with    red
    imported  fire ants,  Solenopsis  invicta
    Buren, in Louisiana pastures.  J. Georgia
    Entomol. Soc. 14:259-62.

 Jouvenaz, D.  P., C. S.  Lofgren and  W.  A.
    Banks.   1981.  Biological control  of the
    imported fire ants: a review of current
    knowledge.  Bull. Entomol. Soc.  27:20-3-
    8

Lofgren, C.  S.  and C.  T.  Adams.   1981.
    Reduced  yields  of   soybeans  in   fields
    infested  with the red imported fire ant,
    Solenopsis   invicta   Buren.    Florida
    Entomol.  64:199-204.
    ant in the United States.  Proc. 9th Int.
    Congress of the Int. Union for the Study
    of Social Insects.  Boulder, CO.  August
    9-13,  1982

 Oliver, A. D., T. E. Reagan and E.  C. Burns.
    1979.  The fire ant—an important preda-
    tor of some agricultural pests. Louisiana
    Agric. 22(4):6-7,9.

 Reagan, T. E.,  G. Coburn and S. D. Hensley.
    1972.  Effects of mirex on the anthropod
    fauna  of a  Louisiana sugarcane  field.
    Environ. Entomol. 1:588-91.

 Reagan, T. E.   1982.  Sugarcane borer pest
    management in Louisiana: leading to  a
    more  permanent system.  Proc. Second
    Inter-American    sugarcane    seminar-
    Insect  and  Rodent  Pests  1981, Florida
    International Univ.  (Oct. 6-8) (In press).

Rhoades,  R. B.,  W. L. Shaeffer, M. Newman,
    R.   Lockey,  R.  M.   Dozier,   P.  F.
    Wubbena,  A. W. Townes, W. H. Schmid,
    G.  Neder, T. Brill, and H.  V.  Wittig.
    1977.  Hypersensitivity to the imported
    fire ant  in  Florida:  A report of  104
    cases.  J. Fla. Med. Assoc.  64:247-54.

Stam, P. A. 1978. Relation of predators to
    population dynamics of Nezara  viridula
    (L.) in  a soybean ecosystem.   Ph.D. Dis-
   sertation L.S.U.  Baton Rouge, LA.

White, E. A.  1980.  The effects of stubbling
   and  weed control in  sugarcane on the
   predation   of  the   sugarcane   borer,
   Diatraea saccharalis (P.).  M.S. Thesis.
   L.S.U.  Baton Rouge, LA. 216 pp.
Lofgren, C.  S.  and C.  T. Adams.   1982.
   Economic aspects of the imported fire

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List of Registrants

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                    REGISTRATION LIST
             IMPORTED FIRE ANT SYMPOSIUM
              JUNE 7-10, 1982 - ATLANTA, GA.
ADAMS, C. T.
USD A Ag. Res. Ctr.
P. O. Box 14565
Gainesville, FL 32604

ALLEN, George
CR/USDA
Room 6440, South Bldg.
14th & Independence Ave. S.W.
Washington, D. C.  20250

ALLEN, John C.
Ag. Res. & Ed. Ctr.
P. O. Box 1088
Lake Alfred, FL 33850

ALLEY, Earl L.
Miss. St. Chem. Lab.
P. O. Box CR
Mississippi State, MS 39762

ALLISON, John R.
Dept. of Agric. Economics
Georgia Exp. Station
Experiment, GA 30212

APPERSON, Charles S.
North Carolina State Univ.
P.O. Box 5215
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ASHTON, W. Eric
Velsicol Chem.
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Chicago, IL 60611

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BFFD-EPA, Rm. 700, CM  #2
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USDA-SEA-AR
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American Cyanamid Co.
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Univ. of Georgia
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Stauffer Chem. Co.
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                                                  111

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                                                   112
DAVIS, James A.
DMA Associates
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Eli Lilly & Co.
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EPA
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 Auburn University
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 Clemson Univ.
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Centers for Disease Control
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                                                     113
  HORTON, P. Mac
  Dept. Ent., Fisheries <5c Wildlife
  103 Long Hall
  Clemson University
  Clemson, SC 29631

  HSIAO, Ting H.
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  Utah State Univ.
  Logan, UT 84322

  ILLNICK, Frank
  Montedison USA,  Inc.
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  INGRAM, Reba L.
  Miss. St. Chem. Lab.
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 Clemson University
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 P. 0. Box 391
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                                                 114
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 Miss. State University
 P. O. Drawer EM
 Mississippi State, MS 39762

 OFIARA, Douglas D.
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 Georgia Exp. Station
 Experiment, GA  30212

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 GA General Assembly
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 EPA - RD 682 -
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 RESELLA,  Dita
Stauffer Chem. Co.
 1200 S. 47th
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REYNOLDS, Harold T.
Dept. of Entomology
Univ. of California
Riverside, CA 92521
 RISCH, Steven
 Dept. Ecol. 
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                                115
  TROSTLE, Mark
  Imported Fire Ant Specialist
  Texas Dept. of Ag.
  Austin, Tx 78710

  TSCHIRLEY, Fred
  Dept. of Botany & Plant Path.
  270 Plant Path. Bldg.
  Michigan State Univ.
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  Florida State Univ.
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 USDA - ARS
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 Tucker Wayne & Co.
 230 Peachtree St. Suite 2700
 Atlanta, GA 30303

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 Dept. of Entomology
 Texas A&M Univ.
 College Station, TX  77843

 WAGNER, J. Noel
 Stauffer Chem. Co.
 P. O. Box 17207
 Raleigh, NC 27619

 WANG, T.
 American Cyanamid Co.
 P. 0. Box 400
 Princeton, NJ  08540

 WEEKS, D. C.
 Plant Pest Reg. Serv.
 Clemson University
 Clemson, SC 29631

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USDA-CR
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  EPA - Pest. & Tox. Substances
  401 MSt.
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  WHITE, T. J.
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  Agric. Div.
  Wayne, NJ 07470

  WILLIAMS, David F.
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  P. O. Box 14565
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 WILLIAMS, Kent C.
 EPA Region IV
 345 Courtland St.
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 WILLIAMSON, Bob
 USDA Rm. 608 Fed. Ctr. Bldg.
 6506 Bellcrest Rd.
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 WOJCIK, Daniel P.
 USDA - ARS
 P. 0. Box 14565
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 WOOD, John
 USDA Rm. 608 Fed. Ctr. Bldg.
 6506 Bellcrest Rd.
 Hyattsville, MD  20782

 WORK, L. Kenneth
 Tucker Wayne & Co.
 230 Peachtree St. Suite 2700
 Atlanta, GA  30303

 WRIGHT, Darwin
Integrated Pest Mgt.  R&D
 EPA
 Washington, DC 20460

YARBROUGH, James D.
Mississippi State Univ.
P. O. Drawer GY
Mississippi State, MS  39762

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Appendices

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                                      APPENDIX A
                            CHEMISTRY AND PROPERTIES OF
                                   FIRE ANT VENOMS
                                     Murray S. Blum
                                        PANEL IV
   The venom of the fire ant, Solenopsis
invicta, in common with those other species
in this genus,  is distinguished by  the  pre-
sence  of  dialkylpiperidine  alkaloids  that
have not been  detected as natural products
of species in any other taxa. These idiosyn-
cratic alkaloids constitute about 95% of the
poison  gland secretion,  being  accompanied
by a  denser aqueous  phase that  contains
traces  of proteinaceous constituents.  These
protein-poor, alkaloid-rich venoms contrast
with those of most stinging ants which are
characterized by high concentrations of bio-
logically active proteins and the absence of
detectable alkaloidal constituents.
   The  venom  of workers of Solenopsis in-
victa is dominated by six 2-methyl-6-alkyl-
piperidines  that  are present  primarily  as
trans isomers;  the cis isomers are relatively
minor constituents. The major alkaloid pro-
duced  is  trans-2-methyl-6-(cis-6-pentade-
cenyl)  piperidine,  Trans-2-methyl-6-(cis-4-
tridecenyl)-piperidine  also  constitutes   a
quantitatively    important     constituent,
whereas  2-methyl-6-(cis-8-heptadecenyl) pi-
peridine  is a minor venomous product.  The
major   saturated  alkaloids  are  trans-2-
methyl-6-n-tridecylpiperdine and trans-2-m
ethyl-6-n-pentadecylpiperidine.  Trans-2-
methyl-6-n-undecylpiperidine  is a quantita-
tively unimportant product.
   The venoms of the four other fire ant
species in  North America are qualitatively
less  complex than  the  venom  of Solenopsis
invicta.  The  venom  of workers of S. rich-
teri, another  introduced species  lacks  the
dialkylpiperidines  with 6-alkyl side  chains
greater than C,3.  The venoms of workers
of the  three  native  species,  S. ryloni, S.
geminata,  and S.  aurea,  are qualitatively
depauperate compared  to  S. invicta  and S.
richteri.   In general the  venoms  of these
native  fire ants contain  only  the cis  and
trans isomer of 2-methyl-6-n-undeeylpiperi-
dine, with the former isomer predominating.
The  venom of S. xyloni is unique in contain-
                         1 2
ing 2-methyl-6-undecyl-W  ' -piperidine as a
minor  constituent, a compound  that  may
constitute  an  intermediate  in the  biosyn-
theses  of  the  cis  and  trans  isomers of 2-
methyl-6-n-undecylpiperidine.
   In contrast to  the  qualitative  diversity
that characterizes  the venoms of workers of
S. invicta  and  S.  richteri,  those of  their
queens  are depauperate. The venoms of the
queens  are dominated by the cis and trans
isomers of 2-methyl-6-n-undecylpiperidine,
the  former  isomer always  predominating.
                                          116

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                                          117
None of the dialkylpiperidines  with 6-alkyl
side chains greater than C^,  which domi-
nate the venoms of the workers of S. invicta
and S. richteri, are present in the venoms of
the queens.  The venom  of  the queen of S.
richteri is  also distinguished by  the presence
of trace amounts  of  2-methyl-6-n-nonylpi-
peridine.  In contrast,  the venoms of queens
of S. xyloni and S. geminata are similar to
the  venoms  of  their  workers  in primarily
containing the cis and trans isomers of 2-
methyl-6-n-undecylpiperidine.
   Considering   the  cis  isomers as being
therm ©dynamically favored  from an ener-
getic standpoint, a hypothetical phenocline
in biochemical evolution for the genus So-
lenopsis  was constructed.   The venoms of
the  queens of  S.  xyloni and  S. geminata
reflect the more primitive state, being qua-
litatively simple and  dominated by  the  cis
isomer  of  2-methyl-6-n-undecylpiperidine.
The  venoms of the workers essentially mir-
ror those  of their queens.  Evolution of a
form in  which the trans isomers predomi-
nates  (a  South  American species)  in  the
worker venom would be followed by elabora-
tion of new trans alkaloids in worker  venoms
with a 6-alkyl side chain greater than Cjj
(S. richteri) eventuating in a form with side
chains containing C15 and GI?  moieties (S.
invicta).  Since the venoms of workers of S.
invicta and S. richteri  are considerably more
necrotoxic  than  the   simple  venoms of S.
ryloni and S. geminata,  it is suggested that
 the  evolution  of new trans alkaloids was
 highly adaptive for  the former pair of spe-
 cies.
   Three to four proteins are present in the
 minor aqueous phase in  the  venom  of  S.
 invicta.  One of these macromoleeular con-
 stituents is hyaluronidase; the other is phos-
 pholipase.   Since the  latter enzyme is con-
 sidered to be the primary allergen in hymen-
 opteran venoms, these minor proteinaceous
 constituents probably are responsible for the
 allergic reactions experienced by  some hu-
 man beings after being stung by workers  of
 S. invicta.
   The dialkylpiperidines present  in  Solen-
 opsis venoms possess a wide range of biolo-
 gical activities  that  had  been  previously
 identified  with these poison  gland  secre-
 tions.   The venom of  S. invicta exhibits
 well-developed  fungicidal,  bactericidal, in-
 secticidal,  herbicidal,  and hemolytic activi-
 ties;  all of  these properties can  be  dupli-
 cated  with the neat alkaloids.   The  fungi-
 cidal activities of some of the dialkylpiperi-
 dines are equal to or are greater than those
 of commercially available  fungicides.  The
 pronounced necrotoxicity of the venom, that
 results in sterile pustules at the sting sites
 on human beings, is directly attributable  to
 the alkaloids.
   A variety of other biochemical lesions
are  produced   by   the   dialkylpiperidines.
These  alkaloids degranulate  most  cells,
which frees a histamine  and produces algo-

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                                           118
genie and allergic reactions in humans. Ad-
ditionally,  these compounds inhibit  ATPase
and oxidative phosphorylation, and deleteri-
ously affect sites at the vertebrate neuro-
muscular junction.  These pharmacological
activities illustrate the wide range  of bio-
chemical lesions that these unique alkaloids
are reported to produce in in vitro  investi-
gations.

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                                     APPENDIX B
                 THE MEDICAL ASPECTS OF THE IMPORTED FIRE ANT
                                 William H. Schmid, M.D.
                                       PANEL IV
   Hypersensitivity  reactions  to  stings of
winged  Hymenoptera  have been  described
since antiquity.   The  imported fire  ants,
Solenopsis  richteri and Solenopsis invicta,
which have been present in the southeastern
United  States  for 40  to 50  years, cause
significant  medical   morbidity  by  their
stings.  In an infested area, IF A stings occur
more frequently than  do bee,  wasp,  hornet
and  yellow jacket stings.  The human reac-
tion to the stings of these two IF A species is
similar.
   The IF A sting produces an uncomfortable
burning sensation  and usually results in the
formation  of  a sterile pustule, 3-5  mm in
diameter at the  point of the sting.  The
pustule usually disappears after a few days.
Multiple stings from IF A occur because indi-
vidual  ants  can administer several stings.
The average victim has several stings and 10
to 20 stings are common. The primary site
is characterized by  redness followed  by  a
wheal and a characteristic pustule within six
to twenty-four hours.  The pustule is  diag-
nostic of an IFA sting.
    The overwhelming majority of IFA stings
are  uncomplicated.  A pigmented  area  often
develops at the sting site which persists as a
blemish for weeks to months.   Secondary
infections can occur  when  the  pustule  is
broken.   Impetigo  is  the  most  common
secondary infection. Severe  infections have
occurred requiring skin grafting, amputation
of an  extremity or  digit, or incision and
drainage of a wound.
   Some  people experience  a  generalized
allergic reaction to an IFA   sting.  These
reactions occur  within minutes  of a sting
and  vary in severity.   The  reactions can
include generalized hives, facial,  genital or
extremity  swelling, nausea,  vomiting and
shock.   Death  also can  occur.   Feet and
ankles usually are stung. The ant anchors to
the  skin with its mandibles  and then stings
once or several times with its  abdominal
stingers.
    The following histories demonstrate the
variety of sting situations.
    Case I
    A  32-year-old Canadian  male was stung
by 10  ants while changing a tire on the edge
of the interstate highway in St. Petersburg,
Florida.  He  became  weak and fainted and
was taken  to  a hospital emergency  room
                                          119

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                                          120
 where he was found to be in shock and was
 hospitalized.    He recalled  hymenoptera
 stings in Canada  without difficulty.  This
 was his first visit to a fire ant infested area
 and his first known fire ant sting.
    Comment:   Over 20% of patients with
 anaphylaxis following  an IFA sting  have a
 severe reaction  on the first sting.
    CaseH
    A 25-year-old,  male, golf-course worker
 experienced  repeated  severe reactions  to
 IFA stings  that required  emergency room
 treatment.   He was placed  on  a fire ant
 desensitization  program  and subsequently
 could tolerate IFA stings without  difficulty.
 However, he was stung by a wasp and died in
 shock 30 minutes later.  There was a child-
 hood history of  bee and wasp stings without
 difficulty.
    Comment:   The incidence of  associated
 bee and wasp sting hypersensitivity is higher
 among  IFA-sensitive patients than  in  the
 normal population.   Desensitization  pro-
 grams are effective in reducing the severity
 of   reactions  in  IFA-sensitive   patients.
 These programs  will lessen the sensitivity to
IFA stings, but not to  bee or wasp stings if
 the patient is also sensitive to these insects.
    Casein
    An 81-year-old male was found comatose
on a fire ant mound in a field near his home
and  taken to  an emergency  room.  He had
multiple bites of the trunk,  face, extremi-
ties, and genital!a.  Live ants were found in
his mouth and nose. The man was intubated
and placed on assisted ventilation. Fire ants
were recovered from the trachael intubation
tube and from uretheral catheter drainage.
He was admitted to an intensive care ward
to the care of a physician who felt that the
patient had a stroke.   The  patient was
completely  well the day following admission
and the diagnosis was revised to  anaphylaxis
to fire ant stings.
   Comment:   Some elderly  patients  are
hospitalized because of shortness of breath,
and shock   which  is attributed  initially  to
heart disease. The correct diagnosis usually
is  made the day following admission when
the characteristic pustules are noted.
   Case IV
   A  25-year-old female was stung by ants
in  Hattiesburg, Mississippi.  She developed
immediate  wheezing and confusion, followed
by shock.  She was taken to an  emergency
room where she was intubated and placed on
assisted ventilation  in  an  intensive  care
ward.   She recovered and  was  discharged.
She  moved to  St.   Petersburg,  Florida,
where   she  again  was  hospitalized  for  a
severe reaction to a fire  ant sting.
   Comment:   There  appear to  be no geo-
graphical differences in  the severity of fire
ant hypersensitivity reactions.
   Case V
   This  4-year-old child  has experienced

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                                          121
four episodes of hives, facial  swelling,  and
wheezing after fire ant stings.  These reac-
tions  have required  emergency room treat-
ment.   Subsequently, her  parents do  not
allow  her    to  play outdoors  for  fear of
future stings.
   Comment: Fire ant sensitivity is a spec-
ial problem in young children who are unable
to avoid fire ants in outdoor play.
   Case VI
   This 63-year-old male tourist from  Min-
nesota  with  known  angina pectoris devel-
oped severe chest pain, hives,  and  shortness
of breath after a fire ant sting.   He  was
hospitalized in a coronary  care unit where
he recovered uneventfully.
   Comment:  A hypersensitive reaction to
a fire ant sting in a patient with underlying
cardio-vascular disease can be  a fatal event.
REFERENCES
Schmid,  W.   1977.  Medical  implications:
   imported fire  ants,  Solenopsis  invicta.
   Cutis  19(June).
James, F. K. Jr., H. L. Pence, D. J. Driggers
   et al.  1976.  Imported fire ant hypersen-
   sitivity:  studies  of  human reactions to
   fire  ant  venom.    J.  Allergy  Clin.
   Immunol. 58:110.
Rhodes, R.  B., W. L. Schafer, W. H. Schmid
   et  al.   1975.   Hypersensitivity  to  the
   imported fire   ant.    J.  Allergy Clin.
   Immunol. 56:84.
Caro,  M. R., V. J. Derbes, R. Jung:  Skin
   responses to the  sting  of the imported
   fire ant (Solenopsis saevissima).   Arch.
   Dermatol. 74:475.
SUMMARY
   In infested states, a hypersensitive reac-
tion to a fire ant sting should be suspected
when  a patient is seen  with unexplained
acute  hives or  shock.  Complications  from
IF A  stings   cause  considerable   medical
expense, human morbidity,  and occasional
mortality.   Until  an  acceptable means of
control is  developed,  physicians practicing
in the  infected areas can expect to  treat
many  complications from the sting of the
insect.

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                                      APPENDIX C
        A BRIEF HISTORY OF CHEMICAL CONTROL OF THE IMPORTED FIRE ANT
                                      R.L. Metcalf
                                       PANEL IV
INTRODUCTION
   The development of chlordane in 1944
(Kearns et al. 1946) provided the first effec-
tive  synthetic  organic insecticide  against
ants (Formicidae).  Chlordane (1,2,4,5,6,7,8,
8-octachloro-2,3,3a,4,7,7a-hexahydro-4,7-
methanoindene)    became   the   standard
remedy for controlling ants about premises-
-a position it occupies today.   Chlordane is
synthesized  from  cyclopentadiene which is
the reactive raw material that became  the
base  for  a  variety of  other  cyclodiene
insecticides      including       heptachlor
(l,4,5,6,7,8,8-heptachloro-3a,4,7,7a-tetrahy-
dro-4,7,-methanoindene)  and  dieldrin (1,2,
3,4,10,10-hexachloro-6,7-epoxy-l,4,4a,5,6,7,
8,8a-octahydro—endo-l,4-earo-5,8-dimetha-
nonaphthalene).  These compounds were sev-
eral  times more toxic  to  ants than chlor-
dane.  Dieldrin, as an epoxide,  was environ-
mentally  the  most  stable  and  persistent.
Heptachlor,  because of its C,=Co, could be
oxidized environmentally and  biochemically
to  form  heptachlor-2,3-epoxide—an  even
more toxic compound  whose environmental
persistence rivaled that of dieldrin.
   The availability  of these effective and
highly  persistent formicides coincided with
the expansion  of the  imported fire ant's
(IFA)  area of infestation (SoZenopsis invicta)
(Buren et al.  1974).  Heptachlor and dieldrin
were  seen  as the most  promising  weapons
for area-wide IFA control programs.

HEPTACHLOR AND DIELDRIN
   With ample funding from  Congress, the
USD A undertook  a massive IFA eradication
program covering millions  of  acres in Flor-
ida, Georgia, Alabama, Louisiansa, and Tex-
as.  The plan was to treat  all  infested lands
with  20 Ib.  of 10% granular  heptachlor  or
dieldrin per  acre.   This  dosage  [2  Ib  Al
(active ingredient)]  was considered suffi-
cient  to eradicate the IFA and to prevent
reinfestation of the treated area for a mini-
mum  of three  years.  This treatment was
conducted  for  two  years with  heptachlor
being used more extensively than dieldrin.
   Heptachlor  and  dieldrin  are  environ-
mentally persistent and  toxic to terrestrial
and  aquatic  wildlife (Pimentel  1971), yet
little   consideration  was  given  to  the
environmental hazards of these chemicals  to
non-target  organisms, and the eradication
program  had virtually no  research  compo-
                                         122

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                                          123
 nent to examine such  hazards.  Damage to
 wildlife in  the treated areas was immense.
 As a result, at the start of the third year of
 the eradication  program,  treatment rates
 were reduced to  1.25  Ib.  technical hepta-
 chlor  per  acre.   Experiments  were  con-
 ducted with two 0.25 Ib per acre treatments
 at a three month interval.
    Wildlife studies in Hardin County, Texas,
 showed that opposums, armadillos, and  an
 abundant racoon population virtually disap-
 peared and were still  depressed during the
 second season after treatment with hepta-
 chlor.  Racoons  that repopulated  the  area
 were contaminated with  heptachlor epoxide
 residues in  the  kidney  averaging 19.9  ppm
 (parts per million) after two weeks,  3.8 ppm
 after six months, 7.8 ppm  after nine months,
 and  4.5 ppm  after one  year (DeWitt and
 George  1960).    Birds  were  particularly
 devastated.    Evaluations  showed  that  in
 Texas and Louisiana the bird population de-
 clined over  85% following treatment; nest-
 ing successes were reduced by 89% or more
 and remained  depressed the following year.
 Ground birds were severely affected (Tables
 1 and 2).
   Dead animals found within three weeks
after treatment in areas  of Texas, Louisi-
ana, Alabama,  Georgia,  and Florida  were
analyzed for total body residues  of  dieldrin
or heptachlor  epoxide.  More than  98% of
the dead animals contained detectable resi-
 dues.  These were highest in a wide variety
 of  birds whose averagebody  residues were
 (1)  dieldrin: 17.9 ± 4.3 ppm (18 species)  and
 (2)  heptachlor  epoxide: 15.3 ± 8.6 ppm  (30
 species).  Residues were  found in a variety
 of mammals, fish, reptiles, and amphibia
Table 1.  Reduction  of  ground   birds  in
          Montgomery  County,  Alabama,
          1959,   following   heptachlor   or
          dieldrin treatments for  imported
          fire ant control.
              Strata
Reduction
low or ground (7 species)         100%
low to intermediate (17 species)   50-99%
intermediate to high (19 species)  no effect
Table 2.  Surveys  of birds seen in Wilcox
         County,     Alabama,    following
         treatment for imported  fire ant
         control.
   Treatment   Live Birds Seen Per Mile

heptachlor
heptachlor
dieldrin
untreated
Robins
0.0
6.0
0.0
22.8
Meadowlarks
0.2
0.0
0.0
25.7

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                                         124
(DeWitt et al. 1960).  Where granular appli-
cations were made to salt marshes and other
aquatic areas,  the   fish populations were
eliminated or seriously damaged.
   The extensive  damage to wildlife from
the IF A eradication  program alarmed  con-
servationists.   Rachel  Carson  (1962)  de-
scribed the program  as ill conceived, badly
executed,  and a thoroughly detrimental ex-
periment  in  insect control that  resulted in
both the  destruction of animal  life and in
loss of public confidence in the USDA.   She
found  it  incomprehensible that  any public
funds were still devoted to it.  The misuse
of  heptachlor  and   dieldrin  in  the  early
stages of the IF A eradication program was a
critical part of  the accumulated environ-
mental outrage  that created Silent Spring
and resulted in  public disenchantment  con-
cerning the widescale use of pesticides.
   About  20  million acres were treated dur-
ing the five  years of the early eradication
program.   From 1957 to 1962  however, the
area infested by IF A had increased from 90
million acres to about 126 million acres

MIREX
   In the  search for a more  ecological way
to  control IFA,  many  synthetic  organic
chemicals were  evaluated.  Hays and Arant
(1960)  at   Auburn  University  showed  that
peanut butter baits containing 0.125% chlor-
decone   (Kepone)    (1,2,3,5,6,7,8,9,10,10-
dodecachlorooc tahydr o-1,3,4-m et heno-2 H-cy-
clobuta-[ccfl-pentalen-2-one) (another cyclo-
diene product of hexachlorocyclopentadiene)
gave  excellent IFA control.   The USDA
Methods Development  Laboratory at Gulf-
port,  Mississippi  found that a very closely
related cyclodiene, mirex (1,2,3,4,5,5,6,7,8,-
9,10,10-dodecachloro-octahydro-l,3,4-me-
theno-2H-cyclobuta-[c,cfl-pentalene) was as
effective as  chlordecone and was  less toxic
to non-target species (Lofgren et al. 1962).
An IFA  bait  formulation  was  developed
consisting  of  once-refined  soybean oil as
food,  corncob grits as carrier, and mirex as
toxicant.  The  bait was effective at rates as
low as 4.2 grams of mirex  per hectare  (1.7
grams per acre).  During development it was
found  that  increasing  the  mirex  content
from  0.075% to 0.3% substantially reduced
the bulk  rate  of application.   This  bait,
properly applied,  averaged 98% control of
IFA from ground applications and 96%  con-
trol on large acreages treated by  aircraft
(Lofgren et al.  1975).  In 1962, 0.3% mirex
bait became  the standard IFA control agent
(Alley 1973).
   Mirex had  a  delayed  stomach poison
action that appeared ideal  for IFA  control.
Its properties  included: (1) delayed killing
action over a 10 to  100 fold dose  range, (2)
easy transfer between ants  through  regurgi-
tation,  resulting in  death of the  recipient,
often  the queen,  and (3) attractiveness to

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                                           125
  the IFA (Waters et al.  1977).  Secretary of
  Agriculture Orville Freeman hailed mirex as
  the perfect  pesticide.  "It  has no harmful
  effect  on people, domestic animals,  fish,
  wildlife,  or  even  bees,  and  it  leaves  no
  residue in milk, meat,  or crops" (Whitten
  1966, Science 1971).
     Armed with mirex, the USDA planned a
  massive eradication program that included
  all  126 million  acreas infested by the IFA.
  The program was to be conducted over a  12
 year period at a cost of $200  million that
 would be financed as a matching fund opera-
 tion between the  USDA  and the partici-
 pating states.    Subsequently,  a  National
 Academy of Science Committee (Mills 1967)
 reported that eradication  of the IFA was
 biologically  and  technologically impossible
 and  was  inadvisable  if  it  were possible.
 USDA eradication trials conducted with the
 mirex bait (Banks 1972),  however, were in-
 terpreted as demonstrating  the feasibility of
 eradication with three or four  sequential
 applications of the mirex bait.
   In  retrospect,  mirex is  far from  the
 "perfect insecticide."  Mirex  contains no
 carbon-hydrogen  bonds and is  one of  the
 most  environmentally  stable  xenobiotics
 known.    Mirex  was  first  synthesized by
 McBee et al. (1956)  and was patented as an
insecticide (Belgium pat. 624,  256, April 30,
 1963, French pat. 1,338,074, September 30,
1963) and, because  of  a melting point of
 349°C,  as a flame-retardant (U.S. Pat. 3,-
 494,973, February 10, 1970).  Mirex is sol-
 uble in water  to  about 20 ppb and  has  an
 octanol/H20 partititon coefficient of about
 10,000.    In laboratory  model  ecosystem
 studies, (Metcalf  et  al.  1973), 14C  mirex
 shown to bioaccumulate through food chains
 and to persist, virtually undegraded, in alga,
 mosquito larva, snail, and fish (98-99% par-
 ent compount).  Rats eliminated 18% of 14C
 mirex  as  unmetabolized  mirex;  the re-
 mainder was stored in body tissues (Gibson
 et al. 1972).
    The  use of  mirex was  followed by evi-
 dence of its persistence and  biomagnifica-
 tion.   In  an area of  Louisiana  that had
 received six applications  of  mirex bait at
 1.25 Ib. per acre over a four year period the
 following residues  were found: 0.01 to 0.75
 ppm in snails, crayfish and fish; 1.2 to 1.91
 ppm in birds; 24.82 ppm in the fat of soft-
 shell turtles; and 73.94 ppm  in the adipose
 tissue of vertebrates at the top of the food
 chain (Hyde et  al. 1973).  In an  estuarine
 environment, mirex in the water at 0.5 ppb
 was  found  to bioaccumulate to 20.4 ppm in
 minnows (40,800X),  to 5  ppm  in shrimp
 (10,OOOX),  and to 1.5  ppm  (2,300X) in blue
 crabs (Tagatz et al. 1975).  A survey of  birds
from South Carolina,  Georgia, and Florida
showed an average  value of 4.32 ppm (liquid
weight) of  mirex  in  eight birds (Dreitzer
1974), while starlings contained levels of 0.1

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                                         126
 to 1.66 ppm (Oberhen 1972).  Adipose tissues
 of  persons living  in  treated  states  were
 found  containing mirex in amounts ranging
 from 0.16  to 5.94  ppm (Kutz et al. 1974).
 More recently mirex residues were found in
 23% of adipose tissues from 624 inhabitants
 of eight southern states (EPA 1980, Severn
 1982-Appendix F).
   As  a result  of these disclosures, the
 Environmental Defense Fund (EDF)  brought
 suit  in  August 1970 to terminate the USD A
 IFA  program. The EPA issued  a cancella-
 tion  order for the  use of mirex, effective
 March 18, 1971.   Allied Chemical Company,
 the sole manufacturer  of  mirex, protested
 the  cancellation.   Following hearings, the
 EPA issued new guidelines for  a modified
 control program.  However, entomologists in
 many of the cooperating states began oppos-
 ing the program, and  the eradication pro-
 gram began to die when several states with-
 drew their matching support (Shapley 1971).
   Meanwhile, additional concerns had de-
 veloped about the continued use of mirex.
 Approximately 3,361,000 Ib.  of mirex  were
 manufactured at Niagra Falls, N.Y. between
 1959 and 1975.   Mirex-containing effluents
 from manufacturing and waste disposal con-
 taminated the southern waters of Lake On-
 tario with concentrations from 1  to  10 ppb.
 A  variety of  fish from the lake contained
 whole-body residues of mirex,  with mean
levels of: white perch 0.10, smelt and small
 mouth bass 0.13, coho salmon 0.17,  Chinook
 salmon 0.21, and lake trout 0.22 ppm.  The
 maximum  level  recorded  was  1.20  ppm.
 Residues of mirex were found in the eggs of
 herring gull, cormorant,  gyrfalcon, prairie
 falcon, peregrin falcon, and pigeon hawk. In
 the pigeon hawk, these residues had a mean
 value of 0.25 ppm and ranged from  0.01 to
 3.16 ppm (Kaiser  1978).
   Mirex undergoes slow  environmental de-
 gradation by both photochemical and micro-
 biological processes and forms two monohy-
 droderivatives  (C^HCl.,),  two  dihydro—
 derivatives  (c10H2C1i(J' and  cnlordecone
 (Kepone*), the  2-C=0 derivative (C1()C1100).
 Alley et al.  (1974a,b) explored the photo-
 chemistry   of    mirex   and   chlordecone.
 Samples of  mirex fire ant bait exposed to
 the elements for five years contained 75.9
 to 81% of mirex, 7.4 to  8.3% mono-hydro
 mirex or photomirex, and  1.3 to 5.7% chlor-
 decone (Carlson et  al. 1976). Concern over
 the formation  of chlordecone  from mirex
 was  heightened by  the  Hopewell, Virginia,
 experience where the James River and much
of Chesapeake  Bay  were contaminated with
an  estimated   100,000  Ib.  of  chlordecone
(Kepone)   effluent.     Factory   workers
suffered reproductive difficulties due to the
estrogenic properties of this substance and
developed  severe  symptoms  of  delayed
neurotoxicity (Sterrett and Boss 1977).
   Mirex and chlordecone were found to be

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                                         127
animal  carcinogens.   Lifetime  feeding  of
mice with  mirex at 26  ppm in  the  diet
produced  liver hepatomas in 45%  as com-
pared to 4% of the control mice (Innes et al.
1969).  Lifetime feeding of mice  at 20 to 40
ppm with  chlordecone produced hepatocellu-
lar carcinomas in 81 to  88% of males and 47
to 52% of females compared  to 16% in male
controls and 0% in female controls (National
Cancer Institute 1976).
    Due to the continued concern  over public
health and environmental quality aspects  of
the large scale  deployment  of mirex bait,
EPA banned the use of  mirex. As  a result,
Allied Chemical Company sold its plant  in
Aberdeen, Mississippi, to the state for $1.
Mississippi then established an Authority for
the  Control of the  Fire Ant  within the
Department of Agriculture and Commerce.
In October 1976, EPA and Mississippi agreed
to  terminate  aerial  application  of mirex
baits by December 31,  1977,  and to permit
ground applications only  through June 30,
1978.  At that time the pesticide registra-
tion of mirex was cancelled.
    Studies of the photodegradation of mirex
showed that environmental dechlorination to
photomirex  and  to further   dechlorination
products  could  be accelerated  by  adding
aliphatic amines and ferrous  chloride (Alley
et  al.  1974c).   An  IFA bait formulation
ferriamicide,  was  developed to   contain
0.05%  mirex,  1.7%  amine   (Keramine  T
1902D),  0.2  ferrous  chloride  hexahydrate,
and 8% soybean oil.  This formulation is to
be applied at 1.5 Ib per acre equivalent to
0.227 grams  mirex  per acre. The ferriami-
cide formulation reduces the environmental
half-life for  mirex  from 12 years to about
0.15  years (Alley 1982-Appendix F).  Con-
cern over the production of  the highly toxic
photomirex as  a principal degradation  pro-
duct has  delayed registration  of ferriami-
cide by EPA.
   In order to  avoid the persistent and  non-
degradable residues of  the  organochlorine
insecticides,  efforts were made to find more
biodegradable  organic  stomach  poisons.
USDA  scientists screened more  than 5000
candidate pesticides and the most promising
substitute for mirex found during the 1970's
was  tetrahydro-5,5-dimethyl-2-(lH)-pyrimi-
done-[3-(4-trifluoromethyl)-phenyD-l[2-(4-
trifluoromethylphenyD-ethenyD-2-propenyli-
dene-hydrazone (trade name Amdro* Willi-
ams  et al. 1980.   Amdro is a slow  acting
stomach poison with  very low water solu-
bility, 5-7 ppb,  and a low octanol/H0O parti-
                                 £t
tion.  It is of low acute toxicity and appears
to be  essentially non-bioaccum illative and
environmentally degradable.   Amdro is ef-
fective against IFA  at 4 to 6 grams per  acre
when applied in a 1% soybean oil-corn grits
bait.   Amdro  was  registered  conditionally
for IFA control by  EPA  in  1980  and  is
available to the general public.

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                                          128
 REFERENCES

 Alley, E. G.  1973.   Use of mirex in control
    of the imported  fire  ant.   J.  Environ.
    Qual. 2:52-61.

 Alley,  E. G.  and  B. R.  Layton   1974a.
    Identification  of  insecticide photopro-
    ducts by  mass  spectrometry.   In:  R.
    Haque (ed.).   Mass  Spectrum.   NMR
    Spectros.  Pestic.  Chem.,  Proc.  Symp.
    1973, Plenum, N.Y. pp. 81-90

 Alley,  E. G.,  B.  R. Layton,  and  J.  T.
    Minyard,  Jr.  1974b.  Identification of
    the  photoproducts on the  insecticides
    mirex and Kepone. J. Agr.  Food Chem.
    22:442-445.

 Alley,  E. G.,  B.  R. Layton,  and  J.  P.
    Minyard, Jr.  1974c.  Photoreduction of
    mirex in aliphatic amines.  J. Agr. Food
    Chem. 22:727-729.

 Barbs, W. A., B. M. Glancey, C.  E.  Stringer,
    D. P. Jouvenaz, C. S.  Lofgren, and D. E.
    Weidhaas   1973.    Imported  fire ants:
    eradication trials  with mirex bait.   J.
    Econ. Entomol. 66:785-589.

 Buren, W. F., G. E. Allen, W.  H. Whitcomb,
    F.  E. Lennartz,   and  R.  N.   Williams.
    1974.  Zoogeography of the imported fire
    ants. J. N.Y. Entomol. Soc. 82:113-124.

 Carlson,  D.  A.,  K.  D.  Konyha,   W.   B.
    Wheeler,  G.  P.   Marshall,  and  R.   G.
    Zaylskie 1976.   Mirex in the environ-
    ment:  its  degradation to Kepone and
    related compounds.  Science.   194:939-
    941.

Carson,  Rachael    1962.   Silent  Spring.
    Riverside  Press,  Cambridge,  Mass.   p.
    162.

CAST.   1976.   Fire  ant control,  2nd ed.,
    Council for  Agricultural  Science  and
    Technology, Rept.  No.  65, Ames, Iowa.
 DeWitt, J.  B.  and  J.  L. George.   1960.
    Pesticide-wildlife  research  1959.   Fish
    and Wildlife Ser. Cir. 84. 36 pp.  Jan.

 DeWitt,  J.   B.,  C.  M.   Menzie,   V.   A.
    Adomaites,  and  W. R. Reichel.   1960.
    Pesticidal  residues in animal  tissues.
    Trans.  25th N.  Amer.  Wildlife  Confer-
    ence, 277.

 EPA.   1982.  Unpublished pesticide  moni-
    toring data.  U.S. Environmental Protec-
    tion Agency.

 Gibson,  J.  R.,  G.  W.  Ivie,  and  H.   W.
    Donough.  1972.   Fate of mirex and  its
    major decomposition products in rats.  J.
    Agr. Food Chem.  20:1246-1248.

 Hays,  S. B. and F. S. Arant.   1960.  Insec-
    ticidal  baits for  the control of  the im-
    ported  fire  ant.   J.  Econ.  Entomol.
    53:188-191.

 Hyde,  K.  M., J-. B. Graves, J. F. Fowler,  F.
    L. Bonner, J. W.  Impson, L.  D. Newsom,
    and J. Haggard.  1973.   Accumulation of
    mirex in food chains. La. Agr. Exp. Sta.
    Bull.  17(1):10-11.

Innes, J. R. M.,  B. M. Ulland, M. G. Valerio,
    L. Petrucelli, L.   Fishbein, E.  R.  Hart,
    A. B. Pallotta, R. R. Bates, H. L.  Falk,
    J. J.  Gart, M. Klein, I. Mitchell, and J.
    Peters.  1969.  Bioassay of pesticides and
    industrial chemists for  tumorigenicity in
    mice:  a   preliminary  note.    J.  Nat.
    Cancer Inst.  42:1101-1114.

Kaiser, K.  L. E.  1978. The rise and fall  of
    mirex.  Environ.  Sci. Technol.   12:520-
    528.

Reams, C. W., L. Ingle, and R. L. Metcalf.
    1946.   A  new chlorinated hydrocarbon
    insecticide.  J. Econ. Entomol.   38:661-
    668.

Kreitzer, J.  F.   1974.  Residues of organ-
    ochlorine  pesticides, mercury, and PCB's

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                                          129
    (polychlorinated  biphenyls)  in  morning
    doves from eastern United States. 1970-
    1971. Pestic. Monit. J.  7(314):195-199.

 Kutz, F. W., A. R. Yobs, W. G. Johnson, and
    G. B. Wiersma.  1974.  Mirex residues in
    human adipose tissues.   Environ.  Ento-
    mol. 3:882-884.

 Lofgren,  C. S., C. E.  Stringer, and F.  J.
    Bartlett.  1962. Imported fire ant toxic
    bait studies:  GC-1283,  a promising toxi-
    cant.  J.  Econ. Entomol. 55:405-407.

 Lofgren,  C.  S., W.  A.  Banks, and  B.  M.
    Glancey.  1975.  Biology and control of
    imported fire ants.  Ann. Rev. Entomol.
    20:1-30.

 McBee,  E.  T.,  C.  W. Roberts, J.  D. Idole,
    Jr., and  R. H. Earle,  Jr.   1956.   An
    investigation   of   the   chlorocarbon
    ClnH10  m.p.    485°  and  the  ketone
            ), m.p. 349 .   J.  Amer. Chem.
Metcalf,  R.  L., I.  P.  Kapoor, Po-Yung Lu,
    and C. K. Schuth.  1953.  Model ecosys-
    tem studies of the  environmental fate of
    six organochlorine  pesticides.  Environ.
    Health Perspect. 4:35-44.

MiUs, H. B.  1967.  Report of Committee on
    Imported Fire Ant, National Academy of
    Sciences, to Administrator  Agricultural
    Research, USD A, Washington, B.C.   15
    pp.

National Cancer Institute.  1976.  Report on
    carcinogenesis  bioassay  of  technical
    grade  chlordecone (Kepone),  Bethseda,
    Maryland, Jan.

Oberheu, J. C.  1972.  Occurrence of mirex
    in starlings  collected  in seven  south-
    eastern states,  1970.   Pestic. Monit. J.
    6(l):41-42.
    Pesticides on Non-Target Species.  Exec.
    Office   President,  Office  of  Science
    Technology, Wash., D.C. 220 pp.

Shapley, D.  1971.   Mirex and the fire ant:
    decline  in  fortunes  of  "perfect"  pesti-
    cide. Science. 172:358-360.

Sterrett,  F. S., and C.  A.  Boss.   1977.
    Careless kepone. Environment.  19(2):30-
    37.

Tagatz,  M.  E.,  P.  W.  Borthwick, and  J.
    Forester.   1975.  Seasonal  effects  of
    leached  mirex on selected estuarine ani-
    mals. Arch. Environ. Contam. Toxicol.
    3:371-383.

Waters,  E.   M.,  J.   E.  Hugg,  and  H.  B.
    Gerstener.   1977.  Mirex, an  overview.
    Environ.  Res. 14:212-222.

Whitten, J.  L.   1966.  That We May  Live.
    Van Nostrand, Princeton, N.J. p. 115.

Williams, D. F., C. S. Lofgren, W. A. Banks,
    C. E. Stringer, and J. K. Plumley.  1980.
    Laboratory  studies with  nine amidino-
    hydrazones,   a promising new  class  of
    bait  toxicants for control of  red im-
   ported fire  ants.    J. Econ.  Entomol.
   73:798-802.
Pimentel, D.  1971.  Ecological Effects  of

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                                       APPENDIX D

     IMPACT OF THE IMPORTED FIRE ANT CONTROL PROGRAMS ON WILDLIFE AND
                             QUALITY OF THE ENVIRONMENT

                                    Maureen K. H inkle

                                        PANEL IV
 EARLY SPRAY PROGRAMS
    In  1957,  the USDA  created a  furor
 among scientists and  conservationists when

 it  unvieled  its  plans  for  eradicating  the

 imported fire ant (IFA).  Objections to the

 program centered on the use of the  chlori-
 nated  hydrocarbon  compounds  heptachlor
 and dieldrin.  Ezra Taft Benson, then Secre-

 tary of Agriculture, was asked to delay the

 program until some  research could be  con-
 ducted (1) to determine appropriate dosages

 and (2)  to determine  the  effects of  the
 compounds on non-target  organisms.   De-

 spite  these objections, in  1958  the  USDA
 initiated the eradication program (see Table

 1)  with  a  $3  million appropriation  from
 Congress.
    Ground  applications of  heptachlor and
 dieldrin killed the IFA though not as well as

 had been forecast; however, they also  ad-

 versely  impacted the surrounding wildlife.

 The 1971 President's Study on the Ecological
 Effects  of Pesticides on Nontarget Species
described the effects of heptachlor:

      In  1957  the  U.S. Department of
    Agriculture in a cooperative program
    with the States treated approximate-
    ly 27 million acres in the Southeast
 with heptachlor  at  a  rate  of 2  Ib/A
 for  control of the imported fire ant
 (Smith  and Glasgow,  1963). Investi-
 gations of the effects of heptachlor
 on wildlife were initiated  after the
 second  year of  treatment  in  south-
 central Louisiana.  On 4 farms the
 following animals died within 3 weeks
 after  treatment: 53  mammals,  in-
 cluding 12 species; 222 birds, includ-
 ing  28 species; 22 reptiles, including
 at least 8 species;  many species of
 frogs; many  kinds  of crayfish;  and
 many   fish,   including   8   species.
 Ninety-five percent of the  dead  ani-
 mals were analyzed,  and  all   con-
 tained some heptachlor.

   Quail  populations in Georgia de-
 clined significantly soon after  the
 land was treated  with heptachlor  at a
 rate of 2  Ib/A,  and the populations
 had  not yet recovered after a period
of 3 years of no further treatment
(Rosene, 1965).   A  decline of cocks
and  coveys of quail  also followed the
 1/2-lb heptachlor applications (signi-
ficant for  cocks,  approaching statis-
 tical significance  for coveys).    A
small 4-acre plot within the treated
area was searched for  dead  and dying
animals and observations were made
on living animals.  Forty-seven days
after treatment,  no live animals were
seen or  heard on  the plot, and a total
of 38 dead  animals had been found.

   A 2-year study carried out to de-
termine the effects heptachlor treat-
ments were having  on  bird popula-
                                           130

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                                          131
    tions in Mississippi disclosed that all
    treatment  rates  of  heptachlor  at
    0.25, 0.50,  and 2.00 Ib/A "decimated
    arthropod  populations,  caused  bird
    mortality,  and altered bird behavior
    patterns."  None of the dosages, how-
    ever,  eradicated  the  imported  fire
    ants as planned.
    In  Silent Spring (1962), Rachael  Carson
 described treated areas  where all  wildlife
 had been destroyed.  Carson also reported
 deaths of  poultry,  livestock  and domestic
 pets due to heptachlor, and she cited Otis L.
 Pointevint a veterinarian from Bainbridge,
 Georgia, who had treated animals within a
 period of two weeks to several months after
 the  treatment.  The  animals  had lived in
 areas  that  were  treated for IF A and  had
 access  to  contaminated food  or  water.
 Every  animal  suffered from  a  sometimes
 fatal disease of the nervous system.   Five
 months after  the  application,  one two-
 month-old  calf was found with 79  ppm of
 heptachlor in its adipose tissues.

NEW CHEMICALS
   In  1960,  the FDA cancelled tolerances
for heptachlor residues  in  pasture  grasses
and  began  exploring other chemicals.  The
first chemical  used was chlordecone  (ke-
pone) in peanut butter (Texas A&M 1981).
Chlordecone, however, was highly  toxic  to
mammals.  Research soon turned up  mirex,
an analog of chlordecone, which was  effec-
tive against the  IF A  but less toxic than
 chlordecone.  Mirex appeared to be the ideal
 chemical control for  the IFA.   Foraging
 workers carried the toxicant back to nesting
 queens,  thus insuring the  death of the col-
 ony.   Mirex  bait  was  comprised of  0.3%
 mirex as  toxicant,  14.7%  soybean oil  as
 solvent and food, and 85.0% corncob grits as
 carrier.  In 1962 this bait, known as mirex
 4X, was applied  over a  large  acreage in
 Georgia, Louisiana,  Alabama, and Texas, at
 the dosage rate of 10 pounds of product per
 acre.  Mirex was soon found to be effective
 at  lower dosages.   In  1963,  the  dosage
 dropped to 2-1/2 pounds of product per acre.
 In 1965,  the dosage  went to 1-1/4 pounds of
 product per acre.  Belief  in mirex's  ability
 to  eradicate the IFA  was high.  Some felt
 that three  properly  timed applications  of
 mirex  (1-1/4 pounds of product per  acre or
 5.1 grams of mirex per acre) over a 1-year
 to 18-month interval "to the entire infested
 area would  almost eliminate the imported
 fire ant from the  United States"   (USDA
 1971).   This  hypothesis  encouraged  those
 who favored eradication,  and in 1967 the
 Senate Appropriations Committee directed
 USDA  to determine  the feasibility of eradi-
 cating  the IFA with mirex (see Table 2).
 Accordingly,  three  large-scale  eradication
 trials were begun.

ENVIRONMENTAL CONCERNS
   With the passage  of the National  Envi-

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                                          132
 ronmental Policy Act (NEPA) by Congress in
 1969, environmental  issues  found greater
 emphasis. The NEPA required environment-

 al issues  to be considered early in the deci-

 sion-making process rather than after the

 fact. In 1970, the Environmental Protection
 Agency  (EPA) was created, and pesticide
 registration moved from USDA  to EPA.  At

 the  same time, Interior  Secretary Hickel
 removed  federal land from the  mirex/IFA
 program.

   In addition,  the newly  formed Environ-

 mental  Defense Fund (EOF), the  first envi-
 ronmental group formed to bring court suits
 on environmental problems and the organi-

 zation that participated in several pesticide

 cancellation   proceedings   throughout   the

 '70's decade, sued USDA to restrain the IF A
 eradication program.    The  December  3,

 1970, settlement called for an environment-

 al impact statement (EIS), completed Jan-

 uary 22, 1971.  In the EIS, USDA stated that
 eradication might  be technically feasible,
 but  logistic  and  financial limitations  to-

 gether with "possible adverse environmental

 effects  resulting from such large-scale  use

 of Mirex  bait" made eradication "no longer
 an objective of the  Federal-State Coopera-

 tive  Control program."   The three large-

scale eradication trials had failed to erad-
icate the IF A.

   USDA  consequently altered the IF A con-
trol program:
       Mirex bait will be applied aerially
    to those areas where the ant  is caus-
    ing trouble, where the property own-
    ers  have   expressed concern,  and
    where  the  State and local  govern-
    mental agencies  have requested Fed-
    eral cooperation in a  control  pro-
    gram.  Under the plan, forested areas
    which  are not prime fire ant habitat
    and sensitive areas such as estuarine
    area's,  and  State and Federal game
    refuges will not be treated. Applica-
    tion pilots  will  be  briefed with re-
    spect to all  sensitive areas, including
    water, and instructed to avoid appli-
    cation to those  areas.    Compliance
    will  be closely monitored by ground
    personnel and aerial  supervision  (EIS
    1971) (emphasis added).

    In response  to questions posed  by the
Appropriations  Committee,   USDA  offered
the following definitions:

    1. How do  we define prime wildlife
      habitat?
      With respect to the imported  fire
      ant control program,  prime wild-
      life habitat is described as Feder-
      al  and   State  game  refuges,
      estuary and marsh areasr wooded
      areas bordering  streams,  rivers,
      and other bodies of water.  Heavi-
      ly wooded areas are  not treated
      because  they  do not  support  im-
      ported fire ant populations (em-
      phasis added).

   2.  What  is  the  largest  continuous
      block that would be treated under
      this one treatment concept?
      In  open  general  farming  areas
      without streams or heavily wood-
      ed areas, 50,000 or more contig-
      uous acres may be treated. As  a
      general guideline, if 75 percent or
      more of the area is open, an elec-
      tronic  guidance  system  is  em-
      ployed.   Cutouts  such as  rivers,
      heavily forested areas, and game

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                                         133
       refuges are  marked on the pilot's
       map,  and the recording tape  in
       the aircraft marks  these  areas
       that are cut out.  When less than
       75 percent of the total area is  to
       be treated,  small  aircraft are
       used  due to  the many cutoffs re-
       quired.
    3.  What  do  we plan  to do along the
       peripheral areas?
       Treatments  are planned  in peri-
       pheral areas when there is  threat
       of spread to uninfested States  or
       to a  new  area  of  an  infested
       State.   These treatments  are  to
       be made in support of the Federal
       quarantine (EIS 1971).
PROBLEMS WITH MIR EX
   On March 18, 1971, within two months of
USDA's  environmental  impact  statement,
EPA announced its intention to cancel mirex
due to the  adverse effects on wildlife and
humans.    Allied  Chemical  Company, the
registrant  of  ten of  the  eleven pesticide
products  containing   mirex,  referred  the
issue to the National Academy of Sciences.
From  this  came  the  National  Research
Council's  (NRC)  report  citing adverse ef-
fects  from  mirex on  aquatic life,  particu-
larly young shrimp and blue crabs.   EPA
accepted  the  NCR's  recommendation  and
prohibited the  use of mirex in coastal areas.
(This  prohibition  was  modified June 30,
1972,  to permit applications to streams and
farm  ponds not  used  primarily for human
consumption.)  Combined with Interior's ban
on federal lands, the  restrictions posed dif-
ficulties since all affected states  bordered
the Atlantic,  the Gulf, or major rivers and
aquatic areas.
   A Notice of Intent to hold a hearing on
whether or not to  cancel  registrations of
mirex was published April 4, 1972.  Hearings
began July 11, 1973, and  continued until
March 28, 1975, when settlement  negotia-
tions began.  On July 14, 1975, Allied with-
drew from negotiations  and announced  it
would stop producing mirex until an agree-
ment could be reached.   Hearings  resumed
sporadically until February 12,  1976, when
Allied stated  it would no longer formulate
mirex bait.
   On  February 26,  1976, hearings were
temporarily suspended.  On May 10,  1976,
Allied transferred registrations to Mississip-
pi. The hearings were dormant while Missis-
sippi  reviewed the  record (13,000  pages of
transcript, over 200 exhibits, testimony of
over 100 witnesses).
   After  reviewing  the  record,  Mississippi
submitted  a plan to phase out mirex regis-
trations and suspend the  hearing. On Octo-
ber 20,  1976,  EPA accepted  the  plan to
allow aerial  application  of mirex through
December  31,  1977, and ground broadcast
and  mound application  through June 30,
1978.
   The  impact of the IF A control programs
on wildlife and the quality  of the  environ-
ment  is summaried from EPA's decision of

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                                         134
December 29, 1976:
      Impurities and  Degradation Pro-
   ducts.   Very recent screening anal-
   yses of formulated Mirex bait at the
   Mississippi  Authority's  formulating
   plant in Aberdeen, Mississippi,  have
   shown   that  Kepone   is  present  in
   Mirex  bait at levels up  to  0.25 ppm
   and in  technical Mirex at levels up to
   2.58 ppm.

      Recent research conducted by the
   United  States  Department  of  Agri-
   culture and  others has shown that as
   much as 10% of Mirex applied in the
   environment  either begins as Kepone
   or is degraded into Kepone  over per-
   iods of fire  and twelve years.  . .  .
   Laboratory studies have shown that
   Mirex  can degrade photolyticly into
   Kepone. . . .
      Persistence.
Because   of  its
   unique chemical  structure,  Mirex  is
   more resistent  to chemical  attack
   than other chlorinated hydrocarbons
   such  as  DDT,  Aldrin/Dieldrin,  and
   Heptachlor.  (Alley Testimony at 4).
   Mirex therefore will likely remain on
   non-living  (and  living)  matter  for
   longer periods of  time than  would
   such chlorinated hydrocarbon  pesti-
   cides as  DDT,  Aldrin/Dieldrin,  and
   Heptachlor.  (Alley Testimony at 4).
   Research  performed  by  USDA  and
   others has shown that as  much as
   50% of the original Mirex  that  was
   applied in  1962  was recovered from
   soil  residues  twelve  years  after
   treatment. . . .

      Bioconcentration.    Unlike most
   chemical   compounds   (Livingston
   Testimony (n) at 1), Mirex continues
   to accumulate to higher  and higher
   levels  in  the  brain,  muscle, liver,
   skin,  and  subcutaneous  tissues  of
   mammals  to  which it is fed as a
   constant  increment of the  diet,  ap-
parently without reaching a plateau.
There  appears  to  be  an unlimited
capacity for accumulation of  Mirex
in some animal tissues, and Mirex can
accumulate  in  vertebrate  animals to
extremely high levels.  (Gibson  Testi-
mony at 3; Gibson TR 157,  165,  168).

   Moreover,  Mirex accumulates in
wildlife and the food of wildlife, in-
cluding Crustaceans, . . . Ciliate pro-
tozoa,  . .  . .and algae.  ...  At even
the most  primary  trophic levels in
the environment the bioconcentration
of Mirex has been demonstrated, of-
ten at  levels thousands of  times that
found in aquatic media.

   In addition, Mirex is highly resis-
tant to metabolic  attack, and as  a
consequence is apparently not  elimi-
nated  from  vertebrate  bodies  as  a
result  of metabolic conversion . .   .
nor is  it readily  excreted  through
normal excretory  channels.  .  .   .
However,  Mirex  can  be  excreted
through special mechanisms, such as
lactation and via egg yolks.  (Refer-
ence 4  at 5-7;  Kimbrough Testimony
at  9).    The  significance  of  these
special pathways  of Mirex  elimina-
tion is two-fold.   First,  man is  a
consumer  of products  which are the
vehicles of  such special  elimination
in other species.  Second, since it has
been shown  that cows will eliminate
significant   quantities  of  Mirex  in
their milk, it is reasonable to expect
that Mirex  will also be excreted in
the milk of female human  beings and
thus transmitted  to their offspring
via breast feeding. .. .

   Mirex is transferred through the
placenta in rates.  The  placenta con-
stitutes a barrier between the fetus
and the mother which is designed to
protect the  fetus.  Dr.  Renate Kim-
brough  characterized  the  finding in
rats as a "warning signal" that it may

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                                         135
   also  take place  in human  beings.
   (Kimbrough Testimony at 12).

       Biomagnification.  Mirex biomag-
   nifies in higher-level organisms as it
   moves up the food chain to man. . . .
   Mirex's great persistence in the en-
   vironment and  its propensity to bio-
   accumulate  and  biomagnify   mean
   that  even though it is  applied at
   relatively small application rates,  it
   will be available for consumption by
   humans,  wildlife,  and  marine  and
   aquatic organisms for a long  period
   of  time.   (Alley  Testimony  at 4;
   Plapp Testimony at 10-11).

       Non-target  insects.  Tests have
   shown that one application of  0.018
   pounds  of technical  Mirex per acre
   reduces the population of carabid and
   staphylinid beetles by 60 percent and
   67  percent  respectively,  (Hensley
   TR2,727).  These insects are among
   the natural predators of the  sugar-
   cane  borer.  (Hensley Testimony at
   3).

       Mirex  leaches from Mirex  bait
   into"sea water.  (Tagatz Testimony at
   5:  Reference 11  at 4).  Mirex can be
   leached from  Mirex bait  by  fresh
   water, and it can thereafter enter a
   salt water  environment.    (Tagatz
   Testimony at 5).  Studies have shown
   that Mirex residues in water resulting
   from  fresh water runoff after appli-
   cation  of  Mirex  in  the  watershed
   range  from  0.1  to  1.0  parts per
   trillion in  fresh runoff waters.  (Alley
   Testimony at  7-8).   Mirex is  tran-
   sported into  aquatic organisms, in-
   cluding  edible   fish,  from  nearby
   treated lands.  (Duke Testimony at 7,
   DukeTR 1,901).

   Additionally,  field studies  demonstrated

that  mirex moved  from treated  land to
estuarine  biota  after application  of mirex
 bait to the Mississippi watershed and mirex
 was detected in streams after heavy runoff
 (Tagatz et al. 1976).  Mirex was also detect-

 ed  in  fish samples from  Lake  Ontario in

 Canada,  where it was never  registered for
 use (Kaiser 1974). In  upper New York State,

 from 0.01  to 3.16 ppm mirex residues were
 detected in waterfowl.

    The effects  of mirex on birds received

 little attention until  1977 when mirex was
 aerially applied to a game management area

 in  Hampton  County, South  Carolina.   In
 adipose tissue of bobwhite quail, mires resi-
 dues showed  up to a five-fold increase with-

 in the first month and peaked in the spring

 following the mirex treatment, correspond-
 ing with  insect emergence (Kendall et al.
 1977).

   In addition, a study found  that  lesions

 produced in the livers of chicks "appeared to

 be related to mirex treatment" (Davison et

 al. 1976).  This find was significant because
lesion  development  was proportional  to

 mirex ingestion and represented irreversible
 cellular damage.

   Humans were  not exempt  from  mirex

residues.  In  1967, EPA analyzed samples of

adipose tissues from persons living in  mirex-

 treated areas and found that the percentage
of  residues  increased  in states that had

heavy  mirex treatments.  Forty-four  per-

cent of persons tested in  Mississippi showed
positive residues  of  mirex compared with

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                                         136
 traces in South Carolina. The average resi-
 due was 0.16 ppm with the range from trace
 to  5.94  ppm.   Twenty-one  percent of all
 samples were positive for mirex (Kutz et al.
 1974).
   The finding of  residues in humans  plus
 laboratory   evidence   of  carcinogenicity
 prompted  the  EPA in  December  1976 to
 conclude  that  mirex posed a carcinogenic
 risk to humans. Further studies showed that
 mirex and kepone  behaved similarly in (1)
 resistance to metabolic attack, (2) failure to
 be  eliminated  through  normal excretory
 channels, and (3) induction of  hepatocellular
 carcinomas in mice and rats.
   With  no  mirex for  aerial  application
 against the IFA in  1978, for the first time
 since  1960, the Office of Management and
 Budget reduced the IFA appropriations from
 $9 million to $900,000.   Congress then ap-
 propriated $959,000 in FY 1978 for methods
 development  and monitoring  activities, $1
 million  for quarantine,  and  approximately
 $4,460,000 for IFA control.

FERRIAMICIDE
   Ferriamicide is  mirex that degrades.  By
 adding an amine [Keramine T 1902D]  (1.7%),
ferrous chloride hexahydrate to enhance de-
gradation of  the toxicant mirex (0.2%), and
soybean oil (8%), and 0.05% mirex, ferriami-
cide  is  mirex transformed into  a  different
compound.  The distinction between mirex
 and ferriamicide appears to be a matter of
 0.025% mirex.  When rnirex was phased out,
 the 1976  EPA notice listed ten registrations
 of mirex. Four  of these were for the IFA:
    Mirex 4X -   0.3% mirex (at  10 Ibs/acre
       = 13.62 grams per acre)
    Mirex 10:5 -  0.1% mirex (at  1 Ib acre =
       0.454 grams per acre)
          0.15% mirex
          0.075%
    Ferriamicide is:
          0.05% mirex (at 1.5 Ibs/acre)
          0.05% mirex (at  1 Ib/acre = 0.227
          grams active  ingredient per acre)
          0.05% mirex  (at  0.75  Ibs/acre =
          0.171  grams active ingredient per
          acre)
          0.025% mirex at 0.25 Ibs/acre
    The distinction  between the  mirex • and
ferriamicide  formulations  appears  to  be
0.075% mirex and  0.05%  mirex (mirex at
0.1% at 1 Ib/acre uses 0.454 grams per acre,
while ferriamicide at 0.05% mirex, at 3/4ths
of  a pound  per  acre, uses 0.171  grams per
acre).
    Initially  ferriamicide was  developed to
prolong the use of mirex (Report of congres-
sional  phone  call,  8/31/76,   from  Sam
Thompson to D.A. Lindquist, re:  "Coopera-
tive agreement  on increasing rate of Mirex
degradation,   Mississippi  State  Chemical
Laboratory."). It was believed  that a 400%
reduction  in mirex  dosage  would  be ade-

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                                         137
quate for fire ant control.
    When Mississippi learned about ferriami-
cide,  they  applied  for a Section 18 (emer-
gency exemption) to use the compound.  Due
to political pressures and  "the need to ob-
tain matching funds from  their own legis-
latures . . . before  they recess for the year"
(February 22, 1978, letter by Barbara Blum,
EPA),  EPA  approved  the  ferriamicide re-
quest despite its admission that
   There  has not been enough  time to
   develop the data on mammalian toxi-
   city necessary to demonstrate human
   safety,  nor  have questions been an-
   swered   about  degradation  products
   and persistence  in the field.  Despite
   apparently rapid breakdown  and re-
   duced shell fish toxicity, we cannot
   say that ferriamicide is or is  not safe
   for  humans,  domestic  animals  and
   non-aquatic species.  It  will  take up
   to 36  months to  fill  the  data gaps
   completely; a conditional registration
   is  possible in 12  months if  pending
   legislation giving the agency author-
   ity for  such registration is  enacted
   (Butler  1978).
   Ferriamicide was allowed only for mound
treatment in Mississippi until July 30, 1979.
By  the time a renewal request  would have
been required to extend the emergency per-
mit, kepone had been found in ferriamicide
shelf samples (see Table 3).
AMDRO  217,300
   In 1979, EPA approved aerial application
of a new  substance to combat  the  IFA—
Amdro,  manufactured by  American Cyana-
mid. Amdro
   is an  amidino-hydrazone  compound
   that is a slow acting stomach insecti-
   cide.  The toxicant degrades  rapidly
   in the environment in sunlight with a
   half  life of less than 24 hours.  It is
   insoluable in water but  is soluable in
   acetone,  methanol, ethanol,  isopro-
   panol and hot ethyl acetate.   AC
   217,300 reportedly does not leach in
   the soil and is degraded by microor-
   ganisms.  It apparently does not bio-
   accumulate in the environment  ac-
   cording to model laboratory studies. .
          After four  years  of  testing,
   Amdro has been shown to be an ef-
   fective toxicant against the imported
   fire ant (USDA 1981).

CONCLUSION
   Chemical control of the IFA is a profit-
able market.  Table 1 shows how  appropria-
tions increased from $2.4 million in 1958 to
$9.5 million in 1977.  The years 1978 to 1980
saw  no  aerial applications for IFA control
and  fewer dollars  were appropriated.   In
1981 aerial  registration for Amdro was ap-
proved and  $6 million were appropriated—
this  from  a  budget-conscious  Congress.
However,  in such large programs,  dollars
should not be a key issue. The environment-
al implications of a control program for the
IFA  are great. Comprehensive management
strategies are needed, not just  large-scale
chemical applications. The Audubon Society
agrees with Homer Collins, a USDA scien-
tist  who said, "not enough research atten-
tion has been given  to  mound  application
treatments for fire ant control" (USDA Fire
Ant  Work  Group  Meeting,   December 5,

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                                         138
1978, Memo December 15,  1978, p. 3).  More
dollars  need  to go to research to develop
effective chemicals, juvenile hormones, in-
sect growth regulators, and chitin inhibitors
for mound treatment.
   The  Department of Interior, commenting
on USDA's Final Programmatic EIS (May 21,
1982), criticized the USD A for continuing to
dwell "almost entirely on aerial application
over large acreages and  this mode of appli-
cation causes great  concern for almost all
forms of aquatic  animal life" (FEIS  1981).
Von  Rumker  et al. (as referenced in Shoe-
maker and Harris  1974)  estimated that less
than one percent  of insecticide applied by
air is absorbed  by insects  through contact,
inhalation, or ingestion.   Him el (as  refer-
enced in Shoemaker and Harris  1974)  des-
cribed the present system  of crop spraying
as "the  most inefficient industrial process
ever practiced."  Clearly, we cannot  afford
environmentally to spray areas millions of
acres of coastal  wetlands, salt  marshes,
wildlife refuges, and river areas for IF A; we
also  cannot afford to use  scarce public funds
for such an  expensive and inefficient  pro-
gram.    Perhaps more   dollars  and  effort
should  concentrate  on   mound  application
compounds, because the mound is the source
of the  problem.   Another  concern  in any
mass spray program is pesticide resistance
by other organisms and this concern  should
be realistically addressed in any large spray
program.
    The risks of pesticides cannot be disre-
garded.   Steps have  been made to  make
chemical  registration  and use  safer; how-
ever, the  quantity  of pesticides produced
increased 80%  in the  1970's.  They  doubled
since Silent Spring.   In the U.S. they will
double in the next 20 years and quadruple in
developing countries.  As long as chemicals
must be used  to protect our food  sources
and ourselves,  risk  to  the  soil,  non-target
species, and humans  abounds.

REFERENCES
AUey,  E.G.  and   B.R.  Layton.     1976.
    Aqueous  photochemistry   of    mirex.
    Paper presented at  172nd National Meet-
    ing of the American Chemical  Society,
    San Francisco, CA,  Fall.
Butler, W.A. 1978.  Memorandum of Points
    and  Authorities  in  Support  of Plaintiff
    Environmental  Defense  Fund's  Motion
    for Summary Judgment, EOF v.  Barbara
    Blum, Civil  Action  No. 78-0577.  June 8,
    1978.
Carson, R.  1962.  Silent Spring. Riverside
    Press, Cambridge, Mass.
Council for Agricultural Science and Tech-
    nology.  1976. Fire  Ant Control.  Report
    No. 62.  Ames, Iowa.
Davison,  K.L.,  H.H.   MoUenhauer,  R.L.
    Younger, and J.H.  Cox.   1976.   Mirex-
    induced  hepatic  changes  in  chickens,
    Japanese quail,  and  rats.   Archives  of
    Environmental Contamination and Toxi-
    cology 4(4):469-482.
Kaiser,  C.L.E.   1974.   Mirex: an unrecog-
    nized contaminant  of fishes from  Lake

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                                        139
   Ontario.  Science 183(4150):523-525.

Kendall, R.J., R. Noblet, J.D. Hair, and H.B.
   Jackson.   1977.  Mirex residues in Bob-
   white quail  after  aerial  application of
   bait for fire ant control, South Carolina-
   1975-1976.  Pestic. Monit. J.  11(2): 64-
   68.

Kutz, F.W., A.R. Yobs,  W.G.  Johnson and
   G.B.  Wiersma.  1974. Mirex  residues in
   human adipose tissue. Environ. Entomol.
   3(5):882-884.

Shoemaker, C. and M.O. Harris.  1974. The
   effectiveness of  SWCPs  in comparison
   with other methods of reducing pesticide
   pollution.   Effectiveness  of Soil and
   Water Conservation Practices for Pollu-
   tion Control, D.A. Haith and R.C.   Loehr
   (eds.). EPA  Report-600/3-79-106.

Tagatz,  M.E.,  P.W.  Borthwick,  J.M. Ivey,
   and J. Knight. 1976.  Effects of leached
   mirex on experimental  communities of
   estuarine  animals.  Archives of  Environ-
   mental  Contamination  and  Toxicology
   4(4):435-442.

Texas A&M  Experiment Station.  1981. The
   Imported  Fire Ant Program: A  Search
   for New Control Methods,  unnumbered.

United States  Department of Agriculture.
   1976.   Cooperative Imported Fire Ant
   Program, Environmental  Impact  State-
   ment. USDA/APHIS, Washington,  D.C.

USD A.   1981.   Cooperative Imported Fire
   Ant  Program, Final programmatic Envi-
   ronmental Impact Statement.  USDA/-
   APHIS, Washington, D.C.

USD A.   1981.  Memorandum  re: Report on
   Ferriamicide  Bait  Samples-Shelf  Life
   Study, to: Dr. R.L. Williamson,  April 14,
   1978.

USDA.   1977.   ARS/APHIS Imported Fire
   Ant Meeting, March 20, 1977.
USDA.   1977.   ARS/APHIS Imported Fire
   Ant Meeting, June 28, 1977.

USDA.   1978.   Report  of  FR/APHIS Im-
   ported Fire  Ant Technical Work  Group
   Meeting, Raleigh, North  Carolina, April
   25, 1978.    USDA/APHIS,  Washington,
   D.C.

United  States   Environmental  Protection
   Agency.  1976.  Administrator's Decision
   to Accept Plan of Mississippi Authority
   and Order  Suspending Hearing for the
   Pesticide  Chemical  Mirex, 41 Federal
   Register  56697-56704,   December 29,
   1976.

United States EPA.   1979.    Supplemental
   Opinion and Order,  Under Section 18 of
   the Federal  Insecticide,  Fungicide, and
   Rodenticide Act, Use of  Ferriamicide in
   Mississippi,  44  Federal Register  11111-
   17, February 27, 1979.

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Table 1.    Estimated acres of D?A infestation, federal IFA appropriations, and control monies (from
           USDA June 2, 1982) (in thousands).
Infested
Year Acres (Est.)
1932 200
1947 2,000
1954
1955
1956
1957
1958
1959 26,000
1960
1961
1962
1963 31,000
1964
1965
1966
1967 106,000
1968
1969
1970
1971 126,500
1972
1973
1974
1975b 135-150M
1976
1977
1978 190,000
1979
1980
1981 230,000

1982
1983C
Federal
Control






736
1,269
1,550
1,465
1,392
1,689
1.258
1,764
2,106
2,835
3,280
2,839
2,843
2,533
2,587
4,519
3,916
4,233
3,253
3,299
584
2,467
2,000
2,800
67,217


State & Local
Coop. Funds






1,506
2,302
1,844
1,420
1,343
1,735
1,896
1,864
2,076
2,002
3,524
3,730
3,720
4,271
4,671
3,533
5,696
4,812
2,184
3,770
4,710
1,394
1,315
2,650
67,968


Total
Control






2,242
3,571
3,394
2,893
2,735
3,424
3,154
3,628
4,182
4,837
6,804
6,569
6,563
6,804
7,258
8,052
9,612
9,045
5,437
7,069
5,294
3,861
3,315
5.450
125,193


Actually Spent
By APHIS*






2,088
2,437
2,610
2,546
2,529
2,967
2,446
2,977
3,910
3,249
4,530
4,595
5,295
6,361
7,108
7,047
7,180
8,708
8,545
6,823
3,529
2,467
4,303
3.852
108,102


Appropriations






2,400
2,486
2,495
2,571
2,571
2,610
2,495
3,270
3,303
5,389
4,809
5,036
5,643
7,762
7,552
7,928
7,195
9,037
9,127
9,487
1,942
1,942
1,996
6,000
115,046
5,915
120,961
Estimates 1932-71: National Academy of Sciences
Estimates 1975: CAST
Estimates 1978: Texas A & M Booklet

aAppropriated and used for survey, regulatory activities, environmental'monitoring, control eradication, and
 method development work, including field tests for evaluating controls.

bFY 1975-1976 includes a transition quarter for the period 7/1/78 - 9/30/76 to new fiscal year beginning
 10/1/76.

C1983 appropriation of $2,625,000 is pending approval of Congress.
                                             140

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Table 2.  Summary of pesticides used and federal action taken for IF A.
Year
    Pesticide
                             Federal Action
1920



1946

1957
1962


1963


1964
1965
1967
1970
1971
calcium
cyanide
 gasoline

chlordane

heptachlor
 dieldrin
1958   2 Ibs/acre

1959
1960    heptachlor
         1-1/4 Ibs/acre
mi rex
 10 Ibs/acre

mirex
 2-1/2 Ibs/acre
1-1/4/acre
 twice/year
Congress appropriated $3 million.
Only a few states appropriated funds at first (Alabama,
Georgia, Louisiana and Florida).

Federal quarantine established in nine southern states.

Alabama stopped  matching funds.  USDA offered  heptachlor
free to Texas landowners who signed release absolving federal,
state and local government of responsibility for damage.

FDA cancelled tolerances for heptachlor residues on pasture
grasses.  (Texas and Florida also  withdrew financial support for
IFA program.)
                      GAO  (Government  watchdog  agency)  accused  USDA  of
                      disregarding  scientific opinion and wasting government funds.
                      Whitten  overuled ARS  budget cut request.    Budget Bureau
                      pressuring reduction in budget.
                      President Johnson eliminated program for FY  1967.   Whitten
                      increased appropriation.  Johnson  froze  $2 million of  the  $5
                      million budget  funds.   USDA asked  NAS for report  which
                      concluded eradication not biologically  or technically feasible.
                      IFA dramatically spread, IF As not caused significant harm to
                      land values, agricultural production or health.

                      Pesticides  transferred ,from USDA to  EPA.  Interior Secretary
                      Hickel removed Interior land  from mirex applications  because
                      of harm to fish.

                      Approximately $800,000 diverted  to extramural research  and
                      apportioned via specific cooperative  agreements  to  various
                      scientists at universities in the south.  (Lofgren, Tall Timbers
                      Conference paper at 2.)
                                               141

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Table 2.  Continued.
Year
Pesticide
Federal Action
1972


1973
1977   mirex phased out
       ferriamicide EUP
1978   ferriamicide Sec.
       18 Emergency Use
1979   Amdro EUP
1980   Amdro conditional
       registration

1981   ferriamicide
       request for condi-
       tional registration
                  National Academy of Sciences Report: mirex poses serious risk
                  to aquatic life, particularly young shrimp and blue crabs.

                  3/28/73-EPA  prohibits  aerial applications to coastal counties,
                  broadcast  applications  on aquatic areas and heavily forested
                  areas.
                  4/4/73-EPA Notice of Intent  to hold a hearing.

                  7/11/73-Hearings  began,  continued until 3/28/75  when  Allied
                  Chemical Company withdrew from negotiations, and announced
                  cessation of production of mirex until agreement reached.

                  6/28/77-USDA said program not  as  effective as  previously,
                  because any individual who  does not  want mirex can request
                  land not be treated.

                  9/29/77-EPA issued experimental use permit for ferriamicide to
                  Mississippi for Florida and Mississippi 9/9/77 to 10/1/78.

                  12/16/77-Mississippi  applied for  emergency exemption  for
                  aerial application of ferriamicide.
                  12/31/77-Mirex no longer legal by aerial application mound and
                  ground broadcast permitted through 6/30/78.

                  OMB reduced appropriations from $9 million to $900,000
                  because "like pouring money down a rat-hole." Treatments only
                  in Mississippi, Alabama, and Georgia.  Rest of states decided
                  not to treat.

                  3/8/78-EPA approved emergency exemption 7/1/78 to 6/30/79.

                  House  of  Representatives  defeats  amendment   to   allow
                  emergency use of  mirex  for two years by vote of 224  to 167
                  (11/28/79).

                  Senator Talmadge directs EPA and USD A to develop a
                  comprehensive strategy.
                                              142

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Table 3.   History of chlordecone.
  Year
Action
1960      First bait experimented with for the IFA was chlordecone (Kepone) in peanut
          butter. Mirex, an analogue of chlordecone, developed.

1974      G.W. Ivie (Dorough and Alley) report that mirex converts to chlordecone.

1976      USDA reported chlordecone as degradate of mirex.

          EPA finds chlordecone in mothers milk in the south.

          NCI  concludes chlordecone  is carcinogenic in both sexes  of  rats and mice.
          (Induces statistically significant numbers of hepatocellular proliferative lesions,
          including hepatocellular carcinomas.)  (January, 1976)

          Mirex samples taken from Mississippi production plant contained chlordecone at
          levels between 0.25 ppm and 2.58 ppm.   (Pesticide Toxic  Chemical News, July
          28, 1976)

          Alley  and Layton present  paper to the  American Chemical  Society concluding
          that "direct photochemical chlordecone  reactions  are not a major route for the
          conversion of mirex to chlordecone."  (paper at 3)

6/17/76   EPA notices  intent  to voluntarily  cancel all  registered products containing
          chlordecone.  Final cancellation takes effect May  1, 1978.

4/6/78    Memo  from  the National  Program Staff of  notification from J.H.  Ford
          Laboratory Director of  National Monitoring and Residue  Analysis Lab that as
          much  as 22 ppm chlordecone was found in 54-day samples of ferriamicide bait
          samples formulated at the  Prairie, Mississippi Plant.

4/14/78   Memo from Dr. Williamson, APHIS, on report of shelf-life  study of ferriamicide
          bait samples.   Fifty samples were analyzed for mirex, photodegradative studies
          and chlordecone.  They were divided into four categories.  All ten samples of
          the Series I, Day 54, bait samples had chlordecone and eight had  detectable 8-
          monohydromirex or photomirex.

          Dr.  Alley in the conversation following this discovery, told  of  his finding that
          between 3-6% chlordecone was formed from the degradation of  technical mirex
          in the bait formulation.  Added that "methanol or ethylene glycol would dissolve
          the  aliphatic  amine, which will inhibit  the production of chlordecone in the
          mirex degradation process."

4/25/78   APHIS IFA Technical Work Group Meeting, discussed finding of chlordecone as
          degradation product of ferriamicide,  which "has  resulted   in  considerable
          confusion in evaluation."
                                         143

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                                       APPENDIX E
                      FERRIAMICIDE: A TOXICOLOGICAL SUMMARY
                                       Earl L. Alley
                                        PANEL IV
    The following summarizes the discussion
 on the toxicological properties and composi-
 tion  of  ferriamicide.   It  is believed that
 aerial broadcast of ferriamicide shows pro-
 mise  for  effective  IFA  control.    Aerial
 broadcast  application increases  the  effect-
 iveness of  ferriamicide bait or other insecti-
 cidal baits and offers more complete cover-
 age than mound application; therefore, rein-
 festation rates  are reduced.  Table  1 com-
 pares the large  amount of toxicant required
 for individual mound treatments versus that
 required  for broadcast  treatments  with
 baits.  Broadcast application of ferriamicide
 requires only 227  mg of  active ingredient
 per acre, but drenches of  individual mounds
 require 400 to 30,000 mg per mound.  Table
 1  also shows that the amount  of toxicant
 needed for IFA  control  has been reduced
 from  50,000  mg per acre for dieldrin/hepta-
 chlor to the 227 mg recommended for ferri-
 amicide.
   Table  2 describes the composition and
 function  of the  compounds in ferriamicide.
 The amine and ferrous chloride  components
 reduce the half-life of mirex from  12 years
 to about 0.15 years. Additionally, propylene
glycol suppresses the production of kepone.
   During  the discussion, the structure and
numbering  system for mirex and its  mono-
 and dihydrogen derivatives were shown and
 the UV spectrum  of mirex, triethylamine,
 and the charge-transfer complex were des-
 cribed.   The relationship  between  wave-
 lengths  of  sunlight  at  the earth's surface,
 the photo-chemical  stability of mirex, and
 the photo-chemical  reactivity  of ferriami-
 cide also were explained.  The absorption by
 ferriamicide  bait  at  wavelengths greater
 than 300 nm produces a dramatic increase in
 the degradation rate of  the active ingredi-
 ent.  The dechlorination  reactions of mirex
 photo-chemistry in ferriamicide leads most-
 ly to substitution at the 10 position.  This is
 important because some  of  the  10-substi-
 tuted  derivatives  are labile  metabolically;
 because of the greater polarity  of the deriv-
 atives, one  might expect lesser  problems
 with bioaccumulation and biomagnification.
    Field degradation studies  on a 300-fold
 treatment over  normal   application  rates
 showed that  after 15 weeks, about 75% of
 the mirex in ferriamicide baits  had degrad-
 ed. After three years,  only about 20% was
left.   One  plot located  in a  shaded  area
showed slightly less degradation than a plot
in full  sunlight.
   Table 3 is an  analysis of the degradates
from the field test described above.  Normal
application  rates  produced residues  that
                                         144

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                                         145
were too small to be determined by electron
capture techniques.   The  compounds  were
confirmed  by two  column capillary  tech-
niques, yet two were misidentified (chlorde-
cone and 8,10-syn-dihydrogen isomer).  This
was shown by comparing authentic standards
of negative ion chemical ionization spectra
with these  samples.   This points out the
problem that arises when identities of com-
pounds have been established by comparing
gas chromatography retention times only.  It
is possible, therefore, that  many of the data
reported in residue  monitoring of  wildlife
and humans may be  similarly misidentified.
This is of particular concern at concentra-
tions near the detection limit  of  the  tech-
nique.
   There  has been some  controversy over
the  toxicity  of  photo-mirex  and  mirex.
Canadian  workers had reported that photo-
mirex was  10 to 100 times more toxic than
mirex.    However, a pathologist  from the
EPA Pesticide  Scientific  Advisory Panel
found  no quantitative  differentiation be-
tween  the toxicities of mirex and photo-
mirex.  It is believed that the Canadian test
materials were impure.
   The amount of mirex applied throughout
all the  control programs was 450,000 kg.  As
a fire retardant,  1,000,000 kg  of mirex has
been used.   When  using  ferriamicide, the
entire  IFA infested  area would have to be
treated ten times to use the same amount of
mirex (450,000 kg).   At maximum foresee-
able rates of use, this would take about one
hundred years (23,000,000 acres per year).
   Perhaps this 450,000 kg, a portion of  the
1,000,000 kg  used in plastics, and the conta-
mination of Lake Ontario is what produced
the residues  observed in humans and  ani-
mals.  That the human residues  reported by
Kutz may have resulted  from less than part
per billion levels of residue in  food  was
deduced  when  extrapolations from   animal
studies  were made assuming  a  five-year
exposure.    These  levels  are  hundreds of
times less  than those in  test animals  for
which  toxicological effects have been  ob-
served.
   Table 4 lists  the positive and negative
aspects of the mirex active  ingredient in
ferriamicide. It is Relieved that the  hazards
evident from toxicological results are miti-
gated  by  the low  exposure  expected  for
humans.  Ferriamicide helps solve  several of
the problems encountered with the  use of
mirex,  such  as  biomagnification,  persist-
ence, lack  of metabolism, and kepone  pro-
duction, because it promotes  degradation to
compounds  whose   chemical  and physical
properties  lessen  the  problems  associated
with these  parameters.   (For in-depth toxi-
cological information, see Table 5.)
   In conclusion,  ferriamicide  is a much
more cost effective approach to  the  fire ant
problem  than   other  currently  available
methodologies.  The effectiveness of this or
other baits is increased  by aerial broadcast
application,  because the more  complete
coverage reduces reinfestation rates.

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                                           146
Table 1.  Chemical control of IF A.
                       Table 2. Ferriamicide bait composition and function.
Chemical
mg Al/acre
dieldrin/heptachlor
kepone
mirex 4X
mirex 2X
mirex 10/5
ferriamicide
Amdro
drenches
> 50,000
2-6,000
1,700
850
454
227
4,000
400-30, 000/mound
                                            Substance
                                            corn cob grit
                                            soybean oil
                                            mirex (0.05%)
                                            Kemamine T1902D
                                            ferrous chloride
                                            citric acid
                                            propylene glycol
                                              Use
                                              carrier
                                              attractant
                                              toxicant
                                              degradation enhancer
                                              degradation enhancer
                                              antioxidant
                                              solvent-kepone inhibitor
               Table 3.  Field degradation of ferriamicide.
Compound
mirex
10H
8H
5,10 A (trans)
5,1 OB (cis)
8,10A(anti)
8,1 OB (syn)
kepone
2,8
3H, 4H, etc.
ppm
0.052
0.006
0.010
0.005
ND
0.037
0.289
0.023
0.069
0.129
Confirmation
yes
yes
yes
yes
yes
yes
no (det.
no (det.
yes
7






0.001)
0.001)


              Table 4. Pros and cons of mirex.
              Pro
                                                   Con
              efficacious
              low rates
              bait—targets toxicant
              broadcast application
              human exposure low
              wildlife—nontoxic
              low residues in human food
              not genotoxic
              adsorbs to clay
                              biomagnifies
                              bioaccumulates
                              no metabolism
                              degrades slowly
                              residues in wildlife
                              chronically toxic
                              liver damage
                              possible carcinogen
                              crosses placental barrier
                              fetal toxicity

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                             147
I
Ul
LJ
O
Q£
Ul
0.
oH
                 	ois 5,10-OIHYDROMIREX


                 	  inmt 5,10-DIHYDROMIREX
Figure 1.
       0      2      4      6      8      10     12     14

                  DAYS FOLLOWING DOSING


       Percent of radioactivity remaining in rats following a single oral dose

       of  C-radiolabeled compound (days 1-6: mean of 12 animals; days 7-14:
       mean of 6 animals).

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                                    148
Table 5. Toxicology summary of ferriamicide.

oral LDso
dermal LD^Q
eye irritation
skin irritation
skin sensitization
inhalation LC5Q
ACUTE TOXICITY1
rats 312 mg/kg
rabbits > 2000 mg/kg
rabbits data not presently available
rabbits data not presently available
guinea pigs data not presently available
rats data not presently available
                          SUBCHRONIC TOXICITY
                                                  1
28-day dietary study on Sprague-Dawley rat
dose levels (ppm):     0.0
biochemistry:
  p450
  liver SDH

histopathology:
  liver
  thyroid
           0.5
             5.0
               50
75
ne
ne
ne
ne
dec
inc
ne
ne
inc
inc
inc
ne
inc
inc
inc
ne
inc
inc
inc
inc
90-day dietary study on Charles River rat
dose levels (ppm):     0
histopathology
                 20
ne
ne
ne
                 80
                         me
                 320
                         me
1280
mortality:
male
female
hemoglobin
white blood cells
urinalysis
body weight
liver weight:
male
female
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
ne
inc
ne
ne
inc
dec
ne
ne
dec
inc
inc
inc
inc
dec
inc
ne
dec
inc
*
inc
1
 Mirex active ingredient

"no dose response
                 ne = no effect
                 inc = increase
                 dec = decrease
                 SDH = Sorbitol Dy Hydrogenase

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                                    149
Table 5, continued

90-day dietary study on beagle dog
dose levels (ppm):     0           4            20           100
mortality:
male
female
ne
ne
ne
ne
ne
ne
inc
inc
alkali n phosphatasae   ne           ne          ne           inc
blood
liver weight           ne           ne          ne           inc
spleen weight         ne           ne          ne           inc
histopathology        ne           ne          ne           ne
                             CHRONIC TOXICITY1

2-year dietary oncogenicity study on mouse (18 males, 16 females/test group)
dose levels:     10 mg/kg/day (7-28) by gavage; then 26 ppm
mortality:       all animals before 18  months
histopathology:  significant increase in hepatomas
2-year dietary oncogenicity study on Charles River CD rat (26/test group)
dose levels (ppm):           0               50              100
histopathology:             ne              inc              inc

2-year dietary oncogenicity study on rat (report due approximately six months)
dose levels (ppm)      0             0.5          -            50
3-generation reproduction study on prairie vole
dose levels:     varied from 0.1 to 25  ppm
results:         difficult to evaluate due to protocol deficiencies
                and statistical inaccuracies

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                                   150
Table 5, continued

                             TER ATOGENICITY1

Study on Wistar rat

dose levels (mg/kg/day):  0.0        1.5        3.0        6.0        12.5
toxicity (male)           ne         ne        inc        inc        inc
deciduoma              ne         ne        ne        ne         inc
death (female)           ne         ne        ne        ne         inc
weight (female)          ne         ne        ne        ne         dec

Study on CD rat

dose level:      10 mg/kg (single or during 4 days)
effect:          cataracts in neonates
note:           toxicity, not teratogenicity

Study on pregnant CD rat

dose level:      dietary 25 ppm
effect:          neonatal liver enzyme induction of p-nitroanisole
                and aminopyrine demethylase
                              MUTAGENICITY1
 Ames test (salmonella)
 mirex                                          negative
 8-monohydro (photomirex)                        negative
 10-monohydromirex                              negative
 5,10-dihydromirex                               negative
 2,8-dihydromirex                                negative

 Hepatocyte primary culture on human cell         negative

   hypoxanthine:  guanine phosphoribosyl
   transf erase assay

 Dominant lethal assay in rats

 dose levels (administered 10 days prior to mating):
   mg/kg/day          0.0          1.5          3.0          Q.Q6
    viable embryos/    ne          ne           ne          ne
     pregnancy
    deciduomas/       ne          ne           ne          ne
     pregnancy
    pregnancy/mating  ne          ne           ne          dec
 ^ one death

 4 one trial

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                                   151


Table 5, continued
                       WILDLIFE AQUATIC TOXICITY1
Static 96-hour LCsn (vertebrates)

   channel catfish     > 100 ppm
   bluegill sunfish     > 100 ppm
   rainbow trout      > 100 ppm

Dynamic Toxicity
   fathead minnow     50-60 ppm, no effect

Reproduction of fathead minnow
dose levels:
ppb
hatching success
spawn production
egg production

0
ne
ne
ne

2
inc
ne
ne

3
inc
ne
ne

7
inc
ne
ne

13
ne
dec
dec

34
ne
dec
dec
mirex accumulation factor:  28,000

elimination rate:            54% at 56 days in mirex-free water


Static 96-hour LCsn (invertebrates)

  daphnia            > 100 ppm
  crayfish            1000-5000 ppm
  hydra              4.1 ppm


                      WILDLIFE AQUATIC TOXICITY5

Static 96-hour LCsn

  vertebrates:              similar to mirex

  invertebrates (daphnia):    generally more toxic than mirex
  5,10-dihydromirex         0.1 - 3.2 ppm
 degradates

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Table 5, continued
                                   152
                           WILDLIFE TOXICITY1
Avian Acute Toxicity—Dietary LCsp (ppm)

  ring-necked pheasant        1540
  bobwhite quail              2511
  Japanese quail              > 5000
  mallard duck                > 5000

Avian Reproduction

  bobwhite quail dose levels (ppm)     0          1          20        40
  results                            no effect at any dose level

  mallard duck dose levels (ppm)      0          1          10
  results                            ne         ne         ne

  herring gull egg dose levels:         doses injected into eggs at natural levels
  results                            no effect on hatchability or chick survival

  Japanese quail                     dosed with radiolabeled 14C-Mirex
  excretion                         85% by 84 days


CONCLUSION:  Mirex poses low risk for effects on avian populations.
6moderate reduction in duckling survival


                                METABOLISM

     SINGLE ORAL DOSE EXCRETION:  14C-RADIOLABELED COMPOUND

Compound
Mirex
8-monohydro
10-monohydro
2,8-dihydro
5,10-dihydro
cis
trans
5,8,10-trihydro

Time (days)
14
28
-
14

14
14
6
% Excreted
Total
32
50
-
19

54
25
32
Urine
0.4
neg
-
0.1

15
4
6

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                                   153
Table 5, continued

                            CHRONIC TOXICFTY7

21-month dietary study of Sprague-Dawley male rat (10 animals/dose group)

dose levels (ppm)     0.0     0.2      1.0      5       25       125
mortality            ne      ne       ne      ne      ne       inc
liver weight          ne      ne       ne      inc      inc      inc
liver SDH            ne      ne       ne      ne      inc      inc
histopathology        statistical significance not reported


                          SUBCHRONIC TOXICITY7

28-day dietary study on Sprague-Dawley male rat, 8-monohydromirex

dose levels (ppm)        0.0        0.5        5.0        50         75
liver weight             ne         ne        inc        inc        inc
liver SDH               ne         inc        inc        inc        inc
histopathology
  liver                  ne         ne        ne        inc        inc
  thyroid               ne         ne        ne        ne         inc
liver p450               ne         ne        inc        inc        inc


90-day dietary study on Sprague-Dawley male rat, 8-monohydromirex

dose levels (ppm)     0.0     0.2      1.0      5       25       125
mortality            ne      ne       ne      ne      ne       inc
liver weight          ne      ne       ne      inc      inc      inc
histological          ne      inc      inc      inc      inc      inc
 8-monohydro (purity of test compound questionable)

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                                       APPENDIX F
       A BRIEF OVERVIEW OF THE REQUIREMENTS FOR PESTICIDE REGISTRATION
                                       D.J. Severn
                                        PANEL IV
    The  following  briefly   reviews  the
 requirements  for  pesticide registration as
 they relate to environmental toxicology, and
 summarizes  how   information  submitted
 under  these  requirements,  together with
 available  monitoring,  is  used  to  prepare
 assessments of exposure of humans and the
 environment to pesticides.

 REQUIREMENTS FOR REGISTRATION OF
 PESTICIDES UNDER THE FEDERAL
 RODENTICIDE ACT (FIFRA)
*Registrants must bear the burden of demon-
 strating the safety of their products.  To do
 this they submit testing data to EPA, which
 generally includes  product  chemistry, envi-
 ronmental  chemistry, toxicology, and eco-
 logical effects data.
*EPA's  registration guidelines  specify  the
 types  of data required  to  be submitted.
 These test  requirements are use-pattern de-
 pendent? for a broadcast  application of  a
 pesticide formulated as a bait, the following
 types of data are generally required:
 product chemistry: identity and composition
 of the  product, physical and  chemical pro-
 perties, analytical methods
environmental chemistry:  degradation, en-
vironmental metabolism, mobility, and over-
all dissipation studies
toxicology: acute oral,  dermal,  and inhala-
tion studies;  teratology  and reproduction
studies; long-term feeding studies
'wildlife and aquatic organisms:  acute avian
and  aquatic organism  tests;  other  tests
depend on results of these.
   Once submitted  to  EPA, the data are
reviewed for scientific quality and utility by
scientists  in the Office of Pesticide Pro-
grams  (OPP).  These  reviews  are used in
making decisions to grant registration under
various   conditions,  to   require   further
studies, or to waive additional requirements.
The registration guidelines allow maximum
flexibility  in carrying  out  the  required
studies and are meant to guide  the genera-
tion of the particular set of data needed to
make the findings  required by  FIFRA for
registration.
   For pesticides registered in the  last few
years,  these data are  generally available.
Older pesticides, however, often have  less
data  available;  reregistration  procedures
underway  in OPP will  require  the missing
                                         154

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                                          155
 data to be submitted.

 EXPOSURE AND RISK CONSIDERATIONS
    FIFRA requires EPA to determine  what
 pesticides will perform their function with-
 out unreasonable risks to man or the envi-
 ronment.  Thus, an assessment of the likely
 risks  of pesticide  use is  made  during the
 course  of approval  of  registration.   This
 assessment   utilizes   the   data  described
 above.
    Risk assessments  require not  only  an
 understanding of the toxicology  of  a pesti-
 cide but also an evaluation of the extent to
 which  man  and  the  environment  may  be
 exposed to the pesticide.   Information  on
 environmental transport and fate, generated
 according to the guidelines  described above,
 provides a substantial basis for this evalua-
 tion.   However,  the  question of direct  or
 indirect human and environmental exposure
 to a pesticide often  arises.   Assessment  of
 human  exposure requires detailed  informa-
 tion about   actual  use  practices,  normal
 human activities at treated sites, and some
 measure of the likelihood of actual  transfer
 to and  absorption of pesticide  residues  in
 humans. In the past, EPA used information
on dermal, inhalation, and dietary exposure
to arrive at estimates of the total exposure
likely to arise from the use of a pesticide.
   For  pesticides  applied for fire ant  con-
trol, very little information has been avail-
able to  estimate exposure of either  applica-
tors or the general public. While  methods  of
 monitoring direct exposure have been devel-
 oped and extensively used to measure expo-
 sure  resulting from other  types of pesticide
 use (Davis 1981), field measurement of ex-
 posure  to bait formulations has  not  been
 carried out.  The exposure of people living
 in areas treated for fire ant control is likely
 to be very low, and the routes of exposure
 to the  bait after application are not clear.
 Field studies, perhaps  using  novel methods
 of measurement,  are needed to define the
 routes and extent of exposure.
   Another approach to measuring exposure
 involves  the  monitoring  of human  urine,
 blood, or adipose tissue samples.  The pre-
 sence of  pesticide residues in human tissue
 provides   direct   evidence  of  exposure,
 although  it does  not  define the  route  of
 exposure.  EPA has for several years carried
 out monitoring surveys for  organochlorine
 pesticide residues  in human adipose  tissue
 samples.  When mirex was first detected in
 these samples (Kutz 1974) a more extensive
survey  was carried  out  in eight  southern
States in 1975  to  1976  (EPA 1980).  A total
of  624  adipose   tissue   samples   were
analyzed; 23% contained  detectable levels
of mirex.   A  distribution of the positive
samples is given in Table 1.
   Mirex,  a lipid-soluble material,  is effi-
ciently  bioconcentrated in mammalian tis-
sues.  While these results do not identify the
actual pathway of exposure, they do demon-
strate that people were  exposed to mirex
from  its use as a fire ant  control pesticide.

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                                         156
      Table 1.   Distribution of positive samples of mirex in adipose tissue.*
State
Alabama
Florida
Georgia
Louisiana
Mississippi
North Carolina
Texas
South Carolina
TOTAL
Zero
36
129
72
83
73
18
38
34
483
Positive
3
8
19
46
63
0
0
2
141
Total
39
137
91
129
136
18
38
36
624
Percent
7.7
5.8
20.9
35.7
46.3
0.0
0.0
5.6
22.6
      * Analyses were electron-capture gas chromatography;  approximately 10%  of  the
      positive samples were confirmed by mass spectrometry.
EPA  also  conducted a  nationwide survey
(Savage  1981)  of organochlorine  pesticide
residues  in human breast milk.  Mirex was
not  detected  in any of  the  1436 samples
analyzed.
   USDA has carried out extensive monitor-
ing surveys for mirex in various components
of the  environment.  A survey  of  mirex
residues in meat and milk of cows grazing in
areas treated  with mirex found no detect-
able mirex in  milk but did detect mirex in
meat.
   In summary,  FIFRA   requires  that  the
risks of  the use of  pesticides be balanced
against  the benefits of  their uses.   Suffi-
cient information on the risks and benefits
of  pesticide  use  for fire ant  control  is
needed to arrive at  reasonable  decisions
regarding this use.    Clearly,  the  use  of
mirex  has led  to mirex residues  in the
human population of  treated areas in the
southern United States.

REFERENCES
Davis  1981 (author unable to be contacted
   to complete citation).
Kutz,  F.W., A.R.  Yobs,  W.G. Johnson, and
   G.B. Wiersma.  1974.  Mirex residues  in
   human   adipose    tissues.      Environ.
   Entomol.  3:882-884.
EPA.   1980.   Unpublished data  from pesti-
   cide monitoring.
Savage 1981 (author unable to be contacted
   to complete citation).

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                                      APPENDIX G
        ENVIRONMENTAL TOXICOLOGY OF PESTICIDE APPLICATION PROGRAMS
                                       H.N. Nigg
                                       PANEL IV
    Most  environmental  safety  decisions
are of necessity based  on small tests, i.e.,
acute  toxicity  to  mammals,  birds,  and
aquatic organisms; chronic  toxicity, espe-
cially mutagenicity, carcinogenicity, tera-
togenicity;   metabolism;  persistence  of
residues; human exposure; and other tests
depending  on the chemical.  Often, how-
ever, companies fail to investigate  what
might  be  termed  the  "human side" of
chemical  use.   For  instance, what  effect
does attractive  packaging  have on child-
ren?   Does  it  entice  them  to test  the
product?   Also,  children around 11 years
old are generally more sensitive to  toxi-
cants.   Many of  the areas infested by fire
ants are  also playgrounds,  school  yards,
football  fields,  etc.   Bait  should  not be
attractive  to children and the persistence
and/or application method should assure
that the potential for exposure to children
is  zero.    Migrant  workers  pose  special
problems, partly due to  their social strata.
They  may  not speak and/or read English.
Often their understanding of  pesticides is
zero.   Who takes responsibility  for these
people for  pesticide exposures?   These
kinds of issues concerning pesticide regi-
stration need to be addressed.
   When evaluating IF A  control programs,
the specifics of each suggested chemical or
program  is  the only relevant  information.
But  people  may  use  a  program  unwisely;
unanswered  questions  and incomplete data
can lead to unforeseen problems.
   The  Environmental Protection  Agency
should focus on the  following three areas
when considering a chemical for registra-
tion:
1.  Environmental Toxicology
   a) toxicity  to aquatic organisms.   Of
      particular importance are the effects
      of  insect  growth  regulator  (IGR)
      compounds   on  Crustacea.     IGR
      compounds also may produce lesions
      in the insect hormone system as  a
      mode of  action.  Similar effects may
      occur  in non-target organisms  and
      should be considered when registering
      these compounds.
   b) toxicity  to avian species.  The same
      comments for aquatic organisms hold
      for avian species.  Apart from acute
      toxicity,    effects   on   reproduc-
                                         157

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                                          158
       tion are particularly important.
 2.  Toxicant/Acre
    One consideration  must be the amount
    of  toxicant per acre necessary to con-
    trol the fire ant.  This may mean that
    broadcast  treatment of large  areas  by
    air  may  result  in less  environmental
    contamination than  a mound  drench.
    However,  mound drench  may  be more
    practical  around  lakes  and  streams.
    This  consideration should be  coordi-
    nated  with  the  known  toxicology  of
    each compound.
3.  Attractiveness of  Baits  to Non-target
    Organisms
    This might be accomplished by (1) test-
    ing the attractiveness with mice or rats
    and chickens, and (2) observing treated
    fields during the  experimental  use per-
    mit stage of registration.
    These  questions can be answered.  Ef-
fective and 'safe' materials  can be placed
on  the market now  and can be developed
for the future.  The  key is a conscientious
recognition that human health and environ-
mental protection have  a high priority  in
developing pesticides for fire ant control.

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                                      APPENDIX H
                            MODELS FOR DECISION-MAKING
                                       John Wood
                                       PANEL IV
    Any large-scale program for controlling
 a  pest such  as  the imported fire ant (IFA)
 has variable impacts on diverse elements of
 society.  The U.S.  Department of Agricul-
 ture (USDA), Animal  Plant Health Inspec-
 tion  Service (APHIS) program  managers
 must make decisions about the impacts of
 large-scale projects in the context of avail-
 able research information,  the  reality of
 social and  political pressures, and the man-
 dates of legislation.  These decisions may be
 international, national, regional, or local in
 scope.
   Problems in  evaluating possible impacts,
 especially  for the  long term,  often  arise
 because (1) program needs  and environment-
 al objectives often conflict, (2) alternative
 strategies that may arise  from research are
 uncertain,  and  (3)  legitimate concerns by
 diverse groups may be  unknown. Because of
 these difficulties, long-range planning  that
 satisfies program needs while maintaining a
 sensitivity  to environmental  impact is an
 extraordinarily complex process.
   To assist  USDA/APHIS in making deci-
sions  on pest programs,  several  computer
simulation  models for  regional and interre-
gional    evaluations    were    developed.
Although many models have been developed
that  deal with  the  environmental impact
evaluation of pesticide  use,  these models
tend  to  be benefit-cost  models, and their
use has been  designed mainly for pesticide
regulation rather than program impact eval-
uation.   Further,  they  have  not  used a
framework within which the adequacy of an
environmental assessment model might be
examined. The  necessity of examination is
motivated by  the widespread use of models
for predicting environmental consequences
of various program  activities and  by  the
reliance  on these model predictions for  de-
ciding whether a particular program  com-
plies with regulatory perspectives.
   The  environmental   pesticide  decision
models developed  by APHIS center  on a
program's environmental situation based on
all  current knowledge  and understanding,
both scientific and intuitive.   The  models
were  designed for producing defendable  as-
sessments of the environmental effects of a
pesticide program and are part of a compre-
hensive APHIS program  consisting  of:  (1)
feeding studies, (2)  local effects of a pesti-
                                        159

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                                         160
 cide program, and (3) large area effects of a
 pesticide program.  Toxicological  data  are
 derived  from   information  developed   by
 registrants, from EPA files, appropriate  lit-
 erature  sources, and  agency  time/dose/re-
 sponse feeding  studies.   The local effects
 model and  the large area  effects  model
 consider seven  types  of impacts:    human
 exposure, off-site area  influence,  research
 area conflicts, rare biota, wildlife,  fish, and
 aquatic forms.
   The decision-making  process is  complex
 and often must  deal with the uncertainties
 of environmental  situations  in  addition  to
 the social and  economic  outcomes.   The
 USDA/APHIS computer models improve the
 ability of pest control  program  managers  to
make environmental decisions on large-scale
programs.

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                                 APPENDIX I
                      CHEMICALS CURRENTLY UNDER
                   INVESTIGATION FOR POSSIBLE IF A USE
                                  Panel IV
     The following summarizes information presented at the IF A symposium by
various  chemical  companies  on   compounds  that  are  registered,  pending
registration,  or  proposed  for registration for use on the IF A.  The  information
includes: (1) chemical name and structure; (2) chemical and physical properties; (3)
metabolic and environmental degradative fate  and  pathways, persistence, etc.; (4)
toxicity; (5)  possible mutagenicity,  carcinogenicity,  and teratogenicity; (6) use
patterns;  and (7) proposed  label directions.  Such  information is essential for
registration by EPA.
     The information presented by the chemical companies includes their own data
interpretation; inclusion of these data and interpretations do not imply acceptance
by the USDA or the  EPA.  The use of these  new chemicals depends on (1) EPA
regulation; (2) efficacy as  determined by USDA, state, and other agencies; and (3)
the marketplace.
                                   161

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                                      162


                      PESTICIDE SUMMARY DATA SHEET
                             A.  MOUND DRENCH
Chemical Name;
     diazinon: Q,Q-diethyl JL-(2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothioate
Empirical Formula;

     C12H21N2°3PS

Form;
     brownish liquid

Chemical Structure;
Molecular Weight;
     304
Odor;
     "faint garlic
                         CH,
                      N
Trade Names;
     Diazinon

Chemical and Physical Properties;                   .
     b.p.: 83-84 C/0.002 mm Hg       v.p.: 4.1 x 10   mm Hg at 20 C

     solubility;
          H20  40  ppm, miscible with  benzene,  cyclonexane,  petroleum  ether,
          alcohol, ether
Degradative Pathways;
                           CH
                                                                   CH
                                          0
                                       tHOP(OC2Hg)
                                                                   CHgOH  CHO  COOH

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                                       163
Toxicology;
      mode of action: irreversible inhibitor of acetylcholinesterase

                                     LD50
      Acute:     rat, oral              76-108 mg/kg
                rat, dermal 1000 mg/kg
                mallard duck, oral     3.5 mg/kg
                pheasant, oral        4.3 mg/kg

                                     LC50
      Acute:     blue-gill              48 n, 0.030 ppm
                rainbow trout         24 h, 0.39 ppm

Uses;
      mound drench

Formulations;
      wettable powder, emulsive concentrate, microencapsulated

Dosage;
      0.5% in water base

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                                       164


                      PESTICIDE SUMMARY DATA SHEET
                             A. MOUND DRENCH
Chemical Name;
     carbaryl: 1-naphthyl n-methyloarbamate
Empirical Formula;


Form;
     tan solid

Chemical Structure;
                           O
                                    Molecular Weight;
                                          201
                                     Odor:
                                         "nearly odorless
Trade Names;
     Sevin, Union Carbide Chemicals

Chemical and Physical Properties;
     m.p.: 142 C

     solubility;
          40 pp

Degradative Pathways;
                                     v.p.*0.005 mm Hg at 26 C
                 OCNHCH-*
                hydrolysis
                conjugation
                                      0 CNHCH.
                                    hydrolysis
                                    conjugation
                                                        0
                                                      0 &NHCH-
                                                       hydrolysis
                                                       conjugation

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                                        165

Toxicology;
     acute toxicity:
          LD-0, rat, oral: 540-800 mg/kg
          LDg|I, rat, dermal:  2000 mg/kg

Uses;
     mound drench

Dosage;
     1.0-1.5 Ib. AI/100 gal. HO, use 1 gt./6 in. mound diameter

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                                       166
                      PESTICIDE SUMMARY DATA SHEET
                             A. MOUND DRENCH
Chemical Name;
	bendiocarb: 2,2-dimethyl-l,3-benzodioxol-4-ol N.-methylcarbamate
Empirical Formula;
Form;
     crystalline solid

Chemical Structure:
Molecular Weight;
     NA
                                    Odor;
     "very slight
                 0-C-NH-CH.
                      II           3
                      O
 Trade Names;
      Ficam W, BFC Chemicals, Inc.

 Chemical and Physical Properties;
      m.p.: 128-130 C

      solubility;
           25 C

      water                0.004%
      kerosene              0.03%
      trichloroethylene      1.0%
      O-xylene             1.0%
      chloroform           20.0%
      dichloromethane      20.0%
      gylcerol formal       30.0%
      dimethyl sulfoxide     30.0%
v.p.; 5 x 10~6 mm Hg at 25 C
      Hydrolysis: 20 C

           pH: 5.0 stable
           pH: 7.0 t 1/2 10 days
           pH: 9.0 t 1.2 150 min
 Uses:
      1.   control of IFA mounds around home (1% dust or 20% WP)
      2.   perimeter spray to prevent IFA entry into buildings (Ficam 1% dust, WP,
           20% WP)
      3.   IFA mound drench for recreational areas, golf courses, residential areas (by
           PCO or turf specialist) (Ficam WP)

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Degradative Pathways;
                                       167
                                             OH
                                    OCNHCH3
Toxicolog
     mode of action: direct, rapid reversible inhibitor of acetylcholinesterase
     Acute:
          rat, oral
          rat, dermal
          rat, oral
          rat, dermal
LD50
40-156 mg/kg tech.
566-800 mg/kg tech.
141-250 mg/kg (76% WP)
1000-2000 mg/kg (76% WP)
     Subacute:
          rat NOEL (ChE depression) 10 ppm
          dog NOEL (ChE depression) 100 ppm

     Chronic:
          rat NOEL 10 ppm
          dog NOEL 20 ppm

     Mutagenicity: negative
     Teratogenesis: negative (rat, rabbit)
     Delayed neurotoxicity: negative (hen)
     Reproductive toxicity: negative (rat)

     ADI calculated at 0.05 mg/kg/day (LD-J:
          mallard duck: 3.1 mg/kg
          bobwhite quail: 19 mg/kg
          chicken: 137 mg/kg

     ADI calculated at 0.05 mg/kg/day (LC-J:
          blue gill: 96 h, 1.65 ppm
          rainbow trout: 1.55 ppm
          daphnia: 48 h, 31.7 ppm
Formulations;
     1% dust, 76% WP, 20% WP

Dosage;
     2-3 teaspoonful in 2 gal. water for large mounds

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                                      168

                      PESTICIDE SUMMARY DATA SHEET
                            A. MOUND DRENCH
Chemical Name;
     Acephate: O,Srdimethyl acetylphosphoramidothioate

Empirical Formula;                  Molecular Weight;
     C4H1(JNO3PS                       183

Form;
     solid

Chemical Structure;

         HaC-S\  O         O
           3     ^  II         II
         H C-*
                       P-NH—C —CH3
Trade Names;
     Orthene, Chevron Chemical Co.

Chemical and Physical Properties;
     m.p.: 82-89 C                  v.p.: 1.7 x 10"6 mm Hg at 24 C

     solubility;
          water: 65%
          acetone: >10%
          alcohol: >10%
          aromatics: <5%

Degradative Pathways;

                 Sv. II    H
                   XPNHCCH3

Toxicolc
     mode of action; irreversible inhibitor of acetylcholinesterase

     Acute:
          rat, oral                  866 mg/kg, 945
          mouse, oral               351 mg/kg
          rabbit, dermal             >2000 mg/kg
          maUard duck              350 mg/kg
          pheasant                  140 mg/kg
          chicken                  852 mg/kg

     Acute:                         LC,.0
          blue g111                  96 hr., 2050 ppm
          rainbow trout              95 hr., 1000 ppm
          channel catfish  96 hr., 2030 ppm
          Gambusia                 95 hr., 6650 ppm

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                                        169


Uses;
     mound drench

Formulations;
     75% soluble powder
     1.3 Ib./gal. soluble concentrate
     9.4% soluble powder

Dosage;
     2 tablespoonful (1 fl. oz.) in 1 gal. water as mound drench

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                                       170


                      PESTICIDE SUMMARY DATA SHEET
                             A. MOUND DRENCH
Chemical Name;
     Chlorpyrifos: O,O-diethyl O(3,5,6-trichloro-2-pyridyl) phosphorothioate

Empirical Formula;                   Molecular Weight;

     C9H11C1 3N03PS                    35°'6
Form;
     white to tan crystals                 mild, mercaptan

Chemical Structure;
                                  0-C2H5
Trade Names;
     Dursban, Dow Chemical

Chemical and Physical Properties;                   ,
     m.p.: 41.5-43.5 C               v.p.: 1.87 x 10  mm Hg at 20 C

     solubility;            octanol/water partition;
           1.2 ppm                       bioconcentration factor 700 (fish)

Degradative Pathways;
     (not available)

Toxicology;
     Acute:               LD50
           rat, oral        118-245 mg/kg (M)
           rat, oral        82-135 mg/kg (F)
           mouse, oral     102 mg/kg

     Chronic:
           rat (2-yr feeding): 0.1 mg/kg/day NOEL

     ADI:
           0.01 mg/kg/day

     reproduction:
           rat: NOEL 1.0 mg/kg/day (3rd generation)

     teratology:
           rat: NOEL 1.0 mg/kg/day

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                                         171
Toxicology: (cont.)

     neurotoxicity: no effect in chickens

Uses;
     1.   individual mound treatment for IFA control
     2.   ant control in potted and balled nursery stock

Formulations;
     Dursban 4E

Dosage;
     1 fl. oz./4 gal. water
     one gallon applied to mound

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                                      172


                     PESTICIDE SUMMARY DATA SHEET
                             B.  BAIT TOXICANT
Chemical Name;
     Avermectin B.

Empirical Formula;

     C47H43°14

Chemical Structure;
Molecular Weight;
     831
                                     H3C'
                                                                 CH,
 Trade Names:
      Merck, Sharp & Dohme

 Chemical and Physical Properties;
      (not available)

 Degradative Pathways;
      (not available)

 Toxicology;
      mode of action: gamma-aminobutyric acid antagonist (no effect on cholinergic
      nervous systems)

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                                         173

Uses;
     IFA control (not yet registered)

Dosage:
     no label, but 0.0077 g/ha prevented reproductive success in IFA colonies

-------
                                      174


                      PESTICIDE SUMMARY DATA SHEET
                             B. BAIT TOXICANT
Chemical Name:
     Ferriamicide (mirex)

Empirical Formula;

     C10CL12

Form;
     white solid

Che mical Structure;
Molecular Weight;
     542
Odor;
    "odorless
               Cl
                                        Cl
 Trade Names;
      Ferriamicide

 Chemical and Physical Properties;
      m.p.: 485 C

      solubility;
           1 ppg; water
           1-30%: organic solvents

 Degradative Pathways;
      degradable bait: dechlorination photochemically and thermally
                        H
         Cl
          12
                                                  H
    •CL
C'
                      lO
                                                                       H
                                                  H

-------
                                      175

Toxicology;
     Acute:               LD50
          rat, oral        312 mg/kg
          rabbit, dermal  >2000 mg/kg

     90-day Subchronic (rat):
          mortality (M): NOEL 320 ppm
          mortality (F): NOEL 80 ppm
          weight: NOEL 80 ppm
          liver wt (M): NOEL 20 ppm
          liver wt (F): NOEL 80 ppm
          histopathology: NOEL  100 ppm

     90-day Subchronic (dog):
          mortality (M): NOEL 20 ppm
          mortality (F): NOEL 20 ppm
          liver wt: NOEL 20 ppm
          histopathology: NOEL  100 ppm

     teratogenicity:
          NOEL 1.5 mg/kg/day

     dominant lethal:
          negative

     acute toxicity:
                          LC50
          bobwhite quail   2511  ppm
          mallard duck   >5000 ppm


                          LD50
          bluegill        >100 ppm
          trout          >100 ppm


Uses;
     broadcast or mound application

Formulations;
     0.05%  mirex; on corn cob grit with amine  and ferrous chloride  degradation
     enhancers plus anti-oxidant (citric acid)

Dosage;
     1 Ib. bait/acre; 0.227 mg Al/acre

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                                      176


                      PESTICIDE SUMMARY DATA SHEET
                             B.  BAIT TOXICANT
Chemical Name;
     N-[l-amino-3-nitro-5-(trifluoromethylphenylJ-2,2,3,3-tetrafluoropropanamide
Empirical Formula;

     C10H6FN3°3

Form;
     yellow solid

Chemical Structure:
         Molecular Weight;
              349
         Odor;
              "Lachrymal
          02N
     O

NH-C-CF2-CF2H
                  CF,
Trade Names;
     Bant, EL468, Nifluridide, Eli Lilly, Inc.

Chemical and Physical Properties;
     m.p.: 145 C

     solubility;
          <10 ppm; water
          soluble organic solvents
          hydrolysis pH:
               5-T1/0 = 15.5 hr
                    LI &
               1 - T1/2 = 3.5 hr

               9 - Tj/2 = 2.0 hr

          photolysis (EL919
               52 days: deionized water
               29 days: natural water

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                                       177
 Degradative Pathways;
        N02
              NHC CF
 Toxicology;
      mouse oral (LD5Q)
      mouse S.C. (LD50)
      rat oral (LDgQ)
     dog oral (LD5Q)
     rabbit dermaiUiD.J
     Acute toxicity: fish & wildlife:
     adult bobwhite (LD5Q)
     Suv bobwhite, 5-day dietary (LC-J
     Suv bobwhite, 5-day dietary (NOEL)
     Suv mallard, 5-day dietary (LC_0)
     Daphnia magna, 49 hr static (EC5Q)
     Daphnia magna, 49 hr static (NOEL)
     blue gill, 96 hr static (LCgo)
     blue gill, 96 hr static (NOEL)
     rainbow trout, 96 hr static (LC5Q)
     rainbow trout, 96 hr static (NOEL)
     earthwork, 14 day (LC5fl)

Uses;
     broadcast bait for IFA control
Formulations;
     0.4-0.75% AI
     27.6-27.12% vegetable oil
     carrier:  72%


EL468
172
-
57
54
48
30
24
27
24
500
fe.
1C»



(NOEL)
LC50>
(EC50>
(NOEL)

)
LC50>
NOEL)

c^

EL919
22
-
17
12
9
7
9
9 (est)
20
200


EL468
25.22
237 ppm
90 ppm
50 ppm
516 ppb
300
291 ppb
62
708 ppb
300
-
H
EL9I9
92452 (N02NH2)
253
237
198 (IP)
-
292
194
176 (IP)
-
400
-


EL919
4.14
50 ppm
-
16.7 ppm
678 ppb
250
269 ppb
56
528 ppb
330
3.68 ppb
                                                                      — CF2CF2H
Dosage;
   "278 g AI

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                                      178
                      PESTICIDE SUMMARY DATA SHEET
                             B. BAIT TOXICANT
Chemical Name;
     Tetrahydro-5,5-dimethyl-2-(lH)-pyrimidone [ 3-] [ 4-trifluoromethyl)-phenyl]
     -1- [ 2- [ 4-(trifluoromethylphenyl)ethenyl ] -2-propenylidenehydrazone]
Empirical Formula;

     C25H24F6N4

Chemical Structure:
                                    Molecular Weight;
                                         494
                          CH=CH-C-CH=CH
                               H3C    CH3
Trade Names;
     AC 217,300, Amdro

Chemical and Physical Properties;
     solubility;
                                    octanol/water partition;
                                         206
Toxicology;
     mode of action: stomach poison

     acute:
          rat (oral) LD-,,: 1213 mg/kg
          rabbit (dermaT) LD  : 5000 mg/kg

     subacute:
          dog (3-month) (testicular atrophy): 3 mg/kg NOEL
          rat (3-month) (testicular atrophy): 50 ppm

     reproduction (multigeneration): 50 ppm NOEL (rat)

     teratogenicity: negative (rat, rabbit)

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Degradative Pathways;
                                      179
             COOH
                                N
                                I
                                N
                                         AC 217,300
HN     NH



CH3   CH3
                                    (SOIL METABOLISM)
                                 "          //   \
                               -~=-
CH - C-CH=CH-V	/~CF3
                                       CH=CH

                                          COOH
Uses;
     conditional registration for IFA control at 4-6 g/acre AI

Formulations;
     0.88% bait formulation
Dosage;
     4-6 g/acre

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                                      180'

                      PESTICIDE SUMMARY DATA SHEET
                      C.  INSECT GROWTH  REGULATORS
Chemical Name;
     Methoprene: isoprop l-(2E,4E)-ll-methoxy-3,7,ll-trimethyl-2,4-dodecadienoate
Empirical Formula;

     C19H34°3

Form;
     amber liquid
     Sp. gr 09261 at 20 C


Chemical Structure;
Molecular Weight;
     3TO
Trade Names;
     Altosid, Zoecon Corp., Palo Alto, CA

Chemical and Physical Properties;

     v.p.: 2.37 x 10"5 mm Hg at 25 C

     solubility;
          water: 1.39 ppm
          soluble in organic solvents

Degradative Pathways;
       HO

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                                        181
Toxicology;

     acute:
           rat (oral) LD^: >34,600 mg/kg
           dog (oral) LIFel: 5000-10,000 mg/kg

     chronic:
           neither mortality nor deleterious effects at 5000 ppm in rat and 2,500 ppm
           in mouse

Uses;
     broadcast bait for IF A

Formulations;
     1% bait

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                                      182
                     PESTICIDE SUMMARY DATA SHEET
                     C. INSECT GROWTH REGULATORS
Chemical Name:
     l-(4-isopropylphenyl)-4,8-dimethyl-8-methoxynonane
Empirical Formula;
     (

Form:
C20H36°
     liquid

Chemical Structure:
     H3C-0
Molecular Weight;
     NA
                              Odor:
                                  "odorless
Trade Names;
     MV-678, Stauffer Chemical Co.

Chemical and Physical Properties;
     b.p.: 192.6 C/10 mm Hg

     solubility;

      water: 1 ppm 20 C
                              v.p.: 9.3 x 10 x 10~° mm Hg at 26 C

                              octanol/water partition;

                                  7.6 x 10"4
      hydrolysis:
           pH 4.2: 0% 20 days, 6% 31 days
           pH 7.0: 0% 20 days, 4% 31 days
           pH 9.2: 0% 20 days, 5% 31 days

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                                          183
   Degradative Pathways;
HO
  Uses;
       broadcast bait for IFA

  Formulations;
       1.2% bait

  Dosage;
       ^178 g Al/acre, spring and fall

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                                      184
                     PESTICIDE SUMMARY DATA SHEET
                     C.  INSECT GROWTH REGULATORS
Chemical Name;
     1- [ (5-chloropent-4-ynyl)-oxy ] -4-phenoxyben zene
Empirical Formula;

     C17H15°2CL

Chemical Structure:
Molecular Weight;
     286.6
Trade Names;
     JH-286, Montedison, USA, New York City

Chemical and Physical Properties;
     m.p.: 28-30 C

     solubility;
          soluble in most organic solvents

Degradative Pathways:
     (not available)

Toxicology;

     acute rat (oral) LD5Q: >3000 mg/kg

     rainbow trout (LC-J 96h:>10 ppm

     goldfish (LC5Q) 96h: >20 ppm

     guppy (LC5Q) 96 h: >10 ppm

     mutagenicity: negative

Uses;
     broadcast bait for IF A

Formulations;
     1% and 2% baits

Dosage;
     11-20 g/ha AI

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                                      185


                      PESTICIDE SUMMARY DATA SHEET
                      C. INSECT GROWTH REGULATORS
Chemical Name:
     ethyl [ 2-(pfhenoxyphenoxy)-ethyl] carbamate
Empirical Formula;
Form;
     solid

Chemical Structure:
Molecular Weight;
     NA

Odor;
odorless
Trade Names:
     RO 13-5223, MAAG Agrochemicals
Chemical and Physical Properties;
     m.p.: 50-53 C

     solubility;

          water: 6 ppm
          acetone: > 24%
          diethyl ether: > 26%
          dimethylformamide: > 21%
          ethyl acetate: > 22%
          hexane: 0.8%
          isopropanol: > 25%
          methanol:> 24%
          N-methylpryrolidone: > 20%
          toluene: > 23%
          hydrolysis: none at  pH 4,7,10

Degradative  Pathways;

     by hydrolysis of OC0HK
                       fi  3
     hydroxylation of phenyl rings
           -7
v.p.: 1.3 x 10   Torr 25 C

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                                       186
Toxicology;
     acute rat (oral) LD.Q: >16,800 mg/kg
     rat dermal (LD,-0):>2000 mg/kg
     mouse oral (LD): >8000 mg/kg
     bluegill (LC-J 96 hr: 2.9 ppm
     rainbow trout (LCgJ 96 hr: 1.6 ppm
     carp (LC): 10.2 ppm
             5Q

Uses;
     broadcast bait for IFA

Formulations;
     1% to 2% bait

Dosage;
     6-12 g Al/ha

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                                       APPENDIX J
                 COMMENTS ON FERRIAMICIDE AND THE IF A PROBLEM
                    Mississippi Department of Agriculture and Commerce
    The Mississippi Department  of  Agricul-
ture and  Commerce  is fully aware of, and
strongly  supports, continued  research for
better,  more  precisely   targeted  control
methods  for  the IFA.    The  Mississippi
Department  of Agriculture  and Commerce
has spent in excess of two million dollars for
research  over  the last five years.   Mean-
while,  in  the absence of cost effective con-
trol,   the IFA  population  increase   has
become critical in Mississippi  and other in-
fested states.
   Today in Mississippi there is an urgent
need   for  a  safe,  economical,  effective
method to control this pest.  There are on
file   at  the   Environmental  Protection
Agency,  in  excess of  10,000  letters  from
individuals,  state  officials,  business firms,
and others explaining the damage caused by
the IFA  and the  need  for  an effective,
economical  control.    Calls  are  received
daily demanding and pleading for assistance
in controlling this noxious, destructive  pest.
Mounds in hay fields have caused farmers to
purchase bigger and more expensive equip-
ment to cope with this problem during har-
vest.   It has  also forced the  soybean grower
to leave a portion of his crop in the  field to
avoid expensive equipment repair and down
time.    A  survey  of  thirty-five  soybean
growers in  Choctaw  County,  Mississippi,
indicates that a loss of one to three bushels
per acre is caused  by  IFA mounds. Today
there  is nothing  to control  this  pest  on
agricultural land.
   There are major health related problems
caused  by  the IFA.  Desensitization of a
child   or  adult   after  a  life-threatening
reaction to  the  IFA is  possible,  but  not
practical for those  other than  high risk,
highly sensitized individuals.   Also it does
not relieve the parent's  concern for their
child  when ants are present.   The presence
of the ant  in large numbers in areas of high
human  population is leading  to increasing
numbers of sensitized individuals;  the very
young and  the  elderly are particularly vul-
nerable. The  multiple stings delivered  by
the ants are a serious health problem  for
these individuals even if they are not sensi-
tized.  What will this problem  problem be 10
to 50  years from  now?  Research indicates
that individuals could become highly sensi-
tive  to  the  venom  after being  bitten  or
stung.
   The  Mississippi Department of Agricul-
                                          187

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                                         188
ture and Commerce has applied to the Envi-
ronmental Protection Agency for condition-
al use of Ferriamicide.   Ferriamicide is  a
safe,  effective, economical bait for control
of the IF A.  This bait can be formulated and
sold to  the  user  for 29 cents  per pound  in
fifty bags FOB plant.
   The  rate of degradation of Ferriamicide
provides adequate time for it  to  be effec-
tive,  but the  toxicant disappears from the
environment 100  times faster than it did  in
the old formulation.
   The  significant and  cogent facts  con-
cerning  Ferriamicide are as follows:  Ferri-
amicide  that  utilizes the  proven  IF A toxi-
cant mirex.   Under conditions of intended
use, Ferriamicide is safe, economical, and
efficacious. It utilizes 227 mg per  acre of
toxicant.  In  addition  to  the toxicant, car-
rier, and attractant, Ferriamicide contains  a
small amount  of amine (approx. 1.7%) and
metal salt,  which enhances the degradation
of the toxicant.  The  half-life of the toxi-
cant  in bait, in  laboratories,  and   field
studies  is about  30 days.  To date, studies
indicate the  Ferriamicide  is  (1)  effective
against  the  IF A, (2) causes the toxicant to
degrade  rapidly,  (3) has less acute toxicity
to  nontarget  organisms  after   toxicant
degradation has occurred, (4)  the degrada-
tion products of the toxicants are  more
polar; consequently, less  likely to  move  in
the   environment   and   less   likely  to
biomagnify, and  (5) there is evidence that
some  of  the  degradation  products  are
further metabolized in mammaliam systems.
   About  1,000,000  pounds of  technical
mirex  was  used in IF A control programs
during the late sixties and early  seventies.
Application rates  were  typically  1700  mg
per acre.  These programs  were carefully
monitored for harmful efects on wildlife and
people.  None were observed.   In contrast,
the negative impact of the ants, particularly
regarding health and death of human beings,
is  well documented.  With Ferriamicide, we
propose a much more limited application of
baits containing only 227 mg of  toxicant per
acre.   The maximum  rates of utilization of
Ferriamicide,  based on  the history of  the
control programs, would be about 15,000,000
pounds per year.  At this  rate,  which is
probably   too high  by  at  least  a  factor of
two, it would take over 130 years to equal
previous   use,  with   a   formulation  that
degrades  100 times faster, and  with a com-
pound that even at the heavier  use patterns
did not cause  problems in the real world.
Most of the hazards associated with  mirex
are perceived in the artificial  environment
of laboratory studies.   Residues in wildlife
and  humans have  been  observed,  but  no
correlation between these residues and  any
adverse  effect  has been made.    Further
level of residues  in humans points to a very
low exposure from  the 1 to 3 million pounds

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                                          189
of technical mirex employed in agricultural
and industrial applications.
   Reports have  circulated for years that
due  to food  chain  magnification  the real
fear of using mirex or its  by-products will
be apparent in  10 to  20  years.  Mirex  has
been  used since 1962 on every size block,
and was treated from one  to three times.
USDA kept complete records as to the date
treated, the amount of mirex applied  per
acre, method of application, etc. Research
studies on  the  habitat of  the  millions  of
acres  treated since the beginning of  the
control   programs  should   remove   any
ecological and environmental fears of using
mirex or its by-products once and for all.
   Because the IF A is  a  real  health and
economic problem to humans, animals, and
the economy, we  request that the  Environ-
mental Protection Agency  review  applica-
tions  for  control of this pest  as quickly  as
possible and give  consideration  to the low
risk involved because of the small quantity
employed and low potential exposure. These
risks  should  then  be carefully balanced
against the considerable benefits that  could
be achieved.

COMMENTS ON SYMPOSIUM
   We  would like to  make  a few  points
regarding to subjects that were discussed at
some length during the symposium.
1. Much  effort  was  expended discussing
    eradication strategies,  heptachlor  pro-
    grams, and other mistakes of the past.
    It is good to  review past errors, but we
    would  hope that  it is clearly recognized
    that  these approaches were  adjudged
    faults  and discarded many years ago by
    those managing the IFA
2.  We heard many times that the programs
    of the  past failed to contain or eradicate
    the  ant.   The programs in later  years
    were not designed  to accomplish  these
    goals.   Localized control for localized
    relief  was the goal, and  this  end was
    effectively achieved.  Most insect con-
    trol programs  are  temporary.    Why
    should any intelligent person assume that
    the IFA programs should be other than
    temporary  unless   they  are  proposing
    eradications?
3.  There is no doubt that when IFA reinfest
    an area where their population has been
    depleted that  initially a large number of
   small colonies will result. It is also clear
   that after a  few years the population
   stabilizes very  close to  pretreatment
   levels.   In the meantime, close to a year
   of  relief  has been achieved,  and the
   resurging  mounds are smaller which in
   many cases present  less problems.  We
   strongly  agree  that  designing   more
   specifically  targeted baits  would  be  a
   major contribution to effective IFA con-
   trol.

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                                                          9/9/82 Revision

                                APPENDIX K
                          FIRE ANT FACT SHEET*
                                  PANEL VI

     The following is a summary of the products (pesticides) currently registered
for IF A control, including approved Experimental Use Permits (EUP's) and pending
products presently  under review.   This fact sheet identifies formulation  types.
                                                                 •»
dosage  rates, sites  of  application,  application methods,  and related  points of
interest for each of the pesticides listed.
•Source: Environmental Protection Agency
                                    190

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                                    191
1.   Chemical: Arodro                          PM-15

     Company: American Cyanamid
     EPA Reg. No's.: 241-260 and 241-261 (0.88% formulation)
     Date Registered: 8/20/80 & 8/17/81, respectively

     Description of Application

     Site: Pasture and range grass, lawns, turf, and non-agricultural lands
     Tolerance: 0.05 ppm (pasture, rangeland grass, and grass hay)
     Dosage Rate: 6.0 grams a.i. per acre (5 level tablespoons per individual
      mound)
     Method: Bait broadcast (ground or air application) and mound to mound
      treatment
      Retreatment 4 to 5 months after first treatment if necessary
     Is use for quarantine program? No
     Restriction: No restriction on user group.

     Points of Interest

     Added control of harvester ants and big-headed ants to existing label.
      Increased storage stability of the product up to three months after opening.


2.   Chemical: Baygon                          PM-12

     Company: Boyle Midway Inc.
     Reg. No.: 475-173 (296 formulation)
     Date Registered: 6/10/77
     Formulation: 2% Containerized Bait

     Description of Application

     Site: Around the home (lawns, yards, etc.)
     Method of Application: Place ant trap near or on  mounds
     Is use for quarantine program? No


3.   Chemical: Bendiocarb (Ficara W)             PM-12

     Company: BFC Chemicals Inc.
     Reg. No.: 45639-1 (76% WP formulation)
     Date of Application: 3-25-81
     Date Registered: 8-11-81
     Site: Mound drench
     Dosage Rate: 0.4 oz./8 gallons water
     Method: Sprinkler can
     Is use for quarantine program? No
     Restriction: For use by pest control operators only

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                                   192
     Company: BFC Chemicals, Inc.
     Reg. No.: 45639-3 (1% Dust)
     Site: Mound (tench
     Method: Sprinkler can (slurry treatment)
     Is use for quarantine program? No
     Restriction: No restriction on user group


4.   Chemical: Carbaryl                        PM-12

     Company: Union Carbide Corp.
     Special Local Need (SLN) No.: SO780024, SC-780025, SC-780026
     Date Issued by States 8/14/78

     Description of Application

     Site: Lawns, pasture, forage grass
     Tolerance: 100 ppm in or on pasture and forage grass
     Dosage Rates 1.0-1.5 pounds active ingredient (Ibs. a.i.) per ido gallons of
       water.  1 quart of dilution per 6 inches of mound diameter
     Method: Mound drench. Repeat if mound activity resumes
     Is use for quarantine program? No

     Points of Interest

     Not renewed by State after 12-31-78


     Company: Amchem Products Inc.
     SLN No.: SC-790030 (50% WP Formulation)
     Date Issued by State: 8/13/79

     Description of Application

     Site:  Lawns
     Dosage Rate: Same as above


5.   Chemical: CHorpyrifos                     PM-12

     Company: Chevron Co.
     Reg. No.: 239-2423 (Amendment) (5.3% EC formulation)
     Date of Application: 3/29/79
     Date Registered: 6/24/80

     Description of Application

     Site: Ant mounds
     Dosage Rate: 2.5 ounces product per gallon of water
     Method: Sprinkler can treatment
     to use for quarantine program? No

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                              193
Company: Dow Chemical Co.
Reg. No.: 464-343,464-360 (22.4% and 40.8% EC formulation, respectively)
Date of Application: 11/5/79
Date Registered: 11/17/80

Description of Application

Site: Potting plants
Dosage Rate: 8 ounces product per 100 gallons of water
Method: Dip and drench treatments
Is use for quarantine program? Yes

Points of Interest

USD A has certified effective control with this product


Company: Dow Chemical Co.
Reg. No.: 464-553 (5% granular formulation)
Date Registered: 12/12/79

Description of Application

Site: Potting media, nursery bench
Dosage Rate: 1.0 Ib. product per cubic yard of potting soil
Methods Mix into potting media granular 5%
Is use for quarantine program? Yes

Points of Interest

USDA has certified effective control with this product


Company: Best Products, Inc.
Reg. No.: 20954-46 (6.7% EC formulation)
Date Registered: 8/25/78

Description of Application

Site: Fire ant mounds
Dosage Rate: 2 ounces product per gallon of water
Methods Sprinkler can treatment
Is use for quarantine program? No


Company: Dow Chemical Co.
Reg. No's.: 464-343, 464-360 (22.4% and 40.8% EC formulation, respectively)
Date of Application: 1/17/80
Date Registered: 1/22/81
Sites Mound drench
Dosage Rates 1 fL oz./2 gallons water
Methods Sprinkler can treatment
Is use for quarantine program? No

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                                  194
     Company; Cessco, Inc.
     EPA Reg. No.: 6959-67 (1% spray formulation)
     Date of Application: 11/12/81
     Site: Mounds-homeowner
     Method: Pressurized-mound injection tube
     IB use for quarantine program? No
     Dosage Rate: 1%-dependent upon mound size as to time tube is left in mound
     Date Registered: 3/26/82


6.   Chemical: Diazinon                         PM-15

     Company: Ciba-Geigy Corp. and others
     Reg. No.:  100-456 (25% EC formulation)
     Date of Application: 10/31/77
     Date Registered: 12/18/79

     Description of Application

     Site: Lawns and recreation areas
     Dosage Rate: 0.016 IDS. a.i. per gallon of water; 1 or more gallon per mound
     Method: Mound drench
     Restriction:  Do not apply to feed/food producing areas
     Is use for quarantine program? No

     Points of Interest

     Claim is only for "aids in control of fire ants."  Product directed towards
      homeowner market.


     Company: Thompson-Hayward Chemical Co. and others
     Reg. No.:  148-1130 (48% EC)
     Date Registered: 8/11/81

     Description of Application

     Same .as above


     Company: Hi-Yield Chemical Company and others
     Reg. no.: 34911-23 Granules (5% and 14%)
     Date Registered: 7/2/81

     Description of Application

   '  Site: Lawns and recreation areas
     Method: Mound application
     Dosage Rate: 0.0125 IDS. a.i./mound
     Is use for quarantine program? No

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                                   195
     Company: Penwalt Corporation
     SLN No.: TX-920015 (23% Flowable Micro-encapsulated)
     Date Issued by State: 4/2/82

     Description of Application

     Site: Lawns and other recreational areas
     Dosage Rate: 1 fluid ounce/gallon of water
     Method: Mound drench (sprinkler can)
     Is use for quarantine program? No


7.   Chemical: EL-468 (Bant)                     PM-15

     Company: Eli Lilly & Company
     BUP No.: 1471-EUP-73 (0.75% formulation)
     Date Renewed: 4/30/82-4/30/83

     Description of Application

     Site: Non-cropland (restricted rangeland and pastureland*)
     Tolerance: NA
     Dosage Rate: 3.5-6.0 gm ai/A
     Methods Bait broadcast or split application (ground or air application)
       Retreatment 4 to 5 months after first treatment if necessary
     IB use for quarantine program? No
     Restriction: Maximum 70 IDS. a.i. over 4600 acres in Texas, Georgia, Florida,
       Alabama, Mississippi, Louisiana, and Arkansas

     *Do not allow beef cattle to graze treated fields until disappearance of the
       bait is assured.
     *Do not slaughter cattle for human consumption which have grazed treated
       fields without direct consultation with Elanco personnel.
     •Do not allow dairy cows to graze treated fields.


8.   Chemical: H8-methoxy-4,8-
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                                   196
     Points of Interest

     Existing stocks could be used until 9/30/82 under cooperation of USDA, State,
      and local government officials.

     Company: Same as above
     EUP No.: 42634-EUP-2
     USDA requested an extension and additional use of MV-678 to be used in
      Brazoria (County) Texas.
     Date Extended:  4/1/82 to 9/30/83
9.   Chemical: Methyl Bromide                  PM-16

     Company: Velsicol Chemical Co.
     Keg. No.: 876-257 (99.9% pressurized gas)
     Date Issued: 9/17/69

     Description of Application

     Site: Around home, non-cropland
     Dosage Rate: 1 ounce of product per 10 square feet mound area
     Method: Soil fumigation
     Is use for quarantine program? No

     Points of Interest

     According to Company this product has not been marketed for EPA control in
       the last four years.


10.  Chemical: Orthene                         PM-16

     Company: Chevron Chemical Co.
     EPA Reg. No.: 239-2436 (15.6% EC formulation)
     Date Issued: 1/21/81

     Description of Application

     Site: Around the home
     Dosage Rate: 1/2 fl. oz./l gal. H20
     Method: Apply on mound and treat a four (4) foot diameter circle around the
       mound with sprinkling can
       Treat new mounds as they appear
     It use for quarantine program? No


11.  Chemical: Pyrethrin I & 0                   PM-17

     Company: Cessco, Inc.
     Reg. No.: 6959-58
     Date of Application: 10/18/79
     Date Registered: 7/2/80

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                                   197
     Description of Application

     Site: Pastures, golf courses, woodlots, building lots, feed lots, buildings,
      parks, and playgrounds
     Dosage Rate: Spray as necessary
     Method: (Pressurized spray) spray directly on ants
     IB use for quarantine program? No
     Restrictions: Not for house-hold use
12.   Chemical: 1,1,1-Trichlore thane             PM-16

     Company: Trichem Industries
     8LN No.: TX-780053, MS-800055, LA-800026, LA-800022
     Date Issued: 12/11/78

     Description of Application

     Site: Fire ant mounds
     Dosage Rate: 2-4 ounce product per mound
     Method: Apply to top center of mound
     Is use for quarantine program? No


13.   Chemical: MK-936 (Avennectin Bj)         PM-15

     Company: Merck, Sharp & Dohme
     EUP Hoc 618-EUP-10 (0.011% and 0.0055% formulations)
     Date of Application: 11/25/81
     Date Issued: 5/3/82-5/3/83

     Description of Application

     Site: Non-cropland
     Dosage Rate: 25 mg-50 mg a.i. per acre
     Method: Broadcast (ground and air)
     Is use for quarantine program? No
     Restriction: Maximum 63 grams a.i. over 1680 acres in Alabama, Florida, and
      Georgia
      Do not graze treated fields.


14.   Chemical: Imidan N-dnercaptomethyl)       PM-15
      phthalimide S-{0,0-diniethyl phoshordithioate)

     Company: Zoecon Corp.
     EPA Reg. No.: 20954-14-(50%  WP in pre measured water soluble packets)
     Date Registered: 7/8/82

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                                   198
     Description of Application

     Sites Residential, institutional, commercial, and recreational areas
     Method of Application: Individual mound treatment (drench)
             1 packet (3.8 gms a.i./gal. water/mound)
     Is use for quarantine program? No
     Restrictions: For sale and use only in the state of Texas
15.   Chemical: Rotenone

     Company: Pennick Corp.
     EPA Reg. No.: 432-677
     Date Registered: 7/20/82

     Description of Application

     Site: Gardens, lawns, fields, agricultural land, golf courses, recreational
      areas, camp grounds and other similar areas.
     Method: Drenching the ant mound
     Is use for quarantine program? No


16.   Chemical: Heptachlor

     Company: Do-It-Yourself-Pest-Controllnc.
     EPA Reg. No.: 13283*4 (5% granular formulation)
     Date Registered: 10/21/74

     Description of Application

     Site: Buried telephone cable closures
     Method: Place 4 ounces (premeasured packet) into buried telephone cable
      closure
     Is use for quarantine program? No
     Restriction: Packaged for the telephone industry

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                                   199
         "Pending1' Registration Actions and EUP's for Fire Ant Control


•1.  Chemical: Amdro                          PM-15

     Company: American Cyanamid
     EPA Reg. No.: 241-260 (Amendment) (PP-2F2627)
     Date of Application: 1/7/82 & 12/1/81

     Description of Application

     Site: Cropland (including pineapple and sugarcane) for control of IF A,
      harvester ants, and big-headed ants
     Tolerance: 0.05 ppm for all rac's
     Dosage Rate: 6.0 gms/ai/acre for imported fire ants and harvester ants;
      10.0 gms/ai/acre for big-headed ants
     Method: Bait broadcast (ground and/or air) and mound-to-mound treatment
     Limitations: All Food Crops:  Do not treat within seven days of harvest.
      Pineapple;  Do not apply more than two broadcast applications per crop
         during any twelve month period.
      Sugarcane; Do not apply more than three broadcast applications per crop.
     b use for quarantine program? No
     Status: Company has submitted outstanding long-term chronic studies.
      Approval of cropland usage  depends upon our review and acceptance of
      these long-term data. Review completion expected by end of June.

2.    Chemical: MV-678 (same as 18 under         PM-17
      registered chemical)

     Company: Stauffer Chemical Co.
     EUP File Symbol: 476-EUP-RNR
     Date of Application: 1/27/82

     Description of Application

     Site: Crop or non-cropland
     Dosage Rate: 4.8 gm/ai/acre
     Method: Aerial application
     Tolerance: None proposed
     Status: EUP rejected 4/1/82  due to the need for temporary tolerances or
      exemption from tolerances  on rangeland and other crops.  Awaiting
      company response.

     Stauffer Chemical also submitted an application for conditional registration
      of MV-678
     EPA File Symbol: 476-EER
     Date of Application: 1/8/82

     Description of Application

     Same as for EUP above.
     Tolerance: An exemption from tolerance was proposed

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                                    200
     Status: Objection letter issued 4/6/82.   "BiorationaT status of chemical in
     question.  Additional data would be needed if chemical  is not a biorational.
     Company responded to our letter 6/1/82.   Our answer to  the biorational
     classification is under consideration.
3.   Chemical; Disodium Octaborate Tetrahydrate PM-16

     Company: R Value, Inc.
     EUP No.: 44313-EUP-R
     Date of Application: 9/11/81
     Site: Mounds on unspecified sites
     Method:  Broadcast application and individual mound treatment
     Is use for quarantine program? No
     Dosage Rate: 4 Ibs. eui./A (broadcast): 1/4 cup product (mound)
     Formulation: 5% bait
     Status: Objection letter sent 12/18/81; no response received to date; the
       applicant had previously indicated that he may try 24(c) registration. The
       application is incomplete; additional information regarding program is
       needed.


4.   Chemical: Methyl chloroform (1,1,1, Trichloroethane)

     EPA File: 40708-R Southwest Trichem Industries, Houston, TX
     Date of Application: 5/17/77
     Site: Urban/rural (non-agricultural)
     Dosage: 2 ounces/ant hill
     Method:  Pouring of chemical on top of ant hill
     Formulation: 94.5%
     Status: Objection letter dated 11/27/78 (additional safety and chemistry data
       needed).  Company indicated on 6/23/82 that they were interested in
       pursuing registration and would respond to our objection letter.


5.   Chemical: Resmethrin

     Company: Cessco
     File Symbol: 6959-AR,  6959-LO
     Date of Applications 10/21/79

     Description of Application

     Sites: Buildings, playground, pastures, parks, feed, and woodlots
     Dosage Rate: Spray as necessary
     Method:  (Pressurized spray) spray directly on ants
     Is use for quarantine program? No
     Restrictions: Not for household use
     Status: Preliminary acceptance letters issued 6/28/82.

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                                  200.1
6.   Chemical: Lindane                        PM-15

     Company: Woolfolk Chemical Co., Inc.
     EPA File: 769-LGE
     Date of Application: 6/9/82

     Description of Application

     Site; Home lawns, parks, cemeteries, and recreational and commercial turf
      areas
     Dosage Rate: 4 Ibs./lOOO sq. ft./ 160 Ibs./acre (4 Ibs. a.i./acre)
     Method: Broadcast ground and individual mound treatment
     Is use for quarantine program? No
     Status: Under review.
7.   Chemical: Methylenebis (thiocyanate)       PM-31

     Company: Vineland Chemical Company
     EPA Reg. No.: 2853-43
     Date of Amendment Application: 11/2/81
     Formulation: 10% liquid

     Description of Application

     Sites Non-agricultural land
     Method: Individual mound treatment (drench)
     Dosage: 2 oz. product/gal, water/35 sq./ft.
     Is use for quarantine program? No
     Restrictions: Not for homeowner use  as labeled
     Status: Additional efficacy data required and additional testing requested of
      applicant by Fire Ant Laboratory (USDA) Gainesville, Florida.

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                                       APPENDIX L
              ERADICATION: AN ASSESSMENT OF CONCEPT AND PRACTICE
                                     Edward H. Smith
                                        PANEL V
    It is clear that human population growth,
 dwindling resources, and global inflation will
 increase  the pressure for more  effective
 pest control. In the case of insect control,
 we will  need all the options we can get.
 Insect resistance to insecticides is a growing
 problem.   Some of the  "third generation"
 insecticides  have not  fulfilled thier earlier
 promise, and the gap  between concept and
 practice is still very wide for some promis-
 ing control technology such as pheromones.
 In addition,  despite a concerted effort to
 prevent  the  introduction  of  new  pests,
 present methods cannot offset the growing
 global  commerce that increases  the likeli-
 hood of new pest introductions.  The time-
 lessness of this assessment is  heightened by
 new technology  which opens  options  that
 were previously  unavailable.   This in  turn
 raises  new  questions  regarding  the philo-
sophical,  social  and  economic  issues  in-
 volved in the concept of eradication.  And
within  the many  facets of the problem lies
the question:   Does  humankind  have  the
power  to eradicate pests, and if so, does it
have the right to  do so?
   Eradication,  the elimination  of a  pest
 from an  environment, has great appeal on
 two counts.  The  first appeals to human-
 kind's  sense  of dominion.   In the  Judo-
 Christian  philosophy,  humans  proclaimed
 their dominion over the earth.  They were to
 "be fruitful and multiply, . . .   have domin-
 ion over . . . every living thing . .."  To kill
 and  eliminate seems to be a deeply rooted
 impulse,  whether dealing with  a  mosquito
 taking a blood meal or fire ants established
 over thousands of square miles.
   The second count, a more rational one, is
 rooted  in cost/benefit  relationships.   The
 control of annually recurring pests involves
 endless effort and  expense.  The futility of
 the annual ritual of boll weevil control with
 the  full  knowledge that one  would be no
 further ahead  the next year  offends  the
 sensibility of rational  people  dedicated  to
 education and  research.   Some of today's
 leaders in plant protection have  vivid child-
 hood memories of long cotton row, sun, rain,
 weeds,  and  insect  pests  which sentenced
 them to endless toil. Through  the drudgery
remained  the conviction that there had to
 be a better way.   Despite the tremendous
gains in  the science and practice  of  plant
                                          201

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                                          202
 protection, however, the magnitude of pest
 losses has not changed greatly over the past
 eighty years (Metcalf 1980).
    All  these things considered, it is not
 surprising that  the concept  of eradication
 greatly  appeals  to  the  human  intellect.
 Modern  agriculture is essentially  the  man-
 agement of resources, the establishment of
 favored plants in ecosystems  where they did
 not  occur naturally, like  maize in  Africa.
 To remove  pest  species  from vast  areas
 follows as a natural aspiration in the evolu-
 tion of agriculture.

SEMANTICS
   Professional  entomologists differ widely
on  the  issue  of eradication.   One  of the
contributing  factors  to  the  controversy is
the difficulty of aggreeing on what is meant
by the term "eradication."  For the purpose
of this discussion, I define  eradication as
eliminating an existing pest population  from
a specified area.   The  term "eradication"
has been so misused and  has fallen  into such
disfavor  that one  wishes  it  could be  dis-
carded  in favor of a term  devoid  of the
ambiguity and prejudice of the past.  As this
semantic  option is not readily available, we
can at least qualify our  use of the term by
including  a specification of  the geographic
area involved.
   Withoug specifying the area from which
the  pest  population  is  to be eliminated,
 discussions are meaningless.  As the target
 area for eradication increases in size, so do
 the  complexities.  While no conceptual and
 philosophical  issues arise in undertaking the
 eradication of a  pest  from  an  individual
 plant,  field, or entire county, many complex
 issues  arise if the scope is regional, conti-
 nental, or global.
   The factor of  time also deserves con-
 sideration.    Presumably,  eradication, the
 elimination of a  pest  population from  a
 specified  area, would  last indefinitely or
 until the  pst  is reintroduced by humans or
 gains access by its own migration,  clearly
 the spatial and temporal dimensions of erad-
 ication require attention.

 PROFESSIONAL PHILOSOPHY
   The primary  reason  whyentomologists
 have not  come to  consensus on eradication
 is that they simply have not addressed the
 issue  seriously.    A review of literature
shows  that the issue  has been largely ig-
 nored.   Other factors  have contributed to
 confusion  and  ambiguity.     As  already
 pointed out,  there is  ambiguity regarding
 the  meaning  of  the  term.   Additionally,
 many entomologists have  direct interest in
 the issue.   The chief proponents of eradica-
 tion  have  been USDA  scientists, and their
leader,  Dr. E. F. Knipling,  acting as  scien-
tist/administrator,  has played a key role in
advancing the  concept and programs.   (Knip-

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                                         203
ling  1979).   Lines became drawn  between
state and  federal workers.    Mistakes of
logistics and  administration  became con-
fused with soundness  of  concept.    Politi-
cians,   producers,   and  environmentalists
gathered  in  the  drama  and  added  their
biases to those of the professionals.
   The  issue of eradication was featured at
the  annual  meeting of the  Entomological
Society  of America in 1977. The title of the
topic was "Eradication of Plant  Pests—Pro
and Con" (Bull. Entomol.  Soc. Amer., 1978,
24(l):35-53).   The  format was that  of de-
bate; however, as noted by one of the speak-
ers (Rabb), this format was not conducive to
an objective treatment of the topic.   To
conclude that two speakers were "for" erad-
ication  and two "against" eradication is in-
accurate  and  an  oversimplification.   The
"con" speakers, Newsom and Rabb,  deplored
the excesses,  weak research data base, es-
calating budgets,  and  decision making pro-
cess  in  some  cases.  They offered caution
but they did not take a stand of unequivocal
opposition to  area eradication.  The "pro"
speakers,  Eden and Knipling,  acknowledged
some mistakes of  eradication  programs, but
urged that  the potential benefits of the
strategy not be overshadowed by failures of
the past, especially in light of  the advancing
technology applicable  to  eradication  pro-
grams.  It is unfortunate that the  areas of
agreement and directions  for the  future
were  not more effectively identified in the
forum.
   The  goal  of  global  eradication  raises
serious  moral and  philosophical questions.
While most  case histories  of  eradication
involved objectives  much more modest than
global eradication, the issue of global eradi-
cation needs to  be  addressed by entomolo-
gists.  The  current  range  of views is well
illustrated by the statements of two con-
temporary leaders.   Newsom (1979) states,
"I do not consider it to be morally wrong and
ecologically disasterous to attempt to eradi-
cate some pest species."  By contrast Met-
calf  says, "I do firmly believe that species
should be regarded as sacred and man indeed
has no right or reason to destroy them"  (as
cited in Perkins, 1982, p. 190).
   Perkins  (1982) has examined the philo-
sophical foundations of entomology as they
have  influenced  the  development  of the
major new pest  management concepts:  in-
tegrated pest management  (IPM) and total
population management (TPM). He proposes
that  these  paradigms  are  imbedded  in a
matrix of ecological theory with the crucial
differences  being in the  position accorded
humans.  He subsequently applies labels to
the .underlying presuppositions of IPM and
TPM:
   "Integrated Pest Management
   •Naturalistic'—A  belief system that man
is a part of  the biosphere but that he cannot

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                                          204
 be the total master of it.  He may manipu-
 late  for his own benefit, but  there  are
 intrinsic limits to his manipulative powers
 that reside in the properties of the material
 world."
    "Total Pest Management
    •Humanistic'—A belief system  that  man
 is part of the biospere and that he can be
 master of it.  He may manipulate it for his
 benefit, and there are no intrinsic limits to
 his manipulative powers that  reside in  the
 properties  of  the  material  world.    The
 limits,  such as  they  are,  stem  from  his
 current ignorance of natural processes."
    Ironically, until the late 1960's, no econ-
 omist devoted serious attention to the prob-
 lems of the entomology.  More ironic is that
 even  more  recently  have the philosophical
 foundations of entomology been considered,
 despite the burning philosophical question of
 our relationships  to  the natural  world and
 our  right to  eradicate  living organisms,
 termed pests,  in  a purely anthropocentric
 classification.  Perkin's work drawing on the
 history of science, philosophy, and a schol-
 arly brush with entomology and its leaders,
 is certain to stimulate consideration by en-
 tomologists of animal rights,  the issues of
 eradication, and related issues  of the era of
 environment and ecology.

INTRODUCED SPECIES
   From  earliest  colonial time,  normal
 commerce  has  resulted in the introduction
 of  exotic insect species.   Sailer (1978)  re-
 ported  that of  the 700 important arthropod
 pests in the  U.S.  (contiguous states), 35%
 are introduced species and these account for
 50% of total insect losses.   Although  the
 threat  represented  by  introduced  species
 was recognized early, it was not until 1912
 that the Plant  Quarantine Act was passed,
 but only in 1920 was it fully implemented.
 Despite concerted  efforts  by regulatory
 agencies, species continue to gain entrance
 at  an  annual rate  of  approximately nine
 species per year (Sailer 1978).
    Clearly even with the growing effective-
 ness of quarantine  programs, introductions
 will continue  due to the tremendous speed
 and volume  which  characterizes  modern
 transportation of goods and people.  Accord-
 ing to Elton (1958):  ". .  . we are living in a
 period  of   the  world's  history  when  the
 mingling of thousands of kinds of organisms
 from different parts of  the world is setting
 up terrific dislocations in nature."
    Bates has  considered the  role of people
 as agents in the spread  of organisms (cited
 in Thomas 1956) and stresses that  "the  in-
 troduction of an organism into a new region
 . .  . purposeful  or  accidental, is often pos-
sible  only  because the  habitat  has  been
greatly  altered  by  other  human activity."
 As  we continue to  manage natural  systems
and commute  between continents, the intro-

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                                          205
 duction  of  insect species is certain  to  in-
 crease;  therefore  two  possible  strategies
 could be exclusion, followed by eradication,
 and finally  containment through  integrated
 pest management.

 THE CONCEPT OF ERADICATION
    The species gaining access to a foreign
 shore is  faced with a formidable problem. It
 must find  a niche,  compete for  it,  and
 contend  with  the natural  enemies.   The
 ecological complexity of the process  is re-
 vealed  in  part by  the  high proportion of
 failures  in  attempts at deliberately  intro-
 ducing species for biological control.  The
 ecological principles involved in  the  inter-
 action are  those inherent in the  biotic po-
 tential of the species versus environmental
 resistance.  The growing body of knowledge
 of the dynamics and behavior of insect pop-
 ulations  should  provide  a sounder base for
 decisions on the feasibility of eradication
 than has been available.
    Eradication seeks to dislodge the species
from  its niche  by increasing environmental
resistance.  Considering the  vulnerability of
a species in a new habitat and the numerous
biotic and abiotic factors that can be man-
ipulated, the concept of eradication is eco-
logically sound and  appealing.   However,
numerous factors influence  its complexity:
size of the area infested, length of time the
species has  had to adapt to its new habitat,
 similarity of  new  habitat  to  the species'
 natural  range, specificity of food require-
 ments, influence of biological control agents
 on the population dynamics of the species,
 technology available for structuring a com-
 prehensive  control program, availability of
 funds  and  personnel,  public  support, and
 cooperation.  These considerations are com-
 plex and we have had limited experience in
 dealing with them.   A systematic approach
 to  evaluating eradication options is urgently
 needed.

 MAJOR ERADICATION EFFORTS
    The early, predominantly rural, Ameri-
 can society was much concerned over  insect
 pests and took legislative action to address
 these and related problems as its agriculture
 expanded.   The  Hatch  Act  of  1888 estab-
 lished  agricultural experiment stations, thus
 providing  an organizational structure for
 conducting  research on agricultural  prob-
 lems.      Similar    organizational  effort
 occurred at the federal level.  Some  major
 insect  problems appeared shortly thereafter:
 gypsy  moth in Massachusetts  (1889),  San
 Jose scale  in California (1893),  and  boll
 weevil in Texas (1894).  These major  intro-
 duced pests provided a rigorous test for the
 political structure, the emerging entomolo-
 gy  profession,  and the concept of eradica-
 tion.   In all three  cases  eradication  was
 recognized, by some at least, as  the  first
line of defense.

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                                         206
   Numerous other eradication efforts have
been attempted since then (Table 1).  Brown
(1961) analyzed four eradication programs,
gypsy    moth,    imported   fire    ant,
Mediterranean  fruit  fly,  and screwworm.
His report is drawn upon for the following
brief  summaries.   His analysis  considered
personnel staffing of the  projects,  research
data base  from which  programs were  pro-
jected, and adaptability of programs as they
proceeded.  He reported striking differences
in the resourcefulness of personnel assigned
to the  four programs and  the  kind  and
amount of  information on which  control
operations were  based^  As  might be ex-
pected,the programs also  differed widely  in
effectiveness.  Based on  this analysis,  four
recommendations were  proposed (the vali-
dity of which were borne out by later exper-
ience):
1. Adequate research must be the founda-
   tion for program development with  fre-
   quent  reevaluation to determine  effect
   and need.
2. Expand funding for USDA research with
   special emphasis on basic studies.
3. Deemphasize  mass  broadcast  of non-
   selective insecticides with augmentation
   by other methods.
4. Establish a permanent  interagency office
   to coordinate control activities and eval-
   uate environmental impact.
The following are summaries of several er-
 adication programs.
    Malaria.   This  program  was  the first
 undertaken on a global scale.  The success
 with DDT and other residual sprays  in the
 late  1940's and  early  1950's prompted the
 idea of eradicating malaria, and, in 1955 the
 World Health Organization adopted a resolu-
 tion in support of this objective.  This action
 was taken despite early signs of anopheline
 mosquitoes developing resistance  to DDT.
 Another factor was  that  financial support
 would wane as early successes reduced the
 urgency for control. Favorable progress was
 made  until  1966.   According  to  Yekutiel
 (1981): "The outstanding detrimental factor
 was inadequate planning and financing . . ."
    Additional  factors  were the increasing
 problem  of  insecticide resistance, unfore-
 seen  behavioral characteristics of vectors,
 and factors  of human  ecology.   In retro-
 spect, the  malaria  eradication  program
 failed to meet a number of prerequisites and
 now seems unduly ambitious in scope and
 objective.
    Smallpox.   In  1959 the  World  Health
 Organization passed a resolution to globally
 eradicate smallpox chiefly by intensive vac-
 cination  campaigns.    Little  progress was
 made in the following seven years.   In 1966
 an intensive program  was undertaken aimed
at eradication within  ten years.  The objec-
 tive was  reached in  1977  by a campaign
involving 46  countries on three continents.

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                                          207
In Dec.  1979  a commission reviewed  the
evidence and certified the global eradica-
tion of the  disease (Yekutiel 1981).  The
presumed  eradication  of this  disease  in
which  vaccination played an important part
bears limited analogy to global insect erad-
ication.
   Screw worm.   The screwworm program
represents success and failure of the male
sterilization technique.   The program  was
conducted in 1958-59 in southeastern U.S.,
principally Florida, and involved the release
of laboratory-reared, sterilized males from
light planes at the rate of 40  million per
week.      Results   were  immediate   and
dramatic.   The screwworm  was eradicated
from the southeastern U.S. at a  cost of $10
million.
    With this success, attention  was turned
to  a  more  ambitious  project;  rolling the
screwworm back from  southwestern U.S. to
a defensible line in southern Mexico. While
the  program failed in its objective of eradi-
cation,  it  did  dramatically  reduce  the
screwworm for the period 1962-76 (Newsom
1978).  This experience highlights the diffi-
culty  in transposing success  from   an area
where the species was  recently established
(southeast) to a larger area  contiguous  with
overwintering areas (southwest). The exper-
ience  also indicated how difficult  it  is  to
estimate  costs of  such a  project.   More
recently,  the failure  of   the  autocidal
method of control has been explained on the
basis  of genetic diversity  between  reared
and  naturally  occurring  flies resulting in
different       reproductive      strategies
(Richardson et al.  1982).  While the south-
west  eradication program  failed based  on
the objective of eliminating the  pest from
the area, it did provide valuable information
on insect nutrition, behavior, and genetics.
   Imported  Fire Ant.   The red imported
fire  ant, Solenopsis invicta Buren,  became
established in Mobile, Alabama, in 1943  and
gradually spread to ten southeastern states.
Its  status  as an economic pest has been
debated for  years.   The original plan pro-
jected  in  1957  called  for eradication  by
spraying border  areas, centers  of  infesta-
tion,  and areas from  which it  was most
likely to spread.   The insecticides, hepta-
chlor  and  dieldrin, were  first  used,  then
replaced by  mirex bait.   The  debate over
environmental effects of mirex was ended
by  agreement with EPA that mirex would
not be used after 1978.   All of the insecti-
cides  for IFA  control  were found  to  ad-
versely effect the environment, especially
wildlife. Thus, the eradication effort ended
with the banning of mirex and with the goal
of eradication further away than ever.  The
striking features of this  case are that eradi-
cation  programs based  entirely on insecti-
cide treatments proceeded with virtually no
research data base on either effectiveness

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                                          208
 against  the target  species  or non-target
 species.
    Boll Weevil.  The boll weevil is the kind
 of  "super pest" that  evokes  thoughts  of
 eradication.   The eradication strategy was
 proposed when the pest made  its appearance
 in Brownville,  Texas, in 1894, but no action
 was taken  and the  pest  migrated to  the
 eastern seaboard by  1922.  The boll weevil
 has been  the target  of two major eradica-
 tion programs: (1) the pilot  program ini-
 tiated in  Mississippi, Alabama, and Louisi-
 ana in 1972, and (2) the boll weevil eradica-
 tion program  initiated in  the North Caro-
 lina-Virginia area in 1980.  The pilot pro-
 gram was to demonstrate  the feasibility of
 an eradication  program, and the second pro-
 gram was to  apply  the  technology.   The
 technology in both cases consisted of mul-
 tiple control measures including the inten-
sive use of insecticides. The results of the
pilot  program  were  hotly debated  based
chiefly  on the issue  of the source of boll
weevil found within the demonstration area
(Perkins 1980).  Were they migrants or  did
they  arise  from  infestations  within the
demonstration  area?   Two  committees
charged with evaluating the  program con-
cluded that eradication had not been demon-
strated (Chiang et al. 1973).  The conclusion
by the committee appointed by the National
Academy  of Sciences to evaluate the more
extensive  eradication program was  that the
objective  of  eradication   had  not   been
reached.  The committee recommended that
"the potential for eradication should be per-
iodically reevaluated" and that  there should
be "an indefinite postponement  of the Opti-
mum Pest Management (OPM)  Boll  Weevil
Eradication (BWE) programs. . . ." (National
Academy of Sciences  1981).   The  debate
over the issues continues (Wade 1981).  The
Committee supported the eradication  con-
cept as  being worthy  of  revaluation,  but
discouraged implementation pending further
advances  in  technology.   The  committee's
view was undoubtedly influenced by the sig-
nificant  advances made in integrated  pest
management of cotton pests  in recent years
(Adkisson et al. 1982).
   Mediterranean Fruit Fly.   There have
been two  major  efforts  to  eradicate this
pest from  Florida and the  adjoining area.
The  first in 1929 involved ten million acres
representing  three-fourths of  the  bearing
citrus land of Florida.  The  major features
of the  program included destruction of fruit
in the  infested area, strict quarantine, and
extensive use of  bait  spray  (brown sugar,
molasses, and lead arsenate  or  copper  car-
bonate).   In the short span from April  6,
1929, when infested fruits were discovered
until July 1930, the fruit fly was eradicated.
   The strategy for  dealing  with the 1959
infestation was  considerably altered  from
that used in 1929.  Destruction of fruit was

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                                          209
 deemphasized  in favor of fumigation.  The
 crude bait used  earlier  was  replaced by
 protein  hydrolysate  and malathion  applied
 by air.  Eight  hundred thousand acres were
 sprayed  one or more  times.   In addition,
 detection methods were developed using An-
 gelica seed which was later replaced by a
 synthetic  attractant,  siglure,   containing
 esters   of  cyclohexane   carboxylic  acid.
 Through these  combined efforts, the  fly was
 eradicated in  less  than two years with no
 serious  effect  on  wildlife  and   relatively
 little imposition on the public.   A striking
 feature  of the  1956 experience was the
 effectiveness  with which the research find-
 ings,  developed by  L. F.  Steiner at  USDA
 station in  Hawaii, were applied to this pro-
 blem  on  the continent.
    The cases  briefly cited in the foregoing
 represent both successes and failure.   From
 this limited cross section of cases,  several
 conclusions seem evident:
    Early Detection.   The  Mediterranean
 fruit  fly was  on  two occasions detected
 early  and dealt with effectively.  We  tend to
 assume that this  is  likely to be the case
 considering our infrastructure of informed
growers, extension and industry  personnel,
and resource specialists in state and federal
agencies, but  early detection  was not the
case.with the  cereal leaf beetle experience.
The cereal leaf beetle was  identified in
 1962,  but  had  apparently  been present for
 some time and had reached sufficient num-
 bers of 1959 to warrant spray treatment on
 the initiative of farmers.  This  occurred in
 Michigan, a state well staffed by plant pro-
 tection  specialists.   The  development of
 surveillance  programs for new pests which
 provide  effectiveness  at  reasonable cost
 poses a severe problem.
   Research Base.  Control programs must
 be based on research findings.   Research,
 however, is  difficult to  provide, especially
 when a new  pest  is  discovered and the
 element of urgency is often invoked as justi-
 fication to proceed without essential infor-
 mation.  It is likely that far more is lost by
 proceeding with weak programs than by de-
 laying until essential data are available.
   Budgeting  for  Eradication   Programs.
 Accurate budgeting  is  extremely difficult
 especially for  efforts characterized  by so
 many imponderables. This is to be expected
 and tolerated to a point, but it is important
 to distinguish  between  the factor  of the
 unknown and the practice of covering mis-
 takes by increasing  the budget.   Skill in
 assessing progress and adjusting  budgets  is
 needed  together  with  advances  in  tech-
 nology.   Above all, science and technology
 must  take precedence over public relations
 and  politics  if credibility of  the profes-
sionals is to be maintained.
   Growing  Technology  and  Experience.
Chemical control has been the  prevailing

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                                          210
strategy for  the  majority of  professional
entomologists.   Such  strategies  required
little imagination  and ingenuity,  and  the
legacy of the low ceiling  imposed by their
use is still  with us.   Each case history in
eradication  has added to  our knowledge,
despite  mistakes that  cannot be justified,
but growing experience and technology offer
a brighter outlook for future programs.

PREREQUISITES FOR ERADICATION
   Based on  experience  of  the  past  and
current knowledge  of population dynamics,
it  should be possible to  determine  with
better accuracy the probability of success in
eradication  efforts.  A listing of issues that
should be considered follows:
1.  High socioeconomic importance  of  the
   pest. The eradication strategy generally
   involves  a comprehensive  research pro-
   gram to  develop the needed technology.
   This  phase  is  followed by a  complex
   phase  involving  extensive  control  pro-
   grams.    Such  major  effort should be
   reserved for insect  pests of high socio-
   economic importance.
2.  Specific  advantages of eradication over
   suppression.   Unless  there is  a clear
   advantage to eradication  over  suppres-
   sion, undertaking eradication is not justi-
   fied assuming effective technology  and
   modest costs for suppression programs.
3.  Effective  monitoring technology.  It is
    essential that effective technology for
    monitoring pest populations be available.
    Without such technology it is impossible
    to  determine the  area infested  by the
    pest or the results of treatment.  Recent
    advances in  pheromone chemistry  and
    technology  offer promise here.
4.  Effective  control  technology.  In  most
    cases, eradication efforts will involve a
    combination of  measures.    The effec-
    tiveness of the  total  effort  must  be
    determined with  a high degree of cer-
    tainty  before undertaking  eradication.
    This poses  special problems  because of
    the  difficulty  of  interpolating  from
    small,  preliminary  tests to  large  area
    tests.  The  paucity of  data  on effective-
    ness of fire ant treatments was a major
    weakness of early eradication efforts.
5.  Environmentally   acceptable  programs.
    The impact of control programs  on the
    environment must  be assessed as a pre-
    requisite to launching eradication  pro-
    grams.   This poses a  difficult problem
    because of  the time element  involved in
    making preliminary determinations.
6.  Favorable  logistical odds.   Large-scale
    application  programs must be  basically
    simple or the element of human error is
    likely to doom  the program  to failure.
    the accuracy of aerial application, or the
    thoroughness  of scouting  for  infested
    areas are the kind of operations alluded

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                                         211
   to here.   The likelihood  of failure in-
   creases as the area increases.  Similarly,
   the longer the pest has been established,
   the better it adapts to its environment.
7. Adequate  funding  to sustain  programs.
   In a number of cases, realistic estimates
   of costs have not been agreed on before
   programs  are  initiated.    Undertaking
   programs  with   open-ended  budgets  is
   likely to place the program in jeopardy
   for lack of funding or loss of credibility
   due to excessive costs.
8. Adequate  administrative   resources  to
   sustain  programs. A high level of admin-
   istrative  competence   is  required  to
   insure coordination of  the many facets
   of an eradication program.  This essen-
   tial input  is more difficult  to provide
   when  programs  extend across state and
   national boundaries.
9. Favorable   socioecological   conditions.
   The success of eradication programs may
   depend  on  the  cooperation  and active
   participation of  residents of the area.  It
   is essential that a high level of support is
   assured  and that  regulatory  authority
   can   be   invoked   to   take  required
   measures.
10. Favorable   cost  benefit   relationships.
   The  great  appeal  to  eradication  pro-
   grams is that through the  initial "capital
   investment"  phase  the  pests  will be
   eliminated, thereby avoiding the recurr-
   ing  costs  of  control  programs.   These
   cost/benefit relationships need to be cal-
   culated very realistically to avoid disal-
   lusionment.
   Prerequisites  cannot  assure  successful
eradication  programs.  An  element of risk
will  always  remain.   But  by  analyzing  a
program against the list of prerequisites can
increase a program's success.

CONCLUSION
   Controversy has plagued the eradication
concept since its inception.  It appears that
the weaknesses in technology, logistics,  and
administration inevitably became confused
with basic  concept.   The  result  has been
that a  strategy  which  should  have  great
appeal has been placed in disrepute, and the
stigma has become part of the conventional
wisdom of  entomology.   The  myth of  the
unsoundness of eradication  is passed on in
the classroom. Objective people would not
defend glaring mistakes  of  past eradication
programs, neither  would  they  deny that in
some situations  eradication offers a high
probability for large gains and that a rigor-
ous  analytical process  can be applied  in
determining which cases offer such promise.
Based  on experience to date  and future
outlook,   the  following  conclusions  are
drawn.
1. The concept  of  eradicating  an insect
   pest from an extensive geographical area

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                                          212
    is  sound biologically, socially, and eco-
    nomically.
 2.  The eradication strategy has been much

    maligned because  of  the errors of past
    programs.

 3.  Global eradication or extinction  of  an

    insect  pest species appears  to be  an

    unreasonable  objective   on   technical
    grounds at  this point in the state of art
    and technology.

 4.  Global eradication poses complex  philo-

    sophical  considerations that  should  be

    addressed.  Pending better understanding

    of  the  implications of extermination, it
    should not be acceptable on philosophical
    grounds.

 5.  The eradication strategy should be  ac-
    cepted as  a viable option  subject  to

    rigorous  assessments  to determine its

    appropriateness in specific cases.

 6.  To remove  the constraints currently im-
    posed  on the  eradication strategy will
    require  new  alliances  of  biologists,

    economists, philosophers, and politicians.


REFERENCES

Adkisson,  P. L., G. A. Niles, J. K. Walker, L.
    S. Bird and H. B. Scott.  1982.  Controll-
    ing cotton's insect  pests:  a new system.
    Science 216(4541):19-22.

Brown, W.  L. Jr. 1961. Mass insect control
    programs:   Four case  histories.  Psyche
    68(2-3):75-lll.

Chiang, H. C.,  E. H. Glass, D.  L Haynes, P.
    Oman,  H.  T.  Reynolds and W. G.  Eden.
    1973.   The pilot boll  weevil  eradication
    experiment.  Bull.  Entomol.  Soc. Amer.
    19(4):218-221.

Eden,  W.  G.   1978.  Eradication of plant
    pests—pro.  Bull.  Entomol. Soc. Amer.
    24(l):52-54.

Elton,  C. S.  1958.  The Ecology of Invasions
    by  Animals and  Plants.  N.Y.  John Wiley
    and Sons, Inc. 181 pp., ill.

Knipling, E. F.  1978.   Eradication of plant
    pests—pro.  Bull.  Entomol. Soc. Amer.
    24(1):44052.

Knipling, E. F.   1979.   The Basic Principles
    of  Insect   Population Suppression  and
    Management.  USD A, Agriculture Hand-
    book No. 512.  659 pp.  USD A, Washing-
    ton, D.C.

Metcalf, R.  L.   1980.   Changing role of
    insecticides in  crop  protection.   Ann.
    Rev.  Entomol.  25:219-56.  Annual  Re-
    view Inc., Palo Alto, CA.

National Academy  of Sciences. 1981. Cot-
    ton Boll Weevil:  An Evaluation of USD A
    Programs.     National Academy  Press,
    Washington, D. C.  130 pp.

Newsom, L. D.   1978.  Eradication of plant
    pests—con. Bull. Entomol. Soc.  Amer.
    24(l):35-39.

Perkins, J. H.  1980.  Boll weevil eradica-
    tion.  Science 207:1044-50.

Perkins, J. H.  1981.  Insects, Experts  and
    the Insecticide  Crisis.   Plenum  Press,
    233 Spring St., New York.  304 pp.

Rabb,  R.  L.    1978.   Eradication of plant
    pests—con.  Bull.  Entomol. Soc.  Amer.
    24(l):40-44.

Richardson, R. H.,  J.  R.  Ellison and W. W.
    Averhoff.   1982.   Autocidal  control of

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                                         213
   screwworms in North America.  Science
   215(4531):361-9.

Thomas,  W. L. ed.   1956.   Man's role in
   changing the face of the earth.  Man as
   an agent in the spread of organisms,  pp.
   788-804.  Univ. of Chicago Press,  Chi-
   cago, IL. 1193 pp., ill.

Wade, N.  1981. Weevil war simmers unre-
   solved.  Science 213:147-879.

Yekutiel, Perez.   1981.  Lessons from  the
   big eradication  campaigns.  World Health
   Forum 2(4):465-90.

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                                      APPENDIX M
        BIOLOGICAL CONTROL:  ITS HISTORIC USE VS. PROSPECTIVE VALUE TO
                          CONTROL THE IMPORTED FIRE ANT
                                    Frank E. Gilstrap
                                        PANEL V
   Biological  control of  pest  organisms is
currently receiving a great deal of attention
from  the public,  agriculture,  and  govern-
ment.   Some  of this attention undoubtedly
relates  to the frequent notion that biologi-
cal control  is simply  a  matter of getting
some  "good"  organisms and  turning  them
loose to provide control of a "bad" organism.
Actually, far  more  is  required for success
than simply releasing  or protecting "good"
organisms.  But if success is achieved after
the appropriate effort,  the payoff  is gener-
ally well worth the  time, energy, and cost.
Though  originally employed only in  entomol-
ogy to  control  insects,  biological control
now includes plant pathology and weed sci-
ence,  the former  using microorganisms  as
antagonists to prevent plant disease, and the
latter  using  insects or  plant  diseases  to
control  weedy plants. Neither  plant science
nor plant pathology are germane to  the
present topic  and  will not be referred  to
further.
   Most biological  control specialists  in
entomology describe biological  control as an
ecological process  wherein pest individuals
are killed by natural enemies and each pest
death  produces one  to  many new natural
enemies.  Biological control occurs only as
the result  of human activity; when people
are not actively involved either by protect-
ing or releasing natural enemies, the same
process is  called natural control.  In  prac-
tice, biological control is the study and use
of natural  enemies  to regulate  pest  abun-
dance at levels where they  cause no signifi-
cant detriment to people.  Put very simply,
biological control is  two sets of three items.
The first set names the kinds of  approaches
used,  i.e.,  conservation, augmentation,  and
importation of natural enemies;  the second
set names the kinds of organisms used, i.e.,
parasites, predators, and pathogens.
   Conservation is the practice of conserv-
ing or protecting natural populations of  a
known natural enemy, thus encouraging its
suppressive  action on the  pest  population.
This technique is used for a natural enemy
that does not obtain its potential because of
some  adverse condition  or  missing environ-
mental  requisite (e.g.,  pesticides,  lack  or
proper habitat,  lack of  continuity in habi-
tat). The solution is to eliminate the adver-
sity or  provide the  missing requisite, as is
                                         214

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                                          215
 commonly done  in insect pest management.
 Augmentation of natural  enemies  seeks  to
 enhance the  effect of an  exotic or indige-
 nous natural  enemy by releasing  field-col-
 lected or laboratory-reared natural enemies
 in  places  where they are needed.   Both
 conservation  and augmentation  assume the
 use of a relatively effective natural enemy,
 but one that for  some reason cannot achieve
 its  potential.   Importation of  new  exotic
 natural enemies  is the best first option for
 biological  control of an exotic  pest.  This
 type of biological control, usually  referred
 to as classical biological control, consists of
 introducing one to several exotic species of
 natural enemy for permanent establishment
 in the area where the exotic pest is causing
 damage.    The   term  "classical"  applies
 because  the historical origins of biological
 control are tied  to numerous successful im-
 portation programs of the past.
    Importing natural enemies is  conceptual-
 ly based on the  fact that often an exotic
 pest  is accidentally established in a new
 environment without the controlling effects
 of natural enemies from  its native home.
 Exotic arthropods are  only rarely  pests in
 their aboriginal  homes, largely  because  of
 natural enemies  that effectively control it.
 The biological control program seeks  to
 identify these natural enemies in the pest's
 area  of  origin,  ascertain  their beneficial
status, and then import and release them for
 establishment.  This type of biological con-
 trol has  obtained  a worldwide  total  of  at
 least 120 successful programs on 120 differ-
 ent pest  insects; 42 of these programs have
 resulted in complete and permanent control
 of the subject  pest  (Coppel  and Mertins
 1977).  Put another way, each  of  these 42
 programs was so successful that the object
 pest no longer causes any significant loss or
 damage.  The remaining 78  programs  have
 resulted in  less than total control, but clear-
 ly  contributed towards solving  the   pest
 problem.    Examining the  record  a  little
 differently, of ca. 2300  species  of natural
 enemies introduced for control of pests in
 ca.  600  different  situations  (essentially
 same pests  as before but counting each pest
 control success  separately),  34% of the
 natural enemies became established causing
 partial  to complete control in 60% of the
 situations (Hall et al.  1980).  In all success-
 ful cases  of classical biological control, the
 outcome  has  proven  economical  and has
 invariably been environmentally safe.   The
 President's  Science   Advisory  Committee
 (1965)   reported  that  biological  control
returned ca.  $30  for each  research dollar
invested.  This compares to  a return of ca.
$4 and $15  for insecticides and insect resis-
tant plants, respectively.   These  benefits
from successful biological control programs
continue  to accrue ad  infinitum or  until
disrupted.   In terms of economical return

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                                         216
and safety, the record of classical biological
control successes is the product of routine
commitment, proper  training, and appropri-
ate caution exercised by importing person-
nel, and it is the product of properly strin-
gent  importation  regulations  enforced  by
governmental agencies.  Classical biological
control has historically  not been the  first
control tactic  considered  for  dealing with
long established  or even  new  exotic pest
insects.  Considering long established pests,
17 of  28  identified major  insect and  mite
pests  in the U.S. are exotic in origin (Van
den Bosch 1975).  Some of the more  notori-
ous  insects  and  mites  of  exotic   origin
include the codling  moth,  European  corn
borer,  cotton  bollweevil,  pink  bollworm,
gypsy moth, Japanese beetle, imported fire
ant,  alfalfa weevil, green  peach aphid, pea
aphid, greenbug, cabbage maggot, and Euro-
pean red mite (Knipling 1979, Van den Bosch
1975). Some have been the object of biolo-
gical  control,  but  most  have  not  and  all
continue to cause serious damage.

BIOLOGICAL CONTROL AND INSECT
PEST MANAGEMENT
   Any given crop typically supports several
to many phytophagous arthropods, each  of
which could cause severe  damage  if not
controlled. Those not under natural control
may be further suppressed  by use of (1) crop
cultivars that are resistant to pest damage
(= host plant resistance); (2) crop production
practices that avoid or minimize pest dam-
age (= cultural control); (3) release of steri-
lized  pests that mate with naturally-occur-
ring pests causing production of non-viable
eggs  (=  autocidal control);  (4)  chemicals
(hormones)  that  disrupt  a  pest's  normal
internal processes such as growth and devel-
opment,   or  chemicals (pheromones)  that
interfere  with   normal   communication
between   pest  individuals  of  the  same
species;  (5) pesticides  that  kill pests (and
often non-pests) by ingestion, inhalation, or
contact with poisons; and (6) biological con-
trol that kills pests using other living organ-
isms.  These  tactics are used unilaterally or
in concert  depending on  the  crop,  pest
insect complex, and  level of understanding
for the  crop's  ecology.   Integrated  pest
management (IPM) occurs when several of
these tactics are  combined, or  when one to
several are  used  based on a  well-founded
economic threshold, or when the purpose of
a control procedure is to optimize yield with
costs  of production.
   Historically,  the   crisis  of  insecticide
resistance provoked  the serious study  of
biological control as  a major component of
IPM.  Significantly, this push-pull  relation-
ship between insecticide resistance and bio-
logical   control   is  changing.     Current
emphasis on biological control is  inspired
more  by economic and environmental pro-

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                                          217
 tection  considerations than as a choice of
 last resort.   Crop production systems  that
 use  biological  control  almost always use
 other tactics. Thus, the concept of IPM  is
 one  whereby  one  to  several tactics are
 selectively employed in a mutually compati-
 ble  framework, are  based  on an economic
 threshold, and/or are used to optimize yield
 with costs of production. Biological control
 is the cornerstone for such IPM  programs,
 whether they be  for glasshouse crops, row
 crops, field  crops, or tree  crops.   In IPM,
 effective  natural enemies  are encouraged,
 protected, or increased for certain pests and
 other controls are selected for other  pests
 not  amenable to biological  control.   The
 alternate tools are those least disruptive to
 important natural enemies needed to control
 other phytophagous species.
   All three  biological  control tactics are
 employed in some IPM programs. For exam-
 ple,  citrus pest  controls in  the  Fillmore
 district of Ventura County (California) con-
 sist  of  classical biological  control  of four
 once-major pests,  augmentative releases for
 two  pests, and  occasional pesticides  for
 three  pests   only  partially  controlled by
 natural   enemies  (DeBach   1974).     Other
 examples of IPM using biological controls as
 the focus include  peaches in California and
apples in Washington (Hoyt  and Caltagirone
 1971),  glasshouse  crops  in  Europe  (Hussey
and Bravenboer 1971, Markkula 1978), citrus
in Israel (Harpaz and  Rosen 1971), and sor-
ghum  pests  in Texas (Young  and  Teetes
1977,  Teetes  et  al.  1973,  Starks  et  al.
1972).  In each example,  effective natural
enemies are either imported and established
for essentially permanent control, released
periodically  when   normal  natural  enemy
activity is insufficient for control,  or  are
conserved  when non-biological controls are
needed for pests not  controlled by natural
enemies.
   The invasion of an  introduced pest is
potentially  the most disruptive event  to
affect  a  well-researched  IPM  program.
Introduced pests usually originate in a for-
eign  country  and  are not yet  adequately
studied for immediate use of biological con-
trols.   Eradication  efforts  in  response  to
such invasions often result in serious local
disruptions  to  extant  biological  controls
used  in  IPM,  and  can  hinder  progress
towards classical  biological  control  of  the
new pest. Three recent programs are excel-
lent  examples of such an  effect.  The pro-
grams  are  citrus  blackfly,   Aleurocanthus
woglumi Ashby, on citrus  in Texas (Hart et
al. 1978; Hart, personal communication) and
Florida (Selhime et al. 1982), and the Corn-
stock  mealybug,  Pseudococcus comstocki
Kuwana, on citrus in the San Joaquin Valley
of California  (Anonymous 1979, Meyerdirk
et al. 1981).  In each, it  was  clear from  the
outset that prospects  for  complete biologi-

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                                          218
cal control were excellent,  based on previ-
ous programs on each pest in other parts of
the U.S. or Mexico.  Eradication efforts for
each  pest  in  each  area caused localized
outbreaks  of other  pests previously under
control by natural enemies;  made pursuit of
classical  biological  control very difficult;
and failed in spite of intensive  efforts and
considerable  expenditure  of  tax  dollars.
Exotic natural enemies  for  each pest were
eventually  established by agencies  outside
those  involved  in the  eradication  effort.
The  natural enemies brought complete bio-
logical control.
   The issue is not  that eradication was
attempted, but that eradication interfered
with  the  pursuit of  alternative control ef-
forts  long after it was clear  that eradication
was  not possible.  Clearly,  an ingredient  is
missing in present protocol for dealing with
an introduced pest.
   The invasion of  the pink bollworm on
cotton  in  the  lower deserts  of southern
California  is an  exception  to  the  general
rule that invading pests are usually poorly
.researched.  This insect had been well re-
searched  in Texas  where  it  was suppressed
primarily by cultural  controls (Noble 1969).
However, the key Texas tactics of growing
short season  cotton  varieties and of early
crop  destruction  were  not  well  suited to
California conditions.  Thus, the pink  boll-
worm became a new key pest and required
frequent,  large  volume insecticide  applica-
tions. These pesticides totally disrupted the
biological controls used in the previous IPM
program.   Natural  enemies suppressing the
cotton leaf  perforator,  boUworm,  cabbage
looper, salt marsh caterpillar, spider mites,
and other pests were  killed and these pests
resurged to damaging levels.   Not  only did
cotton producers adopt non-selective pesti-
cides and  use  them  heavily,  but  such use
greatly accelerated the development of in-
secticide  resistance in the target pink boll-
worm and even in other, non-target pests.
Thus, a  previously  well-founded IPM pro-
gram has become  totally useless  until the
new key pest is controlled in a non-disrup-
tive manner (Emerson 1974, Reynolds et al.
1975).  The pink bollworm  remains  a key
pest  in spite of considerable research into
classical  biological  control and other tac-
tics,  and  the normally non-damaging cotton
leaf  perforator  has  risen to  pest  status
causing such heavy damage that the future
of cotton production in southern California
deserts is threatened.
    The programs on  citrus blackfly, Corn-
stock mealybug, and  pink  bollworm  exem-
plify what is likely to occur more frequently
in the future when an introduced arthropod
becomes  a serious pest in a new area.  The
likely, and generally  appropriate,  response
will  be an area-wide eradication  program,
though the issues are occasionally not clear-

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                                          219
 cut as revealed  by Newsom  (1978), Rabb
 (1978), Knipling  (1978,  1979),  and Eden
 (1978). However, at the onset of an eradi-
 cation effort more funds should  be  devoted
 to  developing  alternative  controls should
 eradication fail or  falter.   This point was
 made  extremely well  by W. L.  Brown, Jr.,
 who   over  20  years  ago  (Brown  1961)
 reviewed  four area-wide,  mass  insect con-
 trol programs, one of which was the import-
 ed  fire ant. Brown was highly critical of the
 programs  because research was not integral-
 ly involved at the  onset of each program.  In
 Brown's own words:
    Every   mass  control campaign  should
    have   an  adequate  research  program
    functioning  as   far  ahead as   possible
    before control operations get  under way.
    The control work should  be guided by the
    research and not the reverse, and every
    campaign    should   be   re-evaluated
    frequently  to  see  if   a need   for  it
    continues.
    It  seems  clear that we  have  made very
little progress towards Brown's suggestion, a
fact that is  extremely unfortunate as so
much progress is needed in view of today's
complexities for protection  of crops, animal
and human health, and the environment.

PROSPECTS FOR BIOLOGICAL CONTROL
AGAINST  IFA
   Though the  imported fire ants (IFA),
Solenopsis richteri Forel and S. invicta Bur-
en,  have been residents of the U.S.  for ca.
64  and 39  years  (Hung and  Vinson 1978),
respectively, biological control of each has
progressed only to very early  stages. Some
natural enemies have been identified in the
IFA aboriginal  home in South America, but
they have not been studied for their roles or
ecological impact.    This must  be  done
before importations can be seriously consid-
ered.   Jouvenaz  et  al.    (1981)  recently
reviewed  the current knowledge of biologi-
cal control prospects  for  IFA and  pointed
out  that  disease,  parasites, and  predators
are scarce and ineffective controls in the
U.S.—an expected  conclusion given the con-
tinual  problems by IFA.  They also  pointed
out  that  preliminary  searches for  natural
enemies of IFA had  been done in South
America.  The tone of  their review was that
at present, exotic pathogens are almost cer-
tainly the only  hope for effective  biological
control of IFA. Such  conclusions however,
are  premature  and  counterproductive  as
adequate field evaluations are not yet avail-
able for any natural enemy of IFA.  Accord-
ing to Jouvenaz et al. (1981) most  biological
control work has been supported through the
USDA-ARS  IFA Research Laboratory  at
Gulfport,  Mississippi, and has been done by
either  personnel at the  laboratory  or  by
SAES personnel at  the  University of Florida
or  Mississippi  State   University.    If  the
analysis of the Jouvenaz  et  al.  review is
allowed to stand as the operative statement

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                                         220
for future biological control work,  and if
only the extant group working on biological
control of IFA continues without addition of
others who  are  trained  specifically  in  the
principles of biological control,  chances are
quite remote for a successful  project  on
biological control of IFA.
   The IFA invasion and spread in the U.S.
is  paralleled in some respects by the inva-
sion of  the  Argentine  ant  (described  by
Elton  1958).  The Argentine ant, like  the
IFA, is an extremely intense and successful
competitor.   As  it invaded  new areas, it
caused  significant reductions in native  ant
populations.   Native  ants  most  affected
were those  that  occupied  similar niches.
The  crux of  the Argentine ant story is that
when the competitive  advantage of Argen-
tine ant was  reduced, by chemicals or other-
wise, the native  ants  quickly  regained a
temporary competitive position.  The same
kind of  phenomenon would  probably  occur
with the IFA in  the U.S.  if an acceptable
non-chemical and  economical  device  is
developed or imported  to  reduce IFA com-
petitiveness.  The rationale  for  area-wide
control if IFA could be compared to that
needed for biological control of  weeds, as
biological weed  control  is  also based  on
reducing the competitive advantage  of the
exotic weed (Huffaker 1962).
   Parasites
   Known parasites of IFA are  members of
either fly family, Phoridae,  or  the wasp
family,  Eucharitidae.  Species of Euchariti-
dae (Orasema spp.) have been reported at-
tacking IFA in Uruguay and Brazil (Williams
and Whit comb  1973).   The ants apparently
are not disturbed  by  the presence of these
parasites during the parasite  developmental
time  within the  ant nest.   At  least  14
species  of  phorid flies  belonging to two
genera, Pseudacteon  and Apodicrania, have
been  reported associated with fire ants in
either  Brazil or  Argentina  (Williams  and
Whitcomb 1973).  According  to Borgmeier
(1963, as cited  by Williams  and  Whitcomb
1973),  all  species of Pseudacteon  attack
ants belonging to Solenopsis,  Lasius, Dory-
myrmex, or Crematogaster.   In  nearly  all
species of phorids attacking ants, the para-
sites  are  attracted  to  disturbed mounds.
Generally, only worker caste  individuals are
parasitized.  The larvae, depending on the
parasite species, develop in the head  capsule
of  the adult ant (in which  case the ant's
head  falls off at pupation of the parasite) or
in the body of the ant larva.  In all cases the
parasitized individual  is killed and  a  new
adult parasite is produced.
    According to Jouvenaz et al. (1981) (and
those they consulted), none  of these para-
sites offer much potential for suppressing
IFA.    However,  work  initiated  by  Feener
(1981)  should  be studied  further   before
developing any conclusions.  Feener's studies

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                                           221
 strongly suggest that  phorids can  cause a
 shift  in the competitive  balance between
 ant species.  His studies were conducted in
 Texas, on Pheidole  dentata and a native fire
 ant,  Solenopsis texana,  and  showed  that
 Pheidole was unable to respond naturally in
 the presence of the phorids. Thus, it did not
 recruit  normal  numbers of  major worker
 ants to  ward off an invasion by the Solenop-
 sis.  In the absence of the phorid parasite,
 Pheidole  dominated   most  confrontations
 with Solenopsis, but in the  presence of the
 parsite, the outcome was usually reversed.
 This reversal of dominance was shown to be
 seasonal and dependent on the phenology of
 the parasite.  Feener concluded that the
    notorious imported  fire ant . .  . appears
    free  of phorid parasites in  the United
    States,  despite  the  diverse  array of
    phorid  flies  (attacking) this species and
    its  close  relatives  in  South  America.
    This  freedom may partly explain the high
    densities of  IFA  and  its  competitive
    dominance over the (indigenous) fire ant
    in southeastern United States.
    Parasites for IFA may be  far more im-
portant because they disrupt IFA's competi-
tive advantage rather than simply increasing
IFA mortality.
    Predators
    Indigenous predators  of  IFA have  been
reported by Bass and Hays (1976), Whitcomb
et  al.  (1973),  O'Neal (1974), and Lucas and
Brockman (1981). Reports of predators of
IFA in South America  are essentially  only
those of .Silveira-Guido et al.  (1972) which
 are very general. However, the phenomenon
 of predation by other species of ants was
 examined in  Florida  by Nickerson  et al.
 (1975)  who  reported that  predation  could
 cause up  to  60% mortality in post-nuptial
 IFA queens.  Silveira-Guido et al. (1972) in
 their review  of predation in South America,
 reported on Solenopsis (= Labauchena) dag-
 uerrei  Santschi, a  socially  "parasitic"  ant
 that  takes over nests  of IFA in Argentina
 and Uruguay.  When the invader ants  are
 present  in the IFA  nest, the IFA workers
 stop tending their own brood and tend those
 of  the invader.  Eventually, the IFA colony
 vigor  attenuates  and  the  nest becomes
 extremely unthrifty.  According to Jouvenaz
 et  al. (1981),  these ants have little potential
 for biological control, due  either  to poor
 searching  ability and/or  other  factors that
 inhibit their ability to find colonies of host
 ants.  Additional study is warranted to pro-
 perly identify causes for  low frequencies of
 occurrence (ca. 4%),  and  to identify reasons
 previous investigators were  unable to suc-
 cessfully  import  these  parasitic ants  to
 other locations.
    Pathogens
    Diseases  of IFA  are  reported to  occur
naturally in the U.S.  and in  South America
(Lofgren et al. 1975). The indigenous patho-
gens are apparently  relatively  few and do
not seem to exert any significant control in
field  populations.    However,   disease  is

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                                         222
reportedly fairly common in South America
where 20  to 25% of the colonies show pre-
sence of disease organisms.  Jouvenaz et al.
(1977, 1980) reported that 22  species in the
IF A  species  complex  have  been   found
diseased in either Brazil,  Paraguay,  Uru-
guay, or Argentina.   Considerable work has
been done on microsporidan diseases  of IF A
in the U.S. (Jouvenaz and Hazard 1978) and
in South America (Allen and  Silveira-Guido
1974, Knell et al. 1977); however, none have
yet been  reported as field evaluated either
in South America or the U.S.
   According  to Lofgren et al.  (1975), the
findings of Allen and Buren (1974), working
with a  microsporidan disease, is the  most
promising.  Knell et  al. (1977) report 50  to
95% of  the adult ants in some colonies are
infected  with the microsporidan pathogen,
causing a  diseased condition resulting in less
vigor and  destruction of fat bodies. Jouven-
az et al.  (1981) appropriately point out that
debilitating diseases  might stress fire ant
sufficiently to allow other indigenous ants
to  become more successful in competing
with IF A.

RECOMMENDATIONS
1.  Studies should be initiated to quantita-
    tively evaluate arthropodial  and patho-
    genic  natural enemies  of IF A.   These
    studies should consist of life table analy-
    ses  and/or experimental methods (as out-
   lined by DeBach and Bartlett  1964) and
   be conducted for two to five years in the
   IF A aboriginal home.
2.  Studies  to identify  the  IFA  natural
   enemy fauna should be continued in the
   IFA distribution area in South America.
3.  A laboratory should be established  near
   the  center of  origin  of IFA  in either
   Argentina  or  Brazil.    This  laboratory
   should be staffed by the  minimum num-
   ber of permanent scientists and be easily
   accessible  to U.S. scientists on tempor-
   ary duty studying some aspect of IFA.
4.  The  classical biological control program
   for IFA should be expanded  and should at
   very  minimum  include a biological  con-
   trol   specialist  (with  formal  academic
   training in biological control), an insect
   pathologist, a specialist in  taxonomy  of
   parasitic Hymenoptera (Chalcidoidea) or
   Diptera, a quantitative ecologist, and a
   taxonomist of Formicidae.
5.  Funding should be  generated to support
   field studies of natural enemies of IFA in
   three or five or more IFA-infested states
   in the  U.S.    These  studies  should  be
   oriented to understanding the ecology of
   IFA,  its competitors, and its  natural
   enemies.   Research  locations  would
   serve as  loci  for  release  of  exotic
   natural  enemies   when  they  become
   available.
6.  A review  panel should  be established,

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                                         223
    consisting of  an individual  from  each
    facet of the total IF A program  (regula-
    tory and  each research component) and

    the  various  parts of  the public sector

    (health, environmental protection, com-

    merce,  etc.). This panel's role would be
    to regularly review progress in  the IFA
    regulatory,  control,  and  research  pro-

    grams and  to  critique each.  A public
    meeting should follow each  such panel

    meeting.


REFERENCES
Allen, G. E.,  and W. F. Buren. 1974.  Micro-
    sporidan and fungal diseases of Solenop-
    sis  invicta  Buren, in Brazil.  J.  N.  Y.
    Entomol. Soc. 82:125-30.

Allen,  G.  E., and  A. Silveira-Guido.  1974.
    Occurrence of microsporida in Solenopsis
    richteri and Solenopsis sp.  in  Uruguay
    and   Argentina.     Florida  Entomol.
    57:327-9.

Anonymous.  1979.  The Comstock mealybug
    in California citrus.  Citrograph 64:51-2,
    66.

Bass, J. A., and S. B. Hays.  1976. Predation
    by  the  mite, Tyrophagus putrescenticte,
    on  eggs of the  imported fire ant.   J.
    Georgia Entomol. Soc.   11:16.

Brown, W. L., Jr. 1961. Mass insect control
    programs:   Four case  histories.   Psyche
    68:75-111.

Coppel, H. C.,  and J. W. Mertins.   1977.
    Biological   Insect  Pest  Suppression.
    Springler-Verlag, Berlin. 314 pp.

DeBach, P.   1974.   Escape from the pesti-
    cide dilemma.  Chapter 10. In:  Biologi-
   cal Control by Natural Enemies.  Cam-
   bridge University Press,  New York.  323
   pp.

DeBach,  P., and B.  R. Bartlett.    1964.
   Methods of colonization,  recovery and
   evaluation.  Chapter 14, In:  Biological
   Control  of Insect  Pests  and  Weeds.
   Reinhold Publ. Co.  843 pp.

Eden, W. G.  1978.   Eradication of  plant
   pests—pro.  Bull. Entomol.  Soc.  Amer.
   24:52-61.

Elton, C. S.  1958.  The Ecology of Invasions
   by Animals and  Plants.   Chapman and
   Hall,  Publ. London.  181 pp.

Emerson, L. V.   1974.   Investigations  of
   insect predators  and parasites  of the
   cotton leaf hopper, Bucculatrix thurberi-
   ella Busck.  UnpubL Ph.D.  dissertation.
   Univ. California, Riverside. 183 pp.

Feener, D. H.  1981. Competition between
   ant  species:    outcome  controlled   by
   parasitic flies. Science 214:815-7.

Hall,  R.  W., L.  E.  Ehler,  and B. Bisabri-
   Ershadi.    1980.   Rate  of success  in
   classical  biological  control of  arthro-
   pods.  Bull. Entomol. Soc. Amer.  26:111-
   4.

Harpaz, I., and D. Rosen.   1971.  Develop-
   ment of  integrated control programs for
   crop  pests  in Israel.   Chapter  20. In:
   Biological Control, (ed. C. B. Huffaker).
   Plenum Press.  New  York-London.  511
   pp.

Hart, W. G., A. Selhime, D. P.  Harlan, S. J.
   Ingle, R. M. Sanchez, R. H. Rhode, and
   R. L. Garcia.  1978.  The introduction
   and establishment of parasites of citrus
   blackfly, Aleurocanthus woglumi in Flor-
   ida.  Entomophaga 23:361-6.

Hoyt, S.  C., and  L. E. Caltagirone.   1971.
   The  developing programs  of  integrated

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                                         224
   control of pests of apples in Washington
   and peaches in California.  Chapter  18.
   In:   Biological Control (ed. C. B. Huf-
   faker).  Plenum Press.   New York-Lon-
   don. 511 pp.

Huffaker, C. B.  1962.  Some concepts on
   the ecological basis of biological control
   of weeds. Can. Entomol.  94:507-14.

Hussey, N.  W.,  and L. Bravenboer.   1971.
   Control of pests in glasshouse culture by
   the  introduction  of  natural  enemies.
   Chapter 8.  In:  Biological Control (ed.
   C. B.  Huffaker).   Plenum Press.  New
   York-London. 511 pp.

Hung, A.  C. F., and S. B.  Vinson.   1978.
   Factors affecting the distribution of fire
   ants in Texas (Myrmicinae: Formicidae).
   Southw. Nat. 23:205-14.

Jouvenaz, D. P., G. E.  Allen, W. A. Banks,
   and D.  P.  Wojcik.   1977.  A survey  for
   pathogens of fire ants, Solenopsis spp., in
   the southeastern United States.  Florida
   Entomol.  60:275-9.

Jouvenaz, D.  P.,  W.  A. Banks,  and J.  D.
   Atwood.  1980.  Incidence of pathogens
   in fire  ants, Solenopsis spp., in Brazil.
   Florida Entomol.  63:345-6.

Jouvenaz, D.  P., and  E. I.  Hazard.   1978.
   New family, genus, and species of micro-
   sporida (Protoaoz:  Microsporida)  from
   the tropical fire ant,  Solenopsis gemi-
   nata  (Fabricius) (Insecta:  Formicidae).
   J. Protozool. 25:24-9.

Jouvenaz, D. P., C. S. Lofgren, and W. A.
   Banks.  1981.  Biological control of im-
   ported fire  ants:   A review  of  current
   knowledge.   Bull. Entomol. Soc.   Amer.
   27:203-8.

Knell, J. D., and G. E. Allen.  1977.  Light
   and electron microscope study of Thelo-
   hania solenopsae n. sp.  (Microsporida):
   Protozoa) in the red imported fire ant,
   Solenopsis invicta.   J. Invert.  Pathol.
   29:192-200.

Knipling, E. F.  1978.  Eradication of plant
   pests—pro.  Advances in technology for
   insect population eradication and  sup-
   pression.    Bull  Entomol.  Soc.  Amer.
   24:44-52.

Knipling, E. F.  1979.  Role of insecticides
   for  insect  population  eradication  and
   containment.  In: The Basic Principles of
   Insect Population Suppression and Man-
   agement,   (pp.  263-5).  USDA Handbk.
   No.  512.  659 pp.

Lofgren, C.  S.,  W.  A. Banks, and  B. M.
   Glancey.  1975.  Biology and control  of
   imported  fire ants.  Ann. Rev. Entomol.
   20:1-30.

Lucas, J. R., and H. J. Brockman.   1981.
   Predatory interactions between ants and
   antlions (Hymenoptera:  Formicidae and
   Neuroptera: Myrmeleontidae).  J.  Kans.
   Entomol. Soc. 54:228-32.

Markkula, M.  1978.   Studies and  experi-
   ences on  the biological control of the
   most important  insect  pests on  glass-
   house cultures in Finland.  Bull. S. R. O.
   P. Int.  Org. Biol. Cont./West  Palearc.
   Reg. Sec.  (1976)4:19-24.

Meyerdirk, D. L., I. M. Newell,  and R. W.
   Warkentin.  1981.  Biological control  of
   Com stock mealybug. J. Econ. Entomol.
   74:79-84.

Newsom, L. D.  1978.  Eradication of plant
   pests—con.  Bull.  Entomol. Soc.   Amer.
   24:35-40.

Nickerson,  J. C., W. H. Whitcomb,  A.  P.
   Bhatkar, and M. A. Naves.  1975.  Preda-
   tion  on  founding queens  of Solenopsis
   invicta   by   workers  of  Conomyrma
   insana.  Florida Entomol.  58:75-82.

Noble, L. W.  1969.  Fifty years of research

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                                         225
    on  the  pink  bollworm  in  the  United
    State. USDA Handbook No. 357.  62 pp.

O'Neal, J. 1974.  Predatory behavior exhib-
    ited  by  three species  of  ants  on  the
    imported  fire ants: Solenopsis  invtcta
    Buren  and  Solenopsis  richteri  Forel.
    Ann. Entomol. Soc. Amer.  67:140.

President's  Science  Advisory  Committee.
    1965.  Restoring  the quality of our envi-
    ronment.     Kept.  Environ.  Pollution
    Panel, Pres. Sci. Advisory Comm.  The
    White House, Washington D. C. 317 pp.

Rabb, R. L.   1978.   Eradication of plant
    pests—con.  Bull.  Entomol.  Soc.  Amer.
    24:40-4.

Reynolds, H.  T., P.  L. Adkisson, and R. F.
    Smith.  1975.  Cotton insect pest man-
    agement.   Chapter  11. In:  Introduction
    to  Insect  Pest  Management  (W.   H.
    Luckmann  and R. H. Metcalf, ed.).  PubL
    John Wiley and Sons, Inc.

Selhime,  A.   G.,  W. G.  Hart,  and  D. P.
    Harlan.  1982. Dispersal of Amitus hes-
    peridum  and Encarsia  opulenta released
    for the biological control of citrus black-
    fly in south Florida.  Florida Entomol.
    65:165-8.

Silveira-Guido,  A.,  J. Carbonell,  and C.
    Crisci.  1972.  Animals  associated with
    the Solenopsis (fire ants) complex, with
    special reference to Labauchena daguer-
    rei.  pp. 41-52.  In: Proc. Tall Timbers
    Conf. on Ecol. Anim. Contr. by Habitat
    Management.  February 25-7, 1971. Tal-
    lahassee, Florida. 286 pp.

Starks,  K. J., R.  Muniappan,  and  R.  D.
    Eikenbary.   1972.  Interaction between
    plant resistance  and parasitism  against
    greenbug in barley and  sorghum.   Ann.
    Entomol. Soc. Amer. 65:650-5.
   greenbug  control and  effect  on certain
   beneficial insects.  Tex. Agr. Expt.  Sta.
   PR-3116.  6pp.

Van den Bosch, R. 1975. Biological control.
   In:     Integrated  Pest   Management:
   Rationale,  Potential,  Needs  and  Im-
   provement.   (E. Glass, Coord)  (pp. 31-
   44).   ESA Spec. PubL  75-2.   Entomol.
   Soc. Amer. Publ.  141 pp.

Whitcomb, W.  H.,  A. Bhatkar,  and J. C.
   Nickerson.  1973.  Predators of Solenop-
   sis  invicta  queens prior  to  successful
   colony    establishment.         Environ.
   Entomol.  2:1101-3.

Williams, R. N., and W. H. Whitcomb. 1973.
   Parasites  of  fire ants in  South America.
   pp.  49-59, In:  Proc. Tall Timbers Conf.
   on Ecol.  Anim. Contr. by  Habitat Man-
   agemt.  March 1-2, 1973.  Tallahassee,
   Florida. 244 pp.

Young,  W. R.,  and  G. L.  Teetes.   1977.
   Sorghum  entomology.  Ann.  Rev. Ento-
   mol. 22:193-218.
Teetes, G. L.,  G. W.  Brothers, and  C.  R.
   Ward.   1973.   Insecticide  screening for

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                                      APPENDIX N
         IMPACT AND MANAGEMENT OF INTRODUCED PESTS IN AGRICULTURE
                                      Marcos Kogan
                                        PANEL V
    When insects and plants coexist in evolu-
tionary time, a process of mutual adaptation
becomes established.  This process known as
coevolution results from the accumulation
of several lines of defense in the plant and
the gradual adaptation of a few herbivorous
species to overcome such defenses. In fact
some of these defensive  traits become posi-
tive stimuli capable of eliciting the behav-
ioral  responses characteristic of an herbiv-
orous insect's relationship to its host plant.
Many of the defensive traits are of a chemi-
cal nature and  are  known as  allomones.
However,   many  plant  chemicals  have  an
allomonal  function against the  majority of
the herbivores but a kairomonal  (or positive)
function for a few species (Norris and Kogan
1980).  These latter  species are the  co-
evolved ones.  Key to this adaptive coevolu-
tionary process is the existence of the her-
bivore and the plant in the same geographic
area over  an extended period of time.
   In addition to the adaptation of the her-
bivore to  the plant, another level of coevo-
lutionary  process  permits  parasitoids  and
predators  of the herbivores to adapt to the
habitat provided  by the plant  with its  full
complement  of defensive morphology  and
biochemistry.  This is the so-called interac-
 tion at the third  trophic level (Price et al.
 1980).
    Current revolutionary  theory  assumes
 that plants have evolved to produce an opti-
 mal defense strategy against its  associated
 fauna.   In turn  the herbivores  evolved to
 produce optimal foraging and host selection
 strategies.  The confluence of these  opti-
 mization processes is a very dynamic system
 of herbivore/plant interactions. The lines of
 defense  usually presented to the  herbivores
 by  the plant include morphological charac-
 ters such  as  hairiness, thorns and  spines,
 thickening of  epidermal tissues,  accumula-
 tion of waxy  layers, etc.  Another  line of
 defense  is represented by secondary meta-
 bolites.  Most  of the allomonal and kairomo-
 nal compounds mentioned above are second-
 ary metabolites.  Under  natural  conditions
 the defensive repertoire of a plant operates
synergistically with the complement of na-
 tural enemies that regulates herbivore popu-
lations.  Through man's interference in  agri-
cultural systems plant natural defenses and
natural enemies are often disturbed and the
consequences  are   "ecological  explosions"
(sensu  Elton 1958) of the kind that  brought
about the present situation with the import-
ed fire ants in the southeastern U.S. (Lof-
                                         226

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                                         227
 gren et al. 1975).

 GEOGRAPHIC ISOLATION OF PESTS
 AND POTENTIAL HOSTS
    When  Painter  first defined  the various
 categories of  resistance in plants against
 insects in 1951, he established the category
 of  pseudoresistance  to  encompass  those
 mechanisms that  involve the escape of  the
 plant in space or  in time from  a damaging
 encounter with a potential pest.  This is not,
 in  fact, a true  mechanism of resistance.
 Not all plants are exposed to all potential
 pests because  many simply do not coexist in
 the  same  geographic  area.  As a  conse-
quence of the geographic isolation of pests
and potential  hosts one can identify two
 factors that often account for the explosive
outbreaks that often result from the immi-
gration of a pest  into  a new  region.  First
the pest may find  suitable host plants in  the
new region.  Provided that the feeding nich-
es  are not adequately occupied  by well
adapted native species,  the invader will find
the plant defenseless. The historical case of
the invasion of Europe  by the grape Phyllox-
era, Phylloxera vitifoliae, illustrates this
point.   This  North American pest  species
appeared  in  France  in 1861  and  rapidly
spread to  vineyards in  other  European and
Mediterranean  countries.    By  1880  the
French wine  industry was on the brink of
collapse.  Complete control of the pest was
achieved after French  vineyards  were  re-
 constituted  using grafts of the susceptible
 European grape vine scions on the resistant
 North American rootstocks.  The European
 vine, Vitis vinifera,  was extremely suscepti-
 ble to the Phylloxera, whereas the American
 species of Vitis, such as V. riparia, V. rupes-
 tris, and others, are virtually immune to the
 pest.
    The  other  more  commonly  reported
 mechanism  is the release of the  immigrant
 pest from the pressure  of efficient natural
 enemies upon invasion of a new area. There
 are  many well documented cases of this
 phenomenon which remains as the conceptu-
 al foundaton of classical biological control.

 BREAKING THE GEOGRAPHIC ISOLATION
 BETWEEN HOST PLANT AND PESTS
   The escape mechanisms  reported above
 are obviously disrupted when the geographic
 isolation between a  plant  and  a potential
 pest is eliminated.  There are two possible
 ways whereby geographic isolation between
 hosts and potential pests is overridden.  One
 is the  intentional expansion of  crops  into
 new  areas.   The second is  the  inadvertent
 introduction  or the  accidental immigration
 of a pest into new regions.  Most studies on
 the impact of immigrant pests have used the
 examples of  successful colonization of  her-
 bivores in new regions.  These can be illus-
 trated  by  the  many  cases of  immigrant
pests.  Also, the successful  biological con-
trol of many weed species  illustrates what

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                                         228
can  be done  if  the plant is  the migrant
species and the herbivores are then inten-
tionally introduced to control the host.  Less
attention, however,  has been  given  to the
consequences of introduction of a crop into
a new region (i.e.,  soybeans). In either case,
however, the result  is an imbalance  on the
established  plant/herbivore system.  If  the
host happens to be  a crop plant,  the  eco-
nomic impact can be catastrophic.

OVERALL ASSESSMENT
OF IMMIGRANT PESTS
   Sailer  (1978) made  an  interesting study
on the  number of immigrant species into the
continental  U.S.   He took into account the
total number of species by order  including
those that were  intentionally  imported for
biological control of insect pests and weeds.
According  to  Sailer, of  1,379 species for
which  economic  importance  has been as-
signed,  236 are in  the category of important
pests,  that is, species that cause economic
losses.  Of  these, some 80 species are ex-
pected  to be  serious pests.  According to
Glass  (1975),   of  the  35   most  important
insect  pests in the United  States, some 20
are of foreign  or  exotic origin.  Among the
most important agricultural pests of foreign
origin  are the European corn borer, the pink
bollworm, the boll weevil, the alfalfa  wee-
vil, the southern green stink bug, the green
bug, and the pea aphid. By comparison with
immigrant pests of perennial plants such as
forest  or  orchard trees,  range plants, etc.
one has the impression that annual agricul-
tural crops are less vulnerable to the ravag-
es of immigrant pests.  If one compares the
area planted to annual field crops to other
crops and to the impact of immigrant pests
of these crops around the world this impres-
sion may have some foundation.  There are
some  possible  natural restrictive barriers
for the successful colonization of insects
associated with annual field crops.  Some of
these barriers have been mentioned by Sail-
er (1978).
    1)  The absence  of adequate host  upon
arrival  of  the  immigrant;  A  tropical pest
arriving in an area where the host is not
grown will have very little chance of surviv-
al, for example, pests of  soybeans that may
be on  board airplanes arriving  from  the
Orient  and landing in San  Francisco (see
below).
    2)  Inhospitable conditions;   A  similar
situation  as mentioned above  would  have
happened  if the same airplane  landed in
Chicago in the middle of the winter.   The
crop  would not be present and the climatic
conditions would be such that any immigrant
pest would have very little chance for sur-
vival.
    3)  Predation by  general  native preda-
tors;  The immigrant pest may be welcomed
in the new country by a horde of birds and
other general predators that usually abound
near the possible ports of entry. In this case

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                                         229
the unprotected  potential pest would have
very little chance for survival.
   4)  Inbreeding  degeneration:    Usually,
under   current   quarantine  regulations,
invaders are  those  few  individuals that
manage  to escape  the  controls.    These
individuals,   assuming   that   they   will
reproduce,  bring  a very limited gene pool.
The  successive  generations  resulting from
these few initial colonizers will be intensely
inbred which may have as a consequence an
extreme concentration  of  semi-lethal  or
lethal  alleles  that will eventually lead the
population to degenerate and dwindle.
   With these introductory  remarks as a
background  I would like  now to use three
examples of introduced pests  in their impact
on the development of crops and their influ-
ence in the ecological research that lead to
their control.  Then I will discuss the oppo-
site situation, that is, when the plant is the
"migrant" and is exposed to a new  set of
environmental conditions,  including  a new
spectrum of potential pests.

CASE HISTORIES-EXAMPLES  OF
ACCIDENTAL INVASIONS BY IMMIGRANT
PESTS IN AGRICULTURAL CROPS
   Among  the numerous examples of pests
of foreign  origin, three  illustrate  the ap-
proaches and the impact that these pests
had,  not only on  the  economy  of the crops
that  the>>  ittacked, but also on the  direc-
tions of the research that was stimulated by
the very upsurge of these pests.  As we will
see  later,  a common consequence of the
impact of  an immigrant pest is public sup-
port to promote allocation of manpower and
funds  to  the problems  that they  create.
These  pests are the European corn borer on
corn, the cereal leaf beetle on small grains,
and  the imported  crucifer  beetle,  a very
recent  invader that causes  economic losses
to horseradish.
European Corn Borer
   This lepidopterous pest of probable  Euro-
pean origin was first detected in the U.S. in
1917 in the neighborhood of Boston, Massa-
chusetts.  It is,  however, probable that the
pest had been around since  the early 1900s,
because after  its detection and correct
identification, it was recorded over a rather
large area, indicating that spread had oc-
curred in previous years. There is excellent
documentation  about  the possible means of
invasion.  In the early part of the century
rather large amounts of  broomcorn  were
imported by New  England broom  manufac-
turers.  Much of this broomcorn was import-
ed from Hungary  and  Italy where the crop
was known to be commonly infested by the
borer.   Since the  imported  broomcorn was
often stored for many months prior to pro-
cessing, the larvae probably completed de-
velopment  within  infested  broomcorn and
the  emerging  adult   moths escaped  and
proceeded  to  colonize  neighboring  corn
fields and fields of other  host crops.

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                                         230
   The European  corn borer  is  a rather
polyphagous  species  capable  of developing
on a very large number of grasses as well as
broadleaf plants.  It has some definite pre-
ferences for  grasses such as barnyard grass,
corn, sorghum, and millet, but does well also
on many dicot weeds and crop plants.  This
rather broad host range certainly  enhanced
the chance  for  survival of the initial colo-
nizers.
   The spread of  the  European corn borer
from the  initial focus was rather rapid and
continues.   According  to  Brindley et  al.
(1975),  each year the borer spreads into a
few  more uninfested  counties  within  the
states that are known to be infested.
   Detailed  biological  studies started  al-
most immediately with the detection of the
pest.   Today the European  corn borer  is
perhaps one of the best studied insects.  Of
great  interest to  the  management  of the
pest was the early identification of three
ecotypes:   a northern  univoltine, and  two
multivoltines—central and southern.  Table
1 summarizes the chronological expansion of
the research activities  on various aspects of
the biology and control of the European corn
borer (based on Chiang  1978).
   In  summary,  after  the failure of early
attempts at  eradication, the  current status
of the European corn borer in  much of the
midwestern  corn  belt  is one  of a  dynamic
equilibrium  with fluctuating climatic condi-
tions  as  well  as  with  biological control
Table 1.   European corn borer research
          activity in the U.S.
1917,  1st  reported  by S.  C. Vinal  near
   Boston, Massachusetts.
1917-27,  Mass. Ag.  Exp.  Sta.  <5c  Bur.  of
   Entomol.   (USDA):    Surveys,  biology,
   economic impact control methods.
1930-50s, Intensification   of   research  at
   state  exp.  stations   with  geographic
   expansion  of pest, laboratory founded in
   Ankeny, IA; biology, ecology, biocontrol,
   host plant  resistance, chemical control.
1953-62,  Regional   cooperative   research
   project   on   causes   of   outbreaks:
   Monitoring    regional    fluctuations;
   economic    thresholds;    effect    of
   parasitoids &  diseases;  detection  of
   regional biological races.
1963-70,  Regional cooperation on detection
   of biological races.
1973,  Regional cooperative project on corn
   pest  management:  all  phases  including
   modeling and forecasting.
agents.  The European corn  borer  is  still
considered one  of  the  key pests  of  corn  in
the Midwest, but its impact varies  greatly
from  year  to year.   There  is  continuous
effort to  monitor  and to  understand the
dynamics of these fluctuations and  to  pre-
dict potential outbreaks. Efforts are  contin-
uing to identify  sources of resistance.  Re-
sistant lines to  the  first brood of the Euro-
pean  corn  borer have been identified.  Re-
search on  mechanisms  of  resistance to the
first  brood  led  to the  identification  of

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                                          231
DIMBOA, as a key allomone.  This research
is classic  in  the entomological  literature.
Identifying the resistance source to the sec-
ond brood  has been more evasive. Screening
of the  germplasm is  continuing  with more
effective methods of mass rearing and arti-
ficial  infestation.   Inbred  B52  with high
levels of resistance to the second brood has
been intensified among some 600  accessions
(Brindley et al.  1975). Thus, although, it is a
cause of  concern for  corn growers and re-
searchers, the  situation of  the  European
corn borer has stabilized.  It is an important
economic  factor but  by no  means  is it  a
limiting factor in corn  production  in  the
Midwest.  Farmers, have learned how to live
with the problem and researchers are learn-
ing better ways of coping with the problem.
Cereal Leaf Beetle
   Haynes and Gage (1981) offer  a state of
the art  review on the  cereal leaf  beetle
situation in North America.
   Since  the  discovery  of the cereal leaf
beetle,  OuZema meZanopus, in North  Ameri-
ca in the  early 1960s, research  associated
with this  species is  a  chronology of how
society  deals with the  introduction  of an
exotic  pest.    The numerous facets  of the
programs that  were implemented  to  control
cereal leaf beetle reflect the  priority placed
on structural change in the agricultural pro-
duction system.   The initial response  was
detection,  then  eradication  and contain-
ment, followed by an intensive program of
host  plant resistance and ultimately a bio-
logical  control effort of questionable suc-
cess.  A great  deal of activity and research
effort since the early  1960's added much to
the understanding of  the cereal leaf beetle
problem, but both the activity and the re-
search appear to have had minimal impact
on the present or final outcome.
   The  first official record of cereal leaf
beetle occurrence was made in 1962 in Ber-
rien  County, Michigan.   But,  according to
Haynes,  damaging  populations in the  area
were  probably present since the latter part
of the 1940fs. Thus, actual invasion preced-
ed detection by more than ten years.   Ex-
pansion of the area infested  by the cereal
leaf beetle occurred rather rapidly; the cur-
rent range extends from Illinois in the west
to New  England states in the east, south
into  the northern ranges of Tennessee and
North Carolina, and north  to  Wisconsin.
Strict quarantine procedures and treatment
of  potentially  infested  bales  of hay and
grain were imposed. Later it was  discovered
that  the cereal leaf  beetle  overwintered
under the bark scale  of Christmas  trees.
Certification for  the  movement of  these
trees was required.  Eradication efforts cov-
ered  a  period  of about  seven  years and
included extensive areas in Michigan, Indi-
ana, and Illinois reaching a peak of over 1.6
million acres blanket-sprayed  with  carbaryl
in 1966.  Efforts  at eradication were  aban-
doned after the spread of the beetle was out
of control and the spray program generated
public opposition due  to inconvenience  to
city  dwellers (there  were lawsuits against
the  sprays by  new  car owners  for  pitted
paint on their vehicles).
    With  the spread of the pest, intensive

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                                          232
programs were initiated  in  several  other
areas of research  including:   sterile male
techniques,   artificial media  for  mass pro-
duction of beetles, attractants, and biologi-
cal control.
   Much of the biological control was based
on the  idea of mass rearing  the  parasitoid
Anaphes flavipes  for release.   Since  the
beetles  were  not easily  reared,  cultures
were  maintained on beetles collected  in the
field.  In addition, these stocks of beetles
provided materials  for  an  intensive host
plant resistance program  whereby  a  large
number of  wheat,  oat and  barley lines were
screened. As a consequence of this program
resistance in wheat was found  to be directly
related to thrichome length and density.  No
high levels  of resistance  were detected in
oat and barley lines.
   Meanwhile, the  biological control pro-
gram was intensified by importing additional
natural enemies of the cereal leaf beetle
from  Europe.   Also an imaginative program
was  started  with  the establishment of  a
parasitoid  nursery in the  USDA Parasite
Laboratory at Niles, Michigan.  This nursery
concept allowed redistribution of the parasi-
toids reared on field-infested populations.
   The threat of  the cereal  leaf beetle to
small grain  production in the  Midwest stim-
ulated one  of the most  concentrated  and
intensive efforts  on researching   the  life
history and  ecology of an insect pest.  Per-
haps  the most beneficial  outcome of  this
 activity has been the impetus that it provid-
 ed to the modeling effort at Michigan State
 University.   As  a result of this  effort  a
 program  of early detection  and modeling
 was  initiated  and  provided a  pattern  for
 other such programs in other states. An on-
 line system  was developed and a network of
 weather stations  specifically aimed at pro-
 viding current weather information for users
 of the system was also implemented.
    Through  continuous  monitoring  of  the
 cereal leaf beetle, it  is apparent that  popu-
 lations have generally declined since  1971.
 The causes for this decline seem to be  the
 result of a combination  of factors such as
 weather related mortality, mortality due to
 introduced  parasitoids,  genetic changes in
 beetle populations, and changes in overwin-
 tering habitat (Haynes and Gage 1981).
    As was the case with the European corn
 borer, the cereal leaf beetle is now a per-
 manent feature of the grain production sys-
 tem in North America.  Specialists predict
 that the beetle will remain a sporadic pest
 requiring occasional  treatments. The pro-
 gram also demonstrates that if  infestations
 are not detected very early, efforts at era-
 dication are  usually futile.  Also, given the
 particular pattern of adaptation of the pest
 to  the agro-ecosystem,  an  equilibrium  is
 sooner or later developed.  It behooves  re-
 searchers to strive in the painstaking task of
 documenting the mechanisms of adaptation
so that a better  understanding  is gained as

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                                          233
 to  the  real  status of  these  pests  and a
 perception is also gained as to policies that
 should be adopted to cope with future immi-
 grant pests.
 Imported Crucifer Weevil
    Horseradish is a small but a highly valu-
 able crop in southwestern Illinois.  In 1977 a
 grower  detected  extensive  tunneling  of
 some of his roots.  The causal organism was
 the grub-like larvae of  a weevil later identi-
 fied  as  the European  species  Boris lepidii
 (Bousernan  et al.  1978).  An intensive pro-
 gram  started for the study of the biology,
 damage potential and control of the weevil
 that became known  as the imported crucifer
 weevil.  Because of the small number of
 growers  involved  in horseradish production
 in  the area,  an almost total  survey  was
 accomplished  in a short time.   The problem
 was well defined and a program  for monitor-
 ing  the infestation  was  initiated.   Despite
 the  circumscribed  area  of spread no at-
 tempts were made at eradicating  the  pest,
 because the pest had already  invaded wild
 and  other  cultivated crucifer  species.  In-
 stead, mechanisms were studied to reduce
 the spread and survival of the pest based on
 a  better  understanding  of its bionomics.
 Treatments of sets that are used for the
 vegetative reproduction  of  the crop  were
 tested using a range of methods from hot
 water to immersion in  synthetic pyrethroid
solutions.
   The problem, as  it  happened with  the
other pests discussed above, seems to be at
this  time reduced to only  sporadic infesta-
tions.  Methodologies are being developed to
cope  with  these  infestations.   The main
lesson from this  episode was the ability of
researchers to join forces with growers  and
generate financial support  from state legis-
lators.   This  support afforded,  in turn,  a
concerted  effort towards  the  study  of  the
problem.  Such cooperation between growers
and researchers with official legislative sup-
port has resulted  in  a  better  definition of
the problem and  improved methods of con-
trol.

EXPANSION OF CROPS INTO NEW AREAS
   The other method whereby  the geograp-
hic  barrier between  plants  and potential
pests is broken is the expansion of crops into
new  regions. A good example is provided by
the soybean.  Typically a  temperate zone
plant, soybean has been pushed into produc-
tion  into more and more  tropical regions.
The  soybean in the  midwestern U.S.  is only
sporadically affected by serious insect pest
outbreaks. The crop grows vigorously during
a  rather  short  (100 to 120  day) growing
season; however, when  it is planted further
south, in northern Florida for example, out-
breaks  of insect  pests, in  particular  the
velvetbean  caterpillar,  occur almost  every
year and require one or several spray appli-
cations per season.  The velvetbean  cater-
pillar breeds throughout the year in southern

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                                         234
Florida  and probably in more tropical areas
of the  Caribbean Islands.   They  migrate
north, reaching northern Florida by the time
soybean is growing. Several generations are
possible  during  the  growing season.   The
damage caused by these caterpillars can be
extremely  severe.  Similar outbreaks have
been  observed when  soybean  was  planted
into  the subtropical regions of Brazil.  Ex-
tensive  damage  is detected by the  same
velvetbean  caterpillar  and  a   complex  of
other defoliators. It  is  obvious  that the
phenology  of the pest and  the crop have
been  synchronized to a point  that the
breaching  of  a  geographic barrier has  al-
lowed for a new pest syndrome to develop.
It is  certainly  impossible in  this  case  to
recommend withholding the  expansion of  a
crop into a  certain region,  although  there
are compelling economic reasons for such an
action.  However, it may be useful, from the
standpoint of a  global economic analysis  of
a crop,  to  take  into account these  potential
risks  as a  crop  is considered for extensive
production in a  new area.  Quite often such
decisions are left in the hands of individuals
or groups  who have little or no concern  or
awareness  of the potential threats  that in-
sect  and  disease pests  may  have on the
economic production of a crop.

FORECASTING  RISKY INTRODUCTIONS
    As  a native crop  of  the  northeastern
provinces  of   China,  soybean  has  been
spreading throughout the world as a major
legume crop.  Fortunately,  up to  this point
no major introductions  of  serious oriental
pests have  been detected  in the western
hemisphere.   Two  of  these pests are  of
particular concern:  (1) pod borers, especial-
ly Leguminivora  glycinivorella, and (2)  the
soybean colonizing  species of aphids,  espe-
cially Aphis  glycines.  These pests can  be
extremely serious and could  completely  up-
set the  economic  production of  this crop.
We have  made special efforts to compile  the
literature on these pests and to get  a first
hand  perception  of  their role in soybean
production in the orient, particularly in Chi-
na, Korea, and Japan.   Although  these  ef-
forts cannot guarantee that we will  detect
any  invasions early  enough to avoid their
propagation, they may allow us to establish
beforehand  a  control   strategy  to   adopt
should such immigrations take place.

CONCLUDING REMARKS
   The impact of  immigrant pests in agri-
culture in the U.S. has been noticeable.  In
no event, except for perhaps the spread of
the  boll weevil  and the pink  bollworm in
cotton, have immigrant  pests changed dras-
tically the economic production of agricul-
tural crops.  They have generated an enor-
mous body of information  and  stimulated
very productive research, such as  the  mech-
anisms of resistance in corn to the European
corn borer or the modeling of the  population

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                                         235
dynamics of the cereal leaf beetle.  In most
cases also an equilibrium position has been
established whereby the invading species has

been  relegated  either to  the  status  of  a
sporadic  or  secondary pest,  or its control

became part of a global pest  management
program.  In general, efforts at eradicating

the pest came too late to be of  benefit.
Usually detection of these immigrant  pests

occurred ten or more years after the proba-
ble date of actual immigration.   At that
point the pest had already spread beyond a
reasonable  chance  for  successful  eradica-

tion.  Thus,  for the most part, the recom-
mendation  for  the  control  of  immigrant

pests does not differ from that of our most
serious native pests.   That is, there  is no
substitute for thorough,  intensive scientific

research of  the  population dynamics of the
pest and its life system and the  development
of a global pest management strategy. It  is
extremely important  in the case  of very
serious potential pests to gain  a better un-
derstanding of the potential adaptability of

these pests  prior to their introduction.   It

would be  important,  too,  to  intensify the
efforts towards developing of a methodology
for the early detection of these pests.


REFERENCES
Houseman, J.K.,  D. Sherrod, C.  Eastman,
   W.H.   Luckmann,  R.  Randell,  and  C.
   White.  1978.  Note on the establishment
   in Illinois of Ban's  tepidii, a destructive
   European weevil.   Bull.  Entomol. Soc.
   Amer. 24:407-408.

Brindley,  T.A., A.N. Sparks,  W.B. Showers,
   and W.D. Guthrie.  1975.  Recent advan-
   ces on the European corn borer in North
   America. Ann.  Rev.  Entomol. 20:221-
   239.

Chiang, H.C.   1978.   Pest management in
   corn. Ann. Rev. Entomol. 23:101-123.

Elton, C.S.  1958.  The Ecology of Invasions
   by Animals and Plants. Methuen <5c Co.,
   London.  181 p.

Everett, T.R., H.C. Chiang, and E.T.  Hibbs.
   1958.  Some  factors influencing popula-
   tions of the European corn  borer  Py-
   rausta nubilalis (Hbn.)  in the North Cen-
   tral  States. Univ. of Minnesota Ag. Exp.
   Sta.  Tech. Bull. N.C. Reg. Pub. 87. 83 p.

Lofgren,  C.S.,  W.A.  Banks,   and  B.M.
   Glancey.  1975.  Biology  and control of
   imported fire ants.  Ann.  Rev. Entomol.
   20:1-30.

Glass,  E.H. (ed.)   1975.   Integrated pest
   management:     Rationale,   potential,
   needs  and  implementation.    Entomol.
   Soc. Amer. Special Pub. 75-2.  141  p.

Haynes,  D.L.  and  S.H.  Gage.   1981.   The
   cereal leaf beetle  in  North  America.
   Ann. Rev. Entomol. 26:259-287.

Huber,  L.L.,  C.R. Neiswander,  and R.M
   Salter.   1928.  The European corn borer
   and its environment. Ohio Ag. Exp. Sta.
   Bull. 429, Wooster. 196 p.

Kogan, M.  1981.  Dynamics of insect adap-
   tations to soybean: impact of integrated
   pest  management.   Environ.  Entomol.
   10:363-371.

Norris,  D.M. and  M. Kogan.  1980.  Bio-
   chemical and morphological bases  of re-
   sistance,  pp. 23-61 In F.G. Maxwell and
   P.R.  Jennings  (eds.),   Breeding  Plants

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                                         236
   Resistant to Insects.  John Wiley & Sons,
   New York. 683 p.

Painter,  R.H.  1951.  Insect  Resistance  in
   Crop Plants.  The  Macmillan Co., New
   York.  520 p.

Price,  P.W., C.E. Bouton,  P. Gross, B.A.
   McPherson,  J.N.  Thompson,  and A.E.
   Weiss.  1980.  Interactions among three
   trophic levels: Influence  of  plants  on
   interactions between  insect  herbivores
   and  natural enemies.  Ann. Rev.  Ecol.
   Syst.  11:41-65.

Sailer,  R.I.   1978.   Our immigrant  insect
   fauna.  Bull. Entomol. Soc. Amer. 24:3-
   11.

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                                     APPENDIX O
          SOME CONSIDERATIONS FOR THE ERADICATION AND MANAGEMENT
               OF INTRODUCED INSECT PESTS IN URBAN ENVIRONMENTS
                                  Gordon W. Frankie1
                                    Raymond Gill*
                                  Carlton S. Koehler
                                     Donald Dilly2
                                   Jan O. Washburn'
                                    Philip Hamman3
                                       PANEL V

INTRODUCTION
   Plant pests that are exotic to all or parts
of the U.S. are continually being intercepted
at the  many ports of  entry  around the
nation.  For example, during the period of 1
October  1978 through  30 September  1979,
the  Animal  and  Plant  Health  Inspection
Service  of  the  USDA  intercepted 18,644
plant pests;  14,002  were insects  (APHIS
1981).   The number  of  interceptions has
increased  slightly each year, (APHIS  1979,
1980), which can  be  attributed mainly to
large numbers of travelers using the airways
to commute between countries (G. Snider,
APHIS USDA, pers.   comm.). These inter-
national movements will always represent a
potential for the introduction of pest organ-
isms.
   This paper  will briefly  consider  some
biological,  social,  economic, and  political
consequences associated with the introduc-
tion of pests (primarily insects)  into urban
environments.  Although emphasis is placed
on the California  experience, the  general
trends probably apply to most urban areas
throughout the U.S.
 .Entomology, University of California, Berkeley, CA 94720

2Entomology, California Dept. of Food and Agriculture, Sacramento, CA 95814
Q
 Entomology, Texas A&M University, College Station, TX 77843
                                        237

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                                         238
CALIFORNIA AS A CASE STUDY
   During the past century, numerous intro-
ductions and  establishments of insects and
other pests  have occurred throughout  Cali-
fornia.   No exact figures have been  tabu-
lated for all  taxonomic groups;  however,
some idea of  the frequency and character-
istics of introductions and  establishments
can  be  gained  by  examining records  of
selected Homopteran  families (Table 1).
Compared  with  other insect groups, the
introduction frequencies  are  high  and are
due  to  such factors as:   1) many Homop-
terans are relatively sessile and remain at-
tached to their host plants during transpor-
tation; this feature contrasts with members
of other groups  that  have easily dislodged
life  stages;  2) because of their small size,
life  stages of many  Homoptera are  often
difficult to detect; and 3) high volumes  of
plant materials (nursery stock and  personal
house/yard plants) are  continually moved
across state  boundaries.   When detected
early and when  infestations  are small  in
     o
size,  it has been possible to eradicate some
of the  introduced homopterans, especially
the armored scales.  However, a few intro-
ductions have  disappeared without interven-
tion  by  humans (see Table 2 for more speci-
fic information on the homopterans).
   Of great interest and concern is the fact
that  most  introduced horn opt eran  species
(85%) were  first  reported in  urban  centers
(Tables 1  and 2).   This  is  an important
pattern that  undoubtedly  applies  to  pest
species in  other  toxonomic groups as well.
Points of air and  sea entry into the U.S. are
always located in or near significant popula-
tion centers.   Further,  when people  move
among states  they generally do so from one
urban center to another.  It follows, there-
fore, that urban centers  going to remain the
point of first discovery of most exotic pests,
some  of which have potentially serious con-
sequences to agriculture and forestry.   For
example, the  Mediterranean  fruitfly, Cera-
titis capitata  (Wiedemann), appeared in the
heavily populated San Francisco Bay Area in
1980.   In addition,  the gypsy moth, Lyman-
tria dispar  (L.),  although,  hardly an exotic
pest new to the  U.S., was first  discovered
established in  California  in San Jose in 1976,
and again  in  1982 in Santa Barbara—both
urban  centers  (Hoy 1982).  To  the north,
gypsy moth activity is concentrated in the
Seattle area  of  Washington,  Salem,  and
Portland Oregon, and Vancouver,  B.C.—all
urban regions.  Examples of other economi-
cally important pests, their  first discovery
sites,  and their subsequent eradications are
presented in Table  3.  As  with the Homop-
tera,  most of these species  were first  dis-
covered in urban  areas.
   Past  experience with  introduced  pests
indicates that  species of  agricultural, for-
est, or public health  importance  have re-

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                                          239
 ceived top priority  for  eradication and/or
 subsequent intensive management  efforts
 (for example, Medfly, Japanese beetle, and
 gypsy moth). The vigor of  these efforts,
 some of which require considerable expendi-
 tures  of  resources, directly  relates to ad-
 verse impacts (economic or health) expected
 in the  event  of widespread  establishment.
 However, species more  appropriately char-
 acterized as causing aesthetic or nuisance
 damage, which is typical of urban pests such
 as most ant aphid species that pose little
 immediate  economic or  health  threat (see
 also NAS 1980, Levenson  and  Frankie 1981),
 receive considerably less  attention as tar-
 gets for eradication and/or subsequent man-
 agement.  In addition, many  pests that are
 introduced into urban environments are as-
 sociated with indoor as  well  as garden  or
 yard situations—difficult habitats for eradi-
 cation efforts.   Further,  if surveys reveal
 that these  aesthetic/nuisance  pests range
 beyond one square mile (see footnote 2), the
 California Department of Food and Agricul-
 ture (CDFA) considers them unlikely candi-
 dates  for  total  eradication.    Quarantines
are,  however,  imposed  to keep these in-
festations  localized.   Finally,  other  con-
straints  may  seriously limit the  kinds  of
actions taken against introduced aesthetic/-
nuisance pests.  It follows, in theory,  that
we should expect a  proportionally greater
accumulation of pest  species in urban versus
agricultural or forest environments, of com-
parable size.  For  example, the number of
new insect  pest  species established on the
largest  and  most  important  agricultural
crops in northern California over the past
100 years compared to the number of new
established  species in the largest cities of
the same  region, should show the totals to
be  greater  in the urban environment,  as a
whole.  Surveying to test this hypothesis
would require considerable effort which was
not possible given the short time frame for
paper  preparation; however, the following
case histories exemplify the relative ease by
which  some  pests  become established in
urban environments.
Iceplant Scales Along California Freeways
   From June 1971 to June 1973, two scale
species,     Pulvinaria    mesembryanthemi
(Vallot) and P. delottoi Gill, were found to
be established in  Napa County (north end of
the San Francisco Bay).  An initial, unsuc-
cessful, effort was made in 1971 to eradi-
cate P.  mesembryanthemi from  one  small
suburban  locality.   During the  spring  of
1973, this scale was found in three cities in
nearby Alameda  County.   The  CDFA  con-
cluded that (1) the area infested exceeded
100 acres in three cities in  Alameda County;
(2)  the scale  was  probably not "a  truly
destructive   pest"  (agricultural);  and  (3)
there were several obstacles to  eradication,
which included the difficulty of dealing with

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                                         240
hundreds of private residences.  As a result,
the CDFA did not implement an eradication
program.
   By  1974, iceplant scales were  detected
in three San Francisco Bay Area  counties
where  they  were causing extensive iceplant
mortality in private and  public landscape
areas.    Thus,  this  urban  "nuisance  pest"
became a potentially serious economic  prob-
lem since iceplants are extensively used as
landscape ground cover in urban areas and
for dune stabilization in coastal areas.  Be-
tween  1974 and 1976, the California Depart-
ment of Transportation (CALTRANS), which
maintains the largest acreage of iceplant in
this state (6,000 acres along freeways), be-
came increasingly alarmed as the  potential
impact of the scale was realized.  In  1976,
at the request of CALTRANS,  Cooperative
Extension conducted a pilot study on the
efficacy of  chemical control.  This  study
revealed that some compounds would reduce
scale populations. However, this finding pro-
vided only a partial  answer for the manage-
ment of the pest since much remained to be
learned about the scales' biology,  behavior,
and ecology, and how this information  could
be related to more effective chemical and
other control methods.
   CALTRANS and CDFA  personnel met
with University of California researchers at
Berkeley in  1978 and resolved to develop  a
research program aimed  at  designing and
implementing  an  integrated  management
program  that  would  effectively deal with
the iceplant scale problem.   Two  coordi-
nated projects were initiated and funded by
CALTRANS: one aimed at discovering and
establishing natural enemies and the second
aimed  at  elucidating  the scale biology,  in-
teractions  with host  plants,  and  cultural
practices  that  might lessen scale  damage.
During this same year, foreign exploration
to South  Africa, the suspected geographic
origin  of  iceplant  scales,  was conducted.
Seven species of natural enemies (parasites
and  predators)  were  discovered  and  im-
ported to  California (U.C.   Berkeley)  for
rearing and later  release.  Several of  the
parasitoid  species  are  now  known  to  be
established  in  a  variety  of  the  climatic
zones  where the scales are found.  These
introductions, in addition to natural enemies
already present  (six species of parasites  and
predators), appear to  be providing good con-
trol of the  iceplant scales, which have now
spread (primarily  by  wind) to 17 counties,
including  areas  of the Central Valley  and
Southern California.
   Iceplants were initially chosen as a land-
scape ground cover in California because of
their ability to grow  in poor soils, tolerance
of high temperatures  and salt spray, and  low
water  requirements.  Prior to  the introduc-
tion of the scales, iceplants enjoyed a nearly
pest-free  existence,  and  most landscaped

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                                           241
 areas appeared  healthy  and vigorous.  The
 plant mortality that did occur  was attri-
 buted to poor soil and nutrient stress.  This
 suggested that while iceplants appeared  to
 be  healthy,  they  were  actually  growing
 under suboptimal conditions (J. MacDonald,
 personal communication).  In the presence
 of scales,  iceplant  landscapes  were  sub-
 jected to an additional stress that created
 widespread plant mortality.  While biologi-
 cal contol was effective, considerable time
 was required to colonize and multiply the
 natural  enemies.  This  time frame often
 exceeded the tolerance limits of the plants.
 Laboratory tests indicated  that  improving
 soil   conditions  through  fertilization  and
 watering lessened scale  damage and  im-
 proved iceplant  vigor and health.  By  im-
 proving  the  fertilizer regimes of freeway
 landscapes, it is now possible  to maintain
 landscape quality where  scales are present
 until  the natural enemies can  control  the
 pest.
   The control approach for the scale is an
 integrated system emphasizing  biological
 control.   Presently, a system is  being  de-
 signed that  will transfer  these  research
 findings to CALTRANS personnel.
Cockroaches in Urban California
   The CDF A has recorded the introduction
and establishment of nine cockroach species
in urban  California environments;  all of  the
following species originated from areas out-
  side North America:
         Species            Common name
   Blatta latoralis (Walker)   Turkistan
                            cockroach
   B.  orientalis L.           Oriental
                            cockroach
                            ('black beetle')
   Blattella germanica (L.)   German
                            cockroach
   B.  vaga Hebard           Field cockroach
   PeripZaneta americana (L.) American
                            cockroach
   P.  oustralasiae (F.)        Australian
                            cockroach
   P.  brunneo Burmeister     Brown
                            cockroach
   P. fuliginosa (Serville)     Smoky-brown
                            cockroach
  Supella longipalpa (F.)      Brown-banded
                            cockroach
 In general,   very little effort has been made
 to eradicate any of these species.
  Two of  the most recent  California intro-
 ductions, PeripZaneta fuligionosa and BZatta
 ZateraZis  exemplify how  new  roach species
 may  become established in California. Peri-
 pZaneta fuligionosa was  first  discovered  in
 1970  at Sutter Creek.  Since that time it has
 spread or has been newly  introduced from
 outside the  state to  several northern Cali-
 fornia counties  and  at  least  two southern
 California counties.  Despite  what  may  be
 characterized as spotty  initial infestations
 of this species  over a  12-year period,  no
 concerted effort was made  to eradicate any
 of the infestations (Dilly,  pers.  observ.).
 B. ZateraZis was first discovered in 1978  at
the Sharp Army  Depot near Stockton.  At
that time, army entomologists determined

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                                         242
that the infestation was well established and
widespread (however, it was less than one
square mile:  K. Hansgen,  pers.  comm.)  at
the base and had been there for at least two
or more years. The entomologists also con-
cluded  that  the  infestation  could  not  be
eradicated.   Officials of the state of Cali-
fornia (see next paragraph)  concurred with
this assessment (K. Hansgen), and as a result
the army opted to institute a chemical con-
trol program  to manage the population tat a
low  level.   As of this  writing, the  roach
remains confined  to  Sharp  Army  Depot;
however, a very real  potential still  exists
for range expansion of B.  lateralis  in Cali-
fornia from this one small focus.
    In summary, cockroaches are not viewed
as  agricultural pests and  therefore  do not
receive top priority as candidates for eradi-
cation  by the CDFA.   Responsibility for
these pests has been largely assumed by the
California Department  of  Health Sciences;
however, due to limited  budgets  and com-
peting  (and   more  serious)  public  health
pests, cockroaches also seem to  receive a
relatively low priority  by  that agency.  In
effect,  cockroaches  are  treated  as pests
that cause "only" aesthetic or nuisance dam-
age.   One may  conclude  therefore that a
relatively lax attitude  towards cockroaches
has  greatly contributed to their  successful
                                     2
establishment and spread in California.
BIOLOGICAL IMPACTS
   The urban environment abounds with un-
exploited resources that include a vast array
of native and exotic plant species and vari-
ous  structures  that  humans  erect  (see
Frankie  and Ehler  1978).   In addition  to
physical resources, people may be viewed as
a resource since they often play  an impor-
tant role in the ecology of urban pests.  For
example,  in the case of newly introduced
pests,  people may (1)  subsequently spread
them to adjacent areas after  initial estab-
lishment, (2) take direct  action  against
them,  or (3) fail to take appropriate action
against the pests  when  they are relatively
vulnerable  because of socioeconomic and/or
political  constraints  (Frankie  and  Ehler
1978, Nelson 1978, and Frankie et al. 1982).
   New pest species usually arrive without
their natural enemies.   Although this attri-
bute is recognized for agricultural and for-
est environments, it has been seldom real-
ized in urban environments.  For example, a
vast array  of natural enemies are associated
with the cockroach species in their native
habitat (Roth and Willis 1960).   However,
virtually no effort has  been made to seek
out these enemies to set up biological con-
trol programs  in  the countries  where  the
cockroach  species  have been  long estab-
lished.  A few examples of classic biocontrol
have  been  attempted  against  introduced
pests in urban areas,  primarily plant pests,

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                                          243
and these  are  summarized  in  a National
Academy Report on urban pest management
(pp. 148-153,  I960).4 The potential for clas-
sic biological control has been emphasized
by in a paper  by Olkowski et al. (1978) when
they  used biological control  against herbi-
vores  on  urban  shade trees. Although, the-
oretical classic biological control offers
an attractive means for  dealing with some
introduced  urban  pests,  success is  by  no
means a certainty (consider the gypsy moth
program).
    As noted  earlier,  introductions and  es-
tablishments of pest organisms in urban Cal-
ifornia environments have occurred contin-
uously for many years.   Overall, these  es-
tablishments amount to a gradual and pre-
dictable rate  of species  accumulation  that
could result in devastation of nearby agri-
cultural environments by  the pest species.
Some  introductions  will be recognized im-
mediately for their potential (e.g., Medfly
and other fruit flies).  However,  others will
not manifest themselves immediately.  The
following  case  history exemplifies how a
relatively subtle urban  introduction  could
develop into a serious agricultural problem.
Japanese Bayberry Whitefly
    The Japanese bayberry whitefly, Para-
bemisia myricae (Kuwana), is found in Tai-
wan, the Philippine Islands, and the southern
islands of Japan.  Although the whitefly has
been  intercepted  many  times  in  Hawaii
 (from the Philippines), no evidence indicates
 that it has become established there. It was
 listed as a serious pest of mulberry in areas
 of Japan  in  the  1920's and is also  a  minor
 pest of citrus. The species, however, is well
 controlled by natural enemies in Japan and
 in the Philippines.
   The whitefly  was collected for the first
 time   in the western  hemisphere  from  a
 nursery in Santa  Ana,  Orange County, Cali-
 fornia. Specimens of the insect  were col-
 lected from  Gardenia on 6 October 1978 by
 agricultural inspectors during a routine nur-
 sery inspection.  Independently, Los Angeles
 agricultural  inspectors discovered the same
 species on Robinson naval orange during a
 routine inspection of a wholesale nursery in
 San  Gabriel  on  12 October  1978. A  Los
 Angeles County  entomologist, having been
 informed of  the Orange County find, recog-
 nized the whitefly and sent it to Sacramento
 for confirmation.  Subsequent inspection of
 the San Gabriel nursery  resulted in discov-
 eries  of this insect on Robinson  naval or-
 ange,  Dancy tangerine, Bearss lime, Marsh
 grapefruit,  Eureka lemon,  Washington  or-
 ange, and dwarf birch.
   By 6   November   1978,   the  bayberry
 whitefly had  been found in two nurseries and
 their  urban environs in Orange County and
in two wholesale  nurseries and their urban
environs in Los Angeles County. The known
infested area in   Los  Angeles covered 35

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                                          244
square  miles.  Further, the wholesale nur-
series were shipping infested nursery stock
to other counties in California and to Ari-
zona.
   By 11 November delimitation surveys re-
vealed  the whitefly's presence  in  nurseries
in El Cajon,  Encenitas, and La Jolla in San
Diego County; Hesperia  in  San Bernadino
County;  Carpinteria  in  Santa  Barbara
County; Bakersfield, Delano, and Oakdale in
Kern County; Fresno in Fresno  County; and
Lafayette in Contra Costa County  (and two
locations in nurseries in  Phoenix, Arizona).
The  infested area in Los Angeles  extended
some 200 square miles.
   On 15 November 1978, a committee met
to determine a course of action. The com-
mittee  felt that further data  was needed
before  a  sound  decision  could be  made.
They postponed any recommendation for ac-
tion  for 60 days.  The likelihood of success-
ful chemical eradication already seemed re-
mote.  Based  on  previous experiences  with
eradication of the woolley whitefly, AZeuro-
thrixus  floccosus (Maskell), the committee
estimated that the cost of chemical eradi-
cation for  this new whitefly  would amount
to about 16.5 million dollars over a six-year
period.  Further, eradication would require
the application of about 17.5 million pounds
of insecticide.  In view of the expected cost,
the already widespread  distribution, and the
good  biological control  of the pest  in Japan
and  the  Philippines,  the  CDFA  in  January
decided to take no further chemical control
or quarantine action.   Rather,  a biological
control program was  suggested as an alter-
native and  was initiated through the  Uni-
versity of California.
   By 22 November 1978 the pest potential
of the species in California was already well
recognized. It had been  found  on 45 plant
species including citrus, avocado, and decid-
uous fruit trees.   By late 1979, populations
began to  increase substantially  on  many
hosts.    By June  1980,  a large block  of
commercial lemons in Orange  County  be-
came  so  heavily  infested  that  insecticide
treatments were required.  On lemons  the
growth patterns  of  the  cultural  pruning
practices meant  that  the  trees produced
new  growth almost constantly, an attribute
preferred by this  whitefly.  By early 1981,
many  lemon  groves  throughout  southern
California were heavily infested.
   Due to the whitefly's  short life  cycle in
California (21 days under greenhouse condi-
tions)  and its ability  to reproduce parthen-
ogenetically, the whitefly can develop large
populations rapidly and can spread quickly
from  place to place.   The early stages  are
small and without the noticeable wax adorn-
ment typical of other whitefly species. It is
therefore difficult to  locate in low densities
during delimitation surveys.
   The Japanese  bayberry  whitefly  story

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                                          245
 exemplifies the difficulty of finding,  con-
 trolling, or eradicating an insect pest in an
 urban environment.  When the initial infest-
 ation  was  discovered, it was too  large to
 eradicate.  Biological control was the only
 logical alternative.  Unfortunately,  to  date
 biological  control  has not been  very effec-
 tive in either  commercial orchard  or urban
 situations  in California. This may be due to
 rapidly  developing and  dispersing  popula-
 tions which do not allow natural enemies to
 keep pace.  It  may  also  be due  to poor
 acclimatization   by   recently  introduced
 natural enemies. Hopefully, biological con-
 trol will eventually reduce the whitefly pop-
 ulations.

 SOCIO ECONOMIC  AND POLITICAL
 IMPACTS
    Where  eradication  efforts are mounted
 against exotic  pests,  eradication must  also
 be  conducted in  urban areas.  Although the
 pest in question may be of greater concern
 to  agricultural  or  forest interests than to
 urban  residents, such eradication  efforts
 must be conducted by the ground  rules of
 the  urban,  not rural,  situation.  Even in
 states whose principal industries are  agri-
 culture or  forest products, vocal and highly
 organized  efforts  to  compromise  proposed
"optimum" eradication  programs  can be ex-
pected  from  today's   more  informed  and
sophisticated urban citizenry.
    Recent  U.S.  events  concerning  toxic
 chemicals and  human  health  virtually  dic-
 tate that decision-makers seriously examine
 the attitudes of urbanites towards standards
 of  environmental quality as they relate to
 pest management.  Findings from a recent
 national poll by Louis Harris (as reported in
 Sierra, Vol. 67(4),  1982)  exemplify relevant
 aspects of these attitudes. For example, an
 overwhelming   majority  of  people,  83%,
 "want  the Clean Air Act enforced as strictly
 as it is today or even more so."  A majority
 of  65%  to  32% also  say  they  oppose any
 constraint on  human  helath  standards on
 grounds  of  cost!   Of  considerable  signifi-
 cance  to  the politics of  decision-making is
 the  fact that,  fully  45% of  the voters
 nationwide say that the way a  candidate for
 Congress  voted on clean  air would probably
 or certainly affect their vote for that candi-
 date this fall  [1982], even if  they agreed
 with him or her on most other  issues.  When
 probed further, Harris  found  that "33% of
 the voters this  fall are prepared to defeat
 candidates for  Congress who yield on Clean
 Air."  In another national survey  on environ-
 mental issues,  conducted by the Council on
 Environmental  Quality (CEQ 1980), pollsters
learned that 46% of  the interviewees were
greatly worried about "the presence of toxic
chemicals such as pesticides or PCB's in the
environment"   (see  also  Levenson   and
Frankie 1981).

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                                          246
    When  these  survey  findings  are  con-
 sidered in light of other socioeconomic and
 politiacl patterns (e.g., voting strength is in
 urban rather than in rural areas, and public
 involvement in decision-making is  increas-
 ing),  one may expect a  wider array  of pest
 management decisions in the future.  One of
 these options, that  of  no action,  will in-
 creasingly be  given serious  consideration.
 This  situation in turn  should  place much
 greater pressure on  research and extension
 institutions to provide urbanites with high-
 quality information on the costs  and bene-
 fits of eradication and/or management op-
 tions.

 CONCLUDING REMARKS
   This  treatise is the  first  step  towards
 understanding the processes that lead to the
 introduction and establishment of pest or-
 ganisms in urban environments.  Future in-
 quiry   into this  topic might   include  such
 matters as:
 1. Elucidating the characteristics  of intro-
   ductions and establishments (e.g.,  fre-
   quency of urban  vs. agricultural intro-
   ductions) of  a greater representation of
   pest  organisms in California and other
   states where accurate records are com-
   piled.
2. Developing  generalizations about intro-
   ductions and establishments based on
   case   history  accounts   from   several
   states.  These case histories should also
   include the socioeconomic  and political
   circumstances associated with the intro-
   ductions and establishments.
3. Assessing current nursery practices (in-
   cluding assoicated regulations involving
   movemnets of plant materials) that may
   be responsible for some introductions.
4. Surveying attitudes of people who trans-
   port plant  materials across international
   and  state  boundaries.   Some  effort  to
   survey these attitudes  has  already been
   attempted  by federal quarantine author-
   ities (G. Snider, pers. comm.).
5. Examining   pest  faunas  on native and
   exotic plant species in given urban areas.
   Do natives or exotics, for example, have
   more  pest  problems  (including  plant
   pathogens)?  Further, what are the pros-
   pects for using biological control agents
   against exotics  and  natives (see  Ehler
   1982)?

ACKNOWLEDGEMENTS
   We thank K. Brown, G. Buxton, H.  Fair-
child, K. Hansgen, A. Hardy, and G.  Snider
for providing  us  with unpublished  informa-
tion  and insight into many of  the problems
associtated with introduced pest organisms.

FOOTNOTES
1
 Based on records of the California Depart-
   ment of Food and Agriculture.

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                                          247
  One  square  mile  policy:   The  State of
    California  administers  and  operates  a
    pest  prevention  system  mandated  by
    Section 403 of the Food and Agriculture
    Code.   Its major components are:  pest
    exclusion, pest detection, pest  eradica-
    tion, and  public information and educa-
    tion.  Pest detection involves systematic
    searches for specific pests  outside of a
    known infested  area.   The goal is to
    detect incipient infestations before er-
    adication  becomes  biologically  or  eco-
    nomically uinfeasible.   In  the  case of
    insects, the goal is to  detect pests (and
    take appropriate  action) before  the in-
    festation exceeds 1 square mile.
3
 Many  other pest  groups,  including poten-
    tially serious pests such as termites  and
    wood-infesting  beetles from  overseas
    crating  material,  are  similarly  char-
    acterized and treated in the same man-
    ner (D. Dilley and R. Gill, pers. observ.).
4
 Two errors should be noted in the biocon-
    trol narrative of the NAS report.  The
    second complete  paragraph  on page 15
    should begin with:   "Fifteen pests were
    the targets of classical  biological control
    from  1890-1969  (Laing  and   Hamine
    1976)."
    The third  complete paragraph  on page
151 should  begin  with:   "In  contrast, 106
agricultural, medical/veterinary, forest, and
  greenhouse pests were  the targets for clas-
  sical biological control."

  REFERENCES
  APHIS.   1979.   List  of intercepted plant
    pests (from  July  1,  1973 through Sep-
    tember 30, 1977).   USD A, APHIS publ.
    82-5.
 APHIS.   1980.   List  of intercepted plant
    pests (from October 1, 1977 through Sep-
    tember 30, 1978).   USDA, APHIS publ.
    82-6.
 APHIS.  1981.   List  of intercepted plant
    pests (from October  1, 1978 through Sep-
    tember  30, 1979).   USDA, APHIS publ.
    82-7.
 CEQ.   1980.   Public  opinion on  environ-
    mental issues (Results of a national pub-
    lic opinion survey).   A publication of the
    Council on Environ.   Quality,  USDA,
    DoE, and EPA.
 Ehler, L.E.  1982.  Ecology of Rhopalomyia
    californica Felt  (Diptera:   Cecidomyii-
    dae) and its parasites in an urban envi-
    ronment. Hilgardia 50:1-32.
 Frankie, G.W. and L.E.  Ehler.  1978.  Ecolo-
    gy  of  insects in  urban  environments.
    Ann. Rev. Entomol.  23:367-387.
 Frankie, G.W., J.B. Fraser and V.R. Lewis.
    1982.  Suggestion for implementing sur-
    vey  research results that deal  with pub-
    lic attitudes and behavior towards arth-
    ropod pests  in  urban   environments.
    Proc.  of Symp. on Urban and Suburban
    Tree Health.  Michigan State  Univ.,  E.
    Lansing (in press).
Gill, R.J.  1979.  A  new species Pulvinaria
   Targioni-Tozzetti  (Homoptera:   Cocci-
   dae)   attacking ice plant in California.
   Pan-Pac Entomol.  55:241-50.

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                                         248
 Hoy, M.   1982.   The gypsy  moth - here
    again. Calif. Agric. 36:4-6.

 Levenson, H. and G.W. Frankie. 1981. Pest
    control in the urban environment.  In: T.
    O'Riordan  and  R.K. Turner (eds.) Pro-
    gress in Resource Management and Envi-
    ronmental  Planning.   John  Wiley  and
    Sons, Ltd., England.

 NAS.  1980.  Urban Pest  Management.   A
    report of the committee on urban pest
    management.  National Research Coun-
    cil.  National Academy Press.

 Nelson, B.C.  1978.  Ecology  of  medically
    important  arthropods in urban  environ-
    ments.   In:   G.W.  Frankie  and C.S.
    Koehler  (eds.)  Perspectives  in  Urban
    Entomology,  pp. 87-124.

 Olkowski, W.,  H. Olkowski, A.I. Kaplan  and
    R. van den Bosch.  1978.  The potential
    for  biological  control  in  urban  areas:
    shade  tree  insect  pests.    In:   G.W.
    Frankie and C.S. Koehler (eds.) Perspec-
    tives in  Urban  Entomology,  pp. 311-
    347.
Roth, L.M.  and E.R.  Willis.   1960.  The
   biotic   associations   of   cockroaches.
   Smithson. Misc. Collect. 141.

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                                   249
Table 1.    Numbers of  introduced  homopteran species  that  have established  in
           California environments and their probable sites of introduction (see
           also Appendix I).
Family
                        Nos.  of species
                    intro.   erad.   estab.
                                            a
Probable intro. site
Urban   Agric.   ?
Aleyrodidae
Coccidae
Diaspididae
Pseudococcidae
Totals
7
29
84
29
149
0
4
30
_4
38
6
25
51
21
105
7
22
72
^6
127
0
4
12
_2
18
0
3
0
I
4
 a
lSpecies not accounted for through eradication efforts, apparently died out.

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                                    250
Table 2.    Introduced and  established  species  of selected homopteran  families;
           dates of first discovery in California; current status in California.
Taxa
Aleyrodidae
Aleurocybotus occiduus Russell
Aleurothrixus floccosus (Maskell)
Aleurotuba jelinekii (Frauenfeld)
Aleurotulus nephrolepidis (Quaintance)
Dialeurodes citri (Ashmead)
Parabemisia myricae (Kuwana)
Pealius azaleae (Baker <5c Moles)
Coccidae
Ceroplastes ceriferus (Fabricius)
C. cirripediformes Comstock
C. cistudiformis Cockerell
C. floridensis Comstock
C. sinensis Del Guercio
Coccus hesperidum Linnaeus
C. longulus (Douglas)
C. pseudohesperidium (Cockerell)
C. pseudo m agnoli arum (Kuwana)
Eucalymnatus tessellatus (Signoret)
Eulecanium caryae (Fitch)
Parasaissetia nigra (Nietner)
Parthenolecanium corni (Bouche)
Parthenolecanium fletcheri (Cockerell)
P. persicae (Fabricius)
P. Pruinosum (Coquillett)
P. quercifex (Fitch)
Physokertnes hemicryphus (Dalman)
Protopulvinaria pyriformis (Cockerell)
Pulvinaria citricola Kuwana
P. delottoi GUI: DeLotto Icepl. scale
P. floccifera (Westwood)
P. hydrangeae Steinweden
P. m esembryanthemi (Vallot):Icepl. scale
P. vitis (Linnaeus)
Saissetia coffeae (Walker)
S. miranda (Cockerell & Parrott)
Probable
intro.
site8
Comm. turf
Urb
Urb
Nurs
Nurs
Nurs
Nurs
Urb
Urb
Urb
Urb
Urb
Urb
Urb
Urb
Ag-Citrus
Urb
Ag-fr
Nurs
Ag-fr
Nurs
Urb
9
Nurs
Urb
Urb
Urb
Urb
Urb
Urb
Urb
Ag-fr
Urb
9
First
discovery
inCAD
pre 1950
post 1950
post 1950
pre 1950
pre 1950
post 1950
pre 1950
pre 1950
pre 1950
pre 1950
post 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1900
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950 .
post 1950°
pre 1950
pre 1950 .
post 1950°
pre 1950
pre 1950
pre 1950
Current
status0
MP
SP
MP
DO
MP or CP
SP
R
Erad
Yard pest
R
Erad
Yard pest
CP
R
Erad
Citrus pest
DO
R
R
MP
R
R
Walnut
pest
Oak pest
(minor)
R
MP
Erad
MP or CP
R
R
CP
R
MP or CP
MP

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                                     251
Table 2. (cont'd)
Taxa
S. oleae (Olivier)
Toumeyella liriodendri (Gmelin)
Diaspididae
Abgrallaspis cyanophylli (Signoret)
A. degeneratus (Leonardi)
Acutaspis albopicta (Cockerell)
Andaspis mackieana (McKenzie)
Aonidia lauri (Douche)
Aonidiella aurantii (Maskell)
A. citrina (Coquillett)
A. taxus Leonardi
Aspidiotus destructor Signoret
A. nerii Bouche
A. spinosus Comstock
Aulacaspis rosae(Bouche)
Carulaspis" juhiperi (Bouche)
C. minima (Targioni-Tozzetti)
Chionaspis americana Johnson
C. etrusca Leonardi
C. furfura (Fitch)
C".gleditsiae Sanders
C. wistariae Cooley
Chrysomphalus aonidum (Linnaeus)
C. bifasciculatus Ferris
£• dictyospermi (Morgan)
Clavaspis disclusa Ferris
C. ulmi (Johnson)
Comstockiella sabalis (Comstock)
Diaspidiotus liquidambaris (Kotinsky)
Diaspis boisduvalli Signoret
D. bromeliae (Kerner)
D. coccois Lichtenstein
Dynaspidiotus britannicus (Newstead)
Epidiaspis leperii (Signoret)
Fiorinia fioriniae (Targioni-Tozzetti)
F. japonica Kuwana
F. pinicola Maskell
F. theae Green
Furchadaspis zamiae (Morgan)
Hemiberlesia palmae (Cockerell)
Probable
intro.
site*
Urb
Urb
Urb
Urb
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Urb
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Ag
Urb
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Urb
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
First
discovery
inCAD
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1900
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
Current
status6
SP
U Erad
R
R
Erad
Erad
Erad
SP
MP or CP
Erad
Erad
SP
R
MP or CP
R
MP
R
CP
Erad
Erad
R
DO
R
DO
7
R
DO
MP
SP
R
R
•>
Walnut
pest
R
Erad
Erad
Erad
MP or CP
Erad

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                                    252
Table 2. (cont'd)
Taxa
H. lataniae (Signoret)
H. rapax (Comstock)
Howardia biclavis (Comstock)
Kuwanaspis pseudoleucaspis (Kuwana)
Lepidosaphes beckii (Newman)
L. camelliae Hoke
L. chinensis Chamberlin
L. conchiformis (Gmelin)
L. destefani Leonard!
L. gloverii (Packard)
L. machili (maskell)
L. noxia McKenzie
L. pallida Maskell
L. sciadopitysi McKenzie
L. tokionis (Kuwana)
L. ui'mi (Linneaus)
Leucaspis portaeaureae Ferris
Lindingaspis rossi (Maskell)
Lopholeucaspis cockerelli (de Charmoy)
Melanaspis bromeliae (Leonardi)
M. obscura (Comstock)
Neopinnaspis harperi McKenzie
Nilotaspis halli (Green)
Odonaspispenicillata Green
O. ruthae Kotinsky
Parlatoreopsis chinensis (Marlott)
Parlatoria blanchardii (Targioni-Tozzetti)
P, camelliae Comstock
P. crotonis Douglas
P. oleae (Colvee)
P. pergandii Comstock
P. pittospori Maskell
P. proteus (Curtis)
P. theae Cockerell
Pinhaspis aspidistras (Signoret)
P. buxi (Bouche)
P. strachani (Cooley)
Pseudauiacaspis cockerelli (Cooley)

Probable
intro.
sitea
Nurs
Nurs
Nurs
Nurs
Ag-Citrus
Nurs
Nurs
Ag-Figs
Ag-Olives
Ag-Citrus
Nurs
Nurs
Nurs
Nurs
Nurs
Ag-fr
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Ag-fr
Nurs
Nurs
Nurs
Ag-Dates
Nurs
Nurs
Nurs
Ag-Citrus
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
First
discovery Current
in CAD status0
pre 1950 MP or CP
pre 1950 MP or CP
pre & post Erad
1950
pre 1950 R
pre 1900 MP
pre 1950 R
pre 1950 Erad
pre 1950 MP
pre 1900 MP
pre 1950 R
pre 1950 R
pre 1950 Erad
pre 1950 Erad
pre 1950 Erad
pre 1950 Erad
pre 1900 MP
pre 1950 R
pre 1950 MP
pre 1950 Erad
pre 1950 R
pre 1950 R
pre 1950 R
pre 1950 Erad
pre 1950 MP
pre 1950 MP
pre 1950 R
pre 1950 Erad
pre 1950 R
pre 1950 Erad
pre 1950 MP
pre & post Erad
1950
pre & post R
1950
pre & post Erad
1950
pre 1950 Erad
pre 1950 MP
pre 1950 Erad
pre 1950 Erad
pre & post Erad
1950

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                                  253
Table 2.  (cont'd)
   Taxa
Probable
intro.
sitea
First
discovery  Current
in CA     status0
p. pentagona Targioni-Tozzetti
P. parlatorioides (Comstock)
Quadraspidiotus forbesi (Johnson)
Q. juglans-regiae (Comstock)
§. perniciosus (Comstock)
jlenaspidus albus McKenzie
S. articulatus (Morgan)
S. rubidus McKenzie
Una'spi's euonymi (Comstock)
Ag-fr
Nurs
Ag-fr
Ag-fr?
Urb
Nurs
Nurs
Nurs
Nurs
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
pre 1950
Erad
Erad
R
MP or CP
SP
R
Erad
R
MP or CP
Pseudococcidae
   Antonina graminis (Maskell)
   A* pretiosa Ferris
   Brevennia rehi (Lindinger)
   Cataenococcus olivaceus Cockerell
   Chorizococcus brevicruris McKenzie
   C. lounsburyi Brain
   Crisicpccus azaleae (Tinsley)
   C. pini (Kuwana)
   DysmicoGGUs brevipes (Cockerell)
   D. mckenziei Beardsley
   Ferrisia virgata (Cockerell)
   Heterococcus nudus (Green)

   Hypogeococcus splnosus Ferris
   Nipaecoccus aurilanatus (Maskell)
   N. nipae (Maskell)
   Phenacoccus aceris (Signoret)
   P. graminicola Leonard}

   Planococcus citri (Risso)
   P. kraunhiae (Kuwana)
   fieudantonina arundinariae McConnell
   Pseudoccus calceolariae'Waskell)
   P. comstocki (KuwanaT"
   P. importatus McKenzie
   P. longispmus (Targioni-Tozzetti)
   P. microcirculus McKenzie
   Rhizoeeus dianthi Green
   R. falcifer Kunckel d'Herculais
   R, kondonis Kuwana
   Trionymus diminutus (Leonardi)
Nurs
Nurs
•)
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Ag-Comm.
turf?
Nurs
Nurs
Nurs
Nurs
Urb-Comm.
turf?
Ag-Citrus
Nurs
Nurs
Ag
Urb
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
Nurs
post 1950  DO
pre 1950   MP
post 1950  MP or CP
post 1950  R
post 1950  Erad
pre 1950   MP
pre 1900   R
pre 1950   MP or CP
pre 1950   R
post 1950  Erad
post 1950  MP or CP
pre 1950   R

pre 1950   R
pre 1950   MP or CP
pre 1950   R
post 1950  U Erad
pre 1950   MP

pre 1900   SP
pre 1950   DO
post 1950  Erad
pre 1950   MP
post 1950  CP
post 1950  Erad
pre 1950   MP or CP
post 1950  U Erad
post 1950  MP or CP
pre 1950   MP or CP
post 1950  SP
pre 1950   R

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«j
 Ag = agricultural; Comm. turf = commercial turfgrass; Nursery (Comm.  turf &
 Nursery within or directly adjacent to urban areas).

 Renovation  and  modernization of CA quarantine/detection  service  occurred
 1950.

CMP = minor pest; CP = common pest; SP = serious pest; R = rare; DO = died out;
 Erad = eradicated; U Erad = under eradication.

 In 1949 a collection of  Pulvinaria sp.  was taken  from ice plant at the U.C.
 Botanical  Garden, Berekley; it subsequently could not  be relocated (between
 1949-70).    Then, in the early  1970's two  scale  species, P.   delottoi and  P.
 mesembryanthemi,  were found on isolated plantings of ice plant in the northern
 San Francisco Bay Area.   Although the 1949 Pulvinaria specimens very closely
 resembles P. delottoi, it is not considered conspecific at this time.

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 Table 3.  The most economically important insect  and mollusc pests that have
           been eradicated from Californiaj dates and location (County) of first
           discovery.  With the exception of numbers 3, 5, 7 and 9, all species were
           discovered in urban areas.
                    First discovery date
                           Counties
 white garden snail
 obscure snail
 Mexican bean beetle
 Mexican fruit fly
 wheat sawfly
 melon fly
 Khapra beetle
 Japanese beetle
 Khapra beetle
 white garden snail
 Japanese beetle
 medfly
 gypsy moth
 medfly
 oriental fruit fly
 1929      Orange and Los Angeles
 1933      Los Angeles
 1950      Ventura
 1954      San Diego
 1954      Santa Barbara
 1956      Los Angeles
 1960      Fresno, Tulare,  San  Francisco,  Madera,
           King,  Los    Angeles,   Kern,   Imperial,
           Riverside, and San Bernardino
 1961      Sacramento
 1966      Imperial
 1970      Los Angeles
 1973      San Diego
 1975      Los Angeles
 1977      Santa Clara
 1980      Los Angeles
 1960      Orange
 1960      Santa Barbara
 1966      Orange
 1967      Orange
 1969      Los Angeles
 1970      Los Angeles
 1970      Orange
 1971       Orange and San Diego
 1972       Santa Barbara and Orange
 1973       Los Angeles
 1974       Los Angeles
 1975       San Diego
 1976       Los Angeles and San Diego
1977       Orange and Los Angeles
1980       Orange and San Diego
a
 Hall scale, Nilotaspis halli. which is a serious Homopteran pest (see also Appendix
I), was  discovered in 1952  in Butte and Yolo Counties (agric.  environs).  It was
subsequently eradicated.
                                               •U.S. OOmjMEN! PBIHIINO OJMOE I 1982 0-389-890/70

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