JT. £2.^ ENVIRONMENTAL PROTECTION AGENCY
/ OFFICE OF WATER PROGRAMS
THE MOVEMENT AND IMPACT OF PESTICIDES USED IN FOREST MANAGEMENT
ON THE AQUATIC ENVIRONMENT IN THE NORTHEAST
-------
PESTICIDE STUDY SERIES - 7
THE MOVEMENT AND IMPACT OF
PESTICIDES USED IN FOREST MANAGEMENT
ON THE AQUATIC ENVIRONMENT
AND ECOSYSTEM
This study is the result of Contract No. 68-01-0125
awarded by the OWP, as part of the Pesticides Study
(Section 5 (£)(2) P.L. 91-224) to Cornell Aeronautica
Laboratory, Inc.
The EPA Project Officers were:
Charles D. Reese, Agronomist
David L. Becker, Chemical Engineer
ENVIRONMENTAL PROTECTION AGENCY
Office of Water Programs
Applied Technology Division
Rural Wastes Branch
TS-00-72-07
June 1972
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C. 20402. Price: $3.45, domestic postpaid; $3.00, GPO Bookstore
-------
EPA Review Notice
This report has been reviewed by the Office of Water
Programs of the Environmental Protection Agency and
approved for publication. Approval does not signify
that the contents necessarily reflect the views and
policies of the Environmental Protection Agency, or
does mention of trade names or commercial products
constitute endorsement or recommendation for use.
-------
PREFACE
The first volume of this report summarizes the findings,
conclusions, and recommendations of a research study conducted
during the period of 19 July 1971 to 15 January 1972. This
study was conducted for the Environmental Protection Agency
(EPA) by the Cornell Aeronautical Laboratory, Inc. (CAL) under
contract No. 68-01-0125.
Volume II, the Appendix to the final report, contains
definitive, complete and detailed treatises of the topics
summarized in this volume. Each treatise represents the
findings of the individuals that have contributed to this study,
-------
ACKNOWLEDGMENTS
This Laboratory wishes to acknowledge the great x,?illingness and
cooperation extended to us by individuals of the following agencies and insti-
tutions
New Jersey Department of Agriculture
New York State Departments of:
Agriculture and Markets
Environmental Conservation
Health
State University of New York:
College of Agriculture at Cornell University
College at Buffalo
College of Forestry at Syracuse University
United States Forest Service
Particular appreciation is expressed to personnel of the Bureau of
Forest Insect and Disease Control of the New York State Department of Environmental
Conservation for excellent cooperation in providing all types of useful data and
information.
Significant contribution and authorship to this report have been pro-
vided by J.L. Brezner, E.A. Gasiecki, R.M. Klingaman, R.L. Lapp, R.P. Leonard,
T.R. Magorian, A. Muka, R.E. Reinnagel, C.W. Rogers, R.A. Sweeney, R.L. Talley
and J.T. Wozer. Drs. Brezner, Muka and Sweeney are from the State University
College of Forestry, College of Agriculture, and Great Lakes Laboratory at
Buffalo, respectively. All others are members of the CAL Staff.
iii EQ-5025-D-2 (Vol. 0
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TABLE OF CONTENTS
Section
Title
INTRODUCTION
I.
II.
III.
IV.
V.
VI.
INVENTORY OF USES
A. Historical
B. Inventory of Uses, 1945 to the Present
C. Treatment Efficacy
APPLICATION TECHNIQUES
A. Inventory
B. Application Rate
C. Equipment
D. Procedures
ROUTE OF PESTICIDES INTO THE WATER ENVIRONMENT
A.' Introduction of the Pesticide to the Forest
B. Leaching, Overland Runoff and Sediment Transport
C. Intentional Dumping, Accidental Spills and Container
Disposal
IMPACT OF PESTICIDES INCLUDING METABOLITES ON THE
AQUATIC ENVIRONMENT
A. DDT and the Aquatic Environment
B. Sevin and the Aquatic Environment
C. Synergism in the Aquatic Ecosystem
D. Impact on Humans
LAWS AND REGULATIONS GOVERNING THE SALE AND
USE OF PESTICIDES
ALTERNATIVES TO CHEMICAL CONTROL
A. Native Pest Infestations
B. Non-Native Pest Infestations:
Gypsy Moth Control
1. New Jersey Program
2. Another Alternative
Integrated
VII. CONCLUSIONS
VIII. RECOMMENDATIONS
2
2
4
5
9
9
10
12
12
14
14
17
19
21
22
27
32
33
35
38
38
39
39
42
44
46
IV
EQ-5025-D-2 (Vol. I)
-------
TABLE OF CONTENTS
Section Title Page
A-l INVENTORY'OF USES 1-1
A-l.l Introduction 1-1
A-l.2 Historical Development of Pesticide Use 1-2
A-l.3 Historical Summary of Pesticide Use 1-14
A-l,A Pesticide Inventory - 1945 to the Present 1-16
A-l.4.1 Pesticide Treatment Efficacy 1-21
A-l.5 References 1-26
A-2 APPLICATION TECHNIQUES 2-1
A-2.1 Introduction 2-2
A-2.2 The Distribution Process 2-4
A-2.3 Pesticide Application Techniques Used in
New York State 2-28
A-2.4 References 2-38
A-3 ROUTES OF PESTICIDES INTO THE WATER ENVIRONMENT 3-1
A-3.1 Introduction 3-1
A-3.2 Atmospheric Routes and Rates of Pesticide Travel 3-3
A-3.2.1 Evaporation of the Liquid Carrier 3-5
A-3.2.2 Overdosage Within Treated Area 3-11
A-3.2.3 Off-Target Drift 3-11
A-3.2.4 Atmospheric Contamination by Complete
Evaporation 3-14
A-3.2.5 Washoff of Pesticide by Rain 3-16
A-3.2.6 Summary Statement Concerning
Atmospheric Pathways 3-16
A-3.3 Relevant Descriptions of New York Forest Regions 3-19
A-3.3.1 Topography and Soils of Forest Regions 3-19
A-3.3.2 Forest Types of New York 3-28
A-3.4 Resistence of Pesticides in Forest Soils 3-30
A-3.5 Transport Processes in Forests 3-35
A-3.5.1 Leaching 3-35
A-3.5.2 Runoff 3-37
A-3.5.3 Sediment Transport 3-42
A-3.6 Intentional Dumping, Accidental Spills and
Container Disposal 3-48
A-3.7 References 3-51
A-4 IMPACT OF PESTICIDES, INCLUDING METABOLITES, ON THE
AQUATIC ENVIRONMENT AND FOREST ECOSYSTEM 4-1
A-4.1 Introduction 4-1
A-4.2 DDT and the Aquatic Environment 4-3
A-4.3 Fate of Pesticides in the Forest Ecosystem 4-30
V EQ-5025-D-2 (Vol. II)
-------
TABLE OF CONTENTS (Cont.)
Section Title
A-4.3.1 Non-biological Degradation 4-30
A-4.3.2 Biological Degradation 4-31
A-4.3.3 Bioconcentration and Toxicity of
DDT and Sevin in the Forest Environment 4-36
A-4.4 Antagonism and Synergism 4-41
' A-4.4.1 DDT 4-41
A-4.4.2 Sevin 4-46
A-4.5 Impact on Humans 4-47
A-4.5.1 DDT 4-48
A-4.5.2 Sevin 4-58
A-4.6 References 4-67
A-5 LAWS AND REGULATIONS CONCERNING THE USE AND SALE OF
PESTICIDES IN NEW YORK STATE 5-1
A-5.1 Current New York State Laws 5-1
A-5.2 Considerations in the Formation of Laws,
Rules and Regulations Pertaining to the Research,
Development, Handling and Use of Pesticides 5-10
A-6 ALTERNATIVES TO CHEMICAL CONTROL 6-1
A-6.1 Native Pest Infestations 6-5
A-6.2 Non-native Pests 6-8
A-6.2.1 Gypsy Moth - Porthetria Dispar 6-9
A-6.3 Alternative Control Methods 6-12
A-6.3.1 Silvicultural Techniques 6-12
A-6.3.2 Genetic Controls 6-13
A-6.3.3 Behavioral Controls 6-14
A-6.3.4 Direct Controls 6-17
A-6.3.5 Biological Controls 6-18
A-6.4 Control Alternatives 6-31
A-6.4.1 New York 6-31
A-6.4.2 New Jersey 6-31
A-6.4.3 Other Alternatives 6-36
(1) Destruction of Eggs 6-37
(2) Destruction of Caterpillars 6-48
A-6.4.4 Control Personnel Used 6-54
A-6.5 Summary 6-57
A-6.6 References 6-59
EQ-5025-D-2 (Vol. II)
VI
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LIST OF ILLUSTRATIONS
Figure Title
1.1 Early Application Methods of Forest Pesticides in
New York State 1-13
1.2 Gypsy Moth Control Program in New York State, 1945-1971 1-22
1.3 Treated and Defoliated Acreage on Part of Long Island,
New York 1-24
2.1 Performance Correlation of Flat Fan Nozzles Mounted on
Moving Aircraft by Yeo's Method 2-14
2.2 Performance Correlation of Flat Fan Nozzles Mounted on
Moving Aircraft by Modified Ford and Furmidge Method 2-16
2.3 Typical Droplet Mass Size Distributions Expected for
D6-46 Hollow Cone Nozzle Spraying Water 2-20
2.4 Effect of Mass Median Diameter on Percent of Drops
Penetrating the Foliage Canopies 2-24
2.5 Typical Particle Mass-size Distribution of Sevin SOS 2-34
2.6 Spray Cutoff Near Water 2-37
3.1 Natural Pesticide Routes in Closed-Canopy Forest 3-2
3.2 Pesticide Droplet Evaporation and Drift Characteristics,
Airborne Application 3-7
3.-3 Extent of Present Forest 3-20
3.4 Land Form Categories 3-21
3.5 Excessive Slope 3-22
3.6 Land Form Regions 3-24
3.7 Characteristic Podzol Soil in Adirondacks 3-26
3.8 Breakdown of Chlorinated Hydrocarbon Insecticides
in Soil 3-33
3.9 Typical Forest Stream Bank Cross Section 3-43
4.1 Disappearance of Carbaryl from Oak Leaves Aerially Sprayed
at the Rate of 1 Ib/acre (Plot 12) 4-17
4.2 Disappearance of Carbaryl from Oak Leaves Aerially Sprayed
at the Rate of 1 Ib/acre (Plot 13) 4-17
EQ-5025-D-2 (Vol. II)
-------
LIST OF ILLUSTRATIONS (Cont.)
Figure Title .p.age
4.3 Shackham Brook Study Area 4-23
4.4 Insects Collected as a Percent of Population,
Maximum, in the Test and Control Branch of Shackham
Brook in 1966, 1967 and 1968. Range Markings Represent
95 Percent Confidence Intervals 4-24A
4.5 Concentration of Sevin in Parts Per million Versus
Percent Mortality to Determine LC,-n of Odonata at
18 and 24 Hours 4-27
4.6 Routes of DDT Metabolism 4-33
4.7 Possible Metabolic and Catabolic Products Arising
from Degradation of Sevin 4-35
6.1 Life Cycle of Gypsy Moth 6-9
6.2 Parasite Exorista Segregatta Ovipositing on Gypsy
Moth Larvae 6-34
6.3 Gypsy Moth Life Cycle and Weekly Employment for
Gypsy Moth Control in Massachusetts 6-55
Viii EQ-5025-D-2 (Vol. II)
-------
LIST OF TABLES
Title
Compositional Features of the Total Quantity of
Forest Pesticides Used in New York State, 1945 to
1971 Inclusive 1-18
2.1 Spray-Droplet Distribution on a 22-ft Douglas Fir Tree 2-26
2. II Post-hatch Treatment, 1963 Airplane Spray Tests
With Sevin and Stickers Against Gypsy Moth in
New York 2-30
2. Ill Post-Hatch Treatment, 1965 Airplane Spray Tests
With Sevin and Stickers Against Gypsy Moth in New York 2-31
3.1 Estimates of Increased Accumulated Volume Percentage
Due to Atomization by Air Stream as Compared to
Still Air 3-9
3. II Correlation of Insecticide Soil Resistance with
Water Solubility 3-32
4.1 Residue in Fish and Crayfish Before and After the
Application of 0.5 Ib Technical DDT /Acre 4-6
4. II Gypsy Moth Egg Mass Counts, Cape Cod 4-16
4. Ill Apparent Sevin or Metabolites in the Tissues of
Marine and Estuarine Organisms Collected Both Prior
To and After the 1965 Cape Cod Gypsy Moth Spraying
Program 4-19
4. IV Apparent Sevin or Metabolites in the Tissue of
Freshwater Fish Collected Both Prior To and After
the 1965 Cape Cod Gypsy Moth Spraying Program 4-20
4.V Lawrence Pond, Sandwich, Carbaryl (Sevin) in Water
and Topsoil Prior to and Following Application
for Gypsy Moth Control 4-21
4. VI Residues of Pesticides in Soil Invertebrates and
Their Environment 4-38
4. VII Effect of Anticonvulsant Drugs on Body DDT Burden 4-43
EQ-5025-D-2 (Vol. II)
-------
LIST OF TABLES (Cont.)
Table Title La-Se
6.1 Forest Tent Caterpillar Defoliation and Conconsitant
Pesticide Treatment """-'
6.II Known and Recorded Parasites, Hymenopterous Parasites
of the Gypsy Moth 6-21
6.Ill The Present Status of the Introduced Parasites (1911) 6-23
6. IV Foreign Enemies of Porthetria Dispar and Nygmia
Phaeorrhoea Liberated in North America 6-26
6.V Gypsy Moth Parasite Releases, State of New Jersey 6-33
6.VI Gypsy Moth Control by Destruction of Egg Cluster 6-43
6.VII Summary of Early Gypsy Moth Control in Massachusetts 6-56
EQ-5025-D-2 (Vol. II)
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INTRODUCTION
New York State covers an area of about 30.7 million acres. Of this
total, about 14.5 million acres are forested.
This report summarizes the findings, conclusions and recommendations
relative to the use of pesticides in the forested regions of New York State, and
the resultant impact on the aquatic environment.
This report is organized on a chronological basis. The scope of this
study starts with an historical sketch on the use-development of pesticides in
New York State forest management and concludes with indications as to the potential
role of pesticides in the future. The fate of pesticides and their impact on the
aquatic environment is chronologically summarized by consecutive presentation of
what is applied, how is it applied, how it moves from the forest to the aquatic
environment and finally, the manifestations of the pesticide within the aquatic
environment.
Accordingly, this report is presented in the following principal
sections:
I. Inventory of Uses
II. Application Techniques
III. Route of Pesticides into the Water Environment
IV. Impact of Pesticides Including Metabolites on the Aquatic Environment
x
V. Applicable Laws and Regulation Governing Pesticide Use
VI. Alternatives Used and Degree of Control
Section VII presents broad interim conclusions and Section VIII presents
preliminary recommendations based on this effort.
Since the topics covered in these sections are not mutually exclusive,
some overlap necessarily exists between sections in this presentation.
-1- EQ-5025-D-2 (Vol. I)
-------
I.
INVENTORY OF USES
This section presents a summary of the information obtained relative
to both the historical development of forest pesticide use within New York State
and description and analysis of current pesticide use, including the quantities
and types of chemicals used, the pests toward which they were directed, and
comments on the efficacy of these treatments.
A. Historical
Serious outbreaks of destructive native forest pests were not new
phenomena in New York State forests even at the turn of this century. For
example, areas of both eastern New York and the Adirondacks were ravaged in the
late 1800's by the forest tent caterpillar and the spruce bark beetle. As long
as pests remained in forested regions little overt control was exercised by man.
Rather, reliance was placed in natural control processes such as unfavorable
climate, pest starvation, parasites and predators.
Early chemical control, at the start of this century, was directed
toward the protection of ornamental shade trees and a few selected stands of
forests that received high-use, such as resort areas. Principal chemical control
materials were arsenical compounds which were used as foliar protectants. For
sucking insects, cbntact insecticides as whale oil soap solution and kerosene
emulsions were employed.
_2- EQ-5025-D-2 (Vol. 1)
-------
In 1869 a non-native pest, the Gypsy Moth (Porthetn'.a dispar L.) was
introduced from Europe into this country in the Commonwealth of Massachusetts.
This pest attacks a variety of trees and shrubs, although members of the oak
family are preferred. Early control of a non-native pest as the Gypsy Moth is
generally not effective by natural processes due to decreased availability and
efficacy of indigenous enemies.
In 1912, the Gypsy Moth was first found in New York State. The initial
infestation, located in eastern New York State, was treated, as were several
other small outbreaks. In 1923, a barrier zone was established within the
State to preclude the westward spread of this non-native pest. Isolated infesta-
tions within this zone were also treated, using chemical control materials and
techniques developed for shade tree protection.
The principal pesticide used against the gypsy moth in New York State
was lead arsenate. This stomach poison had been specifically developed in 1892
for gypsy moth control, and was subsequently used in both barrier and local
infestation roles.
During the late 1930's and early 1940's, an unfortunate alliance served
to aggravate the gypsy moth problem of New York. This alliance included a
combination of weather conditions (1938 Hurricane) and pest outbreaks in adjacent
states which led to violation of the barrier zone; the depletion of inspection
and control personnel, due to curtailment of relief (WPA and CCC) labor, and the
(1,,*-xrea]c of World War II. Up to the termination of World War II, somewhat less
than 400,000 pounds of lead arsenate had been applied to selected acreage that
was either infested with or threatened by the gypsy moth.
_3_ EQ-5025-D-2 (Vol. I)
-------
B. Inventory of Uses, 1945 to the Present
At the conclusion of World War II a new pesticide, DDT, was experimentally
applied to 335 acres infested with Gypsy Moth in the counties of Albany, Fulton
and Saratoga. The results were noted as "spectacular" and "amazing". The tempo
of DDT treatment to Gypsy Moth quickened so that by 1949 about 135,000 acres of
central and northern portions of the barrier zone were treated.
In the period from 1945 to 1971, about 3.5 million pounds of pesticide
were used to control insect and disease pests in the forested lands of New York
State. Table 1 presents compositional features of this total.
Table 1
COMPOSITIONAL FEATURES OF THE TOTAL
QUANTITY OF FOREST PESTICIDES USED IN
NEW YORK STATE 1945-1971, INCLUSIVE
PESTICIDE TYPE
DDT (g)
CARBARYL (SEVIN)
OTHERS
TOTAL
QUANTITY
POUNDS
2,411,540
1,084,527
8,000
3,504,067
TONS
1,206
542
4
1,752
PERCENT OF
TOTAL
68.8
30.9
.3
100.0
Of this total, 98.6% (3.46 million pounds) of all forest pesticides
were used to combat gypsy moth. This could lead to a logical, but erroneous,
conclusion that this pest is the only significant pest problem in New York.
Other pests as Forest Tent Caterpillar and the Saddled Prominent have defoliated
millions of acres during the same period. However, against such native pests,
chemicals are used only to protect high-use acreage with principal reliance
being placed on natural control processes.
'union Carbide Corporation Trademark for carbaryl (1-Naphthyl-N-
Methylcarbamate).
_4_ EQ-5025-D-2 (Vol. I)
-------
C. Treatment Efficacy
Figure 1 presents both the yearly allocation of pesticide, by type used
in gypsy moth control, and the annual defoliation by this pest as measured by
aerial survey.
There are several distinguishing features of this graphical presentation.
The vast quantities of DDT used up until the late 1950's reflects the philosophy
of control by eradication. Since that time, the concept of control and
management has prevailed. Also, it should be noted that carbaryl (Sevin) was
first introduced in 1959 in response to concern relative to DDT milk residue and
also due to effects of DDT in trout water areas. Since 1966, no DDT has been
used to control the Gypsy Moth or any other forest pest in New York State.
Exclusive use of the bio-degradable Sevin, and the general upsurge of
Gypsy Moth, has led to speculation that this pesticide may not be effective. Casual
observation of Figure 1, where the great increase in acres defoliated is visually
"correlated" with the use of Sevin, suggests an aura of reasonableness to this
concern. Detailed examination of hard data, however, demonstrates that such an
assertion is not only oversimplifying but is, in large measure, incorrect.
Much of the defoliated acreage has been defoliated because it has not
been treated. New York State treatment policy provides guidelines that (1) the
infected acreage should be at least 50 acres in size (2) should exhibit at least
500 egg-masses per acre at the plot center, and (3) signed landowner consent must
be obtained. These policy factors, coupled with manpower limitations and the
abandonment of an eradication philosophy, are significant causative elements in
the upward trend of woodland defoliation by Gypsy Moth.
-5- EQ-5025-D-2 (Vol. I)
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TREATED ACREAGE -- GYPSY MOTH
NEW YORK STATE
ACRES TREATED EACH YEAR WITH DDT AMD/OR Sf.VIN
2BOO
2700
o
o
o
I-
<
UJ
UJ
oc
400
300
200
100
I
YEAR OF TREATMENT
Y t A 1 {
I'M',
1946
I'll/
I9i)8
191'J
190U
19M
VJ02
1353
1904
190!)
1956
1057
1908
1909
1900
1961
1962
1963
1964
1960
1906
1967
1968
1969
1970
1971
TOTALS
AC HIS tlUT
330
26.131
O4.'<14
73.320
134.370
14C.200
121.648
149.700
122.652
87.742
194.376
440.202
2.774,417
2.040
894
11.282
00.112
146.008
144,608
31.500
13.486
4.747.675
AC1KS StVIN
76.336
8.282
160
300
59.037
32.865
99.969
218.123
41 458
100.454
57.652
120.664
250.700
1.066.050
TOTAI
3.V.
2t, / I'l
64 'I''.
7 1 C'U
134 .1711
146.2(10
121.643
149.700
122.602
87.742
194,376
446 202
2.774.417
2.040
77.230
19.564
55.272
146.30?
203.090
64,365
113.400
218,123
41.456
100 404
57.602
120664
250 '50
5.813.725
GYPSY MOTH DEFOLIATION IN NEW YORK STATE
ACRES DEFOLIATED EACH YEAR
o
o
o
400
J5 300
Q
UJ
H
_l
O
cfl
UJ
t£
200
150
100
50
DATA
NOT NOT
OBTAINED NOTED
NONE
•.
YEAR OF DEFOLIATION
YEAR
1910
1946
1947
1948
19.19
1900
1901
1952
1953
1904
1900
1906
1907
1908
1909
1960
1961
1962
1963
1964
1960
1966
1967
1968
1969
1970
19/1
1(11 AL
ACHES
DATA NOT OBTAINED
i '
675
NOT NOTED
y
10.559
6.649
858
0
1.605
16.490
31.330
61.342
22.600
97.237
148.366
34.655
46.160
47.525
121 t.10
416,2/0
4/9 ISO
1.543.U86
Figure 1 GYPSY MOTH CONTROL PROGRAM IN NEW YORK STATE, 1945-1971
-6- EQ-5025-D-2 (Vol. I)
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Figure 2 qualitatively illustrates some of these points. This area
of Long Island was aerially treated with a water-borne formulation of Sevin at
a rate of 1 pound (active) per acre. Most acreage defoliated was not treated.
Most of the treated acreage was not defoliated. However, it should be noted
that some defoliation (not severe) did occur within the treated blocks that
were adjacent to untreated woodland. This was due to reinfection due to airborne
larvae dispersal from adjacent untrc ted regions. Experience in the past with DDT
indicates that in similar circumstances, the chemical persistence of the pesticide
would have controlled this reinfection, whereas the greatly decreased chemical
persistence of carbaryl does not permit extended protection against the re-
infection threat.
-7- EQ-5025-D-2 (Vol. I)
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SPRAY AREA
(1150 ACRES)
DENOTES 1971 DEFOLIATION
COURTESY: NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION
Figure 2 TREATED AND DEFOLIATED ACREAGE ON PART OF LONG ISLAND, NEW YORK
_8_ EQ-5025-D-2 (Vol.1)
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II.
APPLICATION TECHNIQUES
A. Inventory
In New York State pesticides for gypsy moth control are applied by
spraying selected forested areas, which through annual egg-mass count surveys
(conducted during the fall or winter by personnel of the state Bureau of Forest
Insect and Disease Control) are known to have high levels of gypsy moth in-
festations. Only about one-fourth of the forested areas in New York are under
state jurisdiction, and it is state policy to obtain written consent from
landowners before spraying privately owned property. Most of the spraying is
done by state owned or state-contracted aircraft, both to achieve timeliness of
pesticide application and to permit treatment of large areas, often having limited
overland accessibility. Of the total 5.8 million acres which have been treated
since 1945 about 99% has been treated by airborne application, using both fixed
wing and helicopter aircraft and component boom and nozzle technique. The
remaining one percent has been treated using ground based equipment - vehicle-
mounted or man-portable mist blowers. Ground-based spraying is carried out
chiefly in suburban and recreational areas, where a greater degree of spatial
control of pesticide application must be exercised.
The gypsy moth is currently attacked via droplets of pesticide spray
impacted and retained on leaf surfaces. During the caterpillar or larval stage
of its life cycle, which occurs in May and June, the gypsy moth is a voracious
leaf-eater, and the pesticide acts as an intestinal poison, following leaf
ingestion.
~9~ EQ-5025-D-2 (Vol. I)
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B. Application Rate
The pesticide used in all the early aerial spray work was DDT dissolved
in oil. It was initially applied at a rate of 1 pound in 1 gallon per acre and
later reduced to half this concentration. In 1959 carbaryl (Sevin), a less
persistent pesticide, was found to be highly toxic to gypsy moth and its use
soon became extensive; it completely replaced DDT by 1966. The first tests and
early work with carbaryl used a formulation of 1 pound active carbaryl (1.2 Ib.
of 85% Sevin) plus 4 ounces of sticker in 1 gallon of No. 2 fuel oil. Adequate
gypsy moth control was obtained where this formulation was applied in aerial
sprays of 175 microns volume median diameter at a rate of 1 pound carbaryl per
acre. Half this rate did not give sufficient control. Similar oil-based
formulations including Sevin-4-Flowable have and are still used to some extent
outside New York State. Because of objectionable slick formation with the oil-
based formulas, water-based spray was tested. It was determined that water-based
sprays gave adequate control when applied by air at rates of 0.5 and 1 pound
active carbaryl per acre. Curiously, in New York State essentially the same
formulation is now used, consisting of 1.25 pounds Sevin SOS and 4.0 ounces of
Pinolene 1182 sticker in sufficient water to make 1 gallon, and it is applied at
a rate of 1 pound active carbaryl per acre - twice the rate shown to be required.
Simple mental calculations thus reveal that at an application rate of 0.5 pound
carbaryl per acre, twice the total area could be treated with the same total
amount of pesticide, or alternately, the same area with half the total amount.
For mist blower operations the application rate is about 10 to 15 pounds active
carbaryl per acre.
-10- EQ-5025-D-2 (Vol. T)
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In all the known work on gypsy moth toxicity, there is a notable lack
of diet-based dose-response data. The effectiveness of carbaryl sprays and amounts
required per acre have essentially been established in the field for particular
modes of spray operation and pest attack. The shortcomings of this approach be-
come apparent when one attempts to examine alternate spray operations and
attack modes. In addition, dose-response data for topical application of
carbaryl and several other pesticides against gypsy moth larvae have only
recently been determined. The contact effectiveness of carbaryl was implicit,
however, in the work of Connola in which carbaryl was applied on infested areas
prior to egg hatch. Unfortunately, topical application and contact effectiveness
are not necessarily equivalent. For example, it has been observed that for the
first instar of Pieris larvae on cotton the median lethal dose due solely to
pickup is particle size dependent. A similar effect has been observed in the case
of bark beatles. Whether such an effect exists for gypsy moth in its first instar
stage is not known, but if so, it would offer an alternate approach to the current
use of deposited droplets on foliage. By utilizing a combination of diet and
contact response the timing of spray application could become much less critical.
In a trial conducted in early May 1962 in New York State, Sevin was applied at a
rate of 0.5 pound per acre with sticker, before foliation and before hatching of
the Gypsy Moth larvae. Good control was achieved, presumably through pickup of
Sevin by the emerging larvae in their travel to the emerging foliage.
-11- EQ-5025-D-2 (Vol.. I)
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C. Equipment
The aircraft and dispensing equipment used in New York State are
conventional. The Stearman biplane and some of the more recent fixed wing
agricultural aircraft types have been employed for small plot spray work. The
bulk of the spray operations, however, are now carried out using the Grumman TBM
and helicopters. Typical nozzle and boom arrangements for low volume spraying
are used. Spraying specifications call for use of Spraying Systems Company
diaphragm type quick acting on/off valves together with D8-45 hollow cone nozzle
discs and cores. Various other nozzle types have been used including the flat
fan tips 8002E-8004E and the hollow cone combinations D6-46,D7-56, D8-56 and
D10-25. Available information indicates that water-formulated spray drops pro-
duced at the aircraft using these nozzle types have volume mean diameters (VMD)
in the range of 200 to 500 microns. Spray uniformity is checked prior to the spray
season using an array of horizontal ground impaction cards covering the full width
I
of the spray swath. Flow rate is calibrated simultaneously. Spray droplet
diameters are estimated by state personnel to be in the range of 150 to 200 microns
VMD upon impaction on forest foliage. Aircraft operating conditions are typically
80 to 100 mph at 75 feet above the foliar level.
D. Procedures
The doctrine and definitive procedures for forest spraying operations
are set forth in the Gypsy Moth Control Manual distributed by the New York State
Department of Environmental Conservation. This manual is closely followed in all
aerial and ground spraying operations conducted by the state, and appears to give
quite adequate coverage of operational matters. In particular, strict rules are
enforced relating to the following:
EQ-5025-D-2 (Vol. I)
-------
1. No spraying is to
be done over water or open
land or residential areas
(see Figure 3).
2. The minimum
acerage to be sprayed by
air is a 50 acre plot.
3. Forest areas to
be sprayed only include
those where ground surveys
indicate a total egg-mass
count of 500 or more per a
acre. Records are kept of
all spraying operations.
4. Notification is
given to local residents
regarding spray operations
and what to expect.
5. Proper meteoro-
logical conditions must be met or spraying operations are terminated. In
order to meet near-zero-wind, high relative humidity, and temperature con-
ditions to minimize drift, most spraying is done in early morning or late
evening.
COURTESY: NEW YORK STATE DEPARTMENT OF
ENVIRONMENTAL CONSERVATION
Figure 3 SPRAY CUTOFF NEAR WATER
-13-
EQ-5025-D-2 (Vol. I)
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III.
ROUTE OF PESTICIDES INTO THE WATER ENVIRONMENT
The routes or pathways by which pesticides used in forest management
can reach the aquatic environment include overland drainage, soil erosion and
sedimentation, atmospheric transport, intentional dumping, accidental spills
and disposal of "empty" pesticide containers. These general pathways have been
considered according to the character of the control of prevailing processes. The
first three are controlled by natural processes; the latter three are overtly
controlled by man.
Pathways by which pesticides applied to forests may reach aquatic
environments by natural processes are shown schematically in Figure 4. Estimates
of the magnitude of movement of the two principal pesticides used in large scale
aerial spraying of New York forests (i.e., DDT and carbaryl) are shown. These
estimates are based on a dosage of one pound insecticide per acre as it is
released from the aircraft, which is the normal application mode in New York
State. There have been few studies on the fate and movement of pesticides in
forested areas of New York. Consequently, inferences have been made from studies
on the forested areas of the United States and Canada and from nonfores ted areas
where applicable.
A. Introduction of the Pesticide to the Forpst
Aircraft are used to apply almost all of the pesticides used in New
York State forests. Generally, the aircraft fly 50 feet to 100 feet above the
-14- EQ-5025-D-2 (Vol. i
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AERIAL APPLICATION
OF PESTICIDE
SMALL
EVAPORATION
LOSS
SMALL UNDER
NEW YORK
REGULATIONS
APPROX.
50%
FIELD TESTS
IMPACTION
ON
FOREST FLOOR
LITTER
SURFACE
ADSORPTION
<5 PPB
AT N.Y.
RATE FOR
3% BOGS
& SWAMPS
LARGE
CAPACITY
<0.1 PPM
CARBARYL
<1 PPB DDT
<0.01% OF
SOIL/YEAR
STREAM FLOW
t^^f-~3f£#KsL*j%3
LAKES AND RIVERS
0.1 PPM CARBARYL
-------
forest canopy at speeds of 80 inph to 100 mph. The formulated insecticide is
distributed from the aircraft from boom and nozzle systems operating at a pumping
pressure of about 60 psi. Particle size at the aircraft varies between, typically,
200 to 500 microns VMD, although the particle size distribution is unknown.
Carbaryl is presently used in this State as a water formulation whereas DDT was
applied as an oil-formulated material.
The aerial spraying operation and the atmospheric conditions under
which this operation is conducted are basically characterized as a diffusing
system which operates to decrease the atmospheric concentration of the pesticide.
Under standard operating procedures, a helicopter system releases a 30 foot wide
spray swath which spreads to a 250 foot swath at canopy level. Operationally,
the aircraft paths are spaced so that overlap at the canopy is minimized.
Outside of inadvertent and accidental overlap, there is no reason to believe
that the pesticide dosage at the canopy will exceed the nominal application rate.
Potentially, wind in and above the forest canopy can cause the pesti-
cide spray to drift off-target. In a given light wind small spray droplets
have much greater tendency to drift than large ones. There are two ways that
small droplets can be produced when spraying the carbaryl-water mixture: first
by the nozzle and airstream atomization of spray initially produced at the
aircraft and second, by evaporation of the volatile carrier liquid before the
droplets reach the forest canopy. Results from basic atomization studies indicate
that for the nozzle types and aircraft flight speeds used, the mass-fraction of
spray droplets with sizes sufficiently small to permit significant drift under
typical operating conditions is completely negligible. Evaporative size reduction,
on the other hand, is not necessarily negligible and the potential for pesticide
drift exists.
~16~ EQ-5025-D-2 (Vol. ])
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While in principle off-target drift can exist, in practice, drift is
minimized by rigorous adherence to a policy of,sprayIng only under a selected
set of operational and meteorological conditions. Spraying operations are
carried out in the early morning hours, starting at sunrise, when prevailing
atmospheric conditions minimize evaporation. Winds must be less than 8 mph.
Ambient temperatures must not be over 70°F, to avoid significant convectional
air currents. Material is released only from very low altitude to enhance con-
trollability over the impact zone. To insure that existing conditions actually
result in suitable deposition on target, without drift, a single spray swath is
made and observed before beginning operations. Follow-up observations are
continued while spraying is underway. Any significant off-target drift is
visually detectable and spray operations at the time of occurrence are adjusted
accordingly to minimize this effect - including terminating operations if
necessary.
B. Leaching, Overland Runoff and Sediment Transport
Once the pesticide has reached the forest floor, either at the
time of application or due to subsequent wash-off from the foliage, the relative
importance of the transport processes are as follows.
In New York forested areas, the thickness of organic litter and humus
layers generally ranges from 2 to 4 inches. The forest floor is a living organic
filter, capable of absorbing surprisingly large amounts of a variety of contaminants,
including pesticides. Available evidence indicates that very little of the
applied pesticides would ever pass through these organic forest layers. As a
result, the possibility of ground water contamination by leaching of pesticides
from the organic litter is extremely remote.
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Overland water runoff is unusual under a mature, canopy forest. The
runoff which appears in surface stream channels several hours after each heavy
rain consists almost entirely of interflow, the excess rainwater which seeps into
streams from saturated soil.
Review of the literature reveals no studies on the DDT content of
overland water runoff from forested watersheds. This is probably due to the rarity
of overland runoff from forested watersheds. As an extreme example, calculations
show that for an area with as much as 3% of land area covered with standing water
approximately 1 foot deep, direct spraying with carbaryl at 1 pound per acre will
add 5 ppb to the runoff water. Even on non-forested watersheds containing the
same soil type as commonly found in the Catskill forest region of New York (Muskingum
or Dekalb silt loam), accumulated runoff water was normally found to contain less
than 0.1% of applied chlorinated hydrocarbon pesticides 12 or more months after
application. The chances of carbaryl entering streams before overland water
flow are far less than for DDT because of rapid degradation before and during
transport.
Slopewash or particulate erosion of soil by overland flow under
temperate forests such as exist in New York State is negligible. The suspended
sediment of forest floods originates in the caving and slumping of undercut stream
banks as well as roads and other slope disturbances. Thus, although studies have
shown that sediment transport of chlorinated hydrocarbon pesticides is much more
likely than is significant leaching into overland runoff, both are usually of
little import in forested areas. However, the sudden movement of pesticide-laden
sediments from an eroding clear cut or burned over forest could conceivably introduce
large amounts of persistent and accumulated insecticides such as DDT to drainage
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networks, since once the tree cover is removed by lumbering or fire, rainwash
erosion of litter and topsoil is rapid. Again, the danger from the nonpersistent
carbaryl would be far less. Although mountains such as the Catskills are eroding
much more rapidly than sandy flats like Long Island, and although both areas
have been extensively treated, sediments which reach streams from either area
unde..- forest cover are not likely to contain significant amounts of pesticide
residues.
The evidence indicates that there is little threat of serious
contamination to streams and lakes in forested regions from pesticide transport
by leaching, overland water runoff or sediment losses, when the chemical is
applied by aircraft at 1 pound per acre and under an operational policy that land
adjacent to water is not treated. However, this potential risk may increase if
the pesticide is applied to selective acreage by a truck-mounted mist-blower.
In this case the pesticide application rate is higher due to,the practice of
treating both leaf surfaces "to-drip," the output particle size smaller, and area
may be treated more than once to protect against reinfection from adjacent areas.
Drainage ditches are likely to exist along roadsides and recreational parklands
in which pest control may be desired. Such ditches lead runoff directly into
permanent streams. Therefore, it is not difficult to surmise that relatively high
pesticide concentrations in these ditches potentially could be flushed into streams
or lakes before the pesticide has been degraded.
C. Intentional Dumping, Accidental Spills and Container Disposal
Overt introduction by man of pesticides into the aquatic environ-
ment is distinctly possible, although intentional pesticide dumping is illegal in
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-------
New York State. Cursory examination of records does not indicate any problem in
either dumping or accidental spills. It should be emphasized that most forested
land is under the direct control and supervision of career foresters, who strictly
adhere to operational regulations. If this were not the case, the occurrence
of this type of action could be much greater.
In keeping with centralization of control, pesticide containers are
maintained at the mixing station and disposed of in designated and proper sanitary
landfill areas. In aerial applications, should the pilot require the rapid
discharge of pesticides, he is procedurally obligated to do so away from open
water. Therefore, the relative importance of these factors is low due to the
centralized procedures and policies of those State trained personnel conducting
the forest pesticide operation.
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IV.
IMPACT OF PESTICIDES INCLUDING METABOLITES ON THE AQUATIC ENVIRONMENT
By virtue of the array of biological species habitating the aquatic
environment, and the broad range of effects of pesticides on those species, the
comments provided in the paragraphs below are necessarily quite diverse.
There are several mechanisms through which DDT and Sevin could adversely
/
impact aquatic life. Perhaps the most obvious is that of direct kill, such as
the death of all the fish in a pond due to DDT. This ultimately depends on
not only the rate of application and the impacted species, but also the
DDT formulation. For example, most investigators have found DDT emulsions
to be more toxic to non-target organisms than DDT applied in oil or as a
suspension. More subtle disruptions result when only some of the organisms
in a lake or stream are destroyed by a pesticide. If the biota that was killed
was the food for other animals, the latter also may die. Since this process
could occur at a slow rate, or be manifest in an obscure fashion, it could go
unnoticed for some time.
If the predators and/or competitors of one or more species are
eliminated or significantly reduced, the "balance of nature" may be upset. For
example, if a sizable quantity of the zooplankton in a pond are poisoned by Sevin
the phytoplankton, whose numbers are controlled ordinarily by the zooplankton,
may increase substantially. Following such an algal population explosion or
"bloom," the algae may poison themselves in their own metabolites. When the
dead algae decay, the oxygen in the water may decrease and cause the death of
other aerobic forms.
~21~ EQ-5025-D-2 (Vol. I)
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Even more difficult to trace and evaluate is the movement of pesticides,
such as DDT, through the aquatic food-web. Unfortunately, very little information
is known regarding the trophic relationships of aquatic organisms. It has been
observed that these "who eats who" interactions may change significantly with
seasons. Within a season, feeding habits may be affected by inumerable chemical,
physical and biological factors. Other complicating factors are up-take and
metabolism, each of which are influenced by a myriad of known and unknown
conditions. For example, DDT may be passed within a food-web in the form of
DDT, DDE, DDD and/or several other metabolites. These chemicals vary considerably
in their ability to induce toxicity and other metabolic disruptions.
Still another point that cannot be overlooked is the fact that despite
its widespread use since 1942, the biological liaison (location and bio-chemical
mechanism of action) of DDT is not understood.
Keeping the above problems in mind, a review of the impact of DDT and
Sevin on aquatic environments nevertheless is of value in the formulation of
regulations regarding the employment of these insecticides in forest management.
A. DDT and the Aquatic Environment
DDT has a low volatility and is not normally decomposed by sunlight or
other naturally occurring chemical and physical mechanisms.
As a result, it is one of the most persistent agricultural chemicals
in the environment. Though extremely low in solubility in water (less than 1
ppb), DDT is readily adsorbed onto organic matter. Hence, this pesticide tends
to remain concentrated in the upper level of forest soils, with the potential
that it can be carried, at any time, to streams and lakes via soil erosion.
~22~ EQ-5025-D-2 (Vol. i
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Detritus is believed to be a significant source of introduction of DDT into aquatic
food-webs. In fact, the adsorption of DDT on suspended organic matter was sited as
a means of controlling black-fly larvae.
Hence, the quantity and quality of suspended material in aquatic habi-
tats that may be contaminated by DDT should be considered prior to the application
of this pesticide.
Another relevant property of DDT is the fact that it accumulates in
lipid tissues. It has been demonstrated that DDT and its metabolites were
persistent in some fish up to two years following a single exposure to this
insecticide. In this manner, it may be concentrated and passed-on through the
food-web in ever increasing concentrations (bio-magnification).
There have been few attempts to trace the movement of DDT in natural
aquatic habitats. In 1967 the level of DDT in stream ecosystems before and after
the application of DDT to 104,000 acres of Pennsylvania forest (oak-maple) to
control fall cankerworm was investigated. A quantity of 0.5 Ibs. technical grade
DDT per acre formulated in a mixture of naphtha and fuel oil was applied from a
plane traveling at 165 mph, 100 feet above the treetops. While after a month the
DDT content of stream sediment increased by a few parts per billion, residues in
brook trout were 20 to 100 times higher. White suckers also exhibited substantial
increases in insecticide content. Concentrations in crayfish also increased but
to a lesser extent. Between 30 and 122 days following application of the insecti-
cide, residues decreased to near pre-application levels.
Algae and other water plants can concentrate DDT and thereby pass this
insecticide up the aquatic food-web. For example, several varieties of freshwater
algae concentrated DDT between 99 and 964-fold following a 7 day exposure to
_23_ EQ-5025-D-2 (Vol. I)
-------
water initially containing 1.0 ppm DDT. Bacteria and fungi can accumulate 40 to
100 percent of the DDT from the media in which they are cultured. Similar
observations have been made with marine species. Non-living algae and other plants
also will concentrate DDT.
There have been innumerable studies regarding the impact of DDT on stream
insects. While the above studies differ considerably with respect to rates,
method, formula and time of application of the insecticide, some general con-
clusions can be drawn. DDT produced marked reductions in the quality and quantity
of stream insects. In streams, some species were destroyed more than others.
However, in other areas the reverse may have been true. If no DDT was applied,
normally present taxa repopulated the stream in two to three years. This
is believed due to the fact that insect eggs, which frequently have a thick "shell,"
are less adversely affected by DDT than are larvae or the adults. Very slight
return of the "natural" stream fauna was observed where spraying took place on
an annual basis. Recovery of individual species was proportional to "normal"
reproductive capacities. Contaminated and drifting insects represent a significant
potential source of DDT uptake by fish, many of which feed on those paralyzed
invertebrates. Insects sprayed with oil-formulated DDT were more susceptible
than those insects that had come into contact with DDT in suspension. Likewise,
some insect mortality, particularly downstream, was related to their eating of
attached plants that had accumulated DDT.
Numerous instances of fish kills following the application of DDT
to control insects have been reported. There have been many more cases where
more than one pesticide was applied to an area prior to a fish kill. In such
an instance, it is virtually impossible to determine if DDT was the most signi-
ficant factor which induced death of the fish.
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Temperature appears to be an important factor which influences DDT
toxicity. For example, DDT toxicity to rainbow trout and bluegills increased
below 13°C and above 18.5° to 23°C.
Turbidity may also influence the toxicity of DDT. Organic particles
in suspension may remove DDT from water. However, the DDT may re-enter an
aquatic food-web if the organic matter is eaten by bottom organisms. Hence,
suspended material could decrease acute toxicity and simultaneously increase
chronic toxicity of this insecticide.
Generally speaking, within a given species, younger and smaller specimens
are more susceptible to DDT poisoning than are older and larger fish. This may be
related to the fact that the latter have more lipid tissue in which the DDT can
be dispersed.
The negative impact of DDT on fish eggs and fly eggs can be significant.
After a fish initially hatches, it is almost entirely dependent on the yolk
sac for its initial source of food. As the contents of the yolk sac are
consumed, the DDT in the remaining lipid in the sac becomes more concentrated.
During the last stage of yolk sac absorption, mortality among the fry of numerous
species has been observed. The eggs may be a vehicle through which DDT is
passed to offspring. This may result in significant decline in the population
of some species, such as trout. In fact, this was believed to be the prime
factor in the destruction of the lake trout fishery in Lake George, New York.
1
One recent, and perhaps biologically significant finding, was the
discovery of DDT-resistant fish and frogs. These organisms can accumulate
sufficient DDT to pose a threat to higher organism, including man, if consumed.
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The literature on the degradation of DDT is vast. Several excellent
reviews are available to delineate pathways and products. In general, the
pathways seem to be species-specific precluding the assumptions of general
biological degradation. Very little work has been done on other than labo-
ratory reared animals, plants and bacteria. With species-dependent reactions
it is difficult to apply findings from domestic and laboratory cultures to the
environment. This can be illustrated by pointing out that one of the principal
metabolites in man is DDE, whereas in monkeys this metabolite has not yet been
demonstrated. Biological degradation of DDT yields five principal products.
These include DDA, ODD, DDE, Diochlorobenzophenone and kelthane. Ring cleavage
has been demonstrated by a variety of microorganisms inhabiting the soil. In
DDT-resistant insects the principal product appears to be a DDE resulting from
an enzyme which has received a great deal of attention, DDT dehydrochlorinase.
Although selected insects have demonstrated DDA and kelthane, these have not been
reported with great frequency or for many species.
Many of these degradation products do possess insecticidal activity,
as for example, DDD and kelthane. Others, while showing little acute toxicity,
have been implicated in vertebrate steriod metabolic upset. DDE has been
implicated in calcium upset for several species of birds and has been identified
as the agent responsible for the "thin eggshell syndrome". It is interesting to
note that even this effect is not uniform among avian populations. Whereas
some birds do show reduced eggshell thickness in the presence of DDE, other birds
show an increase in shell thickness with the same compound. These factors
demonstrate once again that generalizations and attempts at deriving information
from other species is a dangerous exercise.
_26- EQ-5025-D-2 (Vol. I)
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Because of the long term persistence of DDT or its breakdown products
in forest soils (amounting to greater than 10 years), long term effects on soil
dwelling organisms and food chains must be considered. Studies have shown that
DDT does accumulate in skiders, earthworms and other forest soil organisms to
the expent or greater than residual soil concentrations. It has further been
shown that robins and other birds feeding on forest soil organisms accumulate
DDT residues to even greater concentrations than present in soil organisms.
B. Sevin and the Aquatic Environment
The impact of this pesticide was not investigated in the field to any
degree until 1959, and there is considerably less information regarding its
effects on non-target organisms in comparison with the voluminous literature
concerning DDT. In comparison with DDT, Sevin readily dissolves in water (40mg/l
at 20°C). It is reported that Sevin, at concentrations above 0.1 ppm, is
toxic to most algae. However, it has been further noted that there is only a
16.8% decrease in carbon fixation by a natural population of phytoplankton following
a four (4) hour exposure to 1.0 ppm of DDT.
While reports prior to 1959 indicated that Sevin was highly toxic to
bees, there was no information available on its effects on aquatic insects, until
Burdick and co-workers demonstrated a detrimental impact on stream insects. They
applied an unspecified quantity of Sevin (95T) in fuel oil to a 75,000 acre
area near Oneonta, New York. The study area included two streams. The spraying
did not result in any direct toxic impact on fish, which will be discussed later,
but did reduce the stream insects by 50.7 to 97.2 percent. Mayflies, stoneflies,
and caddisflies particularly were killed. He states: "Sevin should not be used
where spray can fall on flowing streams....".
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This study, however, was the result of direct application to the
experimental stream, and used a hydrocarbon carrier.
Coutant made similar observations of insect kill in Pennsylvania
streams "in spite of precautions against direct spraying of open water, washing
spray equipment in the stream, and other 'misuses' often blamed for kills.
It must be clear, however, that it is standard procedure for New York
State operations for spray aircraft to shut down when crossing or adjacent to
aquatic sites. In two comprehensive studies dealing with impact on the aquatic
biome, spray operation was routine, i.e., standard State procedures v?ere followed
for insecticide application. No pesticide was applied directly to any water.
In each study, Sevin was aerially applied at one pound per acre as a water
suspension. One study at the College of Forestry at Syracuse University,
completed in 1969, was of three years duration. One year was devoted to prespray
evaluation of chemical levels and stream invertebrate populations, followed by
similar evaluation in two post-spray years, including analysis of a control
stream. As can be seen from graphic presentations, (Figure 5), no population
changes due to spray operations can be detected; the control and prespray
population fluctuations within limits defined by environmental conditions
(summer drought in 1966, etc.). In addition, no changes in species composition
were noted. The conclusions from this study were that carbaryl is of an
innocuous nature to the aquatic habitat, so long as standard State operational
procedures were used.
A study of similar scope in Massachusetts, completed in 1966, followed
routine spray operations of the previous year. Tompkins, in that report,
indicated that: "Drift collections on the water surfaces of a pond whose
-28- EQ-5025-D-2 (Vol. I)
-------
YEAR 1 (1936): PRESPRAY
YEAR 2 (1967): POSTSPRAY
YEAR 3 (1968): POSTSPRAY
I
o
I J
I
l-o
I
N3 o so
TIME [MONTHS)
80
= TEST
< CONTROL
TIME (MONTHS)
TIME (MONTHS)
Figure 5
COURTESY: D.R. FELLEY, UNPUBLISHED PH.D. THESIS, THE EFFECT OF SEVIM
(1-NAPHTHYL N-METHYL CARBAMATE) AS A WATERSHED
POLLUTANT, 1970, STATE UNIVERSITY COLLEGE OF FORESTRY
AT SYRACUSE UNIVERSITY, SYRACUSE, NEW YORK.
INSECTS COLLECTED AS A PERCENT OF POPULATION, MAXIMUM, IN THE TEST AND CONTROL
BRANCH OF SHACKAM BROOK IN 1966, 1367 AND 1968. RANGE MARKINGS REPRESENT
95 PERCENT CONFIDENCE INTERVALS.
-------
entire periphery was sprayed indicated that such drift, under conditions
prevailing at the time of application, were negligible."
Reduction of the insect crop could have a negative effect on the
fish which feed upon these invertebrates. However, no information has been
generated to support this premise. Likewise, no data were found regarding
recovery of the insect population with time.
Sevin has been found to be extremely toxic to crayfish, crabs and
shrimps, and Daphnia, a waterflea.
Concerning fish, it is reported that 28 ppm technical Sevin in oil
resulted in a 48 hour LD for goldfish. A 50 percent wettable powder formulation
had an LD of 14 ppm. Values from other laboratory studies ranged from 1.75 to
13.0 ppm. Sevin has been found to be less toxic to fingerling brown trout in
soft, acidic water rather than in hard, alkaline water, this was attributed to
an interaction between Sevin and the components of water rather than a physio-
logical reaction of the fish to a water condition.
Further, Sevin toxicity to fish increases with increasing temperature.
However, its rate of decay to 1-naphthol via hydrolysis also increases with
temperature and sunlight. While Sevin is more toxic to crustaceans than to fish
and mollusks, the reverse is true for its metabolite.
The metabolite picture of Sevin has also been examined intensively.
At least eleven metabolites have been identified and many other hypothesized
from a variety of organisms. Many mammals demonstrate hydrolytic reactions with
naphthol as a principal product. The original insecticide or its metabolic
products may then be conjugated to form glucuronides or sulfates for subsequent
kidney excretions. Unpublished work at the College of Forestry has demonstrated
Sevin may also be used as a carbon source by many sludge bacterial.
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In general, major routes of metabolic degradation of Sevin include
decarbamylation, ring hydroxylation, and cleavage of the C-O-N bonds. This
pesticide may be degraded by plants almost as rapidly as by animals with a host
of additional products.
While the metabolism of Sevin has been extensively studied with respect
to terrestrial plants and animals, no literature was found regarding the break-
down of this insecticide by aquatic forms. However, it has been observed that
Sevin persists longer in soil water than in lake water.
In the Massachusetts study, residues of the pesticide Sevin in fresh
water and estuarine organisms were negligible, with residues literally non-
existent one month post spray. No further tests were run. Population
estimates demonstrated that "...Sevin has no immediate effect on the fish and
shellfish populations therein.", and further, "no fish mortality could possibly
occur under normal operation conditions,...". Another contributor to this
study, Boschetti, examined the effect of spraying operations on a small isolated
pond. Insignificant residues of Sevin were found. No effect was noted on the
pond algae and the author concluded that proper delivery of Sevin poses no
hazard to the environment.
In summary, while DDT and its metabolites tend to accumulate in lipid
tissues, Sevin and its more polar soluble metabolic products tend to be more
rapidly excreted. Therefore, bioconcentration of carbaryl through food chains
probably does not occur.
In view of the evidence showing bioconcenti'ation of the persistent
DDT residues through forest soil to birds and other feeders, it appears that
continued use could result in serious long term ecological consequences.
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Carbaryl can cause ecological disturbances, but nonpersistent and rapid de-
toxification in biological systems would probably not produce long term
ecological disturbances in forest environments if used judiciously.
C. Synergism in the Aquatic Ecosystem
The action of a combination of materials upon a system is termed
synergistic if the resultant effect is greater than that expected from the
individual effects. One compound may synergize another, therefore, while either
compound by itself may represent little or no threat to the system.
Syngergism in the aquatic biosphere may arise from any one of four
types of material combinations. The first of these is the effect of a pesticide
and a naturally occurring material. It has been shown that DDT in solution
with sodium humate is approximately twenty times as bioactive as an equivalent
solution of DDT alone. The second case is synergism by some relatively
innocuous pollutant. For example, certain fish show an increased susceptibility
to DDT when detergents are present in the water. This phenomenon is similar
to the uptake of nutrients by cells when surfactants are present.
The third case is that of the increased effectiveness of a pesticide,
carbaryl for instance, in the presence of another chemical (e.g. derivatives of
propynyl naphthyl ethers, aliphatic thiocyanates) added for the sake of its
synergistic action. Since the last case is knov/n for terrestial insects, it
is presumed that a similar mechanism could be operative for aquatic insects. The
fourth combination type involves the bioaccumulation of persistent pesticides
as a function of the. presence or absence of a congener. For example, it has
been shown that DDT accumulation in rainbow trout is enhanced by the presence
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of dieldrin, while DDT markedly decreases the rate of accumulation of dieldrin.
Similarly, DDT elimination was decreased by the presence of dieldrin, but dieldrin
elimination was not enhanced by the presence of DDT.
Synergistic effects in the aquatic ecosystem have not been established
as a serious threat. However, this potential problem should not be dismissed.
Consideration should be given to synergism prior to application of any insecticide.
D. Impact on Humans
The impact on humans of DDT and carbaryl is a topic covered in varying
depth depending on the nature of the exposure, the effect of the exposure, and
the control achieved in countering the exposure.
The literature concerned with the impact of DDT on humans has been
broader than that of the impact of carbaryl, probably due to the fact that
DDT has been used for a much greater period of time. Investigators have surveyed
human populations working with DDT in manufacturing and application, people not
occupationally exposed to DDT, and persons on specially restrictive diets. By
and large much of the data has verified that fact that DDT has a large
potential for accumulation in biological systems, particularly in fatty tissue.
Additionally, high chronic occupational exposure has been linked to various
disorders of the detoxifying body systems, due to overloads and other stresses
introduced as a function of detoxification and elimination of the pesticide.
Certain antagonistic effects have also been found, the best example of which is
the lack of DDT accumulation in persons, even those with high occupational
exposure, who are taking anticonvulsant drugs.
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The effect of carbaryl on the human body is much less than that of
DDT except when carbaryl is taken as massive oral doses (as in suicide). In
this case, the cholinesterase inhibiting action of the agent is overwhelming.
For low level exposure, however, the material is rapidly degraded by the human
body. Therefore, no long-term effects of carbaryl exposure are anticipated,
contrary to the situation with DDT. The most important current threat con-
cerning carbaryl is its possible teratogenecity (tendency to produce birth
defects) which has been demonstrated in certain test animals.
While the application to humans of results from experiments with
laboratory animals suggest that carbaryl could be injurious to man, it is
noted that humans employed in the manufacture of this insecticide, who were
exposed to concentrations that far exceed levels that would be encountered
in spraying areas, did not exhibit any adverse symptoms.
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V.
LAWS AND REGULATIONS GOVERNING THE SALE AND USE OF PESTICIDES
The laws and regulations of the State of New York and of the Federal
Government, which relate to the sale and use of pesticides have been reviewed
as to specific content and the apparent underlying philosophy of the law as
enacted and practiced. The applicable laws and regulations on this subject
cover a wide spectrum and exhibit very complex interrelationships, such that
specific comments on a specific regulation would generally require legal
opinion and argument. We feel that such argument is not appropriate here in
view of the broader philosophical questions involved.
In an overview of the total body of law considered in this study, it
appears that primary control is sought through placing restrictions on product
availability, and through record keeping, with only limited attention given to
the competence and the knowledge of the user.
Serious consideration should be given to expanding the laws and
regulations of the State of New York and of the Federal Government to include
the licensing of applicators. Through the examination and licensing of the
applicator, and the control of the availability of pesticides classed for
restricted use, the use of dangerous pesticides would be in the hands of
responsible and qualified personnel who would be expected to operate in a
professional manner to insure the maximum benefits with the minimum of hazard.
It is undoubtedly unrealistic to assume that good and meaningful,
timely pesticide control can be achieved withort the full qualification of the
personnel engap/'d in the application of hazardous pesticide due to the extremely
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large number of combinations of use situation, the constantly changing
pesticide market, and the unmanageable task of governmental monitoring or
surveillance of the activities of the applicators.
In matters where the public safety or the public good is involved,
state or federal licensing, is a time honored control mechanism. In an over
simplification of the question of state or federal licensing, it may be
generalized that the state issues licenses on a more or less personal services
basis, whereas federally granted licenses tend to relate to services or functions
in the public domain. The ICC licenses radio station operators, the FAA licenses
aircraft pilots; whereas the states license medical doctors and engineers. It
would appear that the applicators of hazardous pesticides should be federally
licensed for the following reasons:
(1) The effects of pesticides do not stop at state lines, hence,
interstate control is necessary.
(2) The pest does not inhabit on the basis of state lines, hence
interstate uniformity in control systems is highly desirable.
(3) Examination and licensing on a national basis can lead to a higher
and more uniform level of professionalism.
The social and economic importance of pest control and the absolute
magnitude and characteristics of the problem are highly variable from state to
state and from time to time. Approaches or techniques adopted by one state can
I^CM! to direct conflict with approaches adopted by a neighboring state. Pest
control can be best studied and implemented on the basis of geographical areas
determined by the pest itself, rather than by state boundaries. Such pest
management procedures as quarantines, buffer zones, criteria for treatment and
EQ-5025-D-2 (Vol. I)
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materials to be used may be applied in a much more effective manner when specific:
problems are treated on an area of involvement basis and in consideration of the
national import.
Since a very large percentage of the pesticides in use today are applied
by units of government, laws and licensing should be equally applicable to
government and non-government uses. This has not always been the case in laws
and licenses. It bears special attention in this instance, and points to the
advisability of federal laws and licenses.
37 EQ-5025-D-2 (Vol. I)
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VI.
ALTERNATIVES TO CHEMICAL CONTROL
The availability and use of non-chemical alternatives are different
for native and non-native pest infestations. The most important difference is
the ease with which biological control can be invoked.
A. Native Pest Infestations
In spite of the fact that there is extensive use of pesticides,
evidence demonstrates that New York State relies on natural processes to combat
and control native forest pest infestations. Pesticides are used minimally and
generally only in high-use areas. Table 2 presents, as an example of this
reliance on natural control mechanisms, a tabulation of acreage defoliated by
the Forest Tent Caterpillar along with concomitant chemical treatment for that
pest.
Table 2
FOREST TEST CATERPILLAR DEFOLIATION AND
CONCOMITANT PESTICIDE TREATMENT
YEAR
1952
1953
1954
1955-59
1960
ACRES DEFOLIATED
TOTAL
3,500,000
7,489.049
15,321,047
NOT MENTIONED
24,425
HEAVY
500,000
919.834
2,007,447
5,000
ACRES TREATED
WITH PESTICIDE
1,000
1,800
3,200
SOME IN 1955 ONLY
0
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The demise of this infestation resulted from a combination of factors
as adverse climate, starvation and the action of predators, parasites and pest
disease. The important point is that chemicals were not extensively used but
were, rather, integrated to protect high-use acreage. Similar integrated
chemical control was used again in 1967 through 1969 to control the Saddled
Prominant, a native, northern hardwood defoliator.
B. Non-native Pest Infestations; Integrated Gypsy Moth Control
In the 1890*8, the Commonwealth of Massachusetts conducted a vigorous
campaign of integrated techniques to "eradicate" the Gypsy Moth. When the pest
intruded into other states, New York and Pennsylvania, for example, similar
efforts were pursued. These included the use of pesticides, the use of sex lures,
the introduction of parasites and predators and the use of manpower to scrape and
kill egg masses, band trees, prune trees, and destroy protected egg-laying habitat.
While these measures proved to be useful, little effort has been made in New York
State since 1945 to resort to these practices. While several attempts have been
made to use a bacterium, Bacillus thuringiensis, and other pathogens and parasites,
there is no evidence of a concerted effort to use these agents.
New York State is not alone and, while there is interest in the
potentiality of biological control agents in all infected states, New Jersey is
the only state that has manifested a commitment.
1. New Jersey Program
By 1963 the intrusion of Gypsy Moth in northern New Jersey was
so great that: the philosophy of eradication was abandoned in favor of integrated
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control. Since New Jersey had long been active in the collection and
rearing of parasites to control introduced agricultural pests, it was a logical
step to adopt biological control measures as an important element of this program.
Accordingly in 1963, six (6) parasites of gypsy moth that were already
established in New England were collected and released in New Jersey. In
addition, three (3) others were reared in New Jersey and field released.
The main objective of the New Jersey program is to establish
populations of various insect parasitoids throughout the distribution of the
gypsy moth in that State. It is anticipated that these efforts, part of an
integrated approach to managing this pest, will assist in maintaining gypsy moth
populations at a level where their impact on the forest and urban ecosystems can
be tolerated, both economically and ecologically.
Biological controls are utilized in the remote forested
areas and chemical control (Sevin: 1 pound/acre) in the high-use urban areas.
Decision to spray is voluntary and is vested solely in the municipalities, although
the State does use funding mechanisms to exercise professional control.
The biological program is divided into two parts: insect rearing
and field evaluation. The insect rearing facilities and techniques used
are well organized, staffed and maintained. The rearing and releasing techniques
developed by New Jersey should serve as excellent models for the establishment
of similar facilities in other states.
The most critical part of the program, however, is the field
evaluation undertaken to determine the success or failure of the biological control
effort. It is too early at this time to critically review this part of the
project, although it is evident that the main interest is in determining whether
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or not populations of various parasitoids had become "established" at the various
release sites. Establishment is considered successful if a particular species
is recovered from field collections three years after releasing an individual
parasitoid.
However, mere "establishment" of populations of various parasitoids
in the gypsy moth life system is not sufficient evidence for determining the
success or failure of the program. Unfortunately, basic research is lacking
on both the individual parasitoids that are being used, and the sampling
techniques employed for field evaluations. This is unfortunate and is a mani-
festion of contraints of time and additional scientific manpower. The importance
or potential of a particular parasitoid can only be determined, in most cases, by
a detailed examination of the biology, behavior, ecological adaptability, and
responses (functional and numerical) of individual species to changes in host
density.
It has been intimated that biological control efforts in New
Jersey have successfully reduced the duration of heavy defoliation from 3 to 2
years in some areas. Also, field observations to date suggest that certain
parasitoid applications are playing a significant role in stabilizing gypsy moth
populations at tolerable levels, although, as noted above, sufficient information
is not available at this time.
However, it must be noted that biological controls require time to become
established. The results are not instantaneous as with chemical sprays and losses
must be both expected and accepted. The following table shows mortality sustained
in a 17,855 acre forest on the Newark watershed subjected to heavy defoliation for
3 yenrs before the gypsy moth infestation collapsed from disease and parasitism.
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Table 3
YEAR
1968
1969
1970
1971
CUMULATIVE
% OAK
MORTALITY
6.5
14.3
38.0
57.7
TOTAL # DEAD OAKS
IN AFFECTED FOREST
116,693
257,112
686,881
1,033,269
2. Another Alternative
In the example cited above, the loss of over 1,000,000 oak trees may be
too high a price to pay for non-chemical control. The value of the woodlands in
one state is not necessarily the same in another state. This is, in fact, the
reason for different treatment philosophies within the northeastern states.
Examination and study of historical and technical literature, coupled
with discussions with several individuals, have revealed that modern integrated
control procedures basically ignore the use of manpower as a central ingredient.
In the past personnel have, with minimal training, served as effective
gypsy moth control agents. Efforts have included scraping and creosoting of
egg masses, trapping and disposal of larvae, banding of trees, and the
destruction of protected egg-laying habitat. These measures have, in the
past, been effective in minimizing the ravages of this pest.
In the past, hundreds of personnel have been involved in this
work. Year around efforts are possible in not only overt control but also in
the inspection and evaluation of woodlands for evidence of the pest. There is no
reason why this technique should not or could not be resurrected and relied upon
in integrated control efforts. It is evident that total reliance on chemicals
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is not necessary, that biological control will have minimal short-run impact on
epidemic populations and that, perhaps, the intelligent use of relatively large
numbers df people will not only serve to bridge the gap, but could also provide
a healthful and useful employment opportunity.
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VII.
CONCLUSIONS
This section presents preliminary conclusions based upon the results
of this study to date. It is emphasized that these conclusions have been drawn
from a case study of the use of pesticides in forest management in New York State.
Within New York State almost all of the forest pesticide currently used is
carbaryl (Sevin), and it is used almost exclusively to control the ravages of
the non-native pest, Gypsy Moth (Porthetria dispar L.). Pesticide application
operations are either conducted by career foresters of the New York State
Environmental Conservation Department or under their direct supervision.
Natural processes are relied upon to control native pest infestations.
Since the policy and operations with regard to the use of pesticides
vary within the several northeastern states, the conclusions presented herein
are not necessarily applicable to regions outside New York State.
The case study, itself, is further restrictive in the sense that it
addresses only past and current experience. In turn, the impact of pesticides
on the aquatic enviornment and ecosystem applies principally to the present
state of affairs. Responsible prediction of the future impact of pesticides
requires considerations far more extensive than mere extrapolation of current
trends. A few such considerations have been explored and their implications
are cast in the form of recommendations in the following section. The con-
clusions which follow should not provide a harbor for comfort; rather they
should be viewed as elements in a larger and longer-range assessment.
"44~ EQ-5025-D-2 (Vol. I)
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We conclude:
1. The application of carbaryl (Sevin) as a water suspension from
aircraft at a rate of one pound per acre to control pests as the Gypsy Moth,
and in consort with current equipment and techniques, policy, regulations and
management does not have significant adverse impact on the aquatic environment.
2. Changes in treatment practice, pesticide formulation, dispersal
equipment, policy, regulations and management should not be undertaken without
a sound basis, because changes, themselves, can alter many of the interrelations
between pesticides and the environment and can easily have a negative rather
than positive impact not only on forest pest control but also the aquatic
environment and forest ecosystem.
3. The current application rate of carbaryl formulated in water is
excessive for Gypsy Moth control, based on reported post-spray observation of
egg-mass reduction within treated average.
4. DDT should not be (and is not in New York State) used in the
forest due to bioconcentration effects.
5. The short-term hazard to humans of carbaryl and DDT in dosages
and conditions associated with forest pest control operations appears minimal,
although not unequivocal.
6. The long-term effects of carbaryl and DDT on humans are unknown.
7. The laws governing the use of forest pesticides are insufficient
to prevent environmental damage.
8. The long-term efficacy of biological control of the (non-native)
Gypsy Moth is presently unknown, although short-term evidence indicates that
these techniques show promise.
9. It is technically feasible to employ manpower as a control agent
in integrated Gypsy Moth control programs.
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VIII,
RECOMMENDATIONS
Based on the results of this study, the following preliminary
recommendations are presented:
1. The aerial application rate of water-formulated Sevin should be
reduced from 1 pound per acre to 0.5 pound/acre for Gypsy Moth control and
possibly further, pending outcome of 2 below.
2. Field tests should be conducted to determine the minimum appli-
cation rate of Sevin, formulated in either wa^er or oil, necessary to achieve
adequate control of the Gypsy Moth and other important forest pests.
3. The economic feasibility of large-scale use of manpower as a
part of integrated Gypsy Moth control should be evaluated and, if appropriate,
the EPA should fund a field demonstration program.
4. Federal laws should be developed which control the application
of pesticides through national examination and licensing of applicators; which
together with control of the availability of pesticides classed for restricted
use, would insure that employment of dangerous pesticides be limited to
responsible and qualified personnel.
5. The possible adverse impact on the aquatic environment and
ecosystem due to long-term effects of large scale forest pest infestations
(extensive defoliation, tree mortality and subsequent erosion) should be
determined.
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6. Additional research should be conducted on the fundamental
aspects of chemical control of forest pests, with emphasis on an integrated
approach considering biological aspects and behavior of the pests, environ-
mental influences and hazards, pesticides and formulations, application
techniques and attack modes, and the type and amount of control deemed
necessary.
7. Additional research should be conducted to quantify the long-term
impact of pesticides on the aquatic environment and ecosystem.
8. Additional research should be conducted on the fundamental
aspects of biological control necessary to determine the efficacy of these
forest pest management techniques.
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A-l
INVENTORY OF USES
A-l.l Introduction
This section presents information relative to both historical pesti-
cide uses within New York State, and descriptions and analysis of current pesti-
cide us.', including the quantities and types of chemicals used, the pests toward
which they were directed, and comments on the efficiency of these treatments.
Before discussing these factors, an overview of New York forests is
presented. This information has been largely abstracted from the Atlas of
Fores try in New York " .
Hew York State encompasses an area of about 30.7 million acres, of
which about 14.5 million acres are forested. There are three principal forested
regions. The Adirondack - North Country Regions contains about 5.4 million acres
of predominantly spruce, fir and northern hardxroods; the Catskill-Hudson Region
is comprised of 2.6 million acres predominated by oak and mixed northern hard-
woods; and the western New York Region contains 4 million acres of oak and mixed
northern hardwoods. The remaining 2.7 million acres is scattered in central
portions of the State.
About 17% of the forested land in New York is categorically noncommer-
cial. Most of this land is part of the State Forest Preserve which, by mandate
of the New York State Constitution, must remain "forever wild".
The remaining 83% has commercial potential. Of this total 6% is owned
by the State; 8% is owned by forest industries, 24% is in farm woodlot operation;
and 45% is under "other" private ownership. In short, nearly half of the forested
lands in New York are not owned by farmers or forest industry but, rather, by
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EQ-5025-D-2 (Vol. II)
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rural nonfarmers and/or city dwellers (absentee ownership). The land parcels
under private ownership tend to be small; about 55% of the private forests are
in parcels of less than 100 acres. However, many of these parcels merge to
form large forested land blocks.
Further, it is emphasized that commercial exploitation (timber and
maple sugar) is not the only important use value.ascribed to forested land.
These other values include recreation (camping, hunting, fishing); soil
stabilization; and watershed development and maintenance. These several values
engender the concept of multiple use, a concept which prevails in current forest
management practices. Under this practice, New York forests are selectively
treated with pesticides to protect those high-use (tangible) and/or high-value
(perhaps subjective) areas threatened by pest infestation.
A-1.2 Historical Development of Pesticide Use
The following statement by Ephraim Porter Felt, New York State
Entomologist, appears on pages 253-254 in his monumental two-volume work
1 9
entitled, "Insects Affecting Park and Woodland Trees".
"It must not be forgotten that most of the species listed as
important enemies of shade trees, also feed, as previously pointed
out, on forest trees, and that sometimes these earlier noticed
forms may be exceedingly destructive in the forest land. Our fal 1
webworm, Hyphantria textor Harr., for example, is occasionally very
abundant on forest trees and causes a considerable amount of injury.
The spiny elm caterpillar, Euvanessa antiopa Linn., lives by
preference on willows and poplars, occasionally defoliating exten-
sive areas, and the depredations of the forest tent caterpillar
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EQ-5025-D-2 (Vol.
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Malacosoma disstria Hubn., are too well known to require more than
mention in this connection.
"Conditions are such in this country that we must rely very
largely on natural agents of one kind or another to prevent serious
injury to forest trees. This will ordinarily be accomplished
through the activities of various predaceous and parasitic forms,
which rarely attract attention because of their abundance. Fungous
diseases and unfavorable climatic conditions also play an important
part in checking insect ravages. Some of our native species, in
spite of these checks, are occasionally very injurious over large
areas. One of the most striking cases is that of the forest tent
caterpillar, a species which feeds very largely on hard maples, and
at irregular and rather widely separated intervals becomes so
enormously abundant as to defoliate extensive areas year after year,
spreading therefrom to our shade trees.
"The dangerous nature of introduced species has been generally
recognized and it is well known that a considerable percentage of
the more serious enemies of general agricultural crops have come
to us from abroad. It is fortunate that comparatively few destructive
forest pests have been brought into the country. The two most impor-
tant at the present time are the gipsy moth, Porthetria dispar Linn,
and the brown tail moth, Euproctis chrysorrhoea Linn. Inability to
fly on the part of the first named makes it a local species,
dangerous only because of its voracious appetite and the large number
of food plants subject to attack. The latter species flies readilv
and within recent years has shown a marked tendency in America to
spread into woodlands, particularly white oaks, large areas of which
EQ-5025-D-2 (Vol. II)
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have been defoliated. It is nearly as destructive to hard maples
and as a consequence both species are serious menaces to our wood-
lands. It is obviously impractical to advise extensive spraying
of forests with poison, the general collection or destruction of
egg masses in woodlands or similar measures, because of the enormous
expense involved. It is most sincerely to be hoped that either the
native parasites or introduced forms, some of which have already
been imported, will prove adequate checks on both of these dangerous
species and obviate the necessity of employing more expensive methods
for checking these pests. Experience with the larch sawfly,
Lygaeonematus erichsonii Hartg., is not encouraging, since this
species has for a number of years defoliated larches over wide areas
in the Adirondacks and is still a serious pest."
The importance of Felt's statement cannot be overemphasized. Its
importance is vested in the combination of what was said and when it was said.
For example, while more overt attention was directed toward shade
tree and agricultural diseases in 1905, Felt pointed out that the pests of shade
trees can spread into the forested lands and vice versa. He cites the ravages
of the forest tent caterpillar in spreading from the forest to the shade tree.
Secondly, Felt cites a reliance on biological control in the manage-
ment of forest pest populations. While Felt implies that these techniques are
successful, they do not always work as in the case of the larch sawfly.
Finally, both the introduction and danger of non-native pests as the
gipsy (gypsy) moth are clearly discussed. Felt indicates that biological control
measures were being evaluated including introduction of foreign predators. Also
the impracticality of both wholesale forest spraying with chemical control
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EQ-5025-D-2 (Vol. II)
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materials and the mechanical collection of egg masses to check the development
and spread of such pests was asserted.
Thus far, two erroneous impressions could be drawn from the discussion.
The first is that little attention had been directed to forest pest problems in
New York State. This is not true for, while the literature prior to 1900 did
not abound in forest entomology, Felt listed the following publications of rele-
vance to New York.
1857 Fitch, Asa. Insects Infesting Evergreen Forest Trees.
Ins. N. Y. 4th Rep't, p. 5-67.
1858 Insects Infesting Deciduous Forest Trees. Ins.
N. Y. 5th Rep't, p. 1-74.
1881 Packard, A. S. Insects Injurious to Forest and Shade Trees.
U. S. Ent. Com. Bui. 7, p. 1-275.
1890 Insects Injurious to Forest and Shade Trees. U. S.
Ent. Com. 5th Rep't, p. 1-945.
1893 Hopkins, A. D. Catalogue of West Virginia Scolytidae and
their Enemies. W. Va. Agric. Exp. Sta. Bui. 31, p. 121-68.
1893 Catalogue of West Virginia Forest and Shade Tree
Insects. W. Va. Agric. Exp. Sta. Bui. 32, p. 171-251.
1895 Packard, A. S. First Memoir on the Bombycine Moths. Nat.
Acad. Sci. 7:291.
1896 Marlatt, C. L. Revision of the Nematinae of North America.
U. S. Dep't Agric. Div. Ent. Tech. ser. 3, p. 1-135.
1898 Felt, E. P. Insects Injurious to Maple Trees. Forest, Fish
and Game Com. 4th Rep't, p. 367-95.
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1899 Insects Injurious to Elm Trees. Forest, Fish and
Game Com. 5th Rep't, p. 351-79.
1901 Beutenmuller, William. Monograph of the Sesiidae of American
North of Mexico. Am. Mus. Nat. Hist. Mem. 6, p. 217-352.
1901 Hopkins, A. D. Insect Enemies of the Spruce in the Northeast.
U. S. Dep't Agric. Div. Ent. Bui. 28, n. s., p. 1-48.
1903 Felt, E. P. Insects Affecting Forest Trees. Forest, Fish
and Game Com. 7th Rep't, p. 479-534.
Concern in forest pest control was certainly more than of passing
interest as Felt notes serious injury to the Adirondack spruce forests in the
years 1874 to 1876.
In addition to the loss of forest trees, of great concern was the
damage of ornamental shade trees. For example, the elm leaf beetle destroyed
1 o
several thousand trees in the cities of Albany and Troy in 1898 . The
importance of shade trees was well recognized. Again, a direct quotation of
1. 2
Felt on page 5 states:
"The welfare of the human race is closely connected with that
of our trees, and any work looking to their better protection makes
for the advancement of mankind. The value of our street and park
trees is much greater than the cost of their production, and a city
or village blessed with such has treasure which should be jealously
guarded, since these magnificent growths have an important influence
in modifying climatic conditions, besides adding materially to the
beauty of the surroundings. This is not only true in cities and
villages but also in the country at large, particularly in such
resorts as the Adirondacks, where thousands go for recreation and
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health. The trees in such places not only afford most agreeable
shelter from wind and sun, but the evaporation from the immense
leaf areas modifies the temperature and the exhalations from the
coniferous needles undoubtedly aid very much healing diseased lung
tissues.
The protection of shade trees is a serious problem, largely
due to the introduction into this country of certain very destruc-
tive species, such as the gipsy moth, the elm leaf beetle, the elm
bark louse, the leopard moth and the San Jose scale, all exceedingly
injurious and all, except the gipsy moth, well established in New
York State. It is only a question of time before the latter crosses
our borders. The above are a few of the important exotic species
which aid such destructive native forms as the white marked tussock
moth, the bagworm, the fall webworm, the scurfy and oyster scales
and the cottony maple scale in their nefarious work."
Recognition of the great differences in both growing habit and intrin-
sic value between ornamental shade trees in cities and parks as compared to
those in forested lands led to the use and development of remedial measures
for the "more highly prized" trees of roadsides, parks and lawns. Felt, in
discussing these recommendations, was specific in stating that, at that time,
remedial measures involving pesticides were not directed at forestry application.
Biting insects were treated with a class of arsenical poisons: lead
arsenate, paris green, and london purple. The role of these poisons was to
protect the foliar surface by the poison deposits. Thus, when the insect
ate the leaf, sufficient poison was ingested to cause death.
1-7 EQ-5025-D-2 (Vol. II)
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The sucking insects, that extract fluids from the leaf through a
slender beak, were not affected by the surface protective treatment of the
arsenical. Contact insecticides were used in this case. Formulations in this
category included kerosense emulsion, whale oil soap solution, and lime-sulfur
washes. In addition, fumigation techniques were used on relatively small trees
during the period of dormancy. Hydrogen cyanide was the agent of choice for
fumigation.
The costs attributable to spray programs for ornamental shade trees
varied considerably, depending on the price of labor.
In Albany, New York, the average cost of a spray program was 220 per
tree in 1900. However, Felt implied that this cost could be reduced if the pro-
gram was not conducted under civil service regulations. These regulations
required that men had to work only 8 hours per day and further, that both a
tnotorman and driver were required.
The spray apparatus of note in the early 1900's was a horse-drawn
spring wagon which contained a 100-gallon tank of pesticide. This mixture
was pumped through hose lines, each line being handled by a man on a ladder.
A Gould force pump was powered by a Daimler gasoline motor. Felt noted that
this motor was advantageous because it was essentially "noiseless in operation
and is scarcely noticed by passing horses".
The premonition by Felt in the early 1900's relative to the intrusion
of the gypsy moth into New York came true when the insect was discovered near
1 "}
Wampus Pond in the eastern part of the State in 1912.
In 1921, a Barrier Zone was proposed along the lands east of the
Hudson Riv^r that border the New England States. This zone, located east of
1-8 EQ-5025-D-2 (Vol.
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Hudson River, extended from Long Island to the Canadian Border. It was about
250 miles long and about 30 miles wide. By 1924, more than 100 men were work-
ing under the auspices of New York State to keep the gypsy moth from entering
her forests. While the results were encouraging, the state inspectors dis-
covered 12 colonies comprised of 896 egg masses of gypsy moth scattered in
eastern New York counties and Long Island. In addition to inspection, remedial
measures were instituted to control the scattered colonies. In 1929, it was
noted that this included the application of creosote on egg masses and spray
application of lead arsenate on larvae. In 1929 the following statement was
reported in the annual report of the New York State Conservation Department to
the Legislature:
"When any program is so planned that a test of several years
demonstrate it a practical and successful one, changes therein
would, to say the least, be unwise. That, briefly, is the situa-
tion in the gypsy moth control project."
Principal effort continued to be centered around surveys and inspec-
tion for this introduced pest. In 1930, for example, 109,347 acres were
examined. While this pest was still basically excluded from New York State, a
few colonies were found on Long Island. These were treated with an aqueous
formulation of lead arsenate. It is interesting to note that elements of the
state inspection were costly because in regions with many nurseries, like Long
Island the inspectors had to search for evidence of this pest "on their hands
and knees".
In 1931, pockets of the gypsy moth were treated within the barrier
zone. Wherever an infection pocket was located, an area of 600 feet around the
pocket was treated with lead arsenate. This chemical was specifically developed
1-9 EQ-5025-D-2 (Vol. II)
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in 1892 to control the gypsy moth ' . This control chemical, the efficacy of
which had been evaluated in Massachusetts in the mid 1890*s, was applied as
0.8 weight percent water suspension. Seventeen tons of lead arsenate were
applied in this manner * .
A similar formulation of lead arsenate had been evaluated in Massachu-
setts in 1893 and 1894 " and found to be quite effective, although its use and
effectiveness was qualified accordingly on pages 473-474 as follows:
"A careful study of the comparative effect of equal weights
of the three substances used in the preceding experiments shows
that there is practically no choice between Paris green and Paris
green and lime, so far as the destruction of the caterpillars is
concerned. The largest amount of these poisons which can be used
without injuring the foliage is about 1 Ib. to 150 gal. of water,
and at this, or even a much larger rate, the percentage of cater-
pillars destroyed is not satisfactory. Since arsenate of lead in
almost any strength is not injurious to foliage, a much larger
amount can be used than.of any of the more soluble arsenical com-
pounds; thus the superiprity of this poison as an insecticide is at
once evident. While arsenate of lead may be considered the best
insecticide for destroying the gypsy moth in the caterpillar stage,
even this poison is of small value in exterminating this.insect
since many of the caterpillars survive after feeding upon leaves
sprayed with large proportions of this poison.
"The experiments previously recorded show that a considerable
amount of time is required for the poison used to affect the cater-
pillars. Those in the earlier molts were killed in a short time,
1-10
EQ-5025-D-2 (Vol.
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but in the later molts a much smaller per cent was destroyed,
many of the caterpillars transforming and producing imagoes.
"In considering these experiments, it should be remembered
that the insects were in confinement, and obliged to eat the
poisoned leaves, while in field work they may sometimes find leaves
that have not been sprayed, or that have received but little of the
poison, and, therefore, the results in some cases might be somewhat
different from those obtained in these experiments.
"The remarkable ability of the gypsy moth to resist the action
of arsenical poisons is shown in the case of other poisons. Mr.
Moulton covered a piece of lettuce leaf with strychnine, and fed it
to a caterpillar. In about an hour the caterpillar appeared to be
dead, but soon revived and fed again for a short time upon the
poisoned leaf, when it rolled over on its back and for several hours
remained apparently dead, but afterwards revived again and appeared
as well as ever."
Non-chemical control techniques were also being used to control the
gypsy moth. In the 1932 annual report, the New York State Conservation Depart-
ment noted that oil burning was "very effective" against this pest in the Milan,
New York area during 1931. Mr. W. E. Masterson, who has since retired from State
service, was contacted relative to this notation. According to Mr. Masterson,
a large weed burner that used kerosene as a fuel was used to burn or cook egg
masses that were laid on or within stone walls ' .
While control of the gypsy moth received much attention, other forest
pest pi-"!--Jems were not neglected. In the same year, 1931, various poison sprays
and dusts were evaluated against both the European Pine Shoot Moth and The Scotch
I--11 EQ-5025-D-2 (Vol. II)
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Pine Weevil. None gave much encouragement, although 12 to 16 ounces of a 50-
75% solution paradichlorabenzene was effective against the Scotch Pine Weevil
when spread around the soil of each tree.
In 1932, unemployment relief funds were used to support efforts in
the inspection of about 300,000 acres of lands for gypsy moth. A few local
infestations were found and, as before, the foliage was treated with lead
arsenate in circular area (600 feet diameter) around the outbreak. About 12
tons of lead arsenate in a fish oil carrier were used in this manner over 554
acres. Figure 1.1 shows the early methods of applying forest pesticides in
New York. Again, the apparent success of the gypsy moth control program is
manifest in the following statement " .
"[The Gypsy Moth is] one of the few serious forest pest
enemies that can be controlled and its spread prevented."
Although a severe outbreak of gypsy moth was discovered in the Bronx
in 1934, few colonies of this pest were found during a vast inspection program
throughout eastern New York State. This program was conducted from 1934 to
1936, and encompassed survey and inspection of about 1.5 million acres.
Personnel from the Civilian Conservation Corps (CCC) carried out this work
until the 11 camps were abandoned in late 1936. In 1937, 82 tons of lead
arsenate were used to treat local infestations. Again in 1939, 37 tons of
lead arsenate were used against the gypsy moth on 3,089 acres. It is interest-
ing to note that in 1938, 1.75 million "microplectron" were introduced to control
the European spruce sawfly, although the efficacy was not noted.
After 1939, the gypsy moth was discovered to have violated the Barrier
1 3
Zone ' . The reason for this intrusion has not been identified, although it
has been surmised that the violent winds of the 1938 hurricane spread the pest
1-12
EQ-5025-D-2 (Vol. II)
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COURTESY: NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION
Figure 1.1 EARLY APPLICATION METHODS OF FOREST PESTICIDES IN NEW YORK STATE
1-13
EQ-5025-D-2 (Vol. II)
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beyond the zone. Additionally, wind-borne larvae could have been blown beyond
c.
the Barrier Zone from the Connecticut Valley, where a major infestation had
built up during the years of 1937 - 1939.
Coupled with the spread of gypsy moth, the additional factors of cur-
tailed relief labor, and the involvement of the United States in World War II
undoubtedly lead to the spread of this pest.
Even so, control was attempted during the 1940s. Lead arsenate in fish
oil was applied to limited acreage during 1940, 1942, 1943 and 1944. For example,
in 1940, about 29 tons were used to treat 1200 acres and 17 tons on 1105 1/4
acres in 1942. In 1943, cryolite (sodium aluminum fluoride) was used to treat
gypsy moth on about 750 acres in the greater Albany area. While it was noted
that this chemical was not satisfactory, an additional 5 tons was used the
succeeding year on 360 acres in scattered portions of eastern New York.
A-1.3 Historical Summary of Pesticide Use
The preceding discussion, while no means exhaustive, provides
sufficient detail to develop a credible historical perspective on the use develop-
ment of pesticides in the control of forest insect pests and diseases in New York
State.
Serious forest pest outbreaks were not a new phenomenon in the forests
of New York even at the turn of the century. Citation has been made of the
ravages of the forest tent caterpillar and the spruce back beetle. While in
forested regions, control of these ravages was exercised through a reliance on
natural control mechanisms; unfavorable climate, pest starvation, parasites and
predators.
1-14
EQ-5025-D-2 (Vol. II)
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Early chemical control was directed toward the protection of ornamen-
tal shade trees and selected stands of forested regions in high-use areas such
as resorts. Principal chemical control materials were the arsenical compounds
which were used as foliar protectants against biting and chewing insects. How-
ever with the sucking insects contact insecticides were used. Two such materials
are predominant: whale oil soap solution and kerosense emulsions.
The gypsy moth was first located in New York in 1912. This and several
other small infestations were located and treated. In 1923, a barrier zone was
established to preclude the westward spread of this introduced pest. This zone
proved to be effective, and, although areas within this zone were infected with
the gypsy moth, the chemical control methods and materials used for shade trees
in the cities were used to hold the pest in check. The methods were principally
hydraulic spray apparatus dispensing foliar protectants - principally lead
arsenate. This chemical, although shown to be somewhat effective against gypsy
moth outbreaks in Massachusetts some 40 years earlier, did not enjoy unqualified
endorsement by the economic entomologists of even that time. In Massachusetts
and New York, the use of manpower to kill egg masses and collect larvae strongly
complemented the use of broadcast pesticides.
During the late 1930's and the early 1940's an unfortunate alliance
served to aggrevate the pest control problems of New York State. This alliance
was
(1) reliance on one type of pesticidal treatment with a chemical
control material that was not an unqualified success,
(2) a combination of weather conditions and pest outbreaks within
regions bordering the State which led to the violation of the
barrier zone by a non-native pest, the gypsy moth,
1-15
EQ-5025-D-2 (Vol. II)
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(3) a depletion of inspection personnel due to curtailment
of relief labor, and
(4) the outbreak of World War II.
A-1.4. Pesticide Inventory - 1945 to the Present
At the conclusion of World War II in 1945, trapping surveys were
conducted on about 3,000,000 acres of forested land. In addition to this,
DDT as an oil solution, was applied for the first time to 335 acres in the
counties of Albany, Fulton and Saratoga. This experimental effort was
undoubtedly prompted by the successful use of DDT in the Southern Pacific
campaigns. This newly available control chemical was evaluated against both
gypsy moth and the Spruce Budworm. The results were "spectacular".
Applied by aircraft, the cost was noted as $2.00/acre for the DDT treatment
as compared to $15-$20/acre with ground blowers dispensing lead arsenate
formulations.
The next year "amazing results" were obtained with DDT dispensed
both by aircraft and turbine blowers over an area of about 27,000 acres. While
most of this treatment was directed at the gypsy moth, efficacy against the
larch case bearer and the white pine weevil was also evaluated.
The tempo of DDT treatment quickened so that in 1949, 3 years
after the experimental evaluation of DDT on some 300 acres, about 135,000
acres of the central and northern portions of the barrier zone were treated.
It is also noteworthy that the amount of DDT applied to an acre was reduced,
by experimentation, from 1 Ib in 1945 to 0.5 Ib in 1949. This dosage con-
tinued to be used until the end of 1965, at which time the use of DDT was
halted.
1-16 EQ-5025-D-2 (Vol. II)
-------
Having presented a brief narrative on the transition to the use
of DDT, it is interesting to view the total amount of pesticides used in
forest pest control in New York from 1945 until the present. These data
were extracted for compilation and analysis from the annual reports of the
New York State Conservation Department to the New York State Legislature.
In the period from 1945 until 1971, about 3,504,067 Ib of insecti-
cide have been used to control insect and disease pests in the forested lands
of New York. Table I.I presents compositional feature of this total.
The precision cannoted in Table I.I reflects the detail to which
the inventory records were examined. While this compilation was carefully
developed, it is not reasonable to ascribe concomitant accuracy. For example,
estimates were used in the development of the quantity of pesticides other
than DDT and Sevin for, in many instances, at least one element of information
required for accurate compilation, e.g., solution concentration, was not
available. In such cases, judgements based on prior years where all data
were noted, was applied.
The following pesticides are included in the "Other" category:
endrin cygon
heptachlor lead arsenate
lindane trichlorfon
malathion dylox
Dylox and cygon were experimentally evaluated for gypsy moth control
whereas the other control chemicals were applied to selected acreage to control
a variety of pests including white pine weevil, birch leaf miner, sawflys,
biting flies and mosquitos.
EQ-5025-D-2 (Vol. II)
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Table I.I
COMPOSITIONAL FEATURES OF THE TOTAL
QUANTITY OF FOREST PESTICIDES USED IN
NEW YORK STATE 1945-1971, INCLUSIVE
PESTICIDE TYPE
DDT
CARBARYL (SEVIN)
OTHERS
TOTAL
QUANTITY
POUNDS
2,411,540
1,084, 527
8,000
3,504,067
TONS
1,206
542
4
1,752
PERCENT OF
TOTAL
68.8
30.9
.3
100.0
1-18
EQ-5025-D-2 (Vol. TV)
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Therefore, it is reasonable to conclude that, of the total weight of
pesticide used in the forested land of New York State in the inclusive years
between 1945 and 1971,
(a) over 99 % of all pesticides used in forest pest control was
either DDT or Sevin, and
(b) the DDT use-budget was about double that for Sevin.
The pesticide inventory information thus far discussed is presented in
tabular form later in this section.
Of the total amount of DDT used in this period in forest management
operations, about 99 % has been employed in gypsy moth control programs. Of
equal significance, about 98 % of all Sevin used has been directed against the
same introduced pest.
Put into perspective in yet another way, of the approximate total of
3.5 million Ib of all types of pesticide used in forest operations in New York
from 1945 to 1971, about 3.46 million Ib have been used against a single pest,
the gypsy moth.
Based upon the preponderant use of DDT and Sevin to control the gypsy
moth and coupled with minimal quantities of all types of chemical control agents
against other forest pests in New York, it could be concluded that the gypsy
moth is the only significant pest to intrude forested lands.
Such a conclusion, while logical, is simply not true. This can be
demonstrated by consideration of forest acreage defoliated. Over the past 20-year
period (1951-1971), 30,481,132 acres of forested land have been defoliated.
This figure includes all acreage where measurable defoliation has occurred, and is
not meant to imply that all leaves are stripped from the trees on any given acre.
The interesting fact is that, of this total acreage figure, only 1,543,086 acres
1-19
EQ-5025-D-2 (Vol. II)
-------
were defoliated by the gypsy moth. While this figure represents a relatively
small percentage (5.06 %) of the total, it would have undoubtedly been a much
greater percentage without chemical treatment. A great deal of the acreage
defoliated was caused by the Forest Tent Caterpillar and Saddler Prominent.
Chemicals were not used to control these native pests. Rather, reliance was
placed on natural control mechanisms. This is more fully discussed in Section
A-6.
Is emphasized that defoliation is a manifestation of but one class
of forest pest. Other classes such as borers, fungal diseases, and the like
are also important. However, defoliation is not only an important type of
damage but it is also amenable to aerial surveys and thus, these types of data
are readily and reliably obtained.
In summary, it is demonstrable that significant quantities of
pesticides have been used in the control and management of forest pests in
New York. Two principal types of chemicals have been used: DDT, a persistent
chlorinated hydrocarbon, and Sevin, a less persistent carbamate.
Importantly, chemicals are not relied upon to control all forest
pest problems. Rather, reliance is placed upon natural control of native pests.
Chemical treatment is restricted to situations where (1) a pest threatens a high-
use area and/or (2) the pest is not adequately controlled by predators, para-
sites, and disease. Such is the case in New York with gypsy moth, an introduced
r>"f*-
L '
As a result, the overwhelming use of pesticides is directed against
this specific pest. The next paragraph deals with the efficacy of the pesticide
treatment in gypsy moth control programs conducted within New York.
1-20
EQ-5025-D-2 (Vol. II)
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A-l.4.1 Pesticide Treatment Efficacy
Figure 1.2 presents both the yearly allocation of pesticide, by
type used in gypsy moth control, and the annual defoliation by this pest as
measured by aerial survey. These data can also be used to provide the informa-
tion on the quantity of pesticides used as previously presented in Table I.I,
when used in conjunction with application rate. Basically, DDT was applied at a
rate of 1 Ib/acre until 1949, and at a rate of 0.5 Ib/acre from 1949 until 1965
inclusive. Sevin has been applied at a rate of 1 Ib/acre.
Referring to Figure 1.2, several distinguishing features are apparent
in this graphical pre< atation. The vast quantities of DDT used until the late
1950's reflects the philosophy of control by eradication. Since that time, the
concept of control and management has prevailed. Also, it should be noted that
Sevin was first introduced in 1959 in response to concern relative to DDT milk
residue and also due to effects of DDT in trout-water areas. Since 1966, no DDT
has been used to control the gypsy moth or any other forest pest in New York.
Exclusive use of the bio-degradable Sevin, and the general upsurge of
gypsy moth, has led to speculation that this pesticide may not be effective.
Casual observation of Figure 1.2 where the great increase in acres defoliated is
visually "correlated" with the use of Sevin, suggests an aura of reasonableness
to this concern. Detailed examination of hard data, however, demonstrates that
such an assertion is not only oversimplifying but is, in large measure, incorrect.
The first concern in exploring the question of treatment efficacy is
that of the pesticide itself: Does Sevin, applied at a rate of 1 Ib/acre provide
effective initial treatment? The data demonstrate that Sevin is effective. This
is discussed in greater detail in Section A-2.
1~21 EQ-5025-D-2 (Vol. II)
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TREATED ACREAGE - GYPSY MOTH
NEW YORK STATE
ACRES TREATED EACH YEAR WITH DDT AND/OR SEVIN
2800
2700
500
o
400
Q
01
<
ill
cc
I-
w
u
o:
u
300
200
100
YEAR OF TREATMENT
YEAR
1945
1946
1947
1948
1949
1950
19S1
1952
1953
19S4
1955
1956
1957
1958
1959
I960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
TOTALS
ACHES - DDT
335
26.739
64.944
73,320
134.370
146.200
121 048
149.750
122.652
87.742
194,376
446.202
2.774.417
2.040
894
11.282
55.112
146.008
144.658
31.500
13.486
4.747.675
ACRES SCVIN
76.336
8.282
160
300
59,037
32.865
99.969
218.123
41.458
100.454
57,652
120.664
250.750
1.066.050
TOTAI
335
20.73S
64.94«
73.320
134370
146 200
121.648
149.750
122.652
87.742
194.37G
446.202
2.774,417
2.040
77.230
19.564
55.272
146.308
203,695
64.365
113.455
218.123
41.458
100,454
57652
120.664
250.750
5.813.725
GYPSY MOTH DEFOLIATION IN NEW YORK STATE
ACRES DEFOLIATED EACH YEAR
500 -
YEAR OF DEFOLIATION
YEAR
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1900
1961
1962
1903
1904
1965
1901,
1907
1968
1909
1970
1971
TOTAl
ACRES
DATA NOT OBTAINED
i i
675
NOT NOTED
y
10.559
6.649
858
0
1.605
16.490
31.335
61.342
22.600
97.237
148.3G6
34.655
46.160
47.525
121. G10
416,270
4 79. 1 50
1.54.1, DUO
Figure 1.2 GYPSY MOTH CONTROL PROGRAM IN NEW YORK STATE. 1945-1971
1-22 EQ-5025-D-2 (Vol. TI)
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The upsurge in defoliation noted in Figure 1.2 is because much of this
acreage has been defoliated because it has not been treated. New York State
treatment policy provides guidelines that (1) the infected acreage should be at
least 50 acres in size, (2) should exhibit at least 500 egg-masses per acre at
the plot center, and (3) signed landowner consent must be obtained. These
policy factors, coupled with manpower limitations and the abandonment of an
eradication philosophy, are significant causative elements in the upward trend
of woodland defoliation by gypsy moth.
Several examples illustrate these points. In the season just past
(1971), about 480,000 acres in New York were defoliated by the gypsy moth. Of
this total, 150,400 acres were defoliated in Putnam County. One of the principal
reasons was that the seriousness of the infestation was not fully known since
1 8
there was insufficient manpower to survey the area.
Coupled to the insufficiency of manpower, there existed a problem in
timely legislative action in terms of the New York State budget. As a result,
the landowner consent forms were mailed later than normal to those individuals
who owned infested and treatable woodlands. Many were not returned in time for
the final, carefully developed spray treatment program by the Department of
Environmental Conservation. The lack of the returned landowner consent form was
interpreted, as a matter of policy, as being a lack of consent. In other years,
it has been interpreted as a lack of interest and hence, tacit acceptance of
pest control treatment.
Finally, Figure 1.3 schematically delimits differences between
treated and untreated acreage, as well as serving to illustrate an effect associa-
ted with less persistent pesticides. This area of Long Island was aerially treated
1-23
EQ-5025-D-2 (Vol. II)
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DENOTES 1971 DEFOLIATION
COURTESY: NEW YORK STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION
Figure 1.3 TREATED AND DEFOLIATED ACREAGE ON PART OF LONG ISLAND, NEW YORK
1-24
EQ-5025-D-2 (Vol. II)
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with a water-borne formulation of Sevin at a rate of 1 lb(active)/acre. Most
acreage defoliated was not treated. Most of the treated acreage was not de-
foliated. However, it should be noted that some defoliation (not severe) did
occur within the treated blocks that were adjacent to untreated woodland. This
was due to reinfection due to airborne larvae dispersal from adjacent untreated
regions. Experience in the past with DDT indicates that in similar circumstances,
the chemical persistence of the pesticide would have controlled this reinfection,
wherfcas the greatly decreased chemical persistence of Sevin does not permit
extended protection against the reinfection threat.
EQ-5025-D-2 (Vol. II)
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A-1.5 References
1.1 Stout, N.J., 1958, Atlas of Forestry in New York, State University
College of Forestry At Syracuse University.
1.2 Felt, E.H., 1905, New York State Museum Memoir 8: Insects Affecting
Park and Woodland Trees, Vol. I, New York State Education Dept.,
Albany, N.Y.
1.3 1968, Gypsy Moth Control Manual, New York State Conservation Dept.,
Bureau of Forest Pest Control, Albany, N.Y.
1.4 White-Stevens, Robert (ed.), 1971, Pesticides in the Environment,
Chapter 1, pp 67, Marcel Dekker, Inc., N.Y.
1.5 Annual Report of the New York State Conservation Department to
The New York State Legislature, 1911-1971 (inclusive), Albany, N.Y.
1.6 Forbush, E.H., Fernald, C.H., 1896, The Gypsy Moth, Wright and
Potter Printing Co., Boston, Mass.
1.7 New York State Department of Environmental Conservation, letter to
Mr. R.M. Klingaman (at Cornell Aero. Lab) from Mr. E.S. Terrell,
Super. Forest Insect and Disease Control,/s/ J. H. Risley, Associate
Forester, Sept. 17, 1971.
1.8 Personal Communication: E.G. Terrell, Superintendant, Forest Insect
and Disease Control, N.Y. Department of Environmental Conservation
to R.M. Klingaman, CAL.
!_26 EQ-5025-D-2 (Vol. II)
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A-2
APPLICATION TECHNIQUES
To alert the reader to the scope and content of this section, several
points are prefatorily emphasized. The discussions and analyses presented in this
section respond to two stated program goals, namely,:
(1) a discussion of the techniques of forest pesticide application
and,
(2) examination of these techniques to learn how they tend to
maximize or minimize pollution problems.
Since 1945, about 99 % of all forest pesticide treatment in New York has
been accomplished by aerial application. This technique is successful and presents
a minimum of problems due to rigorous adherence of adequate operational guidelines
that have been carefully evolved over the years.
Technically, however, the "heart" of aerial application is the atomi-
zation process for which scientific information is somewhat diffuse and widely
scattered in the literature. This section presents a compilation and analysis of
these data which, hopefully, will be used as foundation material in evaluating
future procedural changes in forest pesticide treatment.
While this information is highly technical, it has been related to other
aspects of forest pesticide use, e.g., pesticide deposition effects on foliar
surfaces.
The main point is that there may be increasing scientific and emotional
pressure to make changes in a single element of the atomization equipment without
appreciating the impact of that change on the environment. We believe that the
following discussion on atomization will serve to further that understanding.
2-1 EQ-5025-D-2 (Vol. II)
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A-2.1 Introduction
The application of pesticides by spraying is the predominant method
currently used in forestry and agriculture for directly controlling the size of
pest populations. Much of this spraying is done with aircraft, both to achieve
timeliness of application and to permit treatment of large areas, often having
limited overland accessibility. Ground-based spraying accounts for the remainder.
The very introduction of pesticides into the environment implies
environmental contamination; the important ecological questions, therefore, are
concerned with "how much", "how important is it", "what are the alternatives",
and "how can it be minimized to a tolerable level". It is now recognized that
through the use of chemicals, agriculture and forestry have been brought into a
highly productive but unstable state. Chemical pest control has been used
extensively in maintaining this unstable state. The avoidance of further en-
vironmental contamination is not a matter of simply prohibiting the further use of
pesticides; the consequences of such an action must also be taken into consideration.
Ultimately, the advantage of pesticide spraying must be weighed against
the disadvantages of its cessation, as well as its hazard to the ecosystem. With
this in mind, the pesticide spraying operations as currently conducted in New York
for gypsy moth control are reviewed. Inasmuch as these operations tend to stress
a special case, the discussion in this section also includes some relevant infor-
mation from other areas. In the weighing process, the most important aspects of
application techniques center on understanding the characteristics of sprays which
are responsible for spray effectiveness and ascertaining the degree of effectiveness
and environmental contamination which has been and might be realized. This point
of view has generally been appreciated for some time, but some of the charac-
teristics required to quantify spray efficacy and hazards are difficult to measure,
2-2
EQ-5025-D-2 (Vol. II)
-------
particularly in the field. As a result, empirical approaches, often with incomplete
parameter determination, have dominated the investigative efforts to such an extent
that many of the features which are necessary for determining what is responsible
for what, aside from what might be done, frequently remain unknown. Further, the
molding of common features in to a consistent and unified scheme is often not pursued
under this approach. The situation as it relates to insect control is adroitly noted
2 1
in the following statement by Himel. '
"In spite of a vast array of experimental difficulties,
the spray application of insecticides has been an un-
qualified Success in the control of insect populations.
This success is amply documented in the scientific and
ancillary literature, but should not be allowed to obscure
the stark fact that very little is known, unequivocally,
concerning the mechanism and mode of transport of spray
droplets to the target. Furthermore, in the present era,
success is not enough. Increasingly complex problems of
insect control in a co-existing ecosystem have to be
faced. Ecological problems are building up and cannot
be ignored. It is probable that ecological factors may
become the overriding consideration in the future allowable
use of insecticides. There exists a critical need for more
fundamental knowledge of the mechanisms of the insecticide
spray process, and a critical need for a direct analytical
methodology by which these mechanisms can be determined."
Something can be said for the empirical approach, however, because it
produces results of direct utility and permits investigations to be carried out in
cases where mechanistic characterization is not presently known to be tractable.
Essentially this approach has been followed in New York; the present spraying
techniques and procedures used in the case of gypsy moth have been developed
operationally. As such, they appear to be capable of achieving success in gypsy
moth control without gross environmental contamination, yet appear to be weak in
providing understanding which can be utilized in defending current practices or
in deriving improved alternate spraying procedures.
2-3 EQ-5025-D-2 (Vol. II)
-------
A-2.2 The Distribution Process
The application of pesticides via spraying techniques involves the
following four key processes.
1. Atomization.
2. Droplet transport from disseminator to target. :
3. Droplet deposition or impaction on the target or other surfaces.
4. Mode of pesticide action against the pest to be controlled.
In relation to these processes other factors are involved, including the pest, its
origin and habits, the nature of the environment in which it is found, the pesti-
cide used, the physical properties of the spray liquid, meteorological conditions,
and the type, relative location and motion of the system carrying the atomizer(s).
The atomization process is fundamental to both pesticide spraying
operations and research, as it is the means by which sprays are generated. In a
more tangible sense, the aspects of principal importance are concerned with the
characteristics of sprays that can be produced with given devices or techniques,
the nature of control which can be exercised in spray production, and prospects'of
generating or tailoring sprays to conform to a prescribed set of characteristics.
Droplet sizes and emission rates are essentially the only features of
a spray that can be controlled during spray generation with any given atomizer of
known design. The extent of the control is, at best, not very great. In attempts
to gain such control, a wide variety of atomizers have been designed, and many
are now commercially available.
The practical realization of what can be achieved in the atomization
process has been far in advance of theory. The fundamental aspects of atomization
are inherently complex because of the many dimensional variables needed to charac-
terize an atomizer, the wide range in properties of liquids or suspensions which
2-4 EQ-5025-D-2 (Vol. u)
-------
can be used, the wide variation in dynamics of liquid flow involved, and the
dependence of ejected liquid instability on liquid interactions with the
surrounding medium. These complexities have thwarted essentially all known
attempts to describe the detailed performance of any atomizer solely in terms
of basic physical parameters. Correspondingly, the literature concerned with
atomization is very extensive; it has been comprehensively surveyed by
2.2 23
DeJuhasz ' and Lapple, et. al ' . The main progress in atomization charac-
terization has come via a less detailed and sophisticated but more practical
semi-empirical approach using dimensional analysis. This scheme has benefited,
on the one hand, from guidance obtained through basic studies, and on the other
hand, from performance characteristics experimentally determined for atomizers
of specific designs. This approach has permitted the correlation of several
parameters which are important in atomizer performance over a rather wide range
of operating conditions. Such unification is significant in simplifying the
engineering aspects of atomizer performance for spray operators and research
workers alike, and should facilitate the conduct of more detailed mechanistic
investigations of the process of spray transport, deposition, and mode of action.
The disintegration of a bulk liquid into droplets can be brought about
in several ways which frequently can be distinquished according to the manner
of supplying energy to the liquid to effect breakup. Atomizers of greatest
interest in pesticide spraying include those which utilize energy arising from
rotary motion, pressure, and the interaction of liquid with high-speed air. Other
Known types employ thermal, explosive shock, acoustic and electrical energy. It
is not unusual to find-atomizers which employ a combination of energy sources.
In rotary devices, such as the spinning disk or cup atomizers, energy is obtained
kj-netically from centrifugal action as the liquid is spun off the periphery of a
2-5 EQ-5025-D-2 (Vol. II)
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rotor. In hydraulic nozzles, including the plain orifice, and 'fan and cone spray
types, the energy available at the moment of breakup is obtained from pressure
built up in the liquid and released in dynamic expulsion. Two-fluid nozzles
utilize, in addition to pressure expulsion of liquid, high-speed air to achieve
further liquid disruption. Additional effects of high-speed air on atomization
occur for each of these types when the atomizers are mounted on a moving aircraft
or in a blower duct.
Rotary atomizers are the only known mechanical devices for generating
nearly monodisperse droplets in sufficient quantities to be practical for use
in the field spraying of pesticides. Their use is presently limited to ultra-
low-volume (ULV) spraying, where application rates of only a few fluid ounces
per acre are employed. The corresponding low liquid flow rates are the key to
rotary atomizer utility in this case, since the requirement of a very low liquid
• 2 4
feed rate per rotor that Walton and Prewett found for the production of
droplets in a narrow size spectrum can be satisfied, yet by using multiple
rotors in parallel, practical emission rates can be achieved. An additional
operational advantage for rotary atomizers is the facility to change droplet
size with rotor speed, without the requirement to change liquid feed rate at
the same time.
Walton and Prewett advanced the following expression to relate the
various parameters governing droplet size in rotary atomization:
where D is a median drop diameter, J is the surface tension of the liquid, p is
the liquid density, V, is the peripheral speed of the spinning disk, d is the
2-6 EQ-5025-D-2 (Vol. H)
-------
disk diameter and C is a constant. Other detailed investigations of rotary
2 5
atomization have been conducted, including those of Friedman, et. al., " and
1 2.6
Fraser, et. al.
For many years there was concern over the unwanted production of small
satellite droplets, in addition to the main droplet output of rotary atomizers.
Customarily, the number of satellite drops increased with increasing feed rate.
Further, at high liquid feed rates the main droplets, themselves, were smaller
than predicted by the drop size expression by Walton and Prewett; often up to
90 % of the total liquid atomized was found in abnormally small droplets. Bals
reported that both these effects can be accounted for in terms of liquid surface
tension and the nature of the issuing point on the rotor periphery from which the
liquid is released.
During the normal build up of liquid to form the primary drop, the
liquid is attracted by its surface tension to the blunt edge of the rotor. When
sufficient buildup has occurred, a filament is formed on which the main drop
hangs prior to its release. Subsequently, this filament shatters into small
droplets of uncontrolled size, forming the satellite droplets. With high feed
rates, the liquid is ejected directly from the rotor as filaments and the nature
of liquid build up at the rotor edge is different. These filaments subsequently
2829
break up in a manner similar to that of a single jet ' ' . The drops so formed
are smaller than predicted by the formula because the dependence of jet breakup
on surface tension is different from that at the rotor edge.
Bals has shown that by using a rotor with fine teeth at the edge, the
liquid buildup phenomenon encountered in normal rotary atomization is substantially
reduced. The net effect is to produce considerably smaller droplets at the same
. 2-7 EQ-5025-D-2 (Vol. II)
-------
flow rate, without the presence of satellite drops. The degree of monodispersity
of drops so formed is slightly poorer than that obtained for normal rotary
atomization.
2 10
Yeo ' studied the drop size distributions from rotary atomizers
spraying from aircraft and obtained the following relation for the volume median
droplet diameter:
where V is now the resultant velocity of the escaping droplet relative to sta-
tionary air, and B is a constant. Presumably this relation accounts for secondary
atomization due to the shattering effect of the passing airstream through the
2. 11
relative velocity V. Sayer ' notes that viscosity of the liquid to be atomized
can be an important parameter affecting rotary atomizer performance, especially
if significant changes in viscosity result from variation in spray liquid temper-
ature. More commonly, viscosity influences the drop size results indirectly by
virtue of changes in rotor loading. This can be overcome using variable flow
control in the system to maintain constant rotor loading regardless of viscosity
changes. Specific performance data for particular rotary device types has been
2.11 2 12 2 13
given, for example, by Sayer ' and Mount, et. al. , *
In spite of the complexity of rotary atomizers, as compared to other
"mechanical atomizers, they exhibit considerable potential for droplet size
control in ULV spraying operations. Further investigation of the output of
these nozzles in high velocity airstreams — particularly when suspensions are
disseminated — appears desirable.
Hydraulic nozzles have been the most widely used types in pesticide
spraying largely because of their simplicity and low cost. The plain orifice
2-8 EQ-5025-D-2 (Vol. H)
-------
types have not been viewed with much favor in the past, because small orifices,
which are highly subject to plugging, must be used to obtain reasonably small
O 1 /
output droplets. Recent work noted by Johnstone ' indicates that for herbicide
application, the plain orifice type nozzle has the advantage of producing a
narrower range of droplet sizes than nozzles of the fan or cone spray types. This
is reported tc hold for both viscous Newtonian and pseudoplastic non-Newtonian
liquids. Unfortunately this effect is known to occur only for sprays with large
volume median drop sizes of the order of 1,000 microns. Hence, the result may
not be of widespread utility.
., ;
Both fan and cone spray nozzles have been used and studied rather
extensively for a period of several years. The atomization process in these two
types is closely related, since at low pressures the nozzle transforms the liquid
into an unstable sheet, either flat or conical in form, which subsequently
disintegrates into droplets of various sizes.
o I c 9 1 A
Dorman " and Yeo " have both made a dimensional analysis of fan
nozzle performance, and by using experimental data have obtained a complete
solution of the equations, yielding a similar relation between the Sauter mean
diameter (D ) of the spray and the physical properties of the spray liquid. For
s
typical size distributions produced by these nozzles, D is related to the
S
volume median diameter (D ) by a constant. Thus both expressions can alternately
be written for D instead of D . Dorman examined the static case, whereas
v s
Yeo examined results for nozzles fitted to aircraft. Yeo's relation, therefore,
which includes the effect of airflow past the nozzle is more general. It is:
2-9 EQ-5025-D-2 (Vol. II)
-------
where Q is the liquid volume flow rate, V is the liquid ejection velocity at
Hi
2.17
the orifice (which has been found by Dombrowski, et. al., " to be essentially
constant over the extent of the liquid fan), V is the resultant liquid velocity
relative to stationary air, and X is an experimentally determined function. The
above relation was established for oil formulations over the viscosity range
3 - 12 cp and the surface tension range of 27-37 dynes/cm.
2 18
Fraser, et. al., ' on the basis of combined theoretical-experimental
treatment that considers the breakup of a spray sheet to be due to wave formation,
arrived at a similar functional dependence of D on the other parameters.
The practical utility of Yeo's expression in applications requiring
more than a rough estimate of the spray volume median droplet diameter rests
squarely on the accuracy and generality of the "X function. The particular form
of the X function determined by Yeo was based mainly on the droplet sizes
obtained from ground deposits of aircraft spray produced with small ceramic
flat fan nozzles with rectangular orifices. Aircraft altitude was about 30 feet
for all tests. To our knowledge no serious attempts have been made to check
Yeo's form of X with other nozzle types, liquid properties, or droplet sizes
representative of the total nozzle output.
Before pursuing this question further, it is significant to note the
2.19-2.22
recent work of Ford and Furmidge dealing with effects of viscosity on
droplet sizes produced by flat fan nozzles. They found that the volume median
droplet diameters produced were a function of the flow parameters given in Yeo's
expression and, in addition, depended on the region of the liquid fan from which
the droplets originated. There are basically two regions of concern; the thin
liquid sheet which forms the central part of the liquid fan and the edges of the
fan, which because of liquid surface tension tend to become curved cylindrical
2-10 EQ-5025-D-2 (Vol.
-------
ligaments. The droplet sizes originating from the sheet and the ligaments are
different; typically those arising from the ligaments are larger. In turn, the
volume median droplet diameter of the spray output, as well as the complete size
distribution, depends on how the total liquid output is divided between the two
regions. Ford and Furmidge characterize this division, and hence the flow
properties of liquid through a fan nozzle, in terms of four ranges of Reynolds
number. These four ranges correspond to fully turbulent flow, transition flow,
laminar flow with sheet formation, and laminar flow with only ligaments present.
Two expressions are then required for expressing median droplet sizes for static
or slowly moving nozzles. For sheet breakup:
——• / = constant,
11 PI ¥3 v ' '
and for ligament breakup:
D
\ / = constant
A \ r\
where A =( —] is the diameter of the ligaments.
\TTVj
Further, Q is the volume flow rate of liquid into the sheet, r is the length
s
of the sheet from the nozzle to the point of breakup, J is the actual spray fan
angle, h is the liquid viscosity, and Q is the volume rate of flow into the
ligaments. In the case of rapidly moving nozzles one might expect the constant
on the right hand side of each expression to be replaced by functions X —-y- ,
similar to that used by Yeo, to account for airstream interactions. The form of
these functions are unknown.
(T 3'p V 2\^3
L £ j represents a sheet instability term which is
directly related to Reynolds number, and hence viscosity. The requirement to
2-11 EQ-5025-D-2 (Vol. II)
-------
know both this factor and the relative proportion of liquid which enters the
central sheet and ligaments presents practical difficulties. These quantities
for various nozzles or series of nozzles commonly used are not known to have been
measured in the laboratory. Further, the nozzle design, manufacturing imperfec-
tions and operating pressure can in principle have a significant effect on the
spray characteristics.
2 23
The opinion expressed by Thompson ' that "the number of variables in
jet-type spray nozzles seems to indicate that this nozzle is poorly suited to
applying insecticides at LV (low-volume) and ULV rates" is not without some
foundation: yet there are mediating aspects. For Reynolds numbers above a
certain value (Re greater than 500 in the cases examined by Ford and Furmidge) the
instability factor appears to be nearly constant and Yeo's expression allegedly
applies. This case is of primary interest for low viscosity liquids and high
liquid ejection velocities. Secondly, the working tolerances and degree of
quality control exercised by reputable nozzle manufacturers are quite good.
Manufacturing imperfections are kept to a minimum. Operator-induced imperfections
resulting from cleaning a nozzle orifice with a sharp instrument are likely to
be more of a problem; such procedures are simply not tolerable. Thirdly, it is
seldom, in practical pesticide spraying operations, that a single nozzle is
employed. Routinely, a bank of 10 or more nozzles are used in aircraft spraying
and imperfections will tend to influence the breadth of the size distribution
rather than an average spray parameter such as the volume median diameter. If a
single nozzle is used it may be necessary to calibrate it separately. Nozzle
wear, unfortunately, is" a factor which cannot be completely overcome. Its effects
can be minimized by employing nozzles with orifices made from very durable
materials such as tungsten carbide — but the cost is rather high. Another
2-12 EQ-5025-D-2 (Vol. II)
-------
alternate is planned replacement after a given amount of nozzle operating time.
There appears to be little one can do to salvage a worn out nozzle.
Reverting to the consideration of Yeo'sX function, it now becomes
more apparent why it generality is of interest. A preliminary comparison of
0 0 /
Yeo's function (converted .to D ) with data of Isler and Carlton and Mount,
2 25
et. al., ' for Spraying Systems Co. Tee Jet fan nozzles with elliptical
orifices in the 80° series is shown in Figure 2.1. It is immediately apparent
that something is different.
In the case of Isler and Carlton's data, the ranges of variation of
parameters is nearly the same as Yeo's except for slightly higher airspeeds and
aircraft altitudes of 50 - 100 ft instead of 30 ft. There are some differences
in droplet sizing techniques, but both involved sizing from spray deposits on the
ground, and this would not be expected to significantly alter the results. The
most likely sources for the variation are differences in nozzle types or spray
altitude. Since the general nature of the functional dependence of the factor
involving size with V_/V is the same, the difference is tentatively attributed to
£i
spray altitude. Spray release altitude can alter the sizes of droplets deposited
on the ground through the cumulative effects of both spray drift and evaporation.
In the case of Mount's data, the difference is almost certainly due
to the way the spray droplets were sized, and the difference in viscosity of the
/
spray liquid. Mount and his co-workers collected droplets of 95 % technical
malathion by impaction directly in the spray output of a nozzle mounted at
various angles in a blower airstream. This simulated scheme gave results which
compared well with the corresponding ones obtained from aircraft dispersal.
As it stands, therefore, it appears that Yeo'sX function is of direct
utility only when the original conditions for which it was derived are closely
2-13 EQ-5025-D-2 (Vol. II)
-------
I.U
0.9
0.8
0.7
0.6
0.5
0.4
/Q <
-------
duplicated. In addition, it seems that the prospect of obtaining such a function
with greater generality depends on basing it on the total size spectrum from
a nozzle or series of nozzles, rather than on the spray which deposits on the
ground after experiencing a variable amount of evaporation and drift. Such a
treatment should also incorporate considerations of viscosity affects, probably
along lines similar to those employed by Ford and Furmidge.
A preliminary indication of the. type of conformity that can be achieved
solely by using the Ford and Furmidge type of expression for sheet breakup is shown
in Figure 2.2. The ordinate parameter group in Figure 2.2 includes the nozzle
discharge coefficient C . These results were obtained by "back solving" for the
instability factor using the measured (or extrapolated) volume mean diameter at
V /V = 1 and normalizing the "X function to unity at this point. Available data
LJ
are not sufficient to allow the complete dependence of the instability factor with
Reynolds number to be estabished this way. However, for each nozzle type examined,
the results — combined with available drop size data for water — appear to
qualitatively follow the type of variation found by Ford and Furmidge.
It will be noted that the preceding discussion is limited almost solely
to the volume median droplet size rather than the complete size distribution.
Data on complete size distributions for various fan nozzles types are relatively
2 ?ft 2 27 2 25
scarce. Hedden ' , Tate and Jansen ' and Mount, et. al., ' give some re-
presentative data. In addition, the Spraying Systems Co. and the Delevan Manu-
facturing Co., for example, have generated some of these data for certain types
of fan (and cone) nozzles under static conditions using water. To date there are
no known investigations which have been successful in relating the complete size
distribution to operational parameters of fan nozzles, even under static conditions,
2-15 EQ-5025-D-2 (Vol. II)
-------
1.0
0.8
0.2
0.1
O T8010 ISLER & CARLTON *
•D T8004 ISLER & CARLTON *
A T80015 MOUNT, et. al. **
0.1
0.2 0.3 0.4 0.5 0.6 0.8 1.0
vE/v
«REF. 2.24
*»REF. 2.25
Figure 2.2 PERFORMANCE CORRELATION OF FLAT FAN NOZZLES MOUNTED
ON MOVING AIRCRAFT BY MODIFIED FORD AND FURMIDGE METHOD
2-16
EQ-5025-D-2 (Vol. II)
-------
Such a result would be of some significance in atomization theory, but its
practical utility is not clear at the moment because typically, fan nozzles
produce a rather broad-size spectrum and the current trend (or desire) in pesticide
spraying is toward the use of sprays in a narrow size range. The answer to the
question of which is better does not lie within the realm of the atomization
process; it must come from other sources.
Hollow cone spray nozzle performance has also been examined by various
2 28 2 29 2 30 2 31
workers, including Knight ' Radcliff ' ' , Nelson and Stevens ' , and Ford
2.22
and Furmidge . Several practical aspects of atomizer design and performance
2 32 2 33 2 34
are discussed by Joyce " , Giffen and Muraszew ' , and Fraser, et. al. . In
principle, the atomization of a conical sheet of liquid produced by a cone nozzle
is somewhat easier to treat than the flat sheet because edge ligaments do not exist.
The production of the sheet itself, however, appears to be related in more complex
way to the atomizer details (e.g., see Nelson and Stevens, and Radcliff).
2.22
Ford and Furmidge found the variation spray droplet size with
viscosity to be similar to that noted previously for fan nozzles. The results
can be considered in terms of three ranges of Reynolds number which correspond
to turbulent flow in the conical liquid sheet, transition flow in the sheet, and
laminar flow. As the Reynolds numbers become small, which corresponds to vis-
cosity becoming large, the angle of the cone becomes smaller and the droplet
sizes increase. When the viscosity becomes quite large a conical sheet is no
longer formed, and the droplets become quite large.
The expression obtained by Ford and Furmidge relating the various
parameters to volume median droplet D size for a static or slowly moving cone
nozzle is:
2-17 EQ-5025-D-2 (Vol. II)
-------
where Q is the total volume emission rate of liquid, V_ is the velocity with which
Ji
the liquid is ejected from the nozzle, ^ is the length of the sheet from the
orifice to the point of breakup, ex. is the cone angle of the sheet, and other
quantities are the same as in the fan nozzle case.
For a nozzle moving at a relatively high speed in air, or spraying
into a high speed air stream, it is expected that the constant on the right hand
side of the above expression should be replaced by a function X ( f ) similar
9 1 (\
to that introduced by Yeo ' . For cone nozzles the form of the "X function
is unknown.
Practical application of the preceding droplet size expressions requires
information on the sheet dimensions A and c*, or alternately "back solution"
for the initiability term from measured volume median diameters. Sufficient data
are not known to be available to permit this to be carried out at present.
Also, the published information does not seem to be sufficient to
characterize the X function for cone nozzles, but preliminary examination of
2 24
this matter using the data of Isler and Carlton ' and the expressions of Ford
2 22
and Furmidge ' suggest that the nature of this X function may be somewhat
-different from that indicated for fan nozzles.
For cone nozzles the available data on droplet sizes are rather meager.
In addition to manufacturers data noted earlier, some information is available
2 35
from the actual and simulated field tests conducted by Coutts and Yates ' ,
? of; 2 25
Butler, et. al., ' and Mount, et. al., ' . Typical droplet size distributions
expected using a D6-46 hollow cone nozzle spraying water into still air and into
2-18 EQ-5025-D-2 (Vol. II)
-------
moving air are shown in Figure 2.3. In this figure,£ is the angle which the
nozzle makes with the thrust line of a fixed wing aircraft. For 6=0° the nozzle
axis is directed into the airstream; for 6 = 90° it is directed vertically
downward.
Hollow cone nozzles have been used rather widely in aerial spraying
operations, in part because of the convenience in using various combinations of
disks and cores to achieve desired application rates and, hopefully, the correct
2 11
droplet size suited to the application. Sayer ' has compared the spread of
droplet sizes obtained on ground deposits from sprays of fan, hollow cone and
spinning disk atomizers and finds the spread generally to decrease in the same
sequence as this order of nozzle type.
The last type atomizer which has been considered for pesticide spraying
is the two-fluid system. Each of the preceding types have been viewed in the two-
fluid sense also because of their interaction with high speed air when mounted on
aircraft or in a blower duct. Mounting any one of the previously noted hydraulic
nozzles in a blower duct essentially constitutes what is involved in configuring
a mist blower, although other design considerations are usually involved as well.
The high speed air employed in mist blowers can often be channelled for greater
interaction with the ejected liquid than is customarily obtained in the aircraft
case, so smaller droplet sizes can be achieved. One additional control aspect of
spray ejected from mist blowers not readily obtained in aerial spraying, is the
ability to direct the spray (a small amount of spray directively is realized, of
course, when spraying from slowly moving helicopters near the ground).
The classical form of two-fluid nozzle system, known as a pneumatic
atomizer, in which air and liquid are closely coupled for maximum interaction has
2-19 EQ-5025-D-2 (Vol. II)
-------
1000
800
600
500
O
CC
O
400
300
cc
01
200
100
80
60
i i i
* !— r--
-i .--. 4 .____J i__ _ ___J ___„
STILL AIR 40 PSIG (EST)
STILL AIR 60 PSIG (SPRAYING SYS. CO. DATA)
100 MPH 40 PSIG (9 = 180°)
100 MPH 40 PSIG (6 = 135°)
100 MPH 40 PSIG (6 = 90°)
100 MPH 40 PSIG (6 = 0°)
COUTTS AND
YATES*
0.1 0.2 0.5 1
»REF. 2.35
Figure 2.3
10 20 30 40 50 60
CUMULATIVE MASS PERCENT
70 80
90
95
98
TYPICAL DROPLET MASS-SIZE DISTRIBUTIONS EXPECTED FOR
D6-46 HOLLOW CONE NOZZLE SPRAYING WATER
2-20
EQ-5025-D-2 (Vol. II)
-------
orily received exploratory attention in pesticide spraying to the present time.
This type system has the potential for producing spray droplets down to a
ftew microns in diameter when properly driven, and may be of interest if future
investigations should indicate that very small droplets are required.
0 ^7
Until the very, recent work of Kim and Marshall , the quantitative
expressions developed to characterize pneumatic nozzle output were far from
satisfactory. These investigators appear to have accomplished a "first" in
atomization investigations by successfully describing the atomizing characteristics
— including both the median diameters as well as the complete mass size distri-
bution — for a class of convergent - type nozzles in terms of operating conditions
and relatively simple dimensions of the atomizer. Their results are not quoted
here, but reference to their original paper should be made if this area becomes
of interest in pesticide spraying.
A final remark in connection with the atomization process seems in
order. Considerable effort ovet the past few years has been expended in attempts
to use spray adjuvantsj duch as spray thickness, invert emulsions, etc. to give
the liquids to be atomized a non-Newtonian character. Typically pseudoplastic
behavior is sought in which viscosity decreases with increasing shear. The
immediate goal of these efforts is to achieve larger droplets than are obtainable
with Newtonian liquids of the same surface tension when sprayed through the same
tiozzle. The alleged benefit of this approach, through the elimination of small
droplets, is to acquire droplet size control, and in the case of aerial spraying
to reduce drift. Indications are that while small droplet production is reduced,
2 38
small droplets are not eliminated. Bouse further notes that "narrower swaths,
less uniform distribution patterns and fewer droplets per unit area for a given
2-21 EQ-5025-D-2 (Vol. II)
-------
application rate are undesirable consequences of the use of large drops. Higher
rates of application are sometimes required to compensate for the reduction in
droplet numbers in order to obtain adequate spray coverage on the foliage".
There is little question that drift, coverage, and droplet sizes
produced are interrelated, but there is no clear cut evidence to indicate that
going to larger droplet sizes to reduce drift will at the same time either
increase pesticide efficacy or reduce environmental contamination in the area
where the spraying is done. The critical feature involved is one of efficiency
of the pesticide itself; the physical form - once reasonable coverage is
achieved - is important primarily to the extent that it effects pesticide
efficacy. The optimum droplet size for pesticide spray droplets, therefore,
is the size that gives maximum pest control with minimum amount of pesticide and
minimum environmental contamination.
The determination of such an optimum size - if indeed one exists for
each pest or certain classes of pests - is not an atomization problem, but does
involve the process of droplet interaction with the target or pest as well as
the mode of pesticide action. Answers to the question of what is an optimum
droplet size have stimulated much controversy. Such answers are not easily
obtained, but the techniques employed for this type investigation received a
2 39
significant boost through the introduction of the FP tracer method by Himel '
The controversy centers around the utility of small droplets in roughly
the 5 to 100 micron size range. If it should be resolved that such small droplets
are highly effective in pest control, which is indicated for certain pests in the
work reported by MacCuaig ' , Himel and Moore ' ' ' , Himel ' , and Mount ,
then conventional spraying techniques and equipment would be completely mismatched
*
in terms of producing droplet sizes of interest. Most of the sprays produced with
2-22 EQ-5025-D-2 (Vol. H)
-------
current equipment emphasizes the large droplet spectrum. It may well be that
the bulk of the spray so produced do little but contaminate the environment.
Obviously, if this should prove to be the case, then conventional aircraft
spraying likely could not cope with the drift problem and the introduction of
new delivery techniques - perhaps still using aircraft as the delivery system -
would need to be developed.
The question of what droplet sizes of pesticide give the greatest pest
mortality, and the way the pest should be attacked to achieve such results are
probably the most needed information in this area. Application techniques should
then be considered accordingly.
The process of transporting spray droplets from an atomizer to the
target is largely a problem involving meteorology, especially for aerial spraying,
but one which has not yet been solved to most workers satisfaction. It is a very
complex problem in general because of the difficulties in characterizing the
atmospheric microstructure in the vicinity of small plants, brush and trees.
Droplet transport as it applies to aerial spraying operations in New York is
discussed in a later section of this report.
The terminal nature of this transport process, in which droplets
interact with or penetrate trees and forest foliage has been considered, for
n 2.45 „ . . .2.46,2.47 T , 2.48 _ ,
example, by Davis, et. al., , Maksymiuk , Johnson , Frear and
Asquith , Bouse and Himel . Some of the fundamental aspects of droplet
2.50
impaction on foliage have been summarized by David
Bouse examined the penetration of large droplet aerial sprays of water
through the canopy of 40-ft tall oaks and an underlying layer of 15-ft tall
yaupon foliage. The effect of mass (or volume) median diameter on penetration
is shown in Figure 2.4. The spray application rate in this work was typically
2-23 EQ-5025-D-2 (Vol. II)
-------
60
50
2 40
Q
< 30
DC
LLJ
20
10
OAK CANOPY
1000 2000 3000
MASS MEDIAN DIAMETER, MICRONS
4000
Figure 2.4 EFFECT OF MASS MEDIAN DIAMETER ON PERCENT OF DROPS
PENETRATING THE FOLIAGE CANOPIES (FROM BOUSE 2.38)
2-24
EQ-5025-E|-2 (Vol. II)
-------
about 4 gallons per acre, which when coupled with the large droplet sizes
employed suggests that increasing penetration with droplet size may be due
primarily to liquid run-off from upper foliage. This appears relevant, because
impaction and retention of droplets with sizes in the range of about 150 to 500
microns (smaller than the sizes used by Bouse) may be limited primarily to the
2 1
outer layers foliage layers, as indicated by Himel * . For deciduous tree
species, droplets larger than about 150 microns would also be expected to deposit
on ground level foliage in the open, or directly on the ground. This part of
the spray would be expected to contribute mainly to environmental contamination.
Aerial spray droplet impaction data taken from foliage samples on a
9.43
coniferous type tree using the FP tracer method has been given by Himel" and
is noted in Table 2.1. No droplets smaller than 39 microns were included in
the count, but Himel notes that a very large number of droplets in the 21 to 30
micron size range was present on all collected specimens of foliage and bark.
The spray employed had a D of 350 microns and an D of 144 microns.
v J * J max v
2-25 EQ-2052-D-2 (Vol. II)
-------
TABLE 2.1 SPRAY-DROPLET DISTRIBUTION ON A 22-FT DOUGLAS FIR TREE
Sample
location
Crown apex
Lateral branches at 15-ft height
Terminal
Center
Base
Lateral branches at 10-ft height
Terminal
Center
Base
Lateral branches at ground level
Terminal
Center
Base
Part
Sam-
pled
needles
bark
needles
needles
needles
needles
needles
needles
needles
needles
needles
D
max
155
115
150
107
92
120
95
105
102
97
94
D
avg
97
64
97
76
67
93
64
73
64
64
64
No.
droplets
counted
431
56
57
33
41
28
35
40
45
85
2-26
EQ-5025-D-2 (Vol. II)
-------
Again droplets larger than about 150 microns will be significant in
environmental contamination.
It appears that the foliage in a forest acts as a size selection mechan-
ism for pesticide spray droplets that are applied from above the canopy. Evidently
there has been some degree of protection afforded the forest pests from aerial
pesticide sprays applied in the past, because complete pest eradication has
never been achieved. Just how significant this protection is, is not. known, but
it undoubtedly varies somewhat with forest type and pest species. The prospects
for altering this screening effect are not good as long as sprays must penetrate
the canopy from above. If spray were released in or below the canopy the effect
may largely disappear. Droplet fallout on the ground would be enhanced, however,
unless small droplet sizes were employed. If droplet impaction on the foliage
is important in the mode of pesticide action against the pest it is possible
that electrostatic charging of the spray could be beneficial. The use of
charged sprays has been explored in agriculture and, while the results are not
always consistent, charging does not degrade impaction on foliage and usually
2.51 2.52
enhances it. Investigations in this area include the work of Bowan, et. al. '
Law and Bowen ' , Roth and Porterfield, ' Sasser ' and Splinter.
What is required for efficient attack of a particular pest is quite
important in view of the preceding mechanistic factors which influence the
ability of sprays to penetrate the environment where the pest exists. In rather
&e..c.ral terms Johnstone ' has outlined certain modes of pesticide action
in the following statement.
"The liquid toxicant may, for instance, act directly by penetration
into and thereby poisoning or disrupting the metabolism of the
organism, i.e. direct contact action. This is the normal mode
for much herbicidal activity, some fungicides and a few insecticides.
Alternatively, the toxicant may act indirectly through residual
activity. For example, in the case of many insecticides, the action
2-27 EQ-5025-D-2 (Vol. II)
-------
may either be by pick-up of the toxic deposit as the pest concerned
traverses a contaminated surface, or by stomach action following
consumption of contaminated foliage. The toxicant may also act in
less obvious ways; for example, by fumigant effects from materials
with relatively high vapour pressures."
At this point it is useful to restrict further discussion specifically
to the gypsy moth, a pest of principal concern in northeastern forests, and to
pesticide spraying conducted in New York for its control.
A-2.3 Pesticide Application Techniques Used in New York State
In New York, pesticides for gypsy moth control are applied by spraying
selected forested areas, which through annual egg-mass count surveys (conducted
during the fall or winter by personnel of the state Bureau of Forest Insect and
Disease Control) are known to have high levels of gypsy moth infestations. Only
about 25 % the forested areas in New York are under state jurisdiction and it is
state policy to obtain written consent from landowners before spraying privately
owned property. Most of the spraying is done by state-owned or state-contracted
aircraft. Of the total 5.8 million acres which have been treated since 1945,
about 99 % has been treated by airborne application using both fixed-wing and
helicopter aircraft and component boom and nozzle technique. The remaining 1 %
has been treated using ground-based equipment — vehicle-mounted or man-portable
mist blowers. Ground-based spraying is carried out chiefly in suburban and
recreational areas, where a greater degree of spatial control of pesticide
application must be exercised.
The gypsy moth is currently attacked via droplets of pesticide spray
impacted and retained on leaf surfaces. During the caterpillar or larval stage
of its life cycle, which occurs in May and June, the gypsy moth is a voracious
leaf-eater, and the pesticide acts as an intestinal poison, following leaf
ingestion. 2'28 EQ-5025-D-2 (Vol. H)
-------
The pesticide used in all the early aerial spray work was DDT dissolved
in oil. It was initially applied at a rate of 1 Ib in 1 gal/acre and later reduced
to half this concentration. In 1959 Sevin, a less persistent pesticide, was found
to be highly toxic to gypsy moth ' ~ ' and its use soon became extensive; it
completely replaced DDT by 1966. The first aerial spraying lasts and early work
with Sevin used a formulation of 1 Ib active Sevin (1.2 Ib of 85 % Sevin) plus 4
4 oz of sticker in 1 gal of no. 2 fuel oil. Adequate gypsy moth control was obtained
where this formulation was applied in aerial sprays of 175 microns volume median
diameter at a rate of 1 Ib/acre. Half of this rate did not give sufficient con-
trol. Similar oil-based formulations including Sevin-4-Flowable have been and
9 f\C\ 7 61
are still used to some extent outside New York '
Because of the objectionable slick formation with the oil-based formulas,
water-based spray was tested. It was determined that water-based sprays gave
*y (**) O fi *3
adequate control when applied by air at rates of 0.5 and 1 Ib/acre '
Results of these tests are given in Tables 2.II and 2.III.
Curiously, in New York essentially the same formulation is now used,
consisting of 1.25 Ib Sevin SOS and 4.0 oz of Pinolene 1882 sticker in sufficient
water to make 1 gal, and it is applied at a rate of 1 Ib/acre twice the rate shown
to be required. Simple mental calculations thus reveal that at an application
rate of 0.5 Ib/acre, twice the total area could be treated with the same total
amount of pesticide, or alternately, the same area with half the total amount.
For mist blower operations the application rate is about 10 to 15 Ib/acre.
How low the application rate of active carbaryl can be and still achieve
gypsy moth control is apparently not well known. Connola ' has stressed the
importance of conducting tests at rates of 0.25 Ib/acre (and smaller rates if
warranted) for this purpose.
2-29 EQ-5025-D-2 (Vol. II)
-------
Table 2.II
POST-HATCH TREATMENT, 1963 AIRPLANE SPRAY TESTS WITH SEVIN AND STICKERS AGAINST GYPSY MOTH IN NEW YORK
Plot
No.
4
5
6
7
8
9
Acres
100
55
80
705
190
365
Date
Sprayed
5/31
5/31
5/31
5/31
5/28
5/31
Amount Sevin
Per Acre
1/2 Ib. + 3 ozs.
"Lovo" 192
1/2 Ib. + 3 ozs.
Fish oil
1/2 Ib. + 3 ozs.
"Ortho" sticker
1 Ib. + 1 oz.
Tung oil
4/5 Ib. + 1 oz.
1 Ib. no sticker
Spray Deposit
satisfactory
satisfactory
satisfactory
satisfactory
unsatisfactory
satisfactory
Estimated Egg
Masses Per Acre
Pre-spray
2128
2088
5384
2904
984
2118
Post-Spray
0
0
24
0
Unsatisfj
18
. Counted Egg
Masses Per Acre
Post-Spray
0
0
6
0
ictory Test
61
txi
I
Ln
O
O
NJ
Possibility of protected unhatched old egg masses.
<
o
-------
TABLE 2.Ill
POST-HATCH TREATMENT, 1965 AIRPLANE SPRAY TESTS WITH SEVIN AND STICKERS AGAINST GYPSY MOTH IN NEW YORK
Plot
no.
1
2
3
4
5
Acres
160
1150
110
150
150
Date
Treated
6/7
6/11-6/12
6/12
6/7
6/12
Additives to
formulations of 1/2 Ib.
carbaryl in 1 gal. spray3 >°
4 oz. Pinolene no. 1882
4 oz. Pinolene no. 1909
4 oz. Ucar Latex no. 40
No sticker
7 oz. Ucar Latex no. 680
Post spray
rainfall on
plot to
6/25 (in.)
1.07
0.62
1.14
1.34
1.90
Avg. estimated no. of
egg masses/1/10 acre
Pre-Spray
184.6
245.8
336.8
553.6
773.6
Post-Spray
0.0
0.0
0.8
4.8
0.0
fc_J S*
,0 Spray dosage was 1 gal of spray/acre.
o b,
All formulations were active Sevin in 1 gal. of aqueous spray.
o
to
<
O
-------
In all known work on gypsy moth toxicity, there is a notable lack of
diet-based dose-response data. The effectiveness of Sevin sprays and amounts
required per acre have essentially been established in the field for particular
modes of spray operation and pest attack. The shortcomings of this approach
become apparent when one attempts to examine alternate spray operations and attack
modes. In addition, dose-response data for topical application of Sevin and
several other pesticides against gypsy moth larvae have only recently been
f\ fc
determined ' . The contact effectiveness of Sevin was implicit, however, in
f\ fr\
the work of Connola ' im which Sevin was applied on infested areas prior to egg
hatch. Unfortunately, topical application and contact effectiveness are not
necessarily equivalent. For example, it has been observed that for the first
instar of Pieris larvae on cotton the median lethal dose due solely to pickup is
particle-size dependent ' . A similar effect has been observed by Lyon " in
the case of bark beetles. Whether such an effect exists for the gypsy moth in its
first instar is not known, but if so, it would offer an alternate approach to the
current use of deposited droplets on foliage. By utilizing a combination of diet
and contact response, the timing of spray application could become much less
critical. In a trial conducted in early May, 1962, in New York Sevin was applied
at a rate of 0.5 Ib/acre with sticker, before foliation and before hatching of the
gypsy moth larvae. Good control was achieved; presumably through pickup of Sevin
'by the emerging larvae in their travel to the emerging foliage.
The aircraft and aerial dispensing equipment used in New York are
conventional. The Stearman biplane and some of the more recent fixed-wing
agricultural aircraft types have been employed for small plot spray work. The
bulk of the spray operations, however, are now carried out using the Grumman TBM
and helicopters. Typical nozzle and boom arrangements for low volume spraying
2-32 EQ-5025-D-2 (Vol. II)
-------
are used. Spraying specifications call for use of Spraying Systems Company dia-
phragm type quick-acting on/off valves together with D8-45 hollow cone nozzle
discs and cores. Various other nozzle types have been used including the flat
fan tips 8002E-80Q4E and the hollow cone combinations D6-46, D7-56, D8-56 and
D10-25. Available information indicates that water-formulated spray drops pro-
duced at the aircraft using these nozzle types have volume mean diamef —^ in the
range of 200 to 500 microns. The mass size distribution of carbaryl typically
used in the water formulation is shown in Figure 2.5. Spray uniformity is
checked prior to the spray season using an array of horizontal ground impaction
cards covering the full width of the spray swath. Flow rate is calibrated
simultaneously. Spray droplet diameters are established by state personnel to
be in the range of 150 to 200 microns volume mean diameter upon impaction on forest
foliage. Aircraft operating conditions are typically 80 to 100 mph at 75 ft above
the foliar level.
Mist blowers employed in gypsy moth control are usually contracted
machines which are also employed at other times for other pests. Typically these
machines employ either an axial-flow or squirrel cage fan to produce an air
stream with exit speed of 110-160 mph. For specificity, the characteristics
of one rather widely used machine, the John Bean Rotomist 100 (Manufactured by
John Bean Div. FMC Corporation, Jamesboro, Ark.) is shown below.
Air discharge rate 28,000 ft /min
Air speed at exit orifice 100 mph
Engine 172 cu in 67 hp
Fan Size 29 in dia
Frequently there is some difficulty in obtaining even spray coverage
on trees with any of these machines, but especially if blowers of inadequate
2-33 EQ-5025-D-2 (Vol. II)
-------
10 20 30 40 50 60 70 80
CUMULATIVE MASS - PERCENT
90 95
98
Figure 2.5 TYPICAL PARTICLE MASS-SIZE DISTRIBUTION OF SEVIN 808
2-34
EQ-5025-D-2 (Vol. II)
-------
9 f\~l
size are used ' . The usual problem is that 2-5 times as much .material may be
deposited on lower branches as in the tops of the trees. The proper combination
of air blast and droplet sizes ejected are important in obtaining good coverage.
For the noted system, typically about 80 % of the spray output (water) consists
of droplets in the 50 - 100 micron size range. Tests made at the Cornell University
indicated that about 70 % of the spray, applied at a rate of 60 gal/acre was
accounted for on above-ground tree surfaces. This figure dropped to 75 % when
the application rate was increased to AOO gal/acre.
Hydraulic sprayers have been used in the past in New York but currently
their use is very minimal. Typically these units were carried on large trucks
together with a spray tank containing 300 - 600 gal. The pump units were con-
nected to hand-operated spray guns by up to 200 ft of high-pressure hose. In
practice, the spray gun operator walked around the tree outside the drip line
shooting short bursts of spray into the foliage and over the tree to cover both
the top and bottom of the leaves, branches and tree trunks. Spray pressures of
2
650 Ib/in were used and 30 - 40 gal of finished spray/acre were required to obtain
coverage to the point of runoff.
The doctrine and definitive procedures for forest spraying operations
are set forth in the Gypsy Moth Control Manual distributed by the New York State
Department of environmental conservation. This manual is currently being re-
vised to include current standard practices. The manual is closely followed in
all aerial and ground spraying operations conducted by the State, and this pro-
cedure appears to give adequate coverage of operational matters. Inasmuch as this
control manual is detailed and extensive in its coverage of topics, ranging from
public relations to technical calibration topics, and from detailed job descriptions
2-35 EQ-5025-D-2 (Vol. II)
-------
to individual forms which are submitted for each operation, no attempt is made
here to reproduce it in its entirety or in sections.
The adherence to regulations during spray operations is facilitated
in that such operations are under the direct control and supervision of career
foresters. Except for Spate-contracted pilots, who also come under the same
supervision, the spray operations are also staffed by career personnel. In
particular, strict rules are enforced relating to the following:
1. No spraying is to be done over water or open land or
residential areas (see Figure 2.6).
2. The minimum acreage to be sprayed by air is a 50-acre
plot.
3. Forest areas to be sprayed only include those where ground
surveys indicate a total egg-mass count of 500 or more
per acre. Records are kept of all spraying operations.
A. Notification is given to local residents regarding spray
operations and what to expect.
5. Proper meteorological conditions must be met or spraying
operations are terminated. In order to meet near-zero-wind,
high relative humidity, and temperature conditions to
minimize drift, most spraying is done in early morning or
late evening.
2-36 EQ-5025-D-2 (Vol II)
-------
COURTESY: NEW YORK STATE DEPARTMENT OF
ENVIRONMENTAL CONSERVATION
Figure 2.6 SPRAY CUTOFF NEAR WATER
2-37
EQ-5025-D-2 (Vol. II)
-------
A-2.4 REFERENCES
2.1 Himel, C.M., 1969, New Concepts in Insecticides for Silviculture
and Old Concepts Revisited, Proc. 4th Int. Agric. Aviat.
Congr. (Kingston 1969): 275-281.
2.2 DeJuhasz, K.J., 1959, Spray Literature Abstracts, Vol. I,
Amer. Soc. Mech. Engrs., 1964, Spray Literature Abstracts,
Vol. II, Amer. Soc. Mech. Engrs., 1967, Spray Literature
Abstracts, Vol. Ill, Amer. Soc. Mech. Engrs., 1969, Spray
Literature Abstracts, Vol. IV, Amer. Soc. Mech. Engrs.
2.3 Lapple, C.E., J.P. Henry and D.E. Blake, 1967, Atomization - A
Survey and Critique of the Literature, Stanford Res. Inst.
Tech. Rept. No. 6.
2.4 Walton, W.H. and W.C. Prewett, 1949, The Production of Spray
and Mists of Uniform Drop Size by Means of Spinning Disc
Type Sprayers, Proc. Phys. Soc. B62(6) No. 354B, pp 341.
2.5 Friedman, S.J., F.A. Gluckert and W.R. Marshall, Jr., 1952,
Centrifugal Disk Atomization, Chem. Engr. Progr. 48(4), 181.
2.6 Fraser, R.P., N. Dombrowski, and J.H. Routley, 1963, Performance
Characteristics of Rotary Cup Blast Atomizers, J. Int.
Fuel 36(271), pp 316.
2.7 Bals, E.J., 1969, Design of Rotary Atomizers, Proc. 4th Int.
Agric. Aviat. Congr. (Kingston, 1969), pp 156.
2.8 Rayleigh, Lord, 1878, On the Instability of Jets, Proc. London
Math Soc. 10, pp 4.
2.9 Tyler, E., 1933, Instability of Liquid Jets, Phil. Mag. 16,
pp 504.
2.10 Yeo, D., 1961, Assessments of Rotary Atomizers Fitted to Cessna
Aircraft, Agric. Avia. 3, pp 131.
2.11 Sayer, H.J., 1969, Ultra-low Volume Spraying Systems Comparison
and Assessment, Agric. Avia. 11(3), pp 78.
2.12 Mount, G.A., C.S. Lofgren, K.F. Baldwin and N.W. Pierce, 1970,
Droplet Size and Mosquito Kill with Ultra-low Volume Aerial
Sprays Dispersed from a Rotary-Disc Nozzle, Mosquito News
30(3), pp 331.
2-38 EQ-5025-D-2 (Vol. II)
-------
2.13 Mount, G.A., N.W. Pierce, C.S. Lofgren and J. Salraela, 1971,
Droplet Size and Kill of Adult Mosquitos with Ultra-low
Volume Aerial Sprays Dispersed from a Rotary-Cylinder Atomizer,
Mosquito News 31(3), pp 326.
2.14 Johnstone, D.R., 1969, Formulations and Atomization, Proc. 4th
Int. Agric. Aviat. Congr. (Kingston 1969), pp 225.
2.15 Dorman, R.G., 1952, The Atomization of Liquid in a Flat Spray,
Brit. J. Appl. Phys. 3, pp 189.
2.16 Yeo, D., 1959, Droplet Size Distributions from Flat Spray
Nozzles Fitted to Aircraft, J. Agric. Engr. Res. 4, pp 93.
2.17 Dombrowski, N., D. Hasson and D.E. Ward, 1960, Some Aspects of
Liquid Flow Through Fan Spray Nozzles, Chem. Engr. Sci. 12,
pp 35.
2.18 Fraser, R.P., P. Eisenklam, N. Dombrowski, and D. Hasson, 1962,
Drop Formation from Rapidly Moving Liquid Sheets, A.I.Ch.E.
Journ. 8(5), pp 672.
2.19 Ford, R.E. and C.G.L. Furmidge, 1966, Studies at Phase Interfaces II.
The Stabilization of Water-in-Oil Emulsions Using Oil-soluable
Emulsifiers.
2.20 Ford, R.E. and C.G.L. Furmidge, 1967, The Formation of Drops
from Viscous Newtonian Liquids Sprayed Through Fan-jet
Nozzles, Brit. J. Appl. Phys. 18, pp 335.
2.21 Ford, R.E. and C.G.L. Furmidge, 1967, The Formation of Drops
from Viscous Water-in-oil Emulsions Sprayed Through Fan-jet
Nozzles, Brit. J. Appl. Phys. 18, pp 491.
2.22 Ford, R.E. and C.G.L. Furmidge, 1969, The Formation of Spray
Drops from Viscous Fluids, in Pesticide Formulations Research,
Adv. in Chem. Ser. 86, pp 155.
2.23 Thompson, G.A., 1970, Jet-Type Spray Nozzle Characteristics,
Mosquito News 30(3), pp 477.
2.24 Isler, D.A. and J.B. Carlton, 1965, Effect of Mechanical Factors
on Atomization of Oil-base Aerial Sprays, Trans. ASAE 8,
pp 590.
2.25 Mount, G.A., C.S. Lofgren, N.W. Pierce and K.F. Baldwin, 1970,
Effect of Various Factors on Droplet Size of Simulated Ultra-
low Volume Aerial Spray of Technical Malathion, Mosquito
News 30(1), pp 48.
2-39 EQ-5025-D-2 (Vol. II)
-------
2.26 Hedden, O.K., 1960, Spray-drop Sizes and Size Distribution in
Pesticide Spray, Trans. ASAE 4, pp 158.
2.27 Tate, R.W. and L.F. Jansen, 1966, Droplet Size Data for
Agricultural Spray Nozzles. Trans. ASAE 9, pp 303.
2.28 Knight, B.E. 1955, Communication on the Performance of a
Swirl Type Atomizer, Proc. Inst. Mech. Engr. 169, pp 104.
2.29 Radcliff, A., 1954, The Performance of a Type of Swirl
Atomizer, Inst. of Mech. Engr.
2.30 Radcliff, A., 1955, The Performance of a Type of Swirl
Atomizer, Proc. Inst. Mech. Engr. 169, pp 93.
2.31 Nelson, P.A. and W.F. Stevens, 1961, Size Distribution of Droplet
from Centrifugal Spray Nozzles.
2.32 Joyce, J.R., 1949, The Atomization of Liquid Fuels for
Combustion, J. Inst. Fuel 22, pp 150.
2.33 Giffen, E. and A. Muraszew, 1953, The Atomization of Liquid
Fuels, John Wiley and Sons, Inc. New York.
2.34 Fraser, R.P., E.-P. Eisenklam, and N. Dombrowski, 1957,
Liquid Atomization in Chemical Engineering: Part 3
Pressure Nozzles, Brit. Chem. Engr. 2(10), pp 536.
2.35 Coutts, H.H. and W.E. Yates, 1968, Analysis of Spray Droplet
Distributions from Agricultural Aircraft, Trans. ASAE 11, pp 25.
2.36 Butler, B.J., N.B. Akessoi. and W.E. Yates, 1969, Use of Spray
Adjuvants to Reduce Drift, Trans. ASAE 12, pp 182.
2.37 Kim, K.Y. and W.R. Marshall, Jr., 1971, Drop-size Distributions
from Pneumatic Atomizers, A.I.Ch.E. Journ. 17(3), pp 575.
2.38 Bouse, L.F., 1969, Aerial-spray Penetration Through Foliage
Canopies, Trans. ASAE 12(1), pp 86.
2.39 Himel, C.M., 1969, The Fluorescent Particle Spray Droplet
Tracer Method, J. Econ. Ent. 62(4), pp 912.
2.40 MacCuaig, R.D., 1958, Spray-collecting Area "of Locusts and Their
Susceptibility to Insecticides, Nature 182, pp 478.
2.41 Himel, C.M. and A.D. Moore, 1967, Spruce Budworm Mortality
as a Function of Aerial Spray Droplet Size, Science 156,
pp 1250.
2-40 EQ-5025-D-2 (Vol. II)
-------
2.42 Himel, C.M. and A.D. Moore, 1969, Spray Droplet Size in the
Control of Spruce Budworm, Boll Weevil, Bollworm and
Cabbage Looper, J. Econ. Ent. 62(4), pp 916.
2.43 Himel, C.M., 1969, The Optimum Size for Insecticide Spray
Deposits, J. Econ. Ent. 62(4), pp 919.
2.44 Mount, G.A., 1970, Optimum Droplet Size for Adult Mosquito
Control with Space Sprays or Aerosols of Insecticides,
Mosquito News 30(1), pp 70.
2.45 Davis, J.M., W.E. Waters, D.A. Isler, R. Martineau and
J.W. Marsh, 1956, Experimental Airplane Spraying for Spruce
Budworm Control, J. Econ. Ent. 49(3), pp 338.
2.46 Maksymiuk, B., 1963, Spray Deposit on Oil Sensitive Cards
and Spruce Budworm Mortality, J. Econ. Ent. 56(4), pp 465.
2.47 Maksymiuk, B., 1963, Screening Effect of the Nearest Tree
on Aerial Spray Deposits Recovered at Ground Level,
J. Econ. Ent. 61(2), pp 143.
2.48 Johnson, N.E., Helicopter Application of Guthion for the
Control of Douglas-fir Cone Midge, J. Econ. Ent. 56(5),
pp 600.
2.49 Frear, D.E.H. and D. Asquith, 1963, Spray Deposits on Apple
Trees Following Applications by Three Types of Sprayers,
J. Econ. Ent. 56(3), pp 399.
2.50 David, W.A.L., 1959, The Accumulation and Adhesion of Insecticides
on Leaf Surfaces, Outlook Agric. 2, pp 127.
2.51 Bowen, H.D., P. Hebblethwaite and W.M. Carlton, 1952, Application
of Electrostatic Charging to the Depoistion of Insecticides
and Fungicides on Plant Surfaces, Agric. Engr. 33, pp 347.
2.52 Bowen, H.D., W.E. Splinter and W.M. Carleton, 1964, Theoretical
Implications of Electric Fields on Deposition of Charged
Particles, Trans. ASAE 7, pp 75.
2.53 Law, S.E. and H.D. Bowen, 1966, Charging Liquid Spray by
Electrostatic Induction, Trans. ASAE 9, pp 501.
2.54 Roth, L.O. and J.G. Porterfield, 1966, Liquid Atomization for
Drift Control, Trans. ASAE 10, pp 201.
2.55 Sasser, P.E., W.E. Splinter and H.D. Bowen, 1967, Effect of
Relative Humidity on the Electrostatic Charging Process.,
Trans. ASAE 10, pp 201.
2-41 EQ-5025-D-2 (Vol. II)
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2.56 Splinter, W.E., 1968, Electrostatic Charging of Agricultural
Sprays, Trans. ASAE 11, pp 491.
2.57 Connola, D.P. and R.C. Sweet, 1961, Aerial Spray Tests Against
Gypsy Moth, Porthetria dispar, in New York, J. Econ. Ent.
54(2), pp 315.
2.58 Keller, J.C., E.G. Paszek, A.R. Hastings and V.A. Johnson, 1962,
Insecticide Tests Against Gypsy Moth Larvae, J. Econ.
Ent. 55(1), pp 102.
2.59 Keller, J.C., V.A. Johnson, R.D. Chisholm E.G. Paszek and
S.O. Hill, 1962, Aerial Spray Tests with Several Insecticides
Against Gypsy Moth Larvae, J. Econ. Ent. 55, pp 708.
2.60 Doane, C.C. and P.W. Schaefer, 1971, Aerial Application of
Insecticides for Control of the Gypsy Moth, Bull. 724,
The Conn. Agric. Exp. Sta., New Haven, Conn.
2.61 Secrest, J.P., W.H. McLane, and J.A. Henderson, 1971, Field
Trials of Insecticides, USDA-Otis AFB Gypsy Moth Methods Div.
Lab. Memo.
2.62 Connola, D.P., 1964, Further Airplane Spray Tests with Sevin
for the Control of Gypsy Moth, Sta. to Sta. Res. News
9(2), pp 6.
2.63 Connola, D.P., J.J. Homiak and R.C. Sweet, 1966, Further
Airplane Spray Tests with Carbaryl Against Gypsy Moth in
New York, J. Econ. Ent. 59(5), pp 1225.
2.64 Connola, D.P., 1971, Private Communication.
2.65 Tomlin, A.D. and A.J. Forgash, 1971, Toxicity of Insecticides
to Gypsy Moth Larvae, Porthetria dispar (L), accepted for
publication in J. Econ. Ent.
2.66 Lyon, R.L., 1967, Formulation and Structure of Residual Insecticides
for Bark Beetle Control, in: Pesticide Formulations Research,
Adv. in Chem. Ser. 86, pp 192.
2.67 Braun, J.L. Jr., 1964, Factors Affecting use of Airblast
Sprayer, Trans. ASAE 7, pp 200.
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A-3
ROUTES OF PESTICIDES INTO THE WATER ENVIRONMENT
A-3.1 Introduction
The routes or pathways by which pesticides used in forest management
can reach the aquatic environment include overland drainage, soil erosion and
sedimentation, atmospheric transport, intentional dumping, accidental spills and
disposal of "empty" pesticide containers. These general pathways have been consid-
ered according to the character of the control of prevailing processes. The first
three are controlled by natural processes; the latter three are overtly controlled
by man.
Pathways by which pesticides applied to forests may reach aquatic
environments by natural processes are shown schematically in Figure 3.1. Estimates
of the magnitude of movement of the two principal pesticides that have been, or
currently are in large-scale aerial sprsying of New York forests (i.e., DDT and
Sevin) are shown. DDT is no longer used in New York. These estimates are based
on a dosage of 1 Ib/acre as it is released from the aircraft which is, at present,
the normal application rate in New York. There have been few studies on the fate
and movement of pesticides in forested areas of New York. Consequently, inferences
have been made from studies on forested areas of the United States and Canada
from nonfcrested areas where applicable.
Biological transport, the spread of pesticide from the treated forest
by animals including birds and insects, is readily shown to be minute compared
with atmospheric or aquatic transport mechanisms.
3-1 EQ-5025-D-2 (Vol. II)
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AERIAL APPLICATION
OF PESTICIDE
SMALL
EVAPORATION
LOSS
SMALL UNDER
NEW YORK
REGULATIONS
IMPACTION
ON
FOREST FLOOR
LITTER
SURFACE
ADSORPTION
< 5 PPB
AT N.Y.
RATE FOR
3% BOGS
& SWAMPS
LARGE
CAPACITY
<<0.1 PPM
CARBARYL
PPB DDT
STREAM FLOW
<0.01% OF
SOIL/YEAR
0.1 PPM CARBARYLFISH TOXICITY
Figure 3.1 NATURAL PESTICIDE ROUTES IN CLOSED CANOPY FOREST
3-2
EQ-5025-D-2 (Vol. II)
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Overt introduction of pesticides by man into the aquatic environment
is distinctly possible, although intentional pesticide dumping is illegal in
New York. Further, it is emphasized that the large-scale use of pesticides in
forest pest control operations is under the direct control and supervision of
career foresters who strictly adhere to operational regulations. If this were
not the case, the direct importance of this type of environmental insult could be
significant. Fortunately, it is not.
A-3.2 Atmospheric Routes and Rates of Pesticide Travel
This portion of the study is concerned with behavior of the pesticide-
bearing spray from its dissemination at the aircraft to its arrival at the forest
canopy or the surface. Spray behavior along this pathway depends on many
variables including underlying terrain, wind, air temperature and humidity,
atmospheric turbulence, and aircraft operational procedure. These variables
range over wide intervals and a study of the entire problem was not the goal of
this project. Rather, the problem was limited to practical proportions by con-
sideration of only the current operational procedure of the New York State
Department of Environmental Conservation (NYSDEC) with respect to control of
gypsy moth by Sevin. Spraying of DDT was not considered as it is no longer
used in New York.
In the present investigation, the information on spray formulation,
types of nozzles, aircraft operations and weather constraints was obtained
from the NYSDEC. Next, extreme conditions contained within the limits of the
operational procedures were chosen to maximize the effect of a particular
atmospheric process on routes and rates of pesticide travel. Under this scheme,
if a process proved to have a negligible effect under these most severe conditions,
3-3 EQ-5025-D-2 (Vol. II)
-------
it was considered obviously negligible under less severe conditions. Where a
process was non-negligible, potential contaminating effects were estimated and the
pertinent data presented.
Operational procedures in New York have been outlined elsewhere in
this report, but they are repeated here as a background for the present discussion.
(1) Over reliatvely flat terrain, the aircraft flies at right angles
to the prevailing wind direction. In mountainous terrain, the
aircraft flies parallel to height contours.
(2) Spraying swaths are spaced approximately 250 ft apart and are
flown 75 ft above canopy top.
(3) Flights are carried out primarily in early morning hours,
with some late evening flights.
(4) Operations are not carried out when the wind speed at
flight altitude exceeds 8 mph.
(5) Operations are not carried out when the relative humidity is
low. In practice, these criteria are specified in terms of
temperature; operations do not proceed when the temperature
exceeds 70°F.
Over relatively flat terrain, the aircraft tracks are flown parallel
and spaced so that continuous coverage will result at the canopy top. The
NYSDEC performed tests in which their helicopter was flown over a test area under
appropriate atmospheric conditions. From a 75-ft altitude, the swath width at
the ground, as determined from deposition of spray on ground-based samplers, was
250 ft.
3-4 EQ-5025-D-2 (Vol. II)
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A-3.2.1 Evaporation of the Liquid Carrier
Evaporation of spray drops affects the rates and routes of travel of
pesticide to the aquatic environment by reducing the terminal fall velocity of
the pesticide between the aircraft and the canopy. Therefore, evaporation causes
the residence time of the pesticide in the atmosphere and the effects of wind
drift and turbulence to increase. Upon complete evaporation of a given droplet,
the pesticide residue is so small that it may be suspended and contaminate
the atmosphere.
To investigate the effects of evaporation quantitatively, computations
were made to determine the change in drop diameter during the 75-ft vertical fall
3 1
between the aircraft and canopy. The equation ' used for droplet evaporation
was
dr _ G re
dt " r CI " 1;
s
where r = droplet radius in cm
t = time in seconds
e = vapor pressure of water
e = saturation vapor pressure of water
s
—6 2 -1
G = 0.9 x 10 cm sec
Even though this is an equation for mass change only, it is derived from
simultaneous solution of the mass transfer and heat transfer equations governing
droplet growth. The effect of heat transfer is contained in the G factor.
This equation was solved in stepwise fashion for each of two constant
values of e/e which correspond to 40 and 80 % relative humidity. The 80 %
S
value is likely to be the minimum encountered during the early morning operation,
and the 40 % value was assumed as the minimum during any operation. To obtain
3-5 EQ-5025-D-2 (Vol. II)
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numerical values of evaporation, -p was computed for each initial value of r and
then used to reduce the radius for a 10-second interval. Simultaneously, the drop
was allowed to fall for 10 seconds with the fall velocity corresponding to the
initial radius. The radius and fall velocity were then reduced and the
computation repeated until the drop either evaporated or fell the 75 ft to the
canopy. This computation does not take account of turbulence whose effect would
be to keep the drops aloft longer and thus increase their evaporation. In practice,
natural atmospheric turbulence is very small under the restricted operating conditions,
but wake turbulence may be significant. Wake turbulence is not well enough under-
stood to permit meaningful estimates to be made of the increased residence time
of a particle in the atmosphere.
The results of these calculations are shown in Figure 3.2. The diameter
below which all drops evaporate completely is 120um for 80 % and 150un for
40 %. The residual pesticide is likely to remain airborne as atmospheric pollution.
Because of the quadratic form of the curves, virtually all droplets larger than
these critical sizes retain diameters exceeding 20um through the 75-ft fall and
truly reach the canopy. The small differential in mass due to pesticide in drop-
lets with final diameters smaller than 20urn which may or may not fall to the canopy
is well within the accuracy of the calculation considering the precision with which
the operation can be flown and variation in initial drop-size distributions. It
is reasonable, therefore, to use these results to estimate the minimum fraction of
pesticide that actually reaches the canopy level.
The drop-size distribution of the spray generated by the nozzle system
at the aircraft is not, in general, known. The drop-size distributions generated
: O O
by the nozzles are known for laboratory conditions of spraying into still air.
3-6 EQ-5025-D-2 (Vol. II)
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UJ
Q
IU
v>
oc
O
in
CO
u.
in
600
500
400
300
^wr
OC
IU
H
Hi
1 10°
5
a.
2 o -
v/*
/ /s>
/ / \f
/ / "
/A
/ /
i / / i i i i i
O n 100 ?nn -win Ann snn «o
O
i
m
ui
a
a.
u.
O
O
100
90
80
70
60
50
40
30
20
10
0
INITIAL DROP DIAMETER
DROP EVAPORATION DURING FIRST 75 FT OF FALL
RELEASE HEIGHT = 75 Ft
WIND SPEED = 8 MPH
NOZZLE - TYPE D6-46
NO EVAPORATION
I
I
I
I
I
100 200 300 400 500 600 700
DOWNWIND DISTANCE FROM RELEASE POINT IN FEET
800
TOTAL AMOUNT OF PESTICIDE REACHING THE CANOPY OVER A GIVEN DOWNWIND LINE SEGMENT
Figure 3.2 PESTICIDE DROPLET EVAPORATION AND DRIFT CHARACTERISTICS,
AIRBORNE APPLICATION
3-7
EQ-5025-D-2 (Vol. II)
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These distributions are presented in the form of accumulated volume percentage
vs drop diameter, i.e., the percentage of spray volume in drops of diameter
smaller than a given value. Effects of atomization on the distribution when water
3.3
is sprayed into moving air have been studied only for one specific nozzle.
These results were extended to other nozzles and estimates made of the percentage
of spray in drops which completely evaporate before reaching the canopy. This
information was then used to estimate the fraction of released pesticide that
reaches the canopy level and presumably is trapped on vegetation or the surface.
3 3
In the Coutts and Yates atomization experiment, spray from a
Spraying Systems Corporation D6-46 nozzle was injected at various angles into air
flowing at 100 mph. One of the configurations was with the nozzle directed at
right angles to the air flow (<(> = 90°), which is the typical orientation of the
nozzles in field spraying operations. The Coutts and Yates data of concern were
those for 150pm and 120ym, the drop diameters below which the computations showed
complete evaporation occurring for relative humidity of 40 and 80 % respectively.
For still air conditions in the laboratory, the accumulated volume percentage at ISOiim
or less was 0.75 %, vfhile for the atomization experiment using moving air it was
10 %, a 10-fold increase. Using this factor, the accumulated volume percentage at
150um diameter for similar conditions of atomization was estimated for other
nozzles used in field operations. A similar analysis was conducted for the 120um
drop diameter, and results from both analyses are listed in Table 3.1. For 40 %
relative humidity (RH) the maximum percentage is 12 % but can go as low as 1 %,
while at the higher 30 % RH, the general level of percentages is around 5 %.
The Coutts and Yates experiment on atomization was based on an airspeed
of 100 mph and nozzle pressure of 40 psi. Operationally, these factors are 80 mph
and CO psi, respectively. The changes of both these factors from experiment to
3-8 EQ-5025-D-2 (Vol..II)
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Table 3.1
ESTIMATES OF INCREASED ACCUMULATED VOLUME PERCENTAGE DUE TO
ATOMIZATION BY AIR STREAM AS COMPARED TO STILL AIR
NOZZLE
D6-46
D8-56
D7-56
D10-25
800 2E
800 3E
8004E
STILL AIR
ACCUMULATED VOLUME PERCENTAGE AT
150 urn OR LESS
0.75
0.1
0.1
1
0.3
0.5
1
120 urn OR LESS
0.1
< 0.1
<0.1
0.3
<0.1
0.1
0.2
MOVING AIR, V = 100 mph; 0 = 90°
ACCUMULATED VOLUME PERCENTAGE AT
150 urn OR LESS
10
1
1
12
3
5
10
120 urn OR LESS
4
< 1
4.1
<12
<1
4
8
3-9
EQ-5025-D-2 (Vol. II)
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operations act to reduce the accumulated volume percentage at the diameters in
Table 3.1. However, in view of the crudeness of the present analysis, it appears
that a reasonable estimate of maximum volume loss from evaporation during field
operations is around 10 %. Thus, for the Sevin SOS slurry with a density of
essentially one, it may be concluded that at least 90 % of the pesticide in the
spray reaches the canopy under the New York spray operation.
At this point it is imperative that the preceding discussion is
brought into both philosophical and technical focus. In the preceding discussion,
an analysis was presented which examined the importance of particle size
distribution of the pesticide formulation as it is released from the aircraft.
While this analysis is by no means exhaustive, iu does demonstrate the criticality
for in-depth knowledge of both thf BpLay equipment and the conditions under which
this equipment is operated. Unfortunately, there is insufficient knowledge available
to thoroughly elucidate these interactions.
Rather than dismiss the problem altogether, it was decided to invoke a
philosophy of the "extreme condition." Therefore, laboratory data were coupled
with theoretical computations to explore a "worst case". Realistic, but extreme,
atmospheric conditions were used to calculate the fate of small spray droplets.
We concluded then that under an extreme or a worst case condition, a reasonable
estimate of the maximum spray volume lost is about 10 %. This is not an
insignificant quantity, if it were to occur. However, under the procedural opera-
tir.g conditions which are used, where there is both high RH and weak natural
turbulence, the maximum volume loss will be much less.
3-10 EQ-5025-D-2 (Vol. II)
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A-3.2.2 Overdosage Within Treated Area
Turbulence acts to spread the plume from its width at the aircraft
to the swath observed at the ground. The complete spreading process is complex
and depends on, among other processes, downwash, wing tip vortex motion, and
atmospheric diffusion. Because of the complexity of the spreading process, it
cannot be treated completely from a theoretical standpoint. Empirically, New York
field tests show that the plume spreads to 250 ft at the ground from a 75-ft
release altitude. However, there is no information about variability of swath
width with wind speed or the variation of the drop-size distribution and
pesticide concentration across the plume at the ground. Such information is
required if the question of overdosage at the canopy top is to be examined. For
example, under calm conditions the pesticide concentration is probably peaked
at the center of the swath, while with a wind this distribution would be skewed
downwind. A definitive and quantitative treatment of this problem must await either
sophisticated computer modeling or more extensive field observations. However, for
purposes of examining contamination of aquatic environment, it seems likely that
any concentration peaks above the application rate will be smoothed out by
subsequent processes acting between the canopy top and entry of the pesticide
into water bodies.
A-3.2.3 Off-target Drift
In the previous section, the effect of atmospheric motions on the
pesticide concentration within the target area was noted. Perhaps a more impor-
tant effect on atmospheric motion is the movement of pesticide away from the down-
wind edge of the target block. Our conversations with the NYSDEC personnel
indicate an acute awareness on their part of the drift problem and a strict
3-11 EQ-5025-D-2 (Vol. II)
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adherence to the operational guidelines provided for eliminating off-target
drift. In view of the care taken in these operations and the calculations
presented here, it appears that for pesticide spraying performed statewide over
a number of years, contamination of water bodies by off-target drift is negligible.
Consider, again, an extreme case in which a pesticide is applied
directly to a body of water 10-ft deep, at the nominal application rate of
1 Ib/acre. The pesticide concentration in this instance would be 36 ppb. Thus,
even for the case of direct application of the pesticide, its resultant concentra-
tion in the water is small. This case is extreme in that it assumes the released
pesticide directly enters the water at the application rate. A more realistic
picture would be that some portion of the spray released over the target area
drifts onto a non-target water body.
By considering the drift problem in terms of the spray released along
the most downwind track in a block, a more quantitative treatment is possible
than with the overdosage problem discussed previously. Because of the variation
of fall velocity with drop size, a spray released into a uniforir. horizontal wind
field reaches the canopy at various downwind distances. This information, combined
with the distribution of pesticide spray mass with drop diameter, can provide
estimates of the off-target drift. In turn, these estimates can be used to specify
the flight track offset needed in order to ensure minimizing off-target drift.
The particle travel distances computed represent the worst case,
whir1- occurs with a wind speed of 8 mph, the upper limit for which operations
are carried out. Using these distances, the drop distributions generated in the
field by a D6-46 nozzle and assuming no evaporation of drops, a computation was
made of the total amount of pesticide reaching the canopy over a given distance
3-12 EQ-5025-D-2 (Vol. II)
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.measured downwind from the release point (Figure 3.2). For example, 25 % reaches
the canopy within 160 ft of release while 50 % falls within 200 ft. At a distance
of 800 ft, 98 % has fallen out. From such a chart, a proper location of aircraft
tracks upwind of water bodies can be determined in order to minimize the amount
of direct contamination by pesticide drift.
The curve in Figure 3.2 was arbitrarily ended at 800 ft, the downwind
distance at which a lOOum diameter droplet reaches the surface at an 8-mph
uniform wind. (If evaporation is considered, droplets of initial diameter equal
to approximately 130 and 170um will reach the canopy 800 ft downwind in
atmospheres 80 and 40 % RH, respectively. The percentage of pesticide that
does not reach the surface within 800 ft of the release point increases to 5 and 14 %,
respectively.) In Table 3.1, it is shown that under the same respective conditions,
4 and 10 % of the released material is contained in drops which can evaporate
completely and consequently remain airborne. Considering evaporation, therefore,
approximately 3 and 4 % of the released pesticide reaches the surface at distances
exceeding 800 ft in atmospheres of 80 and 40 % EH.
Even without further dispersion, it is apparent that the pesticide
contamination of a 1-ft deep pond will be of the order of 1 ppb whenever the
downwind leg of the spray pattern is more than 800 ft away.
In the field, the initial spraying swath is laid down within the
center of a target area in order to estimate the existing drift. Then, based
on the drift of the trial swath, the outermost downwind track is flown at a
distance upwind from the target area boundary such that off-target drift is
minimized. Subsequent tracks are then located successively upwind. In summary,
with strict adherence to the operational guidelines provided for elimination
of off target drift, contamination of non-target areas, while possible, appears
to be small. 3_13 EQ-5025-D-2 (Vol. II) -
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A-3.2.4 Atmospheric Contamination by Complete Evaporation
As a starting point for consideration of atmospheric contamination,
the maximum volume loss by evaporation of 10 % is used. From prior discussion,
this calculated value is an extreme case and, although this value appears at
first glance, to be potentially alarming, it again is pointed out above that 10 %
represents a maximum value possible and not the lower average value which is likely
to occur. This latter value though not presently determinable, is undoubtedly less
than 10 %, and, from this fact alone, actual contamination is less than that
computed. More importantly, even though 10 % represents a significant threat, the
actual threat is reduced considerably when considered in connection with the vast
dispersive characteristics of the atmosphere.
In order to assess atmospheric contamination from the previously-
derived amounts of pesticide injected into the atmosphere, an estimate must be
obtained of the dispersion capability of the atmosphere. The approach taken was
that of computing contamination for an extreme condition of minimum dispersion.
If the pesticide concentrations are low under this condition, the contamination
levels will be even lower under conditions of higher dispersion.
The following computations are based on the 10 % by volume complete
evaporation computed above and the assumption that the slurry (pesticide and
water) is homogeneous. Under these assumptions and a concentration of 1 Ib of
pesticide per gallon of water, 46 grams of pesticide enter the air for each acre
""•"""ad. For a 1-cm thick layer of air covering an acre, 46 gm provide a
concentration of 1150 ppm.
To account for the dispersive properties of the atmosphere, the
O /
material must be distributed in the vertical. Turner " provides data from
Slade " which indicates for very stable atmospheric conditions a plume spread
3~U EQ-5025-D-2 (Vol. II).
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of 15 m in the vertical after 4 km travel of a quasi-instantaneous source. The
source is composed of gas or particles with diameters less than 20 urn. For
Sevin SOS, only about 6 % of the dry material has diameters greater than 20 urn3*6.
Furthermore, computations based on a homogeneous slurry and an initial diameter
of 150 urn for the completely evaporating drop, show that the residual pesticide
particles must be less than 4 urn in diameter. Thus, this dispersion parameter
is applicable to the problem.
Under conditions of even less dispersion where the plume depth is
10 m, for example, after a plume travel of less than 4 km, the pesticide
concentration would be reduced from 1150 to 1.15 ppm. The facts are, however,
that wake turbulence will cause the initial plume to increase to several meters
thickness immediately. Small drops evaporate after only a very short fall while
large drops do not evaporate until just above the canopy; initial thickness of
the particulate plume from the evaporated drops is therefore of the order of
25 m. Even for the very stable situation, this concentration will decrease as
the dispersion operates over a longer time period. Finally, after an early-
morning operation, the stability will decrease as time elapses, leading to
increased dispersion and reduction of the concentration. For initial conditions
of smaller stability, the dispersion will lead to smaller values of concentration.
The pesticide residue from evaporated drops is not permanently suspended
in the atmosphere. Current thinking indicates a mean residence time of 2-3 days,
with the material returning to the earth's surface at a location determined by
synoptic scale atmospneric motions and precipitation patterns.
In the context of this discussion, the value of 1.15 ppm represents
the absolute maximum concentration that can occur in the atmosphere. Pesticide
contamination of the atmosphere by New York forest spray operations is certainly
negligible.
3-15 EQ-5025-D-2 (Vol. II)
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A-3.2.5 Washoff of Pesticide by Rain
An important interaction between atmospheric processes and pesticide
behavior after it reaches the canopy is washoff of pesticide by rain. The
potential for washoff and the rate at which it operates depend on the frequency
of occurrence of rainfall intensities. The only data of this type which are
3 7
available for New York are those published by Dethier * , wherein the probability
of weekly precipitation in amounts of 0.2, 1.0 and 2.0" is given. In order to
examine the rate of washoff of pesticide that is initially impacted on the
canopy, one needs the probability that specific precipitation amounts will
occur after 1, 2, . . ., 10 days during the treatment period. These statistics
do not currently exist, and it is recommended that they be prepared, at least for
selected rainfall recording stations located in the New York treatment areas.
In view of the chemical decay rate of pesticide currently in use in New York
(i.e., Sevin), the data would probably be more meaningful for determining
effectiveness of the spray than for determining the rate of transport to the
aquatic environment.
A-3.2.6 Summary Statement Concerning Atmospheric Pathways
The aerial spraying operation and the atmospheric conditions under
which this operation is conducted are basically characterized as a diffusing
system which operates to decrease the atmospheric concentration of the pesticide.
"--•-•r standard operating procedures, for example, a helicopter system releases
a 30-ft wide spray swath which spreads to a 250-ft swath at canopy level. Opera-
tionally, the aircraft paths are spaced so that overlap at the canopy is
minimized. Outside of inadvertent and accidental overlap, there is no reason
to believe that the pesticide dosage at the canopy will exceed the nominal
application rate.
3-16 EQ-5025-D-2 (Vol. II)
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Potentially, wind in and above the forest canopy can cause the pesti-
cide spray to drift off target. In a given light wind, small spray droplets
have much greater tendency to drift than large ones. There are two ways that
small droplets can be produced when spraying the Sevin-water mixture: first
by the nozzle and airstream atoraization of spray initially produced at the
aircraft and, second, by evaporation of the volatile carrier liquid before the
droplets reach the forest canopy. Results from basic atomization studies indicate
that for the nozzle types and aircraft flight speeds used, the mass-fraction of
spray droplets with sizes sufficiently small to permit significant drift under
typical operating conditions is completely negligible. Evaporative size reduction,
on the other hand, is not necessarily negligible and the potential for pesticide
drift exists.
While in principle off-target drift can exist, in practice, drift is
minimized by rigorous adherence to a policy of spraying only under a selected
set of operational and meteorological conditions. Spraying operations are
carried out in the early morning hours, starting at sunrise, when prevailing
atmospheric conditions minimize evaporation. Winds must be less than 8 mph.
Ambient temperatures must not be over 70°F, to avoid significant convectional
air currents. Material is released only from very low altitude to enhance con-
trollability over the impact zone. To ensure that existing conditions actually
result in suitable deposition on target, without drift, a single spray swath is
made and observed before beginning operations. Follow-up observations are
continued while spraying is underway. Any significant off-target drift is
visually detectable and spray operations at the time of occurrence are adjusted
accordingly to minimize this effect, including terminating operations if
necessary.
3-17 EQ-5025-D-2 (Vol. II)
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The discussion which follows describes and analyzes the pathways by
which pesticides, once on the forest floor, can move from the original point
of application.
3_18 EQ-5025-D-2 (Vol. II)
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A-3.3 Relevant Descriptions of New York Forest Regions
The sections which follow present analyses and discussions of the
pathways by which pesticides are transported within the forest once they reach
the forest floor. In considering these movement and interactions, factors such
as topography, soil type and forest type are relevant. This section provides,
therefore, a descriptive overview of these factors for New York forest regions.
A-3.3.1 Topography and Soils of Forest Regions
The principal forested lands of New York are shown in Figure 3.3.
The occurrence of forested lands in the State is related to topographic, geologic,
edaphic and climatic factors. In general, either virgin forest land was too
steep or rocky for cultivation, infertile, or subject to harsh climate or a
combination thereof. Figure 3.4, depicting land form categories of the State,
when compared to Figure 3.3, shows that the heavily forested Adirondack and
Catskill regions coincide with mountainous land form regions of the State.
Figure 3.5 shows that areas of the State containing slopes greater than 10 %
coincide quite well with the forested lands of the State. The forest regions to
be discussed appropos to soil and topographic characteristics are numbered in
Figure 3.3 and will be discussed in that order.
All of the forests and their soils in the area of this study have
developed since the melting of the last continental glacier. The center ridge
of Long Island marks the southern-most end moraine during the ice age, the first
to be abandoned by melting, some 15,000 years ago. The edge of the Ice then
retreated in approximately a few centuries up the Hudson to the Mohawk Valley,
leaving a large ice cap in the Adirondacks and smaller glaciers in the Catskills
3-19 EQ-5025-D-2 (Vol. II)
-------
PI
-O
O
r-o
L/l
O
o
EXTENT OF 'RESENT FOREST
Figure 3.3
-T-Ti:7• ^f^Y::
Forest land—farms scattered or absent.
Less than 1/3 farmland; wood lots over
50 acres, forest tracts over 1, 000 acres.
Alternating forest and farmland or urban.
Farmland and forest roughly equal.
Farmland—wood lots scattered. Less than
1/3 wood lots and forest tracts; wood
lots less than 20 acres, forest tracts
less than 250 acres.
SOURCE: GEOGRAPHY OF NEW YORK STATE, JOHN H. THOMPSON, EDITOR,
SYRACUSE UNIVERSITY PRESS (WRITTEN PERMISSION FOR
ILLUSTRATION REPRODUCTION PENDING.)
-------
LAND FORM CATEGORIES
nLiii-l Plain*--Slopes mainly [""" ~1 Hound,-d Mouniaiiu.--a*-cp
I. w. ih.in 2 pi-r <-'-MI no local *lO|)Cs usually rjnm-i^ !»•-
, .•],,'( liMlurP*.. 6* "^ t*»-i-n 18 and 37 pi r t n,i hit
SOURCE: GEOGRAPHY OF NEW YORK STATE, JOHN H. THOMPSON, EIDTOR,
SYRACUSE UNIVERSITY PRESS (WRITTEN PERMISSION FOR
ILLUSTRATION REPORDUCTION PENDING.)
-------
EXCESSIVE SLOPH
Figure 3.5
k^m&K^^m'n
, jfSf^^fij^^sg&r
Ye.*^4'e\~?'<';!& fa ,t :*j|.fl A<&- vjff>/
'
^Ms-Msfia,??'.;.;
«.
rflMlpqp^^s
fS%^3$^^*M^'^. ;'.»^f ' ^
SOURCE: GEOGRAPHY OF NEW YORK STATE, JOHN H. THOMPSON, EIDTOR,
SYRACUSE UNIVERSITY PRESS (WRITTEN PERMISSION FOR
ILLUSTRATION REPRODUCTION PENDING.)
-------
until 5,000 years ago. The diversity of the lowland oak forest in the Hudson
Valley developed during this period. In the shorter subsequent 5 millenia, the
birch-beech-maple forest of the upland has developed, although its diversity is
still increasing rapidly under such evolutionary pressures as the gypsy moth.
Region I -Catskills
In a Land Form Region map of New York given in Figure 3.6, it is
seen that the forested Catskill region contains three distinct subregions:
the Catskill Mountains (F-l) containing steep slopes usually ranging between
18-37 %; the Delaware Hills (F-2) with moderate slopes ranging between 9-18 %;
and the Helderberg Hills (F-3) having a similar s}.ope range.
Soils in the Catskills regions were developed from glaciated red shales
and sandstones. Examination of the Soil Association map of Nex? York prepared
O Q
by Cline * shows that the principal Soil Series in the region are shallow
(15-30" depth) Oquaga and Lackawanna soils on the mountainous terrain and deeper
Lackawanna and Wellsboro soils on the high hills bordering the Catskill Mountains
(i.e., Delaware Hills and Helderberg Hills). Many of the soils, especially on
steeper slopes, contain large amounts of stones and gravels. Bedrock exposure
is common on steep slopes.
Textures of A and B horizons range from silt loam to loams and thus
contain about 8 to 25 % clay. (Insecticide adsorption will be primarily on
clay minerals and organic matter. Content of these constituents, therefore,
must be stressed.) Hydrogen ion activity of surface sgils will be pH 4.5 to
5.5. Subsoil pH's will range from 5.0 to 6.0.
Region 2 - Adirondacks
Figure 3.6 shows that subregions of the Adirondacks include the
Adirondack Mountain Peaks (A-l), Adirondack Low Mountains (A-2) and Western
3_23 EQ-5025-D-2 (Vol.
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LAND FORM REGIONS
Figure 3.6
SOURCE: GEOGRAPHY OF NEW YORK, JOHN H. THOMPSON, EDITOR,
SYRACUSE UNIVERSITY PRESS (WRITTEN PERMISSION FOR
ILLUSTRATION REPRODUCTION PENDING.)
-------
Adirondack Hills (A-3). Soils in the Adirondacks have developed on glacial
till from coarse textured granitic rocks. Consequently, soils of the Adirondacks
are coarser textured than those of the Catskills. Substantial portions of the
landscape, especially on the mountain peaks, contain little or no soil cover.
Soils of the Adirondacks are classical examples of Podzols. The
northern 66 % of the region contains predominantly Herman and Beckett soils,
whereas the southern 33% contains predominantly Gloucester and Essex soils.
The ground surface in forested areas of the Adirondacks as diagrammed in
Figure 3.7 is covered with a 2-4" layer of leaf litter and humus. Cline and
3.9
Lathwell " reported the average organic matter content of representative
Adirondack soils to a 3" depth as 53 %. This 3" layer, as will be shown in a
later section, can adsorb all or most of applied insecticides which penetrate
through or are washed off overlying forest canopies.
Below the surface layers of representative Adirondack podozol (A
horizons) soils, there are gray layers about 2-4" thick (A horizons) which
are leached of clay, organic matter, and iron minerals. These constituents
are deposited in the upper part of B horizons giving reddish yellow iron-rich
subsoils.
Region 3 - Tughill
This region is dominated by very stony soils of the Worth Series.
They developed in glacial till from sandstone. Typical profiles and textures
of upland soils in this region are similar to those of the Adirondacks as
presented in Figure 3.7 Reactions of organic humus (AQ horizons and A2 horizons)
in both the Adirondacks and the Tughill Plateau range from about pH 3.5 to 4.5.
B horizons are slightly less acid and range from about pH 4.0 to 5.0.
3-25 EQ-5025-D-2 (Vol. II).
-------
SOIL
DEPTH
(INCHES)
24
36
LEAF LITTER,
HUMUS
GRAY, LEACHED
REDDISH
YELLOW
CLAY, IRON
AND ORGANIC
ACCUMULATION
IN UPPER
PART
GRANITIC
PARENT
MATERIAL
GRANITIC
BEDROCK
SOIL
HORIZONS
Figure 3.7 CHARACTERISTIC PODZOL SOIL IN ADIROIMDACKS*
*PODZOLS IN CATSKILLS ARE SIMILAR EXCEPT FOR
SHALE AND SANDSTONE PARENT MATERIALS
3-26
EQ-5025-D-2 (Vol. II)
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Region 4 - Allegheny Hills
Topography of the Allegheny Hills is characterized by moderate
slopes 'generally ranging between 9 and 18 %. The .-.--ils in this region have
developed in till from sandstones and shales. The principal upland soilr
Lordstown, Oquaga, and Lackawanna series.
Oquaga and Lackawanna soils occur in the Catskills region and were
described previously. Lordstown soils in forested areas will have thin layers
of leaf litter and humus over loam to silt loam A and B horizons. Clay content
comprise 20 to 35 % of soil profiles and bedrock generally occurs at depths of
20-30".
Region 5 - Bear Mountain
Over 75 % of this region is occupied by rock outcrops or very
shallow soils on steep slopes. Forest vegetation occupies local pockets of
deep soil. It would seem that any pesticide spraying in this region could
result in appreciable runoff to tributaries of the Hudson River because of
steep, rocky slopes. Unfortunately there are no known studies of pesticides
in runoff water from such terrain.
Region 6 - Berkshires
This region contains some shallow or very shallow soils on steep to
hilly terrain. These soils are medium textured (8-25 % clay) and stony.
Appreciable portions of this forested area contain soils developed from lime-
stone rather than granite, shale or sandstone which are parent materials of
soils discussed previously. These soils contain appreciable quantities of
play with surface soils containing 10 to 25 % clay and subsoils containing
10 to 35 % clay. Reaction of these high lime soils will be considerably
higher than soils discussed previously with pH's of 6.0 to 6.5 in A horizons
and 6.5 to 7.0 in B horizons.
3-27 EQ-5025-D-2 (Vol. II)
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Region 7 - Long Island
In contrast to other forested regions of the state, forested areas
of Long Island contain principally level plains with slopes mainly less than 2 %.
Since much of the soil on Long Island has developed on loose, coarse textured
(sands and gravels) glacial outwash, they are extremely permeable and droughty.
Two principal soils of the forested areas are the loamy sand to sand
Adams Series and gravelly sandy Colton Series. Both of these soils are strong
Podzols and contain about 5 to 15 % clay.
Other extensive soils on forested areas of Long Island are Plymouth,
Haven and Bridgehampton Series. Plymouth and Haven soils contain somewhat more
clay (approximately 10 to 25 % clay) while Bridgehampton soils consist of fine
sandy loams deposited over gravels. Many soils on Long Island are extremely
permeable to ground percolation but studies on similar soils indicate little
danger of groundwater contamination by normal usage of pesticides in forested areas.
A-3.3.2 Forest Types of New York
The State displays the entire range of forests found in the North-
3 9A
eastern United States. ' Although there are local variations in stands due
to selective cutting as well as location of the soil caterra, the potential zonal
3 10
or climax vegetation as described by Kuchler ' is related to regional climate.
Long Island (Region 7 of Figure 3.3), as part of the Atlantic Coastal
Plain, has a variety of southern oak-pine woodland on the sandy, seaward side.
Pitch pine, scarlet and black oak are dominant on the dry, sandy flats frequently
devastated by hurricans and fires. These oaks have been seriously attacked by
gypsy moths.
3-28 EQ-5025-D-2 (Vol. II)
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The lower Hudson, Susquehanna, Allegheny and Finger Lakes Valleys were
originally covered with Appalachian oak-chestnut forest. Only in Region 5 do
extensive stands of this valley forest remain. White oak is the indicator tree for
the Appalachian forest. Where this tree occurs, other southern hardwoods,
including red oaks and formerly chestnut, now regrowing from sprouts, are also
found. Red maple and an undergrowth of mountain laurel, blueberry and wintergreen,
give the forest floor a shrubby appearance. Gypsy moth attack is widespread along
the Hudson. Northern white pine grow on sandy valley flats and some hemlock occur
in deep, shady valleys.
Isolated stands of elm-ash swamp are found on Bear Mountain (Region 5).
The undrained shallow depressions on this pre-Cambrian ridge are covered with
white ash and formerly American elm, now killed by Dutch elm disease. In this and
the following forest types, gypsy moth defoliation is not so severe.
North of the Appalachian forest type and at higher elevations is found
the characteristic northern hardwood or birch-beech-maple-hemlock forest. This
forest originally covered the remaining lowlands of the state and the foothills
of the Catskills, Berkshires and Adirondacks. It is now found extensively in
Region 4. Sunny, dry south-facing slopes are mostly beech. Maple is most
abundant except where cut over, where yellow birch persists. Steep, shady north-
facing slopes and poorly-drained spots are solidly hemlock in old stands. Bass-
wood, hop-hornbeam and ash are found on richer, more calcareous soils. The under-
growth is restricted to ferns and low herbs. Litter is,, normally thick.
Relatively pure stands of sugar maple and beech were found on the
glacial lake beds of Lakes Erie, Ontario, Champlain and the St. Lawrence River.
Some horsechestnut, hickory, ash, black walnut, yellowpoplar (tulip), black
3-29 EQ-5025-D-2 (Vol. II)
-------
cherry, red oak, basswood and rock elm were found in these lowland forests, now
primarily restricted to farm woodlots.
Above the pure hardwood forest is found a broad zone of yellow birch
mixed with red spruce as well as beech, maple -M-i hemlock (Regions 1,2,3, and 6).
The yellow birch are often very large and of low timber value. At the highest
elevations in the Adirondacks and Catskills (Regions 1 and 2), above the range
of hardwoods, is found the spruce-fir forest or taiga. These dense conifer stands
vary from low matted krummholz at timberline to medium-tall mountain forests of
balsam fir and red spruce with mountain ash and poplars or aspen.
A-3.4 Persistence of Pesticides in Forest Soils
One of the most important properties of a pesticide determining its
degree of threat to terrestrial or aquatic ecosystems is the length of time which
it will persist in components of the environment to which it is applied or trans-
ported. It can reasonably be assumed that the longer a pesticide or a toxic
metabolite thereof persists in a component of the environment the greater the
threat to life forms within that component. This section presents data on the
persistence in soils of the two principal insecticides (i.e., DDT and Sevin)
which have been used in New York forest spray programs. Biological consequences
of persistence are discussed in Section A-4.
DDT
Although there have been numerous studies on the persistence of DDT
in agricultural soils, relatively few studies have been conducted on-DDT persistence
in forest soils. None of these studies were in forested areas of New York.
3 11 3 12
Woodwell ' and Yule ' measured DDT residues in forest soils of
New Brunswick. At one site, containing second growth spruce-fir forest and a loam
3~30 EQ-5025-D-2 (Vol. II)
-------
soil, a total of 4 Ib of DDT per acre had been applied over a 6-year period from
1952-1958. In 1967, 9 years after final application, residual DDT levels of
0.84 Ib/acre were measured, or 20 % of the total aircraft application. At a
second site which received a total DDT application of 4.4 Ib/acre, 16 % of the
total application was present in 1967-68. It is claimed3 that the former site
may have received higher applications than originally thought. Since adequate
data on release conditions were not recorded, there is no way of knowing what
percent of the applied DDT actually reached the ground.
In a Mississippi study conducted on sandy loam plots containing
scattered small trees and shrubs, a known quantity of DDT was distributed on
3 13
top of the soil. After 20 years, between 34 and 50 % of the applied DDT
was recovered.
There have been a large number of studies of the persistence of
n *| /
chlorinated hydrocarbon insecticides in agricultural soils. Edwards
extensively reviewed and analyzed all available studies on DDT persistence in
soils up to 1966. Data from 29 studies on DDT persistence in field soils showed
that the time required for 95 % disappearance of DDT from soil ranged from 4
to 30 years with average persistence of 10 years. It was further calculated
that, on the average, 80 % of applied DDT persists for more than 1 year; 50 %
persists for more than 3 years; after 3 years, the amount persisting ranges from
26 to 70 %, depending on soil type, pH, organic matter and other parameters.
Persistence is greatest in the more acid and highly organic soils. The data
also showed that persistence correlates with solubility of the chlorinated hydro-
carbon pesticide, as shown in Table 3.II.
3-31 EQ-5025-D-2 (Vol. II)
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Table 3. II
CORRELATION OF INSECTICIDE SOIL PERSISTENCE
WITH WATER SOLUBILITY
Most Persistent
1
Least Persistent
Pesticide
DDT
Dieldrin
Aldrin
Lindane
Solubility in Water (ppm)
0.0002
0.10
0.05
10.0
Regression analysis of all available data up to 1966 showing the
breakdown of chlorinated hydrocarbon insecticides in soils was performed by
3 14
Edwards. ' The results of this analysis are shown in Figure 3.6.
It is likely that the persistence of DDT in forest soils is sub-
stantially longer than the decay curve shown in Figure 3.8. This is because of
the demonstrated greater persistence of DDT and other chlorinated hydrocarbons
O 1 / "2 1O
in acid soils high in organic content. ' ' Edwards' data for regression
analysis included many soils having higher pH's and far less organic matter than
normally found in forest surface soils. The Mississippi study referenced earlier
in which up to 50 % of applied DDT was present in a forest soil after 20 years,
lends support to this belief. Dimond, et. al., found no apparent decline
in DDT residues in forest soils 9 years after DDT application of 1 Ib/acre, and
suggested that persistence follows more closely than 35-year half-life determined
3 19
as the upper limit of DDT retention in some agricultural soils. The 35 year-
half-life is probably reasonable to use under the conditions of the present study,
Sevin
In contrast to DDT, Sevin is relatively, non-persistent in soil with
the reported half-life of 8 days. ' Sevin is easily hydrolyzed ' and thus
3-32
EQ-5025-D-2 (Vol. II)
-------
o
2
Z
5
IU
cc
IU
o
V)
IU
o
oc
s
DDT
DIELDRIN
HEPTACHLOR
I I I
I
LINDANE
_| I
8
10 11 12
01234567
TIME (YEARS)
(REGRESSION BASED ON ALL AVAILABLE DATA)
COURTESY: C.A. EDWARDS, "INSECTICIDE RESIDUES
IN SOILS," RESIDUE REVIEWS. V. 13, 1966.
Figure 3.8 BREAKDOWN OF CHLORINATED HYDROCARBON INSECTICIDES IN SOIL
3-33
EQ-5025-D-2 (Vol. II)
-------
will be detoxified before it can be moved any appreciable distance by percolating
waters in forest soils.
The persistence of Sevin has been studied in field studies conducted
on the Shackam Brook Watershed, located j.n Tompkins County, New York. The surface
soils on this watershed are silt loams and loams derived from shaly glacial till,
and are representative of soils which predominate in forested terrain of South
Central and Southwest New York State (i.e., Appalachian Upland, exclusive of
Delaware Hills and Catskill Mountains). This mixed hardwood-conifer watershed was
aerially sprayed with Sevin at a rate of 1 Ib/acre.
Soil samples were collected over a 2-year period following application.
At a detection limit of 0.1 ppm, no Sevin was detected in any of the samples taken
to depths up to 6". No other studies of Sevin in forest soils are known.
It is apparent from available data that DDT or its toxic metabolites
will be available for movement through the forest to the aquatic environment
for decades after application; Sevin on the other hand can be subject to transport
through the forests for only a few weeks.
3-34 EQ-5025-D-2 (Vol. II)
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A-3.5 Transport Processes in Forests
The possible mechanisms by which pesticides could be transported from
soil to the aquatic sector of the forest environment include leaching, runoff
and sediment transport. These mechanisms are discussed in the following sections
A-3.5.1 Leaching
In New York forested areas, the thickness of organic litter and humus
layers will generally range from 2-4". This layer acts as an organic filter and
has a large capacity for adsorbing and retaining applied pesticides, thereby
preventing downward percolation through mineral soil horizons. Careful review
of the extensive literature revealed no studies on DDT or Sevin content of
leachates from New York forest soils.
3.11 3 12
Both Woodwell and Yule ' found DDT residues only in the top few
inches of forest soil. Smith also found very limited movement of DDT through
the soil, with no detection of DDT or its analogues greater than 12" below the
soil surface after 20 years, with an instrument sensitivity of 0.01 ppm
3 13
DDT ' . Thus, although DDT does persist for a long period of time in forest
soil, its movement through soil profiles is extremely limited.
3 23
Riekerk, et.al., ' found DDT concentrations of forest floor, A..
horizons and A« horizons to be an order of magnitude apart with the lowest DDT
concentrations of soil materials a thousand times more concentrated than
percolating leachates. This indicates the large retention action of forest
soils, especially the organic litter and humus.
The extent of pesticide leaching from New York soils may be estimated
from the limited studies in other forested areas and other laboratory and field
3-35 EQ-5025-D-2 (Vol. II)
-------
studies. Field studies of DDT leaching from a fir plantation near Seattle,
3 23
Washington, were conducted by Reikerk, Cole and Gessel ' . Soils on the study
site w^.re permeable sandy loams, underlain by gravels Organic humus layers
overlying mineral soil horizons were less than 1". The Washington study site
thus represented types of' soils found on Long Island and parts of the Adirondacks,
except for generally deeper organic layers in New York soils, and less permeable
subsoil in the Adirondacks.
DDT was applied at rates of 0.5 and 5.0 kg/hectare (approximately
0.4 and 4.4 Ib/acre). Leachate was collected beneath the organic surface layers
and to 15-cm depths. During a 1.5-year period covering two wet seasons, only a
small fraction (less than 2%) of applied DDT was observed to move by leaching
greater than to the 2-cm depth. Less than 1 % of applied DDT was collected in
leachate water at the 15-cm depth.
Although Sevin was not included in the Washington study, another
carbatnate insecticide, Zectran, was. Analyses of leachates in plots treated
with Zectran indicated that less than 1 % passed through the surface soil. The
soils in the Washington study were ones which represent the most extreme vulner-
ability to pesticide leaching because of thin organic horizons, coarse texture,
high rainfall and high permeability. It is, therefore, very doubtful if pesticide
leaching in any forested area of New York would exceed that observed in the
Washington study.
Extensive studies on agricultural soils genera-lly not having a highly
*5 O / O 1 £. O 1 /
organic surface layer also show minor leaching of pesticides ' ' •3*1\
3. 24
Lichenstein ' has conducted numerous studies on agricultural soils and concluded
3~36 EQ-5025-D-2 (Vol. II)
-------
that it is unlikely that water in deeper soil layers can be contaminated with
insecticidal residues from upper agricultural layers.
We may conclude from these studies that the organic litter mat is
sufficient in all New York forests to prevent measurable leaching of any
applied insoluble pesticide.
A-3.5.2 Runoff
A short, light rain falling into a forest evaporates from the leaf,
bark and litter surfaces and consequently does not contribute to the transport
of pesticide. Heavier, longer rains, however, pick up most of the pesticide
present on leaves, bark and litter surfaces by solution and localized scouring,
and can therefore set the pesticide in motion.
Overland water runoff is exceptional under a mature canopy
3.20 3.27
forest ' . The runoff which appears in surface stream channel • several
hours after each heavy rain consists almost entirely of interflow, the excess
rainwater which seeps into stream banks from saturated soil. The available
data show that there is essentially no pesticide in runoff from treated forests.
Northeastern forest soils soak up rainfall at almost any rate. The
soil is fully capable of adsorbing all precipitation. The measured infiltration
3 28
capacity in these forests is 50"/hour or more ' . Runoff, therefore, occurs
3 27
by percolation through the soil. Betson and his TVA colleagues have shown
that forest runoff orginates in only small portions of the watershed area near
the stream channel. Water infiltrating the upland soil adds to the groundwater
or piezeometric head causing surface seepage from the soil at the foot of the
slope. This observation has been confirmed for complex glacial landforms in
3.29
Vermont by Dunne and Black
3_37 EQ-5025-D-2 (Vol. II)
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Water appears on the surface in hollows and flows slowly along well-
established but rarely used drainageways or swales. Frost creep tends to level
these swales so that in New York, even swales will show only 10 to 30 ft of
overland flow.
Seepage from forest soils into ephemeral stream channels can be
predicted from the Laplace equation which applies to groundwater flow in layered
media:
V2 Z = o
where Z is the piezometric head or elevation of the free groundwater surface.
For example, planar solution of the Laplace equation shows that a
small hillslope, while saturated to the surface during a prolonged rainstorm,
will drain toward a surface stream at a rate proportional to its gradient. The
resulting maximum runoff rate to be expected from New York forests varies from
l"/hour on steep Dekalb soils found in the Catskills (measured at Coshocton,
Ohio) to 0.5"/hour (measured at Emery Park, Erie County, September, 1967).
Basic runoff data have been published by the U.S. Forest Service and Agricultural
3.30 3.31
Research Service ' All show that overland flow is negligible for a
wide variety of forests and terrain.
The rain falling directly into the channel, overhung with branches,
runs off immediately. Pesticides originally residing on such locations are
immediately transported to permanent water bodies. However, this small area
runoff cannot contribute significant amounts of pesticide to drainage systems.
As an extreme example, calculations show that for an area with as much as 3 %
*
of land area covered with standing water approximately 1-ft deep (found
primarily in the Bear Mountain range, Region 5), direct spraying with Sevin at
3-38 EQ-5025-D-2 (Vol. II)
-------
1 Ib/acre will add 5 ppb to the runoff water. Even on nonforested watersheds
containing the same soil type as commonly found in the Catskill forest region
of New York (Muskingum or Dekalb silt loam) accumulated runoff water was
normally found to contain less than 0.1 % applied chlorinated hydrocarbon
pesticides 12 or more months after applications.
In hardwood forests, the wet, matted, broad leaves lie on the surface
like shingles on a roof. Such litter is impermeable in spots even where the
underlying soil is unsaturated. Where the surface is permeable, water will
fall into the soil as infiltration. The net effect is that overall surface
flow is minor and usually limited in length to less than 30 ft.
The rainwater, with its suspended and dissolved pesticide load, soaks
into the litter and from there, infiltrates into the mineral soil. As the
water percolates into the litter and soil, it is adsorbed in the thin liquid
film which clings to each particle. A large part of the pesticide is trans-
ferred by diffusion to the adsorptive particle. As infiltration continues,
each film thickens to the drip point so that the water is slowly falling
through the soil. As discussed in A-3.5.1, the highly organic litter and
humus layers, as well as clay minerals, effectively retain pesticides against
the gravitational and drag forces of percolating water.
The soil water is absorbed by tree root hairs and returned to the
atmosphere by transpiration from the leaves. The infiltration capacity for a
given water temperature and vicinity is a function of soil capillarity and the
3.32
distribution of soil voids by size in each soil horizon ' . The high water
capacity of forest soils is due to the large root mass of the trees. The
roots, which normally extend into bedrock, grow and move so as to open
3-39 EQ-5025-D-2 (Vol. II)
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continuous voids for infiltration. These voids are largest near the trunk of
each tree where the stemflow is absorbed. These effects, designed by arboreal
evolution to hoard water for transpiration, also minimize overland flow- The
actual infiltration rate, up to capacity, is dependent on the antecedent
moisture present in the soil. If the water depth is sufficient, gravity will
cause the water to move laterally over the surface as overland flow. Surface
rocks, logs and deadwood imbibe any local overland flow, damming and diverting
it into the soil.
Literature review uncovered no studies on the DDT content of overland
runoff from forested watersheds. This is due perhaps to the rarity of sustained
overland runoff from forested watersheds. Review of literature shows few
studies on pesticide levels in runoff, even from agricultural watersheds.
Studies were conducted on the content of the chlorinated hydrocarbons, dieldrin
and methoxychlor, from cultivated plots located at the Appalachian Experimental
o O£ o o o
Watershed, Coshocton, Ohio ' They are discussed here only to set some
tentative estimates on the magnitude of the problem. Field and laboratory
studies are, of course, needed to obtain more accurate assessment of DDT in
forest runoff.
Both of the aforementioned studies were conducted on Muskingum silt
loam soils. This soil type occurs over a large portion of the Catskill
Mountains and Delaware Hills of New York. The total amount of applied
methoxychlor recovered in runoff for a period of 14 months after application
O 'Jfl
amounted to only 0.004 % of that applied ' . Over 25 % of the loss was
associated with one storm which occurred when the topsoil was frozen.
3-40 EQ-5025-D-2 (Vol. II)
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The second study at the Appalachian Watershed3'33 involved water runoff
of dieldrin from silt loam soils on 13-14 % slopes. Data were collected on two
different watersheds for two different years (1966,1968). In 26 months after
the 1966 application, 0.007 % of applied dieldrin had been lost in solution to
runoff water. In 12 months after the 1968 application (5 Ibs/acre) 0.07 % of
applied dieldrin was collected in runoff water. It was pointed out that the 1968
treatment was performed on soils which had been prepared so as to maximize runoff.
It was further found in the above studies that largest losses in runoff occurred
when soil was bare or had only thin cover.
It can be reasonably concluded that in forest environments, chlorinated
hydrocarbon residues, including DDT, in runoff waters would be far less than those
observed above, as long as forest cover remained intact.
In a study previously alluded to, runoff of Sevin from a forested
3.22
watershed in New York was monitored. ' At a detection limit of 0.01 ppm,
~no Sevin was detected in drainage waters from a watershed treated at 1 Ib/acre.
Samples were analyzed for a period of 2 years after application. The chances of
Sevin entering streams with overland water flow are even far less than for DDT
because of rapid degradation before and after transport.
The most serious contamination hazards involving runoff of applied
insecticides from forest soils may be associated with truck-mounted mist-blower
application to selective acreages. In this case, the pesticide application rate
is higher due to the practice of treating both leaf surfaces "to-drip." The
output particle size is smaller, and area may be treated more than once to protect
against reinfection from adjacent areas. Drainage ditches are likely to exist
along roadsides and recreational parklands in which pest control may be desired.
EQ-5025-D-2 (Vol. II)
-------
Such ditches lead runoff directly into permanent streams. Therefore, it is not
difficult to surmise that relatively high pesticide concentrations in these
ditches could potentially be flushed into streams or lakes before even the least-
persistent pesticide has been degraded.
A-3.5.3 Sediment Transport
Slopewash or particulate erosion of soil by overland flow under
3. 27
mature temperate forests such as occur in New York is negligible. ' The
suspended sediment of forest floods originate in the caving and slumping of
3.32
undercut stream banks as well as roads and other slope disturbances. ' Thus,
although studies have shown that sediment transport of chlorinated hydrocarbon
O Q O O O
pesticides is much more effective than overland runoff, ' we will show in
the following paragraphs that it is usually of little import in intact forested
areas. Serious problems may occur in regions where the natural forest conditions
have been altered by man.
The basic situation at a point on a forested hillslope is illustrated
in Figure 3.9. It must be recalled that, in the discussion of leaching, we
concluded that the pesticide remains in the top 10 cm of soil and/or virtually
Its entire lifetime in the soil.
The erosion of hills and valleys by precipitation-induced processes
include:
(1) weathering of rock to debris by infiltrating precipitation
and creep of wet debris and bedrock,
(2) wash entrainment or lift of loose debris by surface runoff
of excess precipitation and,
(3) landslides or slope failure.
3-42 EQ-5025-D-2 (Vol. II)
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LITTER &
SOIL CONTAINING
PESTICIDE
JOINTS
SMALL BARE AREAS
FORESTED
HILLSIDE
MEAN HILLSLOPE
Figure 3.9 TYPICAL FOREST STREAM BANK CROSS SECTION
3-43
EQ-5025-D-2 (Vol. II)
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The erosional processes of importance are, therefore, limited to those which
cause transport of the uppermost layer of soil. While vegetation promotes the
disintegration of rocks and chemical weathering, it retards the transport of the
weathered material. Where vegetation is profuse there is always an excess of
material awaiting transportation and the limit to the rate of erosion comes to
be merely the limit to the rate of transportation. Under closed-canopy forest,
it is the thick layer of litter and dead wood that prevents overland rainwash
erosion of soil. Saturation of this thick root mat leads to creep. Creep
processes, however, are relatively minor in temperate forests due to the anchorage
O *3 /
of tree roots in bedrock. Leopold, et. al., ' in a summary article shows for
example, that the mean surface creep rate in temperate forest is of the order
of 0.6 mm/year. Obviously, therefore, creep is unimportant in releasing pesticide-
laden sediment to the aquatic environment.
Surface wash erosion of soil requires a relatively high velocity of
overland flow. It was shown in the previous section that under temperate forest
cover surface flow rates are extremely slow and total overland transport is
limited to distances of the order of 30 ft. Erosion due to overland flow is,
therefore, negligible in a standing temperate forest.
Catastrophic landslides are occasionally produced by torrential rains,
associated with very severe weather such as hurricanes, in mountains of the eastern
o oc
United States. In a study performed in Northern Virginia, Hack and Goodlett
found that a maximum of 1 % of the land area in high mountain forest was removed
by slides during the "100 year" storm of 1949. A very simple calculation based
on these data shows that such land slides cannot produce serious pesticide con-
tamination in regions treated with Sevin. If the entire area had been recently
treated with 1 Ib/acre and the slides produced by 4" of rain (lower than the actual
3-44 EQ-5025-D-2 (Vol. II)
-------
case), the concentration of pesticide in the rain water alone would be
approximately 1 ppm. For Sevin, which does not persist from year-to-year and
for which toxicity levels exceed this value significantly, such landslides are
not important. For DDT on the other hand, a single application could produce
pesticide concentrations that are toxic to many species.
In smaller rainstorms, very minor landslides and stream bank caving
produce silt in the stream water. The percentage of the total land area
affected is, of course, extremely small and the contamination problem is
reduced by many orders of magnitude or more. Data from the U.S. Department of
3 35A
Agriculture * show that the total erosion rate into stream channels in
mountainous regions of New York averages approximately 0.01 acre-ft/sq mi/year.
If this mass of material was eroded entirely from the top 10 cm of surface
which contains virtually all pesticide, the total pesticide load introduced into
streams by bank erosion would be 12g/year/sq mi of mountainous area. Considering
average annual rainfall in the same region, it is obvious that introduction of
pesticide into water by stream bank erosion is completely negligible.
The preceding discussion pertains only to intact forest areas. The
problem of erosion is substantially more serious in the forest when cover is
disturbed. When a steep mountain forest is clearcut, disasterous soil erosion
usually follows. It is not the act of clearcutting alone but the roads, log
skidding, slash burning and subsequent land-use practices which lead to
catastrophic soil erosion. Sediment is produced from road and other soil
disturbances including bank erosion by permanent stream channels.
3_A5 EQ-5025-D-2 (Vol. II)
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The sudden movement of pesticide-laden sediments from an eroding
clear-cut or burned-over forest introduce catastrophic amounts of persistent
accumulated insecticides such as DDT to local drainage networks. The magnitude
3.33
of the problem may be estimated from the Coshocton study previously discussed " ,
Dieldrin residues found in sediments eroded from a bare or sparsely vegetated
watershed contained 2.2 % of the applied dosage (5 Ib/acre). This represented
about 30 times as much insecticide as found in runoff water from an adjacent
watershed for the same 12-month period.
The possible release of DDT or other persistent chlorinated hydrocarbon
insecticides in sediment losses from denuded forest watershed is of concern.
Because of the short term persistence of Sevin in soil, the chances of forest
denudation and resultant sediment runoff occuring coincident with Sevin presence
in soils are very small.
Concentration of persistent pesticides that could occur in runoff
if a forest area were clear-cut or burned-out can be estimated. The accumulation
of DDT residues in organic forest soil horizons typically reaches 0.5 Ib/acre
or 40 ppm in 3" of humus, where spraying continues for many years, although
*3 1 /
values as high as 2.2 Ib/acre have been found ' . The sediment concentration,
although known only approximately, is typically of the order of 10-15 % for
serious erosional events on disturbed terrains. Using the nominal concentration
of pesticide in the surface soil of 40 ppm, the concentration of pesticide C
In the stream discharge is as high as:
C = '5 % x 40 ppm = 6 ppm, in the runoff.
3-46 EQ-5025-D-2 (Vol. II).
-------
For drainage basins exceeding 100 acres, depending on soil type,
sediment will be deposited in the stream bed for removal at a later time, and
thus cause continued pesticide contamination. Even with very small cut-over
watersheds, however, toxic local DDT concentrations can be produced in waters
adjacent to the cut-over area. The toxic organic sediment settling in water
bodies from such erosion provides a long-lived source of DDT contamination due
to the low solubility characteristic of persistent pesticides. The DDT con-
centration in sediment will be essentially the same as in the soil removal
since DDT is essentially insoluble in water. From the lake sediment, the
pesticide is further concentrated in the aquatic food chain.
In summary, the available evidence indicates that there is little
threat of serious contamination to streams and lakes in forested regions from
pesticide transport by leaching, overland runoff or sediment losses, when the
chemical is, applied by aircraft at 1 Ib/acre and forest denudation does not
occur. If forest cover is removed from DDT-treated acreages, serious stream
and lake contamination can occur as a result of pesticide-laden sediment
runoff. Even though DDT is no longer used in New York, this threat still
exists because of the long-term persistence of the chemical. Therefore, it
is essential to prevent the denudation of forest acreage that has been treated
with DDT in past years. This threat is negligible, however, on that acreage
that has been treated only with Sevin due to the rapid degradability of this
chemical.
Saturation spraying of selected acreages of forested lands with
truck-mounted mist blowers could result in serious runoff of pesticides along
roadside drainage ditches.
3-47 EQ-5025-D-2 (Vol. II).
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A-3.6 Intentional Dumping, Accidential Spills and Container Disposal
Overt introduction by man of pesticides into the aquatic environment
is distinctly possible, although intentional pesticide dumping is illegal in
New York. Cursory examination of records does not indicate any problem in
either dumping or accidential spills in forest pest control operations. It
is emphasized that most forested land is under the direct control and super-
vision of career foresters, who strictly adhere to operational regulations.
If this were not the case, the occurrence of this type of actions could be
much greater. Control by foresters is exercised not only during treatment
operations conducted by State personnel using State equipment, but also when
the State contracts to commercial applicators for forest treatment.
For example, during the 1971 spray season, almost 70 % of the
approximate 250,000 acres treated for gypsy moth were conducted by aerial
applicator firms under State contracts. In addition to following operational
procedures discussed in Section A-2, these firms must be registered as required
by Article II of The Agriculture and Markets Law, and are subject to Rules and
o o£
Regulations set forth in Part 154 * . Those subsections dealing with disposal
of unused pesticides and pesticide containers are quoted herein.
"154.5 Disposal of Pesticide Containers and Unused Pesticides
(a) No pesticide containers shall be disposed of in any
place other than at a refuse disposal site, a sanitary
land fill, or in an incinerator, all of which shall have
been approved for the purpose. Reusable containers may be
disposed of for uses not prohibited in 154.6 below, providing
such containers are treated as outlined.
3-48 EQ-5025-D-2 (Vol. II)
-------
(b) Containers of pe.--ici es shall be treated in the following
manner before dis^.-.1:
(•1) Disposal of r-Joa-combustible Containers
(1) Rinse at east twice with water or the
pesticide carrier being used. Return
rinses to the spray tank.
(ii) Transport the cleaned containers to the
approved disposal site - see Section 154.5-a.
(iii) Returnable containers shall be rinsed as in
b-l-i above, tightly closed to prevent
leakage, the exterior cleaned, and the
containers returned to the supplier.
(2) Combustible Containers of Pesticides shall be
disposed of as follows;
(i) At the same sites as approved for noncombustible
containers - see Section 154.5-a.
(ii) Small quantities of combustible containers may
be burned with permission under the applicable
provisions of the Public Health Laws and the
rules and regulations existing thereunder, except
containers of volatile hormone type herbicides.
(c) Surplus or unused pesticides shall be disposed of by burial
with at least 18 inches of compacted cover in such a manner
and at such a location within the disposal area that ground
or surface water is not contaminated.
3-49 EQ-5025-D-2 (Vol. II)
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154.6 Re-use of Pesticide Containers
(a) No pesticide containers shall be sold or used for the
storage of human or animal food or water, nor shall such
containers be used for the storage of cooking utensils,
dishes or clothing.
(b) No pesticide containers shall be sold or used for any
other purpose unless such purpose has been approved by
the Commissioner and the containers have been properly
cleaned."
In keeping with centralization of control during forest pest control
operations, pesticide containers are maintained at the mixing station and
disposed of in designated and proper sanitary landfill areas. Further, in
aerial applications, should the pilot require the rapid discharge of pesticides,
he is procedurally obligated to do so away from open water. Therefore, the
relative importance of these factors is low due to the centralized procedures
and policies of those State trained personnel conducting the forest pesticide
operation.
3-50 EQ-5025-D-2 (Vol. II)
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A-5.7 References
3.1 Fletcher, N.H., 1966, The Physics of Rainclouds, Cambridge
University Press.
3.2 1971, Spraying Systems Co., Personal Communication.
3.3 Coutts, H.H. and Yates, W.E., 1968, Analysis of Spray Droplet
Distributions from Agricultural Aircraft, Trans. Amer. Soc.
Agri. Eng. 11(1), 25.
3.4 Turner, D.B., 1969, Workbook of Atmospheric Dispersion Estimates,
National Air Pollution Control Administration, Cincinnati,
Ohio, 41.
3.5 Slade, D.H., 1965, Dispersion Estimates from Pollutant Release
of a Few Seconds to Eight Hours in Duration, Unpublished Weather
Bureau Report, August.
3.6 1971, Union Carbide Corporation, Personal Communication.
3.7 Dethier, B.E., 1966, Precipitation in New York State, Cornell
University Agricultural Experiment Station, New York State
College of Agriculture, Ithaca, N.Y., Bulletin 1009.
3.8 Cline, Marlin, G., 1955, Soils and Soil Associations of New York,
Cornell Extension Bulletin 930, Cornell University.
3.9 Cline, Marlin, G. and Lathwell, Douglas J., 1962, Physical and
Chemical Properties of Soils of Northern New York, Cornell
University.
3.9a Bray, W.L., 1915, Development of Vegetation of New York State,
College of Forestry Tech. Pub. 3.
3.10 Kuchler, A.W., 1964, Potential Natural Vegetation of the
Coterminuous United State, American Geographical Society.
3.11 Woodwell, George M., 1961, The Persistence of DDT in a Forest
Soil, Forest Science, V. 7, No. 3.
3.12 Yule, W.N., 1970, DDT Residues in Forest Soil, Bulletin of
Environmental Contamination and Toxicology, V. 5, No. 2.
3.13 Smith, Virgil K., 1968, Long-Term Movement of DDT Applied to
Soil for Termite Control, Pesticides Monitoring Journal,
V. 2, No. 1.
3.14 Edwards, C.A., 1966, Insecticide Residue in Soils, in;
Residue Reviews, V. 13, New York, Springer-Verlag.
3-51 EQ-5025-D-2 (Vol. II)
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3.15 Dimond, John B. et. al., 1970, DDT Residues in Robins and
Earthworms Associated with Contaminated Forest Soils in:
the Canadian Entomologist, V. 102, No. 9.
3.16 Lichenstein, E.P., and Schultz, K.R., 1959, Persistence of Some
Chlorinated Hydrocarbon Insecticides as Influenced by Soil
Types, Rate of Application and Temperature, J. Economic
Entomology, V. 52.
3.17 Harris, C.R., 1966, Influence of Soil Type on the Activity of
Insecticides in Soils, J. Econ. Entomology, V. 59, No. 5.
3.18 Bowman, M.C. and Schecter, M.S., 1965, Behavior of Chlorinated
Insecticides in a Broad Spectrum of Soil Types, J. Agricultural
and Food Chemistry, V. 13, No. 4.
3.19 Nash, R.G. and Woolson, E.A., 1967, Persistence of Chlorinated
Hydrocarbon Insecticides in Soils, Science, V. 157, pp 924-927.
3.20 Norris, Logan A. and Moore, Duane G., 1971, The Entry and Fate
of Forest Chemicals in Streams in: Forest Land Use and Streams
Environment, Corvallis, Oregon.
3.21 Fleck, Elmer, E., 1966, Chemistry of Insecticides in: Pesticides
and Their Effects on Soils and Water, Madison, Wisconsin,
Soil Science Society of America.
3.22 Fetley, Donald R., 1970, The Effect of Sevin (1-napthyl N.
metylcarbonate) As a Watershed Pollutant, Thesis Submitted
to College of Forestry, Syracuse University.
3.23 Riekelk, H., Cole, D.W., and Gessel, S.P., 1970, The Behavior of
Two Pesticides in a Forest Soil, Final Report to the U.S.
Forest Service, Pacific Northwest Forest and Range Experiment
Station, Portland, Oregon.
3.24 Lichenstein, E.P., 1970, Fate and Movement of Insecticides in and
From Soils, in: ' Pesticides in the Soil. Ecology, Degradation
and Movement, International Symposium held at Michigan State
University.
3.25 Biggar, J.W., 1970, Pesticide Movement in Soil Water, in:
Pesticides in the Soil: Ecology, Degradation and Movement,
International Symposium held at Michigan State University.
3.26 Edwards, William M. and Glass, Bobby L., 1971, Methoxychlor and
2,4,5-T and Lysimeter Percolation and Runoff Water, Bulletin
of Environmental Contamination and Toxicology, V. 6, No. 1.
3-52 EQ-5025-D-2 (Vol. II)
-------
*.27 Betson, J., 1964, What is Watershed Runoff? J. Geophysical Res.,
V. 69, pp 1541-1552.
t
3.28 Hewett, J.F. and Helvey, J.D., 1970, Effects of Forest Clear-
Felling on the Storm Hydrograph, Water Resources Research,
V. 6, pp 768-782.
3.29 Dunne, T. and Black, R.D., 1970, Partial Area Contributions to
Storm Runoff in a Small New England Watershed, Water Resources
Research, V. 6, pp 1296-1311.
3.30 Hobbs, H.W., 1963, Hydrologic Data for Experimental Agricultural
Watersheds in the U.S., 1956-59, Agricultural Research Service,
Misc. Publication 945.
3.31 ibid, 1960-61, Misc. Publication 994, 1965.
3.32 Eagleson, P.S., 1970, Dynamic Hydology, McGraw-Hill.
3.33 Caro, Joseph and Taylor, Alan, 1971, Pathways of Loss of Dieldrin
from Soils Under Field Conditions, J. Agricultural and Food
Chemistry, V. 19, No. 2.
3.34 Leopold, L.B., Wolman, M.G., and Miller, J.P., 1964, Fluvial
Process in Geonurhology, pp 352, San Francisco.
3.35 Hack, J.T. and Goodlett, J.C., 1958, Topography of a Mountain
Area in Virginia, U.S. Geological Survey Professional
Paper 383.
3.35a Cochran, A.L., 1965, Proc. Federal Inter-Agency Sedimentation
Conf. 1963, Agricultural Research Service, Misc. Publication,
970.
3.36 1970, The Agriculture and Markets Law Relating to Custom
Application of Pesticides, Article 11-A, Circular 913 State
of New York Department of Agriculture and Markets, Albany,
New York.
3.53 EQ-5025-D-2 (Vol
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A-4.
IMPACT OF PESTICIDES, INCLUDING METABOLITES, ON THE
AQUATIC ENVIRONMENT AND FOREST ECOSYSTEM
A-4.1 Introduction
The impact of pesticides, including metabolites, on the aquatic
environment and the forest ecosystem is discussed in this section beginning with
an examination of how pesticides affect the aquatic environment. Next, the fate
of pesticides in the forest ecosystem is studied with consideration given to
non-biological and biological degradation and to the bioconcentration and toxicity
of pesticides in the forest environment. This is followed by a discussion of
the antagonistic and synergistic effects of DDT and Sevin. The impact of
pesticides on humans is studied in the next and final paragraphs of this section.
There are several mechanisms through which DDT and Sevin insecticides
could have an adverse impact on aquatic life; the most obvious is that of direct
kill, such as the death of all the fish in a pond due to DDT. This varies not
only with the rate of application and the impacted species but also with the DDT
formulation. For example, most investigators have found DDT emulsions to be more
^
A. 1
toxic to non-target organisms than when DDT was applied in oil or as a suspension.
More subtle disruptions result when only a segment of the organisms in a lake or
stream are destroyed by a pesticide. If the biota that was killed was the food for
other animals, the latter also may die. Since this process probably would occur
slowly, it may go unnoticed.
If the predators and/or competitors of one or more species are
eliminated or significantly reduced, the "balance of nature" may be upset. For
4-1
EQ-5025-D-2 (Vol. II)
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example, if a sizable quantity of the zooplankton in a pond are poisoned by
Sevin, the phytoplankton (whose numbers are controlled ordinarily by the
zooplankton) may increase substantially. Following such an algal population
explosion or "bloom," the algae may poison themselves in their own metabolites.
When the dead algae decay, the oxygen in the water may decrease and cause the
death of other aerobic forms.
Even more difficult to trace and evaluate is the movement of
pesticides, such as DDT, through the aquatic food web. Unfortunately, very
little is known regarding the trophic relationships of aquatic organisms. It
has been observed that these who-eats-who interactions may change significantly
with the seasons. Within a season, feeding habits may be affected by innumerable
chemical, physical and biological factors. Another complicating factor is uptake
and metabolism, each of which are influenced by a myriad of known and unknown
conditions. For example, DDT may be passed within a food web in the form of DDT,
DDE, ODD and/or several other metabolites. These chemicals vary considerably in
their ability to induce toxicity and other metabolic disruptions.
Still another point that cannot be overlooked is the fact that despite
its widespread use since 1942, the biological liaison (location and biochemical
mechanism of action) of DDT is not understood.
Keeping these problems in mind, a review of the impact of DDT and
Sevin on aquatic environments nevertheless is of value in the formulation of
regarding the employment of these insecticides in forest management.
4-2
EQ-5025-D-2 (Vol. II)
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A-4.2 DDT and the Aquatic Environment
The impact of DDT on total aquatic ecosystems has been reviewed by
several authors ' ' whose works provide a general overview.
DDT has a low volatility and is not normally decomposed by sunlight
or other naturally occurring chemical and physical factors.* The degradation
rate in soil and water, in the absence of organisms, generally does not exceed
4.3
5%/year. ' As a result, it is one of the most persistent agricultural chemicals
in the environment. Though it is extremely low in solubility in water (less than
1 ppb),' DDT is readily adsorbed onto organic matter. ' Hence, this insecticide
tends to remain concentrated in the upper level of forest soils, with which it can
4 22
be carried to streams and lakes via soil erosion. ' Detritus is believed to be
a significant source of introduction of DDT into aquatic food webs. The adsorption
of DDT on suspended organic matter was sited as a means of controlling black-fly
4.23
(Simulium articum) larvae. * Hence, the quantity and quality of suspended
material in aquatic habitats that may be contaminated by DDT should be considered
prior to the application of this pesticide.
Another relevant property of DDT is the fact that is accumulates in
4 24
lipid tissues. Cope ' demonstrated that DDT and its metabolites were persistent
in some fish for up to 2 years following a single exposure to this insecticide.
In this manner it may be concentrated and passed on through the food web in ever
4.18
increasing concentrations (biomagnification). * (Movement of DDT through aquatic
fcM webs will be discussed in a later section.)
There have been few attempts to trace the movement of DDT in natural
aquatic habitats. The cost of such studies, as well as the availability of an
uncontaminated and monitorable area, probably have been the major factors in
detering such investigations. One of the earliest experiments to ascertain the
4-3
EQ-5025-D-2 (Vol. IT)
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4.1
impact of DDT on an ecosystem was done in 1945 by Dr. Cottam and his associates. '
Using an airplane, they sprayed a 117-acre tract of Patuxent River bottomland in
Maryland with 2 Ib/acre of DDT in oil. Examinations for kill were conducted up
to 300 days following application. (No attempt was made to investigate the
possible cumulative effects of DDT since this problem was generally not recognized
at the time.) Within 12 hours, dead shiners and bluegill were observed. Represen-
tatives of these species also had been placed in boxes in the Patuxent River above
and below the sprayed areas. Less than a third of the bluegills survived while
the other fish were unaffected. However, in later experiments nearly all species
exhibited 75 % or greater mortality when tested in an area in which 1 Ib/acre
of DDT was applied to a. pond. Hence, factors other than taxonomy appear to be
more important with respect to the impact of DDT on fish. (This observation will
be discussed at length in a later section.)
From the Patuxent study, as well as others conducted in Fort Knox
(Kentucky), Island Beach (New Jersey), Clifton (Pennsylvania) and Black Sturgeon
4 1
Lake (Ontario, Canada) Cottam concluded that mortality among non-target
organisms increased when applications exceeded 1 Ib/acre, particularly when oil
formulations were employed. Invertebrates and cold-blooded vertebrates were more
subject to mortality than were birds and mammals. The variations in the applica-
tion procedure, insecticide formulation, season and area sprayed plus a number of
other factors makes it exceedingly difficult to deduce further conclusions from
this series of investigations.
One experiment having much better controls was carried out by the Ohio
4 10 4 25
Cooperative Wildlife Research Unit ' ' during which 3.9 millicuries of
chlorine-36 ring-labeled DDT was applied at a rate of 0.2 Ibs technical DDT per
acre to a 4-acre marsh in Northern Ohio. Initially (4 hours after application)
4-4
EQ-5025-D-2 (Vol. IT)
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concentrations of the insecticide were detected in the emergent and floating
vegetation (i.e., Potamogeton pectinatus, Lemna minor, Utricularia vulgaris).
Traces were also found in crayfish (Orconectes immunis), tadpoles (Rana pipiens)
and carp (Cyprinus carpio). It was believed that these amounts were the result
of direct spray. The first instance of bioaccumulation was noted in Cladophora,
an attached alga, 3 days after application. This plant had a DDT content of
96 ppm which was 3,125 times higher than the background. A northern water snake
(Matrix sipedon) had 36 ppm after 13 months; carp (Cyprinus carpio) also had their
higher concentration of 19 ppm after 13 months. Generally speaking, plants and
invertebrates accumulated their highest residues within the first week, while
vertebrates took considerably longer.
/ o a
Cole, et. al., ' investigated the levels of DDT in stream eco-
systems before and after the application of DDT to 104,000 acres of Pennsylvania
forest (oak maple) to control fall cankerworm (Alsophilia pometaria). A formula
of 0.5 Ibs technical DDT in naphtha and fuel oil per acre was applied using an
airplane traveling at 165 mph at 100 ft above the treetops. Although the DDT
content of stream sediment increased by a few parts per billion after 1 month,
the residues in brook trout (Salvelinu% fortinalis) were 20-100 times higher.
White suckers (Catostomus commersoni) also exhibited substantial increases in
insecticide content. Concentrations in crayfish also increased but to a lesser
extent. Changes in concentrations of DDT and its metabolites with time are given
in Table 4.1. (Site 1 was 1 mile above the splash dam sampling location.)
Between 30 and 122 days after application, the insecticide residue decreased to
near pre-application levels.
In a Long Island marsh that was sprayed annually with DDT for more
than 20 years to control mosquitos, Woodwell ' discovered more than 32 Ib/acre
4"5 EQ-5025-D-2 (Vol. II)
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Table 4.1
RESIDUE IN FISH AND CRAYFISH BEFORE AND AFTER THE
APPLICATION OF 0.5 LB TECHNICAL DDT/ACRE
(VALUES IN PARTS PER MILLION)
CITP
LYMAN RUN SITE 1
PRE-TREATMENT
TREATMENT +30 DAYS
TREATMENT +122 DAYS
TREATMENT +380 DAYS
SPLASH DAM
PRE-TREATMENT
TREATMENT +30 DAYS
TREATMENT +122 DAYS
TREATMENT +380 DAYS
SITE
LYMAN RUN SITE 1
PRE-TREATMENT
TREATMENT +30 DAYS
TREATMENT +122 DAYS
TREATMENT +380 DAYS
SPLASH DAM
PRE-TREATMENT
TREATMENT +30 DAYS
TREATMENT +122 DAYS
TREATMENT +380 DAYS
CITE
Ol 1 t
LYMAN RUN SITE 1
PRE-TREATMENT
TREATMENT +30 DAYS
TREATMENT +122 DAYS
TREATMENT +380 DAYS
SPLASH DAM
PRE-TREATMENT
TREATMENT +30 DAYS
TREATMENT +122 DAYS
TREATMENT +380 DAYS
BROOK TROUT
DDE
0.34
4.8
0.29
0.33
0.42
1.5
0.31
0.36
TDE
NR
6.1
0.16
0.10
0.10
6.1
0.11
0.10
o,p'-DDT
NR
NR
0.12
NR
NR
NR
0.04
NR
p,p'-DDT
0.54
9.5
0.20
0.23
0.37
10.6
0.07
0.09
WHITE SUCKERS
DDE
2.4
4.7
0.27
0.18
0.72
5.0
0.83
0.25
TDE
NR
5.7
0.13
0.24
NR
7.8
0.54
0.32
o,p'-DDT
NR
NR
NR
NR
NR
NR
0.04
NR
p,p'-DDT
1.8
NR
NR
NR
0.9
NR
NR
NR
CRAYFISH
DDE
NR
0.89
0.09
0.02
1.1
1.4
0.02
0.06
TDE
NR
0.71
0.09
NR
NR
1.6
0.01
NR
o,p'-DDT
NR
NR
NR
NR
NR
NR
NR
NR
p,p'-DDT
0.47
0.88
0.10
0.06
1.9
1.1
0.01
0.07
NR = BELOW LIMIT OF DETECTABILITY (0.002 ppm)
DATA FROM COLE et. al., 4.26
4-6
EQ-5025-D-2 (Vol. II)
-------
in the sediment just below the mud-water interface. The water contained O.OD005
ppm. Plankton had 0.4 ppm DDT; bay shrimp, 0.16; snails (Nassarius sp.), 0.26;
eels (Anguilla rostrata), 0.28; minnows (Cyprinodan sp.) . 0.94; and flounders
(Paralichthys sp.), 1.28. Shore-birds, which fed on the fish, had up to 75.5
4.18,4.19
ppm.
Fredeen and Duffy ' examined the St. Lawrence River Ecosystem after
36,831 Ib of technical DDT were added in six doses of approximately 6,000 Ib
each in the spring and summer of 1966 through 1967. The insecticide was added
directly to the river in slugs of 0.17 to 0.38 ppm emulsified DDT for 16-39
minutes to control undesirable insects in the "Expo" exposition site. Fish were
collected downstream of the treatment area from 3-70 days after the insecticide
was discharged in 1967. The highest average concentrations of 0.74 ppm were
detected in carp (Cyprinus carpio) and catfish (Ameiurus nebulosus); in bottom-
feeding species, snails (Campeloma) and clams (Pisidium), the average was approxi-
mately half as much.
Attempting to avoid the problem of uncontrollable variables, Metcalf,
Sangha and Kapoor ' constructed a model ecosystem with a 7-element food web.
They added Carbon 14-labeled DDT to approximate an application rate in nature of
1 Ib/acre. The insecticide accumulated in mosquito larvae, snails and fish as
DDE, ODD and DDT. A biomagnification of 10,000-100,000 was observed after 30
days.
4 4
Eberhardt, et. al., ' attempted to mathematically -model the kinetics
of DDT in a freshwater habitat, although additional model verification is
necessary.
Macek and Korn^'28 demonstrated in the laboratory that brook trout
_(S_;:il_ve.linu,s fontinalis) accumulated approximately 10 times more of available DDT
4-7
EQ-5025-D-2 (Vol. IT)
-------
from food than directly from water. This reinforces the work of Woodwell, et. al.,
regarding biomagnification.
Some uptake of DDT across the gills by fish directly from the water
does occur.' A noteworthy point is the fact that uptake is stimulated by
increasing salinity. Hence, the detrimental effect of DDT on fish could be
greater if the pesticide were applied to brackish rather than to fresh water.
Stickel provides further information on the impact of DDT on
total ecosystems.
There have been more DDT studies with individual species or groups
of organisms, particularly fish, than have been done with entire ecosystems. The
following discussion of the effects of DDT on specific organisms and taxonomic
groups begins with the lower trophic levels.
The impact of DDT and its metabolites on algae was reviewed by
Christie ' and Sweeney, ' as well as included in a literature survey by
4 33
Ware and Roan. * Christie observed that DDT in concentrations up to 100.0 ppm
was neither toxic to, nor significantly degraded by, Chlorella pyrenoidosa, a
4 34 4 35
common green alga. Similar observations have been made by others.' Ukeles
reported that concentrations exceeding 60.0 ppm were necessary to inhibit the
growth of five species of marine phytoplankton over a 10-day period. The con-
centrations necessary to kill most algae exceed the DDT concentrations found in
nature by more than 10,000-fold.' ' ' However, low concentrations of DDT can
adversely affect phytoplankton. For instance, an exposure for 4 hours to 1.0 ppm
DDT resulted in a 77 % decrease in carbon fixation, a technique for evaluating
photosynthesis-respiration ratios. ' Wurster * reported reductions in carbon
fixation by four species of marine algae of up to 45 and 75 % following a 24-hour
exposure to 1.0 and 100.0 ppb DDT, respectively. Using natural phytoplankton
4-8
EQ-5025-D-2 (Vol. II)
-------
populations from Lake Ontario, Glooschenko^'39 measured up to a 29.1 % decrease
in Carbon-14 uptake following an exposure to 1.0 ppb DDT. Further reductions
were noted at 10.0, 100.0 and 1000.0 ppb.
Perhaps of greater importance is the fact that algae and other water
plants can concentrate DDT and thereby pass this insecticide up the aquatic food
web. For example, several varieties of freshwater algae concentrated DDT between
99- and 964-fold following a 7-day exposure to water initially containing 1.0
4.40
ppm. ' Bacteria and fungi can accumulate 40-100 % of the DDT from the media in
4.41
which they are cultured. ' Similar observations have been made with marine
4.33
species. " Non-living algae and other plant;; also will concentrate DDT.
The mechanism of DDT accumulation by living cells, which may occur
4.32
by adsorption and/or active uptake, is not fully understood. ' There is
evidence to support both postulations.
Zooplankton and benthic animals also can concentrate DDT. Pontoporeia
affinis, a bottom-dwelling amphipod (crustacean) which is an important component
in many freshwater food webs, was found to amass 50 times the concentration of
4.42
DDT, DDE and ODD that was found in surrounding lake sediments.
Most of the studies regarding the interactions of DDT and mollusks have
been done with marine species, such as the easter oyster (Crassostrea virginica)
4 43
and common mussel (Brachidontes recurvus). " These filter feeders are among
the most "efficient" of the aquatic forms at removing and concentrating DDT.
A~,-,ie from increasing the likelihood of the insecticide being passed on within
the food web, a concentration of 7 to 10 ppb DDT in water will inhibit sh-.-ll
deposition by 50 %. While freshwater mussels are less common and correspondingly
of lower importance as a food than their saltwater counterparts, freshwater species
most likely are as adversly affected by this insecticide.
4-9
EQ-5025-D-2 (Vol. II)
-------
There have been innumerable studies regarding the impact of DDT on
stream insects.4'44"4'51 While the studies differed considerably with respect
to rates, method, formula and time of application of the insecticide, some general
conclusions can be drawn. DDT produced marked reductions in the quality and
quantity of stream insects. In streams, some species were destroyed more than
others. However, in other areas the reverse may have been true. If no DDT was
applied, normally present taxa repopulated the stream in 2-3 years probably
because the insect eggs, which frequently have a thick shell, are less adversly
4 52
affected by DDT than are larvae or the adults. ' A very slight return of the
natural stream fauna was observed where spraying took place on an annual basis.
Recovery of individual species was proportional to normal reproductive capacities,
i.e., mayflies (Ephemeroptera) and midges (Chironomidae) recovered more quickly;
stoneflies (Plecoptera) and caddisflies (Trichoptera) more slowly. Contaminated
and drifting insects represent a significant potential source of DDT uptake by
fish, many of which feed on those paralyzed invertebrates. Insects sprayed
with DDT-oil were more toxic than those insects that had come into contact with
4 53
DDT in suspension. ' Likewise, some insect mortality, particularly downstream,
was related to their eating of attached plants that had accumulated DDT.
More literature concerning DDT and fish has been published than on any
other form of aquatic life. This topic was included in a comprehensive literature
review by Johnson. ' Henderson, et. al., ' and Reinert, among others,
published compilations regarding the accumulation of DDT and its metabolites in
fish.
It is virtually impossible to compare laboratory studies concerning
the determination of lethal dosage, or concentration due to the vast differences
in environments (water temperature, pH, etc.), age and the physiological condition
4-10
EQ-5025-D-2 (Vol. II)
-------
of fish, etc. However, generally speaking, the "sport" fish species are more
4 54
sensitive than the trash-species. ' The 72-hour LD s ranged from 0.1 ppm for
goldfish (Carassius auratus) to 0.001 ppm for brown trout (Salmo trutta).
The toxicity of DDE to fish appears to be 10-fold less than DDT. In othe^- words,
it takes 10 times the concentration of DDE to kill the same fish under the same
environmental conditions than is necessary with DDT. '
4 57
Holden " determined that in a 1-ft deep stream, the ratio of the
recommended quantity of DDT to control blackflies (Simulium sp.) to the amount
which destroyed half the trout (Salvelinus sp.) in 24 hours was 1:17. The short-
comings of the utilization of such acute toxicity data was discussed at length
by Rudd and Genelly.
Numerous instances of fish kills follov/ing the application of DDT to
4.59-4.61
control insects have been reported. * ' There have been many more cases
4.62
where more than one pesticide was applied to an area prior to a fish kill.
In such an instance, it is very difficult to determine if DDT was the most
significant factor which induced death of the fish.
Temperature apparently is an important factor which influences DDT
/ /- r\
toxicity. Cope ' reported that with respect to rainbow trout (Salmo gairdneri)
and bluegills (Lepomis macrochirus), DDT toxicity increased below 13°C and above
4 64
18.5 - 23°C. Bridges, et. al., ' observed similar results.
Turbidity may influence the toxicity of DDT. Organic particles in
4 65
suspension may remove DDT from water. ' However, the DDT may reenter an
aquatic food web if the organic matter was eaten by bottom organisms. Hence,
suspended material could decrease the acute toxicity and increase the chronic
toxicity of this insecticide.
4-11
EQ-5025-D-2 (Vol. II)
-------
Johnson4'66 reported a decrease in the toxicity of DDT with increasing
alkalinity. However, since the waters he was observing also were turbid, his
conclusion may be invalid.
Within a given species, the younger and smaller generally are more
susceptable to DDT poisoning than the older and larger fish. * This may be
related to the fact that the latter have more lipid tissue in which the DDT
can be dispersed.
The negative impact of DDT on fish eggs and fly eggs can be significant.
After a fish initially hatches, it is almost entirely dependent on the yolk sac
for its initial source of food. As the contents of the yolk sac are consumed,
the DDT in the remaining lipids in the sac becomes more concentrated. During
the last stage of yolk sac absorption, mortality among the fry of numerous
species have been observed. " The eggs may be a vehicle through which DDT is
passed on to the offspring. This may result in a significant decline in the
4.69 4.70
population of some species such as trout. ' In fact, this was believed
to be the prime factor in the destruction of the lake trout fishery in Lake
George, New York. This factor led to the subsequent extensive use of non-persistent
Sevin.
Environmental stress decreases the resistance of fish to DDT.
Examples of tue above can be starvation, low dissolved oxygen and water
temperatures and physiological changes associated with spawning. ' ' "
These conditions may have occurred during many of the static toxicity tests
/ "71
that have been reported which could invalidate the results from such studies.
Numerous aquatic organisms can metabolize DDT. " ' * »^«JJ Yeasts
4 75
declorinate DDT to ODD (TDE). " Some algae can convert DDT to DDE; however,
the process is fairly slow — 9 % in 3 weeks.
4-12
EQ-5025-D-2 (Vol. II)
-------
Some anaerobic aquatic bacteria, such as Klebsiella pneumonia and
Aerobacter aerogenes degrade DDT to TDE. Reduced Fe (II) cytochrome oxidase
appeared to be the enzyme responsible for this chemical change.4'76 Intestinal
microflora play a major role in the degradation of DDT in fish. These bacteria
can metabolize DDT to DDE and DDD.4'77'4'78
A limited amount of research has been conducted on DDT metabolism
by fish. Atlantic salmon, Salmo salar, degrade DDT to DDE and "
In vitro investigation with carp blood and DDT showed some conversion to DDE,
L 77
DDD and possibly DDMU.
While much literature has been generated regarding the breakdown of
DDT by terrestrial insects, virtually nothing could be found concerning aquatic
anthropods. However, since the metabolic pathways of the latter do not differ
appreciably from the land forms, it can be assumed with reasonable confidence that
aquatic insects also metabolize DDT and related chemicals. For further informatio
4.74
on this subject, the reader is directed to compilations by Dr. Calvin Menzie
. c 4.82
and Spencer.
One recent, and perhaps biologically significant finding, was the
4 83 4 84
discovery of DDT-resistant fish and frogs. ' ' ' These organisms can
accumulate sufficient amounts of DDT to pose a threat to higher organism,
including man, if corns umed.
A determination of the effects of any agent on the forest ecosystem,
requires a comparative investigation. Regrettably, there has been no pre-applica-
tion study of our northeastern forests, delineating the "normal" parameters of
the woodlands, either physical or biological. Most studies have been of short
duration, determining only the effectiveness of the control and the persistence
. . . . , 4.85-4.87
of the chemical.
4-13
EQ-5025-D-2 (Vol. II)
-------
In order to assess the degree of impact of chemical sprays on the
aquatic biome within the forest, it is essential that prespray studies be made
of the biological, chemical and physical parameters. Animal species, their
composition and numbers, aquatic plant varieties, chemical levels of the area
under study, and the physical attributes of the lentic or lotic environment
must be evaluated. These studies should be undertaken several years prior to
spray, so that population dynamics and normal variations due to climatic condi-
tions are included. Then, and only then, can an impact statement be drawn
following pesticide application, since a comparative framework has been
established.
Following World War II, DDT was routinely used in forest pest
management in New York and this was continued for almost 20 years, until
reports of aquatic destruction and food web magnification forced a halt to the
application of this material (N.Y. State Sect. S. A. F., 1964). The carbamate
Sevin has been used exclusively ever since although trials of other pesticides
and biological agents were made in recent years.
No systematic pre- and post-spray long term studies were undertaken
with DDT. Reports of extensive fish kill and stream invertebrate destruction
were reported many times for New Brunswick, Maine, Montana, New York and
Ontario, following DDT sprays for control of gypsy moth and spruce bud worm.
DDT sprays demonstrate persistence for many years following application as found
by a national pesticide monitoring program throughout the country presenting
data on levels of DDT in fish, aquatic insects and water.
Qnly a few long-term studies comparing the post-spray effects of Sevin
to the pre-spray environment have been conducted. Following the rapid change
from DDT to Sevin, several investigators attempted to define the effects of the
4-14
EQ-5025-D-2 (Vol. TT)
-------
latter compound on aquatic ecosystems so that at least some review of
environmental impact may be made. Following a spray operation for the
hemlock looper in Washington State, utilizing Sevin at 1.6 Ib/acre and covering
43,204 acres, a total of five streams were examined, after spraying. No adverse
effects were noted except for a slight reduction in stoneflies in one of the
4 92
streams. ' In 1959, Burdick (unpublished report) indicated that Sevin had
no effect on aquatic insects in North Carolina. In 1960, however, he did note
a rather dramatic reduction (50.7 - 97.2 %) in stream insects in New York,
4 93
following direct application to the stream surface. ' Mayflies (Ephemeroptera),
stoneflies (Plecoptera) and caddisflies (Trichoptera) particularly were killed.
Following a spray application with Sevin in Pennsylvania, Coutant did note a
^
high incidence of aquatic insect drift, although mortality per se was not
4.94
examined.
In 1965 the state of Massachusetts embarked on a comprehensive environ-
mental impact study of aqueous Sevin formulation used in a gypsy moth control
program on Cape Cod. A total of 22,400 acres were sprayed at the rate of 1 lb/
1 gal/acre. Careful attention was paid to the mechanics of the spraying operation
and spray cards corroborated the deposition. An evaluation of the effectiveness
demonstrated fair to moderate larval control. However, the reduction in egg
4 87
mass counts in the fall of 1965 was excellent " (see Table 4.II).
Aerial leaf residues of Sevin disappeared rapidly. In one plot by
day number four post spray, residues were all but gone (Figure 4.1) and in the
4 95
second plot, by the tenth day, little remained ' (Figure 4.2). Little
recoverable material was obtained from the leaf duff and in some cases post
4 96
spray analysis yielded lower quantities than the checks. These results are
in agreement with findings at the State University College of Forestry at
Syracuse University.
4~15 EQ-5025-D-2 (Vol. II)
-------
Table 4.EL
GYPSY MOTH EGG MASS COUNTS, CAPE COD
MASSES/ACRE
1964
100
380
150
1,000
0
1,400
500
o
1,000
500
10,000+
5,000
1,000
1,000
5,000
3,000
10,000+
250
10,000+
1965
0
0
o
0
0
0
0
o
0
0
230
0
0
0
0
0
0
0
0
PERCENT
REDUCTION
100
100
100
100
100
100
100
100
100
100
98
100
100
100
100
100
100
100
100
MASSES/ACRE
1964
10,000+
10,000+
300
10,000+
1.000
30
5,000
10,000+
10,000+
100
130
5,000
6.000
150
130
10,000+
10,000+
10,000 +
200
1965
0
0
0
0
0
0
0
0
0
0
0
0
0
10
0
0
0
0
0
PERCENT
REDUCTION
100
100
100
100
100
100
100
100
100
100
100
100
100
93
100
100
100
100
,
100
MASSES/ ACRE
1964
100
100
10,000+
10,000+
10,000+
5,000
• 0,000+
500
1,000
1,000
1,000
1,000
1,000
10,000+
10,000+
120
60
10,000+
70
5,000
500
1965
0
0
0
0
0
0
0
0
0
0
0
0
0
400
750
0
10
10
0
0
10
PERCENT
REDUCTION
100
100
100
100
100
100
100
100
100
100
100
100
100
96
92
100
83
99
100
100
98
4-1.6
EQ-5025-D-2 (Vol. TI)
-------
200
150
Q.
iioo
oo
cc
50
REPLICATE A
REPLICATE B
* PRECIPITATION IN INCHES OVER
24-hr PERIOD ON DAY INDICATED
DAY
OF
APPLICATION
4 6
DAYS AFTER SPRAYING
10
Figure 4.1 DISAPPEARANCE OF CARBARYL FROM OAK LEAVES AERIALLY SPRAYED AT THE
RATE OF 1 LB/ACRE (PLOT 12)
150
II
|J
DC
<
°- 100
TRACE
50
REPLICATE A
REPLICATE B
* PRECIPITATION IN INCHES OVER
24-hr PERIOD ON DAY INDICATED
DAY
OF
APPLICATION
468
DAYS AFTER SPRAYING
10
Figure 4.2 DISAPPEARANCE OF CARBARYL FROM OAK LEAVES AERIALLY SPRAYED AT THE
RATE OF 1 LB/ACRE (PLOT 13)
4-17
EQ-5025-D-2 (Vol. II)
-------
The Cape Cod area represents both a marine and a fresh water aquatic
habitat thus affording a unique opportunity to examine the impact of Sevin on
both types of aqueous habitats. ' The investigator analyzed a number of
estuarine forms (Table 4.Ill) at up to 1 month post spray and found accumulation
nil. Fresh-water vertebrates (Table 4.IV) demonstrated similar results. The
author felt that Sevin had no effect on the organisms he tested, and further
stated of this pesticide: "No fish mortalities could possibly occur under
normal operating conditions...." Within the spray area lies a small landlocked
pond of approximately 138 acres supporting a diverse warm-water fishery. Forested
areas adjacent to the pond were sprayed by helicopter with the pilot taking
standard precautions for shutdown. Table 4.V demonstrated the very low residue
4 98
up to 4 months post spray in the water and soil. * In addition, algae popula-
tions showed no adverse reaction to the applications, thus justifying the author's
contention that, "...the application of Sevin by helicopter for gypsy moth
control at the rate of 1 Ib/acre, when conducted under the proper conditions and
in accordance with established spraying techniques, will not result in hazardous
contamination in water and soil." Thus, at least two authors emphasize the
importance of standard application procedures to assess the impact of the
pesticide in the environment.
Sevin, as with most biologically toxic and active reagents does have
an LD for all life systems. However, the extension of data on acute toxicity
to low level chronic intake, when such levels exist, is scientifically unsound.
Thus, in 1966, a 3-year study at the State University College of Forestry at
Syracuse University was undertaken to evaluate the impact of Sevin on the
4.99
aquatic ecosystem. The following operating parameters were established
prior to operations.
4-18
EQ-5025-D-2 (Vol. II)
-------
Table 4.111
APPARENT SEVIN OR METABOLITES IN THE TISSUES OF MARINE AND
ESTUARINE ORGANISMS COLLECTED BOTH PRIOR TO AND
AFTER THE 1965 CAPE COD GYPSY MOTH SPRAYING PROGRAM
LOCATION
SHOESTRING BAY
PRINCE COVE
CHILDS RIVEK
WEST FALMOUTH H8R.
MASHPEE RIVER
COONAMESSETT RIVER
PAMET RIVER
SPECIES
MUMMICHOG
ALEWIFE
WINTER FLOUNDER
SOFT SHELL CLAM
OUAHOG
WINTER FLOUNDER
MUMMICHOG
STICKLEBACK
SOFT SHELL CLAM
OUAHOG
AMERICAN OYSTER
SOFT-SHELL CLAM
BAY SCALLOP (SEEDI
OUAHOG
WINTER FLOUNDER
MUMMICHOG
STICKLEBACK
SOFT SHELL CLAM
AMERICAN OYSTER
QUAHOG
WINTER FLOUNDER
MUMMICHOG
SOFT SHELL CLAM
QUAHOG
WINTER FLOUNDER
MUMMICHOG
ALEWIFE
SOFT SHELL CLAM
QUAHOG
WINTER FLOUNDER
ALEWIFE
MUMMICHOG
SILVERS1DE
QUAHOG
SOFT SHELL CLAM
BLUE MUSSEL
MUMMICHOG
SAND LANCE
STICKLEBACK
PRESPHAY
DATE
5/5/65
5/5/65
5/5/G5
5/5/05
5/G/G5
5/5/65
5/5/65
5/5/65
5/5/65
5/S/65
5/5/65
5/G/G5
5/6/65
5/6/65
5/6/65
5/6/65
5/0/65
5/4/65
5/4/65
5/4/65
5/4/65
5/5/65
5/5/65
5/5/65
5/5/65
5/5/65
5/6/65
S/B/65
5/6/65
5/6/65
5/6/65
5/6/65
5/3/65
5/3/65
5/3/65
5/4/65
!,/4/65
&/4/G5
NO.
4
1 (pi
7
1
1
1 (p)
3
50
1
1
2
^
6
2
2
2
27
2
4
1 (p)
3
3
2
G
6
1 Ip)
1
3
1 (pi
1 (pi
4
50
1
1
3
4
6
15
WGT. Igmsl
272
30.2
25.2
32.2
280
25.8
28.5
268
32.8
37.6
26.8
33 2
24.5
25.0
276
25.4
25.9
24.7
37.0
35.1
25.6
28.7
34.6
293
254
256
28.0
26.5
35.1
27.9
2'JB
26.2
27 1
26.1
30.0
289
284
29.0
ppm-
0.15
0.11
0.13
0.13
0.17
0.22
0.20
0.19
0.13
0.07
0.09
0 10
0.13
0.13
0.18
0.13
0.19
0.17
0.14
0.12
0.13
0.09
0.09
0.11
0.06
0.16
0 12
0.12
0.16
009
0.14
0.16
0.09
012
0.17
0.11
0.12
0 2.1
POSTSPRAY
DATE
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/3/65
6/7/65
5/28/65
5/28/65
5/28/G5
5/28/65
5/28/65
6/1/65
6/1/65
6/1/65
6/1/65
6/1/65
6/2/65
6/2/65
6/2/65
6/2/65
6/2/65
6/4/65
6/4/65
6/4/65
6/4/65
G/4/65
6/4/65
NO.
2
1
1
1
1
1
2
62
1
1
3
5
3
2
4
20
2
3
^
1
3
3
1
1
2
1 IP)
2
2
1 (p)
4
35
2
2
2
3
3
22
WGT. (gmsl
33.0
35.6
6.6
301
37.1
25.5
35.8
25.8
26.8
373
250
27.9
31.1
28.7
30.0
25.3
334
31.6
11 "^
O l.D
25.2
30.0
340
32.1
6.8
33.0
25.4
31.2
48.7
41.9
300
27 2
29.7
291
21 9
27.4
28.4
26.2
ppm1
0.19
0.18
0.38
0.05
004
006
0.19
O.OS
0 10
004
0.10
0.09
0.08
0.06
0.11
0.20
0 10
0.05
0 08
0.13
0.17
O.OS
0.24
0.74
0.10
0.20
0.13
0.13
0.16
0.11
021
0.08
0.08
0.23
0.34
0.15
0 19
ppm: PARTS PER Mil LION
REPORT OF THE SURVEILLANCE PROGRAM CONDUCTED IN CONNECTION WITH
AN APPLICATION Oh CARBARYL ISEVINI FOR THE CONTROL OF GYPSY MOTH
ON CAPf COD. MASSACHUSETTS. PUBLICATION OF THE COMMONWEALTH OF
MASSACHUSETTS, PUBLICATION NO. 547, 19G6.
4-19
EQ-5025-D-2 (Vol. TI)
-------
.o
K3
O
I
t_n
O
O
I
to
Table 4.1V
APPARENT SEVIN OR METABOLITES IN THE TISSUE OF FRESHWATER FISH
COLLECTED BOTH PRIOR TO AND AFTER THE 1965
CAPE COD GYPSY MOTH SPRAYING PROGRAM
LOCATION
PAMET RIVER
PAMET RIVER
PAMET RIVER
LAWRENCE POND
MASHPEE-WAKEBY
MASHPEE RIVER
LAWRENCE POND
SPECIES
SUN FISH
SUNFISH
BROOK TROUT
YELLOW PERCH
WHITE SUCKER
AMERICAN EEL
YELLOW PERCH
PRESPRAY
DATE
5/3/65
5/3/65
5/3/65
5/5/65
5/5/65
5/5/65
5/5/65
NO.
3
3
1
10
5
6
5
WGT. (gms)
31.7
25.0
41.2
33.0
31.0
32.2
37.0
ppm*
0.10
0.13
0.08
0.11
0.09
0.06
0.15
POSTSPRAY
DATE
6/4/65
6/7/65
6/7/65
6/4/65
5/30/65
6/10/65
NO.
2
2
2
1
2
1
WGT. (gms)
35.3
34.5
40.0
43.9
34.4
39.5
ppm*
0.10
0.10
0.13
0.11
0.14
0.12
*ppm; PARTS PER MILLION
O
-------
Table 4.Y
LAWRENCE POND, SANDWICH, CARBARYL (SEVIN) IN WATER AND TOPSOIL
PRIOR TO AND FOLLOWING APPLICATION FOR GYPSY MOTH CONTROL
.o
I
o
to
WATER
DATE
1965
6/1
6/5»
6/9
6/24
10/7
LOCATION
SOUTH END
WEST SIDE
NORTH END
SOUTH END
SOUTH END
WEST SIDE
NORTH END
SOUTH END
WEST SIDE
NORTH END
SOUTH END
WORTH SIDE
NORTH END
SEVIN (ppm)
SURFACE
0.000
0.000
0.000
0.001
0.001
0.002
0.002
0.002
0.001
0.001
0.001
0.0007
0.0000
0.0004
DEPTH**
0.000
0.000
0.000
0.002
0.003
0.002
TOPSOIL
DATE
1965
6/1
6/9
10/7
LOCATION
AT SHORE
100' FROM SHORE
200' FROM SHORE
AT SHORE
100' FROM SHORE
200' FROM SHORE
AT SHORE
100' FROM SHORE
200' FROM SHORE
SEVIN
(ppm)
0.008
0.022
0.000
0.018
0.080
0.300
0.034
0.035
0.035
*DATE OF APPLICATION
••SAMPLING DEPTHS VARIED FROM 10-25 FT.
N3
-------
1. The effectiveness of the spray for gypsy moth control
would not be evaluated.
2. A year of prespray examinations of the chemistry and
population levels of the aquatic insects would be made.
3. The State would be instructed to spray the test site
as if this area were a typical spray site.
4. The pesticide concentration and stickers used would
be those currently accepted by State pesticide officials
for use in gypsy moth control programs,
5. The aquatic habitat would be followed for 2 years
post spray.
The area selected for study is part of the Shackam Brook watershed,
near Fabius, New York. It is state-owned land covered largely by second-growth
hardwoods. The area is, for the most part, densely forested, with a solid canopy.
It is an ideal spray site in that it (Figure 4.3) is east of and separated from
the control site by a rather high north-south ridge. The topography is reasonably
steep; streams course their way in both areas and converge south of the test site.
Of the 1,997 acres in the test area, 365 acres were sprayed. A state-owned
Bell 204-E turbojet helicopter dispensed 1 Ib of Sevin, aqueous plus 4 ounces
of Pinolene 1882, per acre. Standard shutoff procedures were followed when the
aircraft approached the aquatic site.
Prespray water samples (1966) consisted of 15 liters monthly for
analysis. In 1967, daily samples were taken in June, July and August; weekly in
September and biweekly for the balance of the year. A monthly schedule was
reinstituted in 1968.
4-22
EQ-5025-D-2 (Vol. II)
-------
30'W
l:x:::::::1 BEAVER POND
TEST AREA
© GAUGING STATION
[ | CONTROL AREA
SPRAY AREA
TO ROUTE 80 (TULLY)
COUNTY
LINE
TO ROUTE 91 (TRUXTON)
Figure 4.3 SHACKHAM BROOK STUDY AREA
4-23
EQ-5025-D-2 (Vol. TI)
-------
Aquatic insect populations were sampled weekly for 2 years, post
spray, and when possible, weekly prespray. Insects were identified and popula-
tions estimated. The results were not surprising, based on findings of several
other studies. At no time did Sevin or Naphthol show residues over 0.1 ppm
(the detection limits). The effect on aquatic insect population for the full
2 year post spray were also negative, (Figure 4.4). Further, no species composition
changes occurred for any of the aquatic insects under study.
An observation comparable to the Massachusetts study was made, viz,
soil and duff samples taken from under the canopy were routinely negative.
Several of the stream Odonata (dragonflies) were recovered and
analyzed for Sevin but all were below the limits of detectability. An LC
determination set the level of Sevin at 2.0 ppm (Figure 4.5).
Thus, as a result of this study:
1. Laboratory analysis of water, soil and insect samples
taken from the Shackam Brook near Tully, New York after
application of Sevin at 1 Ib/acre showed no residues
of Sevin or 1-naphthol above the 0.1-ppm level at any
time during the 3-year study period (June 1966 -
November 1968).
2. Analysis of aquatic insect larval and naiad population
levels over the 3-year period showed no fluctuations
that could be associated with the spraying of Sevin
and subsequent runoff.
3. Fluctuations in population levels of the aquatic insect
larvae and naiads were most probably a function of climatic
conditions, primarily water levels as influenced by rainfall.
4-24
EQ-5025-D-2 (Vol. II)
-------
YEAR 1 (1966): PRESPRAY
YEAR 2 (1967): POSTSPRAY
YEAR 3 (1968): POSTSPRAY
wm TEST
• CONTROL
• TEST
• CONTROL
TlMf (MONTHS'
TIME (MONTHS)
TIME (MONTHS'
Ln
o
N5
^n
O
COURTESY: D.R. FELLEY, UNPUBLISHED PH.D. THESIS. THE EFFECT OF SEVIN
(1-NAPHTHYL N-METHYL CARBAMATE) AS A WATERSHED
POLLUTANT. 1970. STATE UNIVERSITY COLLEGE OF FORESTRY
AT SYRACUSE UNIVERSITY, SYRACUSE, NEW YORK.
Figure 4.4 INSECTS COLLECTED AS A PERCENT OF POPULATION, MAXIMUM, IN THE TEST AND CONTROL
BRANCH OF SHACKAM BROOK IN 1966, 1967 AND 1968. RANGE MARKINGS REPRESENT
95 PERCENT CONFIDENCE INTERVALS.
-------
X
<
Q.
O
Q_
LL
O
t-
2
LLJ
O
DC
111
Q.
0-
120-
110
100
90-,
80
70
60-
50- -
40-
30- - -1-
20
10-
M
J A
TIME (MONTHS)
TOTAL INSECTS COLLECTED, AS PERCENT OF THE POPULATION
MAXIMUM, IN THE TEST BRANCH OF SHACKHAM BROOK FOR
1966, 1967 AND 1968. RANGE MARKINGS INDICATE 95 PERCENT
CONFIDENCE INTERVAL.
Figure 4.4 (Continued)
4-25
EQ-5025-D-2 (Vol. II)
-------
120
110--
100- -
90- -
x
<
H
O
CL
o
o.
LL
O
I-
CJ
cc
LU
Q.
80
.- = 1966
• = 1967
A = 1968
10
0--
O
TIME (MONTHS)
TOTAL INSECTS COLLECTED, AS PERCENT OF THE POPULATION MAXIMUM
IN THE TEST BRANCH OF SHACKHAM BROOK FOR 1966, 1967 AND 1968.
RANGE MARKINGS INDICATE 95 PERCENT CONFIDENCE INTERVAL.
Figure 4.4 (Continued)
A-26
EQ-5025-U-2 (Vol. II)
-------
CONCENTRATION (PPM)
Figure 4.5 CONCENTRATION OF SEVIN IN PARTS PER MILLION VERSUS PERCENT
MORTALITY TO DETERMINE LC50 OF ODONATA AT 18 AND 24 HOURS
4-27
EQ-5025-D-2 (Vol. II)
-------
4. Sevin had no polluting effect upon the test watershed
and deleterious effects were not found in aquatic insects.
Relative to other aquatic environments, Sevin, having a solubility
rate in water of 40 mg/1 at 20°C, readily dissolves in water as compared to DDT.
However, Christie4'100 and Palmer and Maloney ' have reported
Sevin, at concentrations above 0.1 ppm, to be toxic to most algae. However,
only a 16.8 % decrease in carbon fixation by a natural population of phyto-
plankton following a 4-hour exposure to 1.0 ppm of the insecticide was noted
by Butler.4'102
Muncy and Oliver ' found that Sevin was extremely toxic to crayfish,
4 104
crabs and shrimp. Parker, et. al. " made similar observations with respect
to Daphnia, a waterflea.
Concerning fish, Haynes, et. al. * reported that 28 ppm technical
Sevin in oil resulted in a 48-hour LD ^ for goldfish (Carassius auratus).
They stated that 50 % wetable powder had an LD of 14 ppm. Values from other
-IT,,- - j- j f i -7S «. n r, 4.106,4.107 „ , , 4.108
laboratory studies ranged from 1.75 to 13.0 ppm. Henderson, et. al.
observed a 96-hour TL for fat-head minnows (Pimephales promelas) of 6.7 to 7.0
4 109
ppm and 12 to 13 ppm in hard and soft water, respectively. Burdick, et. al.,'
while working with fingerling brown trout (Salmo trutta), found Sevin to be less
toxic in soft, acidic water rather than in hard, alkaline water. They attributed
this to an interaction between Sevin and the components of water rather than to
physiological reaction of the fish to a water condition. The biochemical pathway
of Sevin toxicity in fish is the same as that in insects. "
Sevin toxicity to fish increases with increasing temperature.
However, its rate of decay to 1-naphtol via hydrolysis also increases with
4-28
EQ-5025-D-2 (Vol. II)
-------
4.111
temperature and sunlight. * While Sevin is more toxic to crustaceans than
to fish and mollusks, the reverse is true for its metabolite. '
While the metabolism of Sevin has been extensively studied with
respect to terrestrial plants and animals, ' no literature was found
regarding the breakdown of this insecticide by aquatic forms. However, it
has been observed that Sevin persists longer in soil water than in lake
4.113
water.
4-29
EQ-5025-D-2 (Vol. II)
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A-4.3 Fate of Pesticides in the Forest Ecosystem
Many non-biological and biological factors cause degradation of DDT
and Sevin thus inducing disappearance of the parent compound and increasing the
concentration of metabolites. This section describes some of these pathways
that operate in the forest ecosystem. In addition, effects due to differences
in the chemical persistence of DDT and Sevin are briefly discussed in terms of
bioconcentration or toxicity to forest organisms.
A-4.3.1 Non-biological Degradation
Light, particularly untraviolet, was the major cause of Sevin
4 114
degradation to naphthol and methylisocyanate (CH.,N = C = 0) . ' Further,
several unidentified products were formed when Sevin was irradiated at 254 mm
4 115
as a solid. * As early as 1949, Chrisholm reported that DDT lost activity
against the housefly following sunlight irradiation.
Water will degrade many pesticides when in alkaline condition. DDT
4 114 4 117
loses HC1 to form DDE ' or ODD, ' of which the latter may be implicated
in fish kills. Sevin readily hydrolyzed in water (at a pH of 8 or more) to a
number of products, one of which was 1-naphthol.
Degradation of DDT may be accelerated in the presence of metallic
catalysts in the soil or water. Fleck and Haller described a dehydrohalogenation
due to iron catalysis in soLl. ' * Crosby ' reported the same findings
/ T *?*?
with a definite end product of ODD. Fe and Al accelerated DDT decomposition. '
Heat may also degrade these pesticides, with Sevin forming naphthol and methyl
isocyanate and dehydrohalogenation of DDT, although both picolinic acid and
4 123
salicylol aminoguanidine may inhibit heat composition. ' Other organic
4-30
EQ-5025-D-2 (Vol. II)
-------
reagents may do the same, and include active groups, viz, carboxyl, thiol, amino,
phenolic and aliphatic hydroxyls.
Although these pesticides will degrade, it is accepted that DDT and
its metabolites, DDD and DDE, represent the most persistent compounds of those
used in insect control. In Ohio river water, for example, 100 % of the parent
DDT remained unchanged after 8 weeks, whereas Sevin showed only 5 % residual
after 1 week and nothing by 2 weeks.
4 125
Alexander * presents the following summary of pesticide
degradation.
1. No degradation occurs (recalcitrant chemicals).
2, Degradation is too slow to prevent environmental
contamination.
3. Degradation is complete, but products are harmful.
The following conditions must be met for a pesticide to be biodegradable.
1. An organism must exist or evolve which can
metabolize the chemical.
2. The chemical must be metabolizible.
3. The chemical must reach the organism.
4. The chemical must induce enzymes, since few
of these metabolic enzymes are constitutive.
5. The environment must be favorable for reactions.
A-4.3.2 Biological Degradation
By their very nature, living forms will tend to biotransform if
enzymes for these pathways are present. This is simply a means for survival,
particularly if the compound is toxic. Several of the metabolic pathways for
4-31
EQ-5025-D-2 (Vol. II)
-------
biotrausformation of both Sevin and DDT have been elucidated for laboratory
animals and plants but little is known of these pathways in the wild. Thus
acute poisoning by the pesticide may result in the field yet the effects of low
level doses of the parent compound or its metabolites have not been resolved.
Although the results of pesticide metabolism may be clearly
demonstrated in certain animals and plants, it is dangerous practice to extend
these findings to include other organisms. DDE, for example, is a common DDT
metabolite in man yet monkeys show no trace of this material. Further, the
effects of these chemicals may vary. The thin eggshell syndrome of DDE and falcons
has been verified yet domestic hens show a greater shell thickness with the same
material.
Five products of DDT metabolism represent the major pathways of
degradation; DDA, Kelthane, ODD, DDE and dichlorobenzophenone * (see
Figure 4.6). Two of these products, DDD and Kelthane, are recognized pesticides
in their own right. The most widely recognized pathway involves a dehydro-
chlorination of DDT to yield DDE and has been described in many mammals, fish
and insects. In insects, a high titer of the enzyme dehydrochlorinease will
confer immunity to the pesticide, and in the classic case of the development
of the resistant housefly strains, the genome for this enzyme was selected
for by environmental saturation of DDT.
At this juncture, it would be well to point out that developing
pesticide resistant strains is much more likely if lower concentrations of
pesticides are used. Although environmental contamination may be reduced, for
example, by utilizing only one quarter to one third of a pound per acre of DDT,
and arriving at only an 80 % control figure, the chances of developing a strain
with a potential to detoxify these pesticides is much greater than if one uses a
4-32
EQ-5025-D-2 (Vol. IT)
-------
DICHLOROBEIMZOPHENONE
Cl
CHCI2
ODD
Figure 4.6 ROUTES OF DDT METABOLISM
4-33
EQ-5025-D-2 (Vol. II)
-------
concentration high enough to obtain a 95-99 % kill. The evaluation of
alternatives (environmental contamination versus resistant strains) is, at
best, a subjective choice and offers a real paradox.
One interesting study by Randall ' on the spruce budworm,
suggested that this insect was developing resistance to DDT in New Brunswick
forests. A recent publication by Carolin and Coulter ' in northwest
Canadian forests discounted the former author's findings and further stated
that parasites of the budworm were not affected by DDT sprays.
The principal agents for the degradation of DDT in the forest
ecosystem, however, are not the macroscopic life forms but rather the microbes
4 129
and in particular those in the soil. Kaufman ' indicated that for halogenated
acids, the rate of decomposition decreased with increasing numbers of chloride
atoms. Although individual reports of pathways may vary, the overall pattern
of degradation follows the patterns as outlined above, with the exception that
microbes may utilize ring materials as carbon sources.
The literature on Sevin degradation is not as complete as that of
DDT. A number of products may result from Sevin metabolism (Figure 4.7), and
many others remain unidentified. The principal metabolite resulting from
hydrolytic cleavage is 1-naphthol and in most mammals studied, this product
is rapidly conjugated with glucuronides and sulfates for excretion.
4.134
Baron, et. al. * confirmed one of the metabolites in cow urine and milk as
5,6-dihydro-5,6-dihydroxynaphthol.
Insects, in addition to naphthol, will give rise to a variety of
hydroxy and dihydroxy derivatives.
Sludge bacteria utilize Sevin as a carbon and nitrogen source (Baum,
unpublished report) while other soil microbes may hydrolyze phenyl carbamates.
4-34
EQ-5025-D-2 (Vol. II)
-------
OH
OSO3H
O-Glu
H OH
OH
OCNCH2OH
COOH
COOH
OH
OX = OCNMe Me = METHYL
Glu = GLUCURONIC ACID CONJUGATE
Figure 4.7 POSSIBLE METABOLIC AND CATABOLIC PRODUCTS ARISING FROM
DEGRADATION OF SEVIN
A-35
EQ-5025-D-2 (Vol. II)
-------
4.137
Even green plants may metabolize Sevln into water soluble derivatives.
The picture is a confusing one at present, yet all agree that the parent
molecule is rapidly degraded into a variety of metabolites by many different
/ 1 O £
enzymatic pathways. O'Brien ' refers to cockroach production of a "...galaxy
of metabolites."
A-4.3.3 Bioconcentration and Toxicity of DDT and Sevin
in the Forest Environment
Leaching, overland water runoff and sediment runoff of applied
pesticides from forested areas are normally negligible mechanisms for the
endangerment of aquatic life. A different set of problems is encountered when
the interaction of pesticides with in situ forest soil environments is considered.
Because of the long-term persistence of DDT in forest soils, long-term effects
on soil-dwelling organisms and food chains must be considered.
Chlorinated hydrocarbon insecticides, including DDT, have been
found to be relatively nontoxic to earthworms but do accumulate in fatty tissue. '
4 139
Dimond, et. al., presented data on residual DDT and metabolite concentration
in samples of earthworms collected from contaminated forest soils. He concluded
that although there were too few samples to show a clear pattern of persistence,
residues in worms appeared to reflect residues in soils with all samples from
treated areas being higher in DDT content than those from untreated soils and
with the highest residues in worms coming from soils that were treated
4.140
two or three times. Yule found that surface-dwelling insects in forest
soils contained more DDT than the average (6 in) content of topsoil habitat but
4 141
less than in litter only. Edwards ' summarized available data on chlorinated
4-36
EQ-5025-D-2 (Vol. IT)
-------
hydrocarbon accumulation in soil organisms and calculated concentration factors.
His data concerning DDT are reproduced in Table 4.VI.
Biomagnification of residues in birds resulting from DDT application
in forested areas has been reported. Following DDT treatment of 0.75 Ib/acre
for white fir sawfly control, Herth and Flickinger found that residues
in robins were at or below pretreatment level in 3 months after treatment
whereas juncos and chickadees had accumulated residues of 231 and 638 % of early
post-treatment levels. Dimond, et. al., ' found that levels of DDT in robin
populations from forested areas treated at 1 Ib/acre appeared to reflect levels
of soil contamination and were probably as persistent. His data showed no
decline in residues in robins up to 9 years after treatment even though lower
levels should be expected. Assuming that robins receive much of their DDT
burden from feeding on earthworms, he found that magnification of DDT residues
in robins amounts to one order of magnitude over earthworms. Herth and
Flickinger's data thus conflict with Dimond's. The consistency of DDT
persistence shown by Dimond's data for every year up to 9 years after applica-
tion reinforces the belief that DDT does, in fact, persist in robins for long
periods of time.
There have been studies which strongly implicate the observed mortality
of birds to high accumulations of DDT in body tissue. These studies involved
the ground spraying of Dutch Elms and therefore probably resulted in very high
4 143 4 144 4 139
dosages over localized areas. ' ' ' Dimond, et. al., found that DDT
and metabolite residues in robins collected from DDT-treated forested areas
were well below lethal dosages. He further states that higher levels of DDT
may be present in other types of forest birds (i.e., fish feeders and predators)
and that it is difficult to dismiss the possibility that certain birds are
4-37
EQ-5025-D-2 (Vol. TI)
-------
Table 4-YI
RESIDUES OF PESTICIDES IN SOIL INVERTEBRATES
AND THEIR ENVIRONMENT
LOCATION
GREAT
BRITAIN
GREAT
BRITAIN
GREAT
BRITAIN
GREAT
BRITAIN
GREAT
BRITAIN
U.S.A.
U.S.A.
U.S.A.
U.S.A.
U.S.A.
U.S.A.
U.S.A.
U.S.A.
GREAT
BRITAIN
REFERENCE
STRINGER &
PICKARD
1963 (247)
DAVIS 1968
(55)
EDWARDS
(UNPUB-
LISHED)
WHEATLEY &
HARDMAN
1968 (283)
DAVIS &
HARRISON
1966 (57)
BARKER 1958
(10)
HUNT 1965
(136)
HUNT 1965
(136)
IN DUSTMAN
& STICKEL
1966 (71)
U.S.D.I.
1967 (266)
U.S.D.I.
1966 (265)
U.S.D.I.
1967 (266)
DOANE 1962
(65)
CRAMP &
CONDER
1965 (48)
NO.
OF
SITES
1
10
2
2
1
2
1
1
3
67
1
2
1
1
SOURCE OF
RESIDUE
SOIL (ORCHARD)
EARTHWORMS
(L. TERRESTRIS)
OTHER SP.
SOIL (ARABLE)
EARTHWORNS
SOIL (ORCHARD)
EARTHWORMS
SOIL (ARABLE)
EARTHWORMS
SOIL (ARABLE)
EARTHWORMS
L. TERRESTRIS
A. LONGA
A. CALIGINOSA
A. CHLOROTICA
A. ROSEA
O. CYANEUM
SOIL
BEETLES
SLUGS
SOIL
BEETLES
SLUGS
SOIL
EARTHWORMS
L. TERRESTRIA
L. RUBELLUS
0. LACTEUM
H. ZETEKI
H. CALIGINOSIS
TRAPEZOIDES
SOIL
EARTHWORMS
L. TERRESTRIS
SOIL
EARTHWORMS
SOIL
EARTHWORMS
SLUGS
SLUGS
SOIL
EARTHWORMS
SOIL*"
EARTHWORMS
SOIL
EARTHWORMS
SLUGS
DDT & RELATED COMPOUNDS
MAX.
26.6
13.7
14.0
0.8
0.05
17.2
40.0
-
-
0.8
2.3
17.2
5.2
40.1
-
-
_
3.0
25.0
—
—
_
0.69
1.20
2.55
MEAN
11.4
7.7
8.1
0.3
9.7
19.6
-
0.93
1.1
1.34
2.5
4.6
2.6
1.24
0.3
9.7
9.3
19.2
680.0
173.0
492.0
106.0
9.9
140.6
1.8
17.0
0.98
9.64
42.7
19.7
12.5
43.0
-
CON.
FACTOR f
0.67
0.71
0.06
2.10
1
1.18
1.43
2.68
4.86
2.78
1.33
2.81
0.31
2.33
2.06
73.10
18.6
52.8
11.3
-
14.2
9.44
9.8
-
3.44
1.73
3.70
CONCENTRATION IN ANIMAL
•mg/kg.
CONCENTRATION FACTOR = CONCENTRATION IN SOIL
*'ppm CALCULATED FROM INITIAL DOSE RATE.
4-38
EQ-5025-D-2 (Vol. II)
-------
threatened for periods of many years by one or a few light applications of DDT
over large areas.
In contrast to DDT, Sevin and other carbaraate insecticides are highly
toxic to earthworms and have resulted in appreciable decreases in earthworm
populations in agricultural soils4'145'4'146 and grasslands.4'147 Barrett4'148
conducted intensive studies on the effects of Sevin on a grassland ecosystem
but did not include earthworms. He found that although Sevin applied at a rate
of 2 Ib/acre remained toxic for only a few days, the total biomass and numbers
of anthropods were reduced more than 95 %. After 7 weeks, total biomass but not
total numbers returned to control level.
Of perhaps greater concern with respect to the forest environment
was the highly significant decrease in litter decomposition which Barrett
attributed to be the result of a reduction in microanthropods and other
4.145
decomposers. Edwards also expressed concern for the effect of insecticides
on populations of soil-forming organisms in forest soils (i.e., earthworms,
enchytraeid worms, wood lice, millipedes, mites, springtails, termites, and
beatle and fly larvae). Forest soils could conceivably become infertile without
recycling of nitrogen, phosphorus potassium and other mineral constituents
engendered by microbial and insect degradation of forest litter. The loss of
organic and mineral soil mixing and aeration promoted by earthworms and other
soil organisms could further result in massive soil structure that is not
suitable for root penetration.
The literature review uncovered no studies involving the possible
inhibiting effects of Sevin on soil-forming processes in in situ forest
soils. However, analysis of the disposition of Sevin at the 1 Ib/acre dosage
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normally applied in New York spraying programs indicates that the problem
may not be serious. From field studies, it is estimated that only 50 % of
applied pesticide (i.e., Sevin) or 0.5 Ib/acre directly reaches the ground at
the time of application. Later additions from leaf wash probably have negligible
toxicity because of the rapid degradation on leaf surfaces. Previous studies
showing toxicity of Sevin to soil organisms were at much higher dosages (2 lb/
acre). ' ' " It appears probable that the insecticide reaching the forest
floor would migrate very slowly through the highly organic litter and be
appreciably decomposed before depths of maximum biological activity were even
reached. Nevertheless, studies should be initiated to determine if soil-forming
processes in the forest soils of New York can be impaired by continued usage of
Sevin or other insecticides. First, it is necessary to estimate how much of the
aerially applied pesticide reaches the forest floor at the time of application
and hoxc much is added by leaf wash-off up to a period of 1 week after application.
It is especially important to determine how long it takes for re-establishment
of normal soil biotic communities after application of Sevin. This would provide
guidelines on how often the forest may be sprayed without cumulative or permanent
ecologic consequences to soil biota and related food chains.
There are no studies indicating bioconcentration of Sevin or toxic
metabolites in forest biota. It is doubtful if bioconcentration can occur because
, _, .,„.,,, . fc , _ A.148-4.150
of the rapid Sevin breakdown in natural systems.
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A-4.4 Antagonism and Synergism
The action of one compound upon the effects of another in a single
system may be termed as being either antagonistic or synergistic. These two
terms, long used in describing the effect of additives on pesticides used in
small quantities, will be discussed in this section to illustrate current
literature trends in the fic.ld of pesticide research.
For the purposes of this brief review, the definitions of Williams '
will be used for antagonism and synergism. Williams describes antagonism as the
combined effect of two agents that tends to lessen the gross effect of both the
agents, as in using an antidote to treat a poison case or by speeding up metabolic
rates so that the primary toxicant may be more quickly reduced to less toxic
metabolites. Synergism, on the other hand, is the interaction of two compounds
to produce a potentiating effect greater than the sum of the separate effects
of either agent alone. For example, parathion has a greater toxicity for
individuals who use the tranquilizer chlorpromazine.
A-4.4.1 DDT
The first topic to be considered herein involves the synergistic
4 152
effects of DDT with other materials or physical states. McLean, et.al.,
have shown that rats suffering from protein depletion suffer disproportionately
greater harm from DDT exposure than do rats fed with a normal diet. This occurs
because protein depletion causes activity of the microsomal hydroxylating
enzyme systems and the cytochrome P-450 contents of the liver to fall to one-
third or less of the normal level in only 4 days. Protein depletion may,
therefore, augment liver damage caused by aflatoxin because the toxin is not
metabolized to an inactive product any longer by the microsomal hydroxylating
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enzyme system. Induction of enzyme synthesis by DDT or phenobarbitol is also
inhibited. Protein depletion may protect against liver damage or other effects
when the actual damaging agent is a product of an enzyme system suppressed by
protein lack (e.g., carbon tetrachloride or glycerine). This beneficial effect
is reversed by administration of DDT or phencbarbitol. Protein depletion does
not alter the toxicity of cloroform given as a sing'e oral dose. Enzyme
induction phenytoin was more potent than phenobarbitone in reducing DDE blood
levels. In another case * , a 42-year old pesticide formulator was noted to
contain zero or trace amounts of DDT and DDE residues in his serum. He had been
employed for over 16 years in a plant that formulated DDT prior to 1964. The
last formulation involving DDT took place at the plant in the spring of 1970.
Over the same period that the man had been observed, 1967-1971, his fellow workers
(29 individuals) with 10-25 years experience and consequent exposure had, at
their last measurement in July 1970, 24 ppb p,p'-DDT and only 0.5 ppb p,p'-DDE.
These figures are contrasted with the general population that had, in 1969,
4.4 ppb p,p'-DDT and 14.9 ppb p,p'-DDE. The subject in this case had been taking
30 mg phenobarbitol t.i.d. and 100 mg diphenylhydantoin t.i.d. for over 25 years
to control post-traumatic epilepsy. Table 4.VII lists the effects of these
anticonvulsant drugs on body DDT burden in the larger sampling described by
n • * i 4-154
Davies, et.al.
The activity of synergistis in biological systems is dependent on their
mode of metabolism. Fishbein, Falk, Fawlces and Jordan " investigated the
action of piperonyl butoxide, Tropital and actachlorodipropyl ether. This
brief discussion will focus on the activity and metabolism of methylenedioxybenzcne
derivatives, of which piperonyl butoxide and Tropital are examples. Falk and
Kotin '"' , likewise, treat this subject in a recent paper. They attribute the
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Table 4-VTT
EFFECT OF ANTICONVULSANT DRUGS
ON BODY DDT BURDEN
CONTROL
OUTPATIENT ON PHENOBARBITONE
OUTPATIENT ON PHENYTOIN
OUTPATIENT ON BOTH DRUGS
INPATIENT ON BOTH DRUGS
INPATIENT CONTROL
GENERAL POPULATION
DDE LEVEL (ppb)
IN BLOOD
9.1
3.5
1.9
1.7
0.8
4.5
—
IN FAT
—
—
—
—
0.09
2.08
5.5
DDT LEVEL (ppb)
IN FAT
—
—
—
—
0.17
2.70
8.4
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synergistic action of these compounds with pesticides to the inhibition of
enzyme systems or the prevention of enzyme induction. With chlorinated
hydrocarbons such as DDT, dehydrochlorination to the less active DDE may be
prevented. On the other hand, with thiophosphonate compounds, activation is
prevented with DDT in protein-depleted rats makes them more sensitive to lethal
and hepatotoxic actions of chloroform. Protein depletion may, therefore,
protect one organ at the expense of another. For example, dimethylnitrosamine,
which requires demethylation in a microsomal enzyme system before it can exert
its toxic effects causes severe liver necrosis in normal rats. In protein-
deficient rats, on the other hand, the severity of liver necrosis is greatly
reduced but all survivors die of kidney tumors because of the decrease in liver
clearance of dimethylnitrosamine which allows the toxin to contact the kidneys.
In general, if the site of relevant interaction between a toxin and a cell is
also the site altered by the diet, changes in the diet will probably alter the
toxic effect of the toxin.
It has been shown that diet is important in maintaining metabolic
potential over toxins introduced either intentionally or accidentally into a
living organism. Of equal importance is the interaction of pesticides with
naturally occurring materials found either at the site of pesticide application
or, and perhaps more importantly, found at the site of accumulation of the
pesticides folloxtfing runoff or other natural processes into waterways. Wershaw,
4.157
et.al * have demonstrated that DDT is a 0.5 % solution of sodium humate
which is at least 20 times as bioactive as a DDT solution alone. This tends to
indicate that other naturally occurring polyelectrolytes may act similarly with
members of the spectrum of organocblorine compounds that may be found in the
environment. Another interesting example of syncrgism is the interaction of
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two commonly used pesticides: DDT and dieldrin. Macek, Rodgers, Stallig and
Korn " have shown that in rainbow trout DDT accumulation is enhanced by the
presence of dieldrin, while DDT markedly decreased the rate of accumulation of
dieldrin. Similarly, DDT elimination was decreased in the presence of dieldrin
but dieldrin elimination was not enhanced by the presence of DDT.
4.159
Cain * stated that DDT and 2, 4-D synergise with respect to fish
toxicity. The impact of DDT and parathion are more than additive * .
Dugan, Pfister and Sprague ' studied a New York watershed emptying
into Lake Ontario and assessed its burden of several organochlorine pesticides
and detergents. Following the evaluation, they generated data concerning the
effect on goldfish of the susceptibility to three organochlorine pesticides as
a function of exposure to alkylbenzenesulfonates. They determined that chronic
exposure to 4 ppm alkylbenzene-sulfonates results in a much greater susceptibility
to three types of chlorinated hydrocarbons: DDT, dieldrin and endrin. This
finding is supported by the work of other investigators that found correlation
between nutrient uptake by cells and presence of surfactants.
The antagonistic effect of certain anticonvulsant drugs on the
action of DDT has been shown for humans. Davies, Edmundson, Carter and
Barquet followed the p,p-DDT levels in 77 outpatients and 48 chronically
nonambulant mentally defective inpatients who had been taking anticonvulsant
drugs (phenobarbitone and/or phenytoin or diphenyl hydantoin) for more than
3 months for convulsive disorders. The study was confined to white patients
greater than 6 years old. The DDE levels (principal DDT metabolite) were
strikingly lower in patients on anticonvulsant drugs than in the general
population. It was determined that this lead to a net antagonistic reaction
with these compounds.
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A-4.4.2 Sevin
studied the effects of carbaryl and caffeine on albino rats.
The interaction in this case is antagonistic since the carbaryl treated rats
showed minor tremors, salivation and urination while caffeine treated animals,
in addition to being alert and displaying none of the above symptoms, predictably
increased their performance in activity wheel cages.
In another study, 30 derivatives of propynyl naphthyl ethers were
synthesized and evaluated as synergists for carbaryl against houseflies.
/ T £. Q
Sacher, et.al., * reported that the most active in the series was 1-naphthyl-
3-butynyl ether. The synergistic ratio was 176.5. They also found that the
ether was not harmful to white mice, probably owing to the fact that the ether
is channelled into two different metabolic pathways between the housefly and
laboratory mouse. In another study involving houseflies, Bakry, Metcalf and
Fukuto * investigated benzyl thiocyanates, benzyl isothiocyanates, phenyl
thiocyanates and alkyl thiocyanates for mode of action as insecticides and
carbaryl synergists. They found that for aliphatic thiocyanates the synergistic
ratio with carbaryl increased fourfold from C, to C ?.
Falk and Kotin * in their article on pesticide synergists and their
metabolism, point out two important areas involving these interactions that need
attention and caution. The first concerns the buildup and storage of synergistic
agents in the mammalian (human) organism, and the second relates the danger of
some of these synergists when taken in combination with high doses of certain
drugs as medications.
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A-4.5 Impact on Humans
The evaluation of the human health threat presented by the use of
pesticides has been the subject of many reviews over the past few years. The
exposure of the American public to pesticides has been either very high, as in
the case of pesticide workers (those involved in manufacturing, formulating and
application) or very low (the average non-occupationally exposed person). The
former group represents a ready source of individuals for the study of the
effects of chronically high exposure to pesticides.
The use of pesticides in this country has increased greatly since
the commercial introduction of DDT after World War II. Despite this fact, the
death rate due to pesticides has remained stable since 1939 " . In 1961 the
mortality rate for pesticides (including fumigants) was 0.65 per million
population although the ratio of non-fatal to fatal poisoning cases was 100 to 1.
Since the death rate has remained stable over this period despite the higher use
and greater availability of pesticides, indications point to the fact of greater
safety being exercised with these materials. Additionally, since approximately
one-half of the pesticide fatalities involve children, the current rate can be
potentially halved simply by childproofing pestide containers and embarking upon
a program of education wherein the safer use and handling of pesticides in and
around the home is stressed.
The fate of the pesticide worker in any phase of the production,
formulation or application of pesticides varies with the organization he is
associated with . For example, the pesticide worker in a modern manufacturing
plant, since the corporate structure represented therein demands high working
standards, is exposed to greater hazard driving to and from work than while at
work manufacturing pesticides. Small formulating plants, on the other hand,
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may employ people under working conditions that make pesticide exposure a daily
occurence. Structurally pest control operators characteristically have no fear
of their "favorite" compounds and are not described as being careful. This group
is sometimes heavily exposed but manages to stay on the job by avoiding
excessive exposure.
A-4.5.1 DDT
The literature abounds with reports containing data on the effect of
DDT on the human body in various stages of life. Westermann ' states that the
average American had, in 1969, 50 mg of DDT in his body. Oral doses of 10 to
20 mg have induced toxic symptoms in man and this same dose is sufficient to
kill more than 1000 tons of flies. Durham " indicated that there has been
no significant increase in the storage of DDT by the general population of the
United States since this parameter was first measured in 1950. Many writers and
scientific investigators around the world have been concentrating their efforts
on delineating the problem of the growing DDT residue potential in the human
sphere of influence. Kadis, et.al. * examined 217 tissue samples from autopsies
performed in Alberta, Canada in 1967 and 1968. They found that the mean con-
centration of p,p'DDE, -ODD and -DDT in adipose was 4.34 ppm. The levels in
other tissues were according to the following scale: liver, kidney, gonad, brain.
No correlation was found between accumulated level and age of subject. The
concentration of p,p'DDE and -DDD was higher in ovarian than in testicular
tissue, but the DDT concentration in male fat was higher than in female fat.
The difference in the presence of DDT metabolites in the male and female gonads
is probably due to the difference in cyclic change associated with the organs.
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A survey of 1500 poisoning cases lead to the publishing of a paper
by V.I. Pol'chenko * . In it, the author describes the typical symptoms of
DDT poisoning: ordinary widespread disorders of the gastro-intestinal,
respiratory, nervous and cardiovascular systems, as well as blood, liver and
skin diseases. A literature survey Durham * states that practically the
entire American population has some DDT residues in its tissues. The 1969-
reported mean storage level was 3 ppra as DDT and approximately 8 ppm as DDT
equivalent for metabolites of DDT. It further states that no significant
increase had taken place in the period 1950 to 1969.
4. 28
As fish accumulate DDT primarily through their food chain " , so do
most other organisms. Since man is at the top of the food pyramid, he has the
dubious benefit of receiving the highest intake concentrations because of the
concentrating action of all his predecessors in the food chain. The significance
4 172
of pesticide residues in the food of humans was stressed by Kraybill " in
his article reporting the differences in pesticide levels in foods depending
on preparation source. For the period 1962 to 1964, household meals contained
0.314 mg DDT and 0.173 rag DDE while restaurant ratals contained 0.038 mg DDT
and 0.44 mg DDE as reported by the Public Health Service. This difference is
interesting in that the private shopper (housewife) purchases foodstuffs on
the basis of cosmetic value more than anything else. The restauranteur on the
other hand pruchases for price and value. Consequently, his purchases may not
be as pleasing to the eye as those of a private purchaser, but do represent a
lower level of pesticide content because of the mode of agriculture it represents.
The question of human toxicity has been investigated in people exposed
to varying levels of DDT. This section will deal with the effects of DDT on
4.173
various systems of the body. O'Leary, Davies and Feldman measured blood
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levels of p,p'DDT and -DDE in obstetric patients in Dade County, Florida. The
venous blood of 28 Caucasians and 73 Negroes was sampled following or during
spontaneous abortion. In addition, samples from 45 Caucasians and 107 Negroes
served as controls. The results indicated that gestational exposure to DDT is
not a significant abortifacient stimulus. No relation between age or parity and
DDT levels was noted but DDT levels were significantly higher among Negroes. In
another study, Rappolt, et.al., " reports that 39 stillbirths studied in
Kern County, California in 1964 and 1965 had associated with them high levels
of p.p'DDT and p,p-DDE, its metabolite. The organochlorine compount concentrations
in tissues of 35 pregnant women, 33 non-pregnant women in the fertile portion of
4.175
their lives and 23 neonates were documented in another study " . During
pregnancy, the storage of p,p'-DDT, -ODD, o,p'-DDT and o,p'-DDD, o,p'-DDE and
total o,p'-DDT is reduced in adipose. The same effect was observed for dieldrin
and BHC isomers. All the organochlorine insecticides found in the adipose of
pregnant women was also found in maternal and fetal blood samples suggesting that
in pregnancy the metabolism of organochlorine insecticides is enhanced and these
agents can pass through the placental barrier. The placental passage of pesticides
4 173
was investigated by O'Leary, et.al. by monitoring p,p'-DDT and -DDE levels
in human blood during pregnancy. Fortyfive Caucasians and 107 Negroes in late
pregnancy were sampled. Fortyseven paired samples of maternal and cord blood
were analyzed as well as 70 paired samples from newborns (24 Caucasians and
46 Negroes). The amnionic fluid of 42 women at or near term was sampled, as well
as 12 paired samples of vernix caseosa from back and axilla of newborns, and
12 placental samples. The DDE concentration of 152 blood samples in pregnant
women ranged from 3 to 92 ppb (mean in Caucasians was 10.8 ppb; mean in Negroes
was 15.2 ppb). The DDE concentration in the cord blood of 70 neonates was a
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mean of 4.8 ppb in Caucasians and 5.9 ppb in Negroes. These figures indicate
that the DDE concentration in Caucasians does not differ markedly from that in
Negroes. However, the data on DDT levels among the two racial groups is markedly
different. Caucasian maternal blood has a DDT level of 17 ppb, while that of
Negroes was 32 ppb; the cord blood of Caucasians contained 5 ppb DDT, while that
of the Negroes contained 9 ppb and the amnionic fluid of Caucasians had a DDT
level of 6 ppb, while the Negroes level was higher at 14 ppb. Despite the
implication that the Negro retains higher levels of DDT, it is also apparent
that DDT does indeed permeate the placental barrier. The effects of this on the
fetus are not completely understood and, in the opinion of the authors of the
referenced article, should be thoroughly investigated.
The personnel in the previous study probably didn't have a marked
occupational exposure to DDT in the time during which they were sampled since
they were pregnant. Yet, their tissues contained considerable quantities of
the pesticide. A study undertaken in the Ukraine from 1964 to 1965 bears this
out. Therefore, the problem is not one confined to the United States. The
author of the Ukrainian study (Gracheva, 1969) concludes that the main source
of non-occupationally exposed persons to DDT. contamination must be through the
food chain. So it is with neonates as well. In some countries the primary
source of food for newborn infants is from human milk. A study conducted on
residents of Kiev4'176 and its surroundings indicates that for the urban group,
a substantial proportion (74.6 %) contained detectable amounts of DDT in their
milk. Also examined were women from an agricultural area with a high use rate
of DDT. The group had an identical incidence of DDT in milk with the urban
group, but the mean DDT concentration was higher (0.19 mg/1 vs 0.10 mg/1).
The investigator also generated more data supporting the passage of DDT through
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4.177
the placental barrier. A similar study conducted in Eastern Europe^ was
concerned with milk samples of both urban and rural dwelling women. The
combined level of p,p'-DDT, -DDE and -ODD was 12.87 ppm.
A number of reports have been published in recent years documenting
the state of various human organs after occupational and low-level exposure to
DDT. This section will briefly describe a number of these. Phillips, Ritcey,
Murray and Hoppner " found no obvious correlation between the level of
organochlorine compound ingestion and the incidence of low Vitamin A stores in
the liver.
Paramonchik * reported on the functional state of the liver in
workers engaged in the manufacture of organochlorine compounds, among these was
DDT. Liver function studies were performed on 360 workers with varying exposure
to DDT. Most workers with DDT and hexachlorane for 11-15 years. A few had
other slight contact with organochlorine compounds of hepatotropic action.
Of the 208 workers synthesizing DDT and preparing DDT dust and paste, functional
liver changes were found in 54 individuals. Krasniuk, et.al., * studied
100 workers in a DDT manufacturing facility. The antitoxic function was
disordered in 58 out of 80 tested. In addition, the urinary excretion was up
to 75 % below normal and the carbohydrate function was disordered in 69
workers. Paramonchik and Platonova ' , in yet another study, discussed the
functional state of the liver and stomach in persons occupationally exposed to
the action of organochlorine compounds. The 70 persons were occupationally
exposed to the action of organochlorine compounds.. The 70 persons examined
were employed in the production or use of organochlorine compounds, consisting
of both men and women in the age group 21 to 50 years, most with greater than
10 years experience and consequent exposure. Thirty one members of the examined
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group had symptoms of a mild toxic action. In 20, initial signs of chronic
organochlorine intoxification appeared (toxic diencephalitis, polyneuritis or
initial symptoms of toxic hepatitis). The remaining 19 had no signs of organo-
chlorine-induced disorders. Changes in the gastrointestinal tract appeared as
chronic gastritis and peptic ulcers. Workers with less than 10 years exposure
experienced intensification of the acidogenic and pepsin-secretory functions of
the stomach and insignificant liver disorders. Workers with greater than
10 years exposure had definite disorders of the liver functions, as well as a
depression of the two stomach functions found in workers with less than 10 years
exposure.
The levels of DDE, ODD, DDT, dieldrin, 0-BHC and heptachlor epoxide
were determined at autopsy in the fat and liver of 271 patients who previously
exhibited various pathological states of the liver, brain and other tissues.
Radomski, et.al., " in reporting these findings, compared them with the
results of random autopsies and with a group designated "infectious diseases."
There was a striking lack or correlation between pesticide concentration in
the fat and liver of all the cases. There was, however, a significant correla-
tion between pesticide levels in the fat and brain. In the presence of brain
tumors, no increase in pesticide level in the brain was noted over that found in
normal brain tissue. But a higher level of DDE was found in the brain of those
afflicted with encephalomacia and cerebral hemorrhage. A highly significant
elevation of pesticide levels was found in all cases of carcinoma of various
tissues, particularly, the DDE concentrations in metastatic liver disease was
7 times higher than normal. Significantly elevated levels of DDE and dieldrin
were found in portal cirrhosis, but not in fatty metamorphosis. Levels of DDT,
DDE, DDD and dieldrin were consistently and significantly elevated in the fatty
4~53 EQ-5025-D-2 (Vol. II)
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tissue of those cases that suffered hypertension. Those home pesticide users
who used high levels of these products had 3-4 times the DDT and DUE level as
those who used minimal quantities. This indicates that pesticides used in the
home have a tendency to accumulate in the dwellers, probably because the agents
find their way into the food consumed in the household in high levels.
The functional state of the stomach has been described for workers
exposed to significantly high DDT levels in their ambient environment by
Platonova ' . A significant frequency of complaints of a dyspeptic nature
were the following: loss of appetite, heartburn and nausea, pains in the
epigastric region and right hypochrondium and disordered stools. More than
51 of the 102 workers surveyed and examined had disordered secretory and
acidogenic functions of the stomach (either intensified or depressed). Gastric
enzymatic function was altered, usually as intensification. An increase of the
number of organic diseases paralleled an increase in work experience with
organochlorine pesticides. This discovery led to the hypothesis th. •': changes
in the functional state of the stomach are caused by disorders of neural reflex
regulation of gastric secretions. Krasniuk and Platonova ' investigated 558
persons in contact with organochlorine poisons. Of this number, 234 manufactured
DDT and preparations, 148 worked with DDT and hexachlorane and the balance
worked with hexachlorane alone. A study of the stomach contents and X-ray
examinations established that functional gastric disorders or chronic gastritis
occurred in 2.2 % of the DDT owrkers, 17 % of the hexachlorane workers and 29 %
of the DDT-hexachlorane group. In a control group of 216 persons, the frequency
of similar gastric pathology was 6.5 %. In addition, the stomach disorder
frequency increased with the length of work exposure: 14 % had up to 5 years
experience; 18.9 % had from 6-10 years exposure and 31.8 % had more than
10 years exposure. 4-54
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The renal system is a^so covered in some detail by investigators in
the field. Loganovskii * studied 106 workers with a history of prolonged
exposure to small amounts of DDT, hexachlorane and ether sulfonate. While the
findings confirmed those of other body systems, the urinary findings were pre-
dominantly normal. Renal disorders, it is thought, may be the result of
direct action of organochlorine compounds on kidneys or by way of their injurious
effect(s) on other organs or systems. In another publication * , Loganovskii
investigated the state of glomerular filtration and tubular reabsorption in the
kidneys of persons exposed to organochlorine compounds over long periods. The
exposure time was greater than 10 years. Prolonged contact with small quantities
of DDT, hexachlorane and ether sulfonate leads to disordered glomerular filtration
and tubular reabsorption. These effects are most clearly seen in workers exposed
for from 10-15 years and in those with chronic intoxification. The exposure
for 3-5 years increased the rate of glomerular filtration, while exposures of
from 10-15 years caused this parameter to decrease. Significantly, fewer
disturbances were noted in tubular reabsorption. Krasniuk, et.al., " noted
not only functional changes of the kidneys in accordance with the findings of
others but also characterized morphological alterations within the microstructure
of the kidney. Morgan and Roan * , on the other hand, failed to find evidence
of chronic occupational differences in glomerular filtration and tubular
reabsorption between a group of 65 pesticide workers and 23 controls. However,
the pesticide workers in this test were occupationally exposed to organophosphates
as well as organochlorine pesticides.
Edmundson, Davis and Cranmer " studied the effect of DDT aerosol
exposure on the blood and urine levels of DDT and DDE and DDA. First-day
blood samples showed no correlation between blood levels of DDT and DDE, the
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amount sprayed and the spraying time. There was, however, a slight correlation
t
between the excretion time of DDA and the amount sprayed and the spraying time.
A study was conducted to determine the epidemiological significance of serum DDT
4.190
level in three groups of men exposed to decreasing levels of DDT * . Blood
samples were taken bi-monthly in 1968. No clear relationship was found between
the degree of occupational DDT exposure and the total serum DDT level. All groups
exhibited a 6- fold increase in total serum DDT level in the period between
April and August. They also exhibited a relative decrease in serum DDE level
for the same period. The results indicate that local agricultural and municipal
insecticide programs increase DDT exposure to all subjects, regardless of the
.1
degree of occupational exposure. Also, DDT appeared in the sera soon after
absorption from the external environment.
4.191
Edmundson, et.al. " , published a study of the p,p'-DDT and -DDE
levels in personnel occupationally exposed to DDT. DDT was detectable in 80 %
of the control group but was below the consistently measurable level (7 ppb).
In the occupationally exposed group, the mean of white workers was less than
7 ppb except for white formulators (21 ppb) and aircraft sprayers (25 ppb).
The non-white members of the exposed group were noted to have: 40 ppb for
formulators, 10 ppb for floral sprayers and 32 ppb for agricultural sprayers.
There was no evidence of clinical toxicity during the 2-year observation
period. It was noted that the DDT blood level depends on the recency of exposure
while the DDE blood level is a stable value. Another study ^•1J1 measured the
serum lipoprotein value of persons long exposed to the action of organochlorine
compounds. The exposure was via airborne DDT in various stages of production.
In addition, the levels of hydrogen chloride, chlorobenzene, hexachlorane and
chlorinated derivatives of phenols were quantified. Changes were detected in
4-56
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the ratio of alpha-to-beta-lipoprotein levels in botli directions. A simul-
taneous study demonstrated frequent hypoalbuminemia and hypergammaglobulinemia.
The measurement of serum lipoprotein level proved a valuable supplementary
index of liver function in relation to organochlorine compound exposure.
Ballistocardiography was used to detect the presence of marked
diffuse changes in the myocardium and a disorder of its contractile function
in workers exposed to organochlorine compounds * . Ballistocardiography was
done on 58 individuals with electrocardiographic signs of extracardiac disorders
in cardiac function and on 52 workers with diffused changes of the myocardium of
a dystrophic type.
The therapeutic utility of DDT and .its metabolites is being investi-
4.193
gated by workers in the field. Greim " reported on the toxicity of DDT and
the therapeutic utility in a recent article. The general features of DDT
metabolism are discussed, as well as the reaction of DDT which may render it
useful as a therapeutic aid by increasing the metabolic rate of the agent itself
and also of certain drugs.
4 194
In addition to the use of DDT as a therapeutic aid, Hayes, et.al.,
reported on the effects of long term, high oral doses on the human organism. The
average doses administered were 555 times the average intake of all DDT-related
compounds by 19-year olds in the general population and 1250 times the intake
of DDT itself. The investigators postulate that since no definite clinical or
laboratory evidence of injury by DDT was found, the degree of safety with the
4 195
use of DDT is high for the general population. In a prior study by Hayes * ,
he reports on the feeding of volunteers with DDT dissolved in oil at doses of
0, 3.5, and 35 mg. per man per day. These men were 01 ordinary diets and the
test included, in addition to the ten subjects, four controls. No clinical
effects associated with the DDT dosage were detected.
EQ-5025-D-2 (Vol. II)
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A statement, found in the report by Hayes, ' states: "Some of
the diseases which are claimed to have increased because of DDT, in fact, have
shown no increase. Some of the other diseases are increased largely because of
the changing distribution of age groups in the population of the United States.
Because of improvements in the control of communicable diseases of children and
adults, a greater proportion of people live to be old enough to have cancer and
those forms of heart trouble which strike in middle or old age".
This statement sums up the feeling of pesticide proponents in this
country and probably around the world. There is irrefutable evidence that the
use of pesticides has improved the lot of millions of people around the world;
the malaria campaigns during and after the World War II being the best example.
Pennsylvania has been using pesticides for the control of the gypsy
mol:h menace much the same as have other states in the northeastern part of this
country. A publication describing this program * emphatically states that
DDT as used in the gypsy moth program presents no hazard to human health. The
report cites further work by Wayland Hayes, M.D. that involved a study of 40 men
occupationally exposed to high levels of DDT. Despite storing relatively large
amounts of DDT in their fat (average over 300 ppm), no adverse effect on the
health of the men was noted. In addition, in a program involving the ingestion
of DDT by human volunteers, no sensitization to the material was demonstrated
on the part of the volunteers.
A-4.5.2 Sevin
The toxicity of Sevin of carbaryl (1-naphthyl-N-methyl carbamate) on
humans has not, to this date, been well documented due to its relatively late
entrance ar. an economic poison. Its primary mode of action, however, is as a
4-58 EQ-5025-D-2 (Vol. II)
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cholinesterase inhibitor, and consequently, must be countered accordingly
(atropine treatment, for example).
The mammalian toxicity of Sevin was discussed and examined in a paper
by Carpenter, Weil, Palm, Woodside, Nair III and Smyth4'197. The study subjects
included rats, dogs, rabbits and guinea pigs. The data generated indicates that
under ordinary circumstances accidental exposure to Sevin in conditions accompanying
forest site spraying would not prove harmful to these animals since rats tolerate
200 ppm in their diet without significant deviation from control animals and that
dogs tolerate 400 ppm on the same basis. This study included information on meta-
bolism, cholinesterase inhibition, alleviation of symptoms x«.th atropine sulfate
and their aggravation by pyridine-2-aldoxime methiodide, arid the absence of neuro-
muscular degenerative potential, carcinogenic activity, and sensitizing propensity.
The Sevin was administered as single doses via oral, parenteral, percutaneous and
respiratory routes. Some of the test series included long term administration of
the material via one or more of the above routes. A comparison of effects between
Sevin and another cholinesterase inhibitor, parathion, indicates that although the
Sevin dose was higher than was the parathion dose (0.56 gm/kg body weight versus
0.0093 gm/kg body weight) the parathion produced a slower but more progressive
depression on plasma, erythrocyte and brain cholinesterase systems as compared
with the higher doses of Sevin.
Farago reported a case of fatal, suicidal Sevin poisoning. The
man in question drank 0.5 liter of Sevin 80 solution and was hospitalized
immediately. He was under aocoholic intoxication at the time of ingestion.
Immediately upon hospitalization, gastric lavage was initiated and circulatory
stimulants administered. The development of pulmonary edema and disordered
vision attested to his worsening condition. Atropine was administered every
4~59 EQ-5025-D-2 (Vol. II)
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30 minutes, but atropinization was not observed. After administering 250 mg PAM,
the pulmonary edema progressed. Death occurred 6 hours after ingestion. An
autopsy and chemical analysis of the subject's blood, gastric lavage fluid,
stomach and contents, intestines and contents, liver, kidneys and urine revealed
a Sevin distribution of from 14.8 to 244.8 meg % in the stomach, intestines and
and gastric lavage fluid and 1.4 to 3.1 meg % in the blood, kidneys, liver and
urine. The cholinesterase activity of the blood was strongly inhibited at 0.12
delta pH/hr. Sevin absorption was so rapid that excretion had already begun,
as attested to by the Sevin found in the urine. Since gastric lavage was begun
within 30 minutes and the quantity found in the stomach was less than that found
in the intestines (14.8 vs 17.6 meg %), it is postulated that the lethal dose
was absorbed within 1.5 hours of ingestion. In addition, it is documunted that
from the course the poisoning took, PAM administration was an error, although
death was, in the estimation of the authors, not preventable. In general, the
autopsy results confirmed, in the human system, facts known about Sevin in other
biological systems, viz, Sevin is rapidly degraded in the human system—1 metabolite
was found in the stomach contents, 3 in the intestine contents, 4 in the liver
and kidneys and 5 in the urine. Sevin itself, as noted earlier, was still present
in all these tissues and fluids in lesser quantities.
The massive self-administered dose of carbaryl described in the pre-
ceding paragraph is probably not representative of cholinesterase inhibition
poisoning because other effects due to the mass involved were presumably operative.
4 199
The details of cholinesterase inhibition were discussed in a paper by Main '
The kinetics of this mechanism are detailed in a step-wise fashion for organ-
ophosphates and carbamates. The first step in the process involves the formation
of a binding complex between the inhibitor and cholinerterase. This step,
4-60 EQ-5025-D-2 (Vol. II)
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together with the phosphorylatlon or carbamation reaction, determines the
inhibitory and consequently the toxic power of the compound. The theoretical
and experimental contexts are defined within which valid estimates of the reversible
equilibrium constant may be made. This constant measures the affinity or organo-
phosphate and carbamates in the liver appears to be an important factor in the
metabolism of carbamate insecticides in several animals, including man*'200.
Dealkylation is the mechanism by which some carbamates are degraded to less toxic
metabolites in the liver. In the process of this action, however, phospholipid
snythesis and metabolism in the liver, as well as in the brain and heart, is
lowered in white rats * . This same action has been observed for DDT. Over
a short term, DDT and Sevin are about equal in their power to depress phnspholipid
metabolism. Long-term administration demonstrates DDT to be a stronger depressant
on phospholipid metabolism than is Sevin.
The effect of carbamic acid derivatives on nucleic acid metabolism
4.202
in the rat liver and spleen is described by Anina * . In this study, rats
were sacrificed after receiving maximally tolerated doses of Sevin, carbine,
diptal or TMTD in either aqueous suspension or oil emulsion via stomach tube.
Enzyme activity and nucleic acid quantity were determined in the liver and
spleen. Carbamates were noted to increase ribo- and deoxyribonuclease (RNA and
DNA) activity compared with controls. A decrease in nucleic acids was noted in
the spleen. All the carbamic acid derivatives increased the quantity of RNA
in the liver. This effect was significantly higher with carbine and diptal as
compared with the other derivatives. The effect of DNA varied with the identity
of the derivative. Sevin and TMTD significantly increased the quantity of DNA
in the liver, while diptal exerted a slight depressing action. While the nature
4~61 EQ-5025-D-2 (Vol. II)
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of the increase in nuclease activity remains clouded, the data testifies to the
intensity of the process of nucleic acid breakdown by carbamates.
Rats and mice were used as the subjects of a study of certain pesti-
/ O f\ *3
cides on the hypophysis and its gonadotropic function ' . DDT and Sevin actions
were seen as an increase in the luteinizing function of the hypophysis in white
rats and in mice. The effect was more pronounced with DDT than it was with Sevin.
In addition, both DDT and Sevin increased the esterus cycle and the duration of
its phases in both rats and mice.
4 204
Boyd and Krijnen * studied the effect of protein intake on the
oral toxicity of carbaryl in the rat. They found that the interval-to-death was
not related to the amount of casein in the diet but the timing was inversely
proportional to the dose of carbaryl.
Many of the cited studies were performed on laboratory animals rather
than being observations of carbaryl's effect on the human body because of the
lack of widespread domestic use of the product and because of the rather severe
restrictions with respect to licensing being placed on today's product. That is
to say, before a product can be marketed as an economic poison, it must be
screened using laboratory animals.
Strother * compared the metabolism of certain carbamates by human
and rat liver fractions and determined that the two pathways differ for Sevin in
that the human liver fraction appeared to produce 2 more metabolites than did
the rat liver fraction. With this in mind, the results appearing in the liter-
ature concerning the toxicity and metabolism of Sevin in .laboratory animals
should be considered as approximate or "best estimates".
There has been much recent publicity concerning the teratogenic
effectr- of Sevin in beagle dogs; certain groups have extended this information
4_62 EQ-5025-D-2 (Vol. II)
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directly to human organism. Smally, et.al.,4'206 published a report on the
teratogenic action of carbaryl in beagle dogs which has since become the guide-
line and sourcebook for arguments against large scale use of Sevin in the north-
east against the gypsy moth (Porthetria dispar). Smalley's original work did
demonstrate a teratogenic effect on beagle dogs caused by Sevin but the doses
reported were quite high (3.125 to 50 mg/kg body weight daily). The extension
of these facts to the human situation cannot be considered as completely foolproof
since humans in areas being sprayed for gypsy moth infestation are not exposed to
doses nearing the levels used in the beagle dog study.
Furthermore, the metabolic pathways for Sevin in the man and dogs is
not exactly identical ' The metabolites of Sevin found in the urine
of dogs receiving Sevin doses are not all the same as those found in human urine
specimens of subjects taking doses of Sevin.
The report of the Secretary's Commission on Pesticides and their
4 209
Relationship to Environmental Health ' , which is also known as the Mrak Report
or the Mrak Commission Report, reviews the status of pesticide use and side effects
in the United States. It states that certain of the major pesticide types have
associated with them typical symptomatic responses:
organochlorine pesticides - general action is to increase
excitability of the nervous system. Some compounds
damage the liver as well.
organophosphate pesticides - cholinesterase inhibitors
carbamates - cholinesterase inhibitors
The report further states that the present level of exposure to DDT and aldrin-
dieldrin type pesticides have not produced any observable adverse effects on
controlled studies of volunteers. In organophosphates, there is no residue
risk—only the risk of acute toxicity.
4-63 EQ-5025-D-2 (Vol. II)
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In pesticide toxicity studies, a number of factors have been found
to be important in determining the response of the animal to the toxicant, viz,
species, age, sex, disease, nutrition, environmental temperature and light.
Chapter 6 of the report is entitled, Teratology of Pesticides.
This chapter calls for immediate restriction of Captan, Carbaryl, the butyl,
isopropyl, and isocotyl esters of 2, 4-D Folpet, mercurials, PCNB and 2, 4, 5-T
as a result of the teratogenetic action of these in labo/.itory animals. For
terato;'eneticity screening tests, several guidelines are proposed within this
chapter. An important one involves the selection of the test animals. Using
materials of known purity, stability, etc., it recommends that at least 2 species
be chosen on the basis of metabolic and pharmacokinetic similarity to humans.
4 209
Seven sections " dealing with literature reviews of the teratogenic
effect of pesticides are presented, being highlighted by pesticide identity.
Section b. - Carbaryl, states:
"b. Carbaryl - This was tested at 66.7 and 200 ppm
in the diet of pregnant mice (FAO/WHO, 1967). In 2 litters
at the 200 ppm level, a total of 7 instances of skeletal
malalignment, nonfusion, incomplete ossification, and 1 case
of cleft palate and gross facial malformation were noted
as opposed to no malformations in the lower level group and
2 cases of cleft palate in controls. Teratogenetic findings
for carbaryl are also presented in the Bionetics study. In
a study in which beagle dogs were fed carbaryl during
gestational periods at levels of 50, 25, 12.5 and 6.25
and 3.125 mg/kg body weight daily, teratogenic effects were
found at all but the lowest dose level (Smalley, 1968)."
4-64
EQ-5025-D-2 (vol. II)
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The Bionetics Research Laboratories of Litton Industries Study for
the National Cancer Institute report is included in Chapter 6 . The study
tested various pesticides and related compounds for teratogenic effects. The
paragraphs on carbaryl and 1-naphthol, a principal carbaryl metabolite state:
"Other pesticides producing a statistically significant
increase in the proportion of litters containing abnormal
fetuses and in the increased incidence of abnormal fetuses
within litters were: Captan, Folpet, 2, 4-D isooctyl ester,
2, 4-D butyl ester, 2, 4-D isopropyl ester, carbaryl (Sevin)
and IPC. These pesticides produced elevated inciand in one
solvent only. The results for carbaryl and for IPC were
less consistent than for other compounds. (The pesticides
2, 4, 5-T, PCNB, Captan, Folpet, carbaryl, IPC and the butyl
and isopropyl esters of 2, 4-D were statistically significant
at the 0.01 level, for one or more tests. This criterion is
similar to that adopted by the Technical Panel on CarcinO-
genesis, Chapter 5, to identify "positive" compounds. The
isooctyl ester of 2, 4-D was significant at the 0.05 level.)
Compounds inducing only an increase in the proportion of
abnormal fetuses within letters were: a-naphtol, and 2,
4-D methyl ester. The statistical significance of these
results was relatively weak; further study is required
before any conclusions can be reached. Similarly, 2, 4-D
produced only an increase in the proportion of abnormal
litters during 1965 in AKR mice. Due to the teratogenic
4-65 EQ-5025-D-2 (Vol. II)
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activity of certain of its esters, 2, 4-D should be
studied further.
Carbaryl plus piperonyl butoxide did not show an overall
increase in nonspecific anomalies, but resulted in sig-
nificantly more cystic kidneys for doses above 10 rag/kg
carbaryl plus 100 ul/kg piperonyl butoxide."
4-66
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A-4.6 References
4.1 Cottam, C., 1946, DDT and its Effects on Fish and Wildlife,
Journal of Economic Entomology, 39(1): 44-52.
4.2 Butler, P. A. and P. F. Springer, 1963, Pesticides - a New Factor
in Coastal Environments, Trans, of the Twenty-Eighth North American
Wildlife and Natural Resources Conference, 378-390.
4.3 Springer, P. F. and A, 0. Haugen, 1953, Effects of Insecticides on
Wildlife, unpublished paper presented at Third Army Annual Insect
and Rodent Control Training Conference, Memphis, Tennessee, 5 May 1953.
4.4 Eberhardt, L. L., R. L. Meeks and T. J. Peterle, 1971, Food Chain
Model for DDT Kinetics in a Freshwater Marsh, Nature, 230(5288):
60-62.
4,5 Egler, F. E., 1964, Pesticides - in our Ecosystem, American
Scientist, 52(1): 110-136.
4.6 Egler, F. E., 1964, Pesticides - in our Ecosystem, Communication II,
Bioscience, November: 29-36.
4.7 Fox, G. W., 1970, Pesticides and Ecosystems, Nation Library of
Medicine, U. S. Public Health Service, Literature Search 70-39,
pp 24.
4.8 Fredeen, F. J. H. and J. R. Duffy, 1970, Insecticide Residues in
Some Components of the St. Lawrence River Ecosystem Following
Applications of ODD, Pesticide Monitoring Journal, 3(4): 219-226.
4.9 Headley, J. C. and E. Erickson, 1970, The Pesticide Problem - an
Annotated Bibliography, University of Missouri, College of
Agriculture Research Bulletin Number 970, pp 55.
o£
4.10 Meeks, R. L. and T. J. Peterle, 1965, The Cycling of Cl-labeled
DDT in a Marsh Ecosystem, U. S. Fish and Wildlife Circular
Number 226, pp 46.
4.11 Pressman, R. , 1963, Pesticides. In: McKee, J. E. and H. W. Wolf
(ed.). Water Quality Criteria (2nd ed.), California State Water
Quality Control Board Publication 3-A, pp 355-404.
4.12 Rudd, R. L., 3964, Pesticides and the Living Landscape, University
of Wisconsin Press, Madison, Wisconsin, 320.
4.13 Shane, M. S., 1948, Effect of DDT Spray on Reservoir Biological
Balance, Journal of the American Water Works Association,
March, 333-336.
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4.14 U. S. Department of Interior, 1962, Effects of Pesticides on Fish
and Wildlife in 1960, Fish and Wildlife Circular Number 143,
pp 52.
4.15 U. S. Department of Interior, 1963, Pesticide - Wildlife Studies:
A Review of Fish and Wildliie Service Investigations during 1961
and 1962, Fish and Wildlife Circular Number 169, pp 109.
4.16 U. S. Department of Interior, 1964, Pesticide - Wildlife Studies, 1963,
Fish and Wildlife Circular Number 199, pp 130.
4.17 U. S. Department of Interior, 1965, Effects of Pesticides on Fish and
Wildlife, Fish and Wildlife Circular Number 226, pp 77.
4.18 Woodwell, G. M., 1967, Toxic Substances and Ecological Cycles,
Scientific American, 216(3): 24-31.
4.19 Wurster, C. F., 1968, DDT Reduces Photosynthesis by Marine
Phytoplankton, Science, 159: 1474-1475.
4.20 Gunther, F. A., W. E. Westlake and P. S. Jaglan, 1968, Reported
Solubilities of 738 Pesticide Chemicals in Water, Residue
Reviews, 20: 1.
4.21 Marth, E. M., 1965, Residue and Some Effects of Chlorinated
Hydrocarbon Insecticides in Biological Material, Residue
Reviews, 9: 1-89.
4.22 Lichlenstein, E. P., 1958, Movement of Insecticides in Soils Under
Leaching and Non-leaching Conditions, Journal of Economic
Entomology, 55: 380-383.
4.23 Fredeen, F. J. H., A. P. Arnason and B. Berck, 1953, Adsorption of
DDT on Suspended Solids in River Water and its Role in Black-fly
Control, Nature, 171: 700-701.
4.24 Cope, 0. B., 1961, Effects of Spraying for Spruce Budworm in Fish in
the Yellowstone River system, Transactions of the American Fisheries
Society, 90(3): 239-251.
4.25 Meeks, R. L. , 1968, The Accumulation of Cl Ring-labeled DDT in a
Freshwater Marsh, Journal of Wildlife Management, 32(2): 376-398.
4.26 Cole, H., D. Barry, D. E. H. Frear and A. Bradford, 1967, DDT Levels
in Fish, Streams, Stream Sediments and Soil Before and After DDT
Aerial Spray Application for Fall Cankerworm in Northern Pennsylvania,
Bulletin of Environmental Contamination and Toxicology, 2(3): 127-146.
4.27 Metcalf, R. L., G. K. Sangha and I. P. Kapoor, 1971, Model Ecosystem
for the Evaluation of Pesticide Biodegradability and Ecological
Magnification, Environmental Science and Technology, 5(8): 709-713.
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4.28 Macek, K. Q. and S. Korn, 1970, Significance of the Food^Chain in
DDT Accumulation by Fish, Journal of the Fisheries Research Board
of Canada, 27: 1496-1498.
4.29 Murphy, P. G., 1970, Effects of Salinity on Uptake of DDT, DDE and
DDD by Fish, Bulletin of Environmental Contamination and Toxicology,
5(5): 404-407.
4.30 Stickel, L. F., 1968, Ogranochlorine Pesticides in the Environment,
U. S. Bureau of Sport Fisheries and Wildlife Special Scientific
Report Number 119, pp 32.
4.31 Christie, A. E., 1968, Insecticides and Algae: Toxicity and
Degradation, Ontario Water Resources Commission Research
Publication Number 27, pp 26.
4.32 Sweeney, R. A., 1970, Algae as Indicators of Pesticides, Great Lakes
Laboratory, Special Report Number 4, pp 10.
4.33 Ware, G. W. and C. C. Roan, 1970, Interactions of Pesticides with
Aquatic Microorganisms and Plankton, Residue Reviews, 15-45.
4.34 Palmer, C. M. and T. E. Maloney, 1955, Preliminary Screening for
Algicides, Ohio Journal of Science, 55(1): 1-8.
4.35 Ukeles, R. , 1962, Growth of Pure Cultures of Marine Phytoplankton
in the Presence of Toxicants, Applied Microbiology, 19(6): 532-537.
4.36 Lichtenberg, J. J., J. W. Eichelberger, R. C. Dressman and
J. E. Longbottom, 1970, Pesticides in Surface Waters of the
United States - a 5-year Summary, 1964-68, Pesticides Monitoring
Journal, 4(2): 71-86.
4.37 Nicholson, H. P., 1969, Occurance and Significance of Pesticide
Residue in Water, Journal of the Washington Academy of Science,
59(4-5): 77-85.
4.38 Butler, P. A., 1963, Commercial Fishery Investigation, U. S. Fish
and Wildlife Circular Number 167, pp 11-25.
Q
4.39 Glooschenko, W. A., 1971, The Effect of DDT and Dieldrin upon 14
Uptake by In Situ Phytoplankton in Lakes Erie and Ontario, paper
presented at 14th Great Lakes Research Conference, Toronto,
20 April 1971.
4.40 Gregory, W. W., J. K. Reed and L. E. Priester, 1969, Accumulation
of Parathion and DDT by Some Algae and Protozoa, Journal of
Protozoology, 16: 69.
4.41 Chacko, C. I. and J. L. Lockwood, 1967, Accumulation of DDT and
Dieldrin by Microorganisms, Canadian Journal of Microbiology,
13: 1123-1126.
4~69 EQ-5025-D-2 (Vol. II)
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4.42 Rickey, J. J., J. A. Keith and F. B. Coon, 1966, An Exploration
of Pesticides in a Lake Michigan Ecosystem, Journal of Applied
Ecology, 3 (Supplement): 141.
4.43 Butler, P. A., 1966, Fixation of DDT in Estuaries, Proceedings of
the Thirty-first North American Wildlife Conference, 184-189.
4.44 Dimond, J., 1967, Pesticides and Stream Insects, Maine Forest
Service Bulletin Number 23, pp 21.
4.45 Graham, R. J. , 1960, Effects of Forest Insect Spraying on Trout and
Aquatic Insects of Some Montana Streams, Transactions of Second
Seminar on Biological Problems in Water Pollution, U. S. Department
of Health, Education and Welfare, 62-65.
4.46 Hitchcock, S. W., 1965, Field and Laboratory Studies of DDT and
Aqucii:ic Insects, Connecticut Agricultural Experiment Station,
Number 668, pp 32.
4.47 Hoffman, C. H. and A. T. Drooz, 1953, Effects of a C-47 Airplane
Application of DDT on Fish-food Organisms in Two Pennsylvania
Watersheds, American Midland Naturalist, 50(1): 172-188.
4.48 Keenleyside, M. H. A., 1967, Effects of Forest Spraying with DDT
in New Brunswick on Food of Young Atlantic Salmon, Journal of
the Fisheries Research Board of Canada, 24(4): 807-822.
4.49 Kerswill, C. J., 1967, Studies on Effects of Forest Spraying with
Insecticides, 1952-63, on Fish and Aquatic Invertebrates in
New Brunswick Streams: Introduction and Summary, Journal of
Fisheries Research Board of Canada, 24(4): 701-708.
4.50 Sanders, H. 0. and 0. B. Cope, 1968, Relative Toxicities of Several
Pesticides to Naiads of Three Species of Stoneflies, Limnology
and Oceanography, 13(1): 112-117.
4.51 Schoenthal, N. D., 1963, Some Effects of DDT on Cold Water Fish and
Fish-food Organisms, Proceedings of the Montana Academy of Sciences)
23: 63-95.
4.52 Hoffman, C. H. and E. P. Merkel, 1948, Fluctuations in Insect
populations Associated with Aerial Applications of DDT to Forests,
Journal of Economic Entomology, 41: 464-475.
4.53 Hoffman, C. H. and E. W. Surber, 1949, Effects of Feeding DDT-sprayed
Insects to Fresh-water Fish, U. S. Fish and Wildlife Service Special
Scientific Report: Fisheries, Number 3, pp 9.
4.54 Johnson, D. W., 1968, Pesticides and Fishes - A Review of Selected
Literature, Transactions of the American Fisheries Society,
97(4): 398-424.
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4.55 Henderson, C., W. L. Johnson and A. Inglis, 1969, Organochlorine
Insecticide Residues in Fish, Pesticide Monitoring Journal,
3(3): 145-171.
4.56 Reinert, R. E. , 1970, Pesticide Concentrations in Great Lakes Fish,
Pesticide Monitoring Journal, 3(4): 233-240.
4.57 Holden, A. V., 1964, The Possible Effects on Fish of Chemicals used
in Agriculture, Journal of the Proceeding of the Institute on
Sewage Purification, 1964: 361-368.
4.58 Rudd, R. L. and R. E. Genelly, 1956, Pesticides: Their Use and
Toxicity in Relation to Wildlife, California Fish and Game
Bulletin, 7: 1-309.
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540-546.
4.60 Elson, P. F., 1967, Effects of Wild Young Salmon of Spraying DDT
Over New Brunswick Forests, Journal of the Fisheries Research
Board of Canada, 24(4): 731-767.
4.61 Kerswill, C. J. and H. E. Edwards, 1967, Fish Losses after Forest
Sprayings with Insecticides in New Brunswick, 1952-62, as Shown
by Caged Specimens and Other Observations, Journal of the Fisheries
Research Board of Canada, 24(4): 709-729.
4.62 Nicholson, H. P., 1959, Insecticide Pollution of Water Resources,
Journal of the American Water Works Association, 51: 981-986.
4.63 Cope, 0. B., 1965, Agricultural Chemicals and Freshwater, In:
Research in Pesticides, Academic Press, New York, 115-128.
4.64 Bridges, W. R., B. J. Kallman and A. K. Andrews, 1963, Persistance
of DDT and its Metabolites in a Farm Pond, Transactions of the
American Fisheries Society, 92: 421-427.
4.65 Hoffman, C. H., 1959, Are the Insecticides Required for Insect
Control Hazardous to Aquatic Life, Transactions of Second Seminar
on Biological Problems in Water Pollution, Public Health Service
Report Number W60-30, pp 51-61.
4.66 Johnson, H. E., 1963, DDT and Trout, Montana Academy of Science,
23: 96-110.
4.67 Buhler, D. R. and W. E. Shanks, 1970, Influence of Body Weight on
Chronic Oral DDT Toxicity in Coho Salmon, Journal of the Fisheries
Research Board of Canada, 27(2): 347-357.
4.68 Johnson, H. E. and C. Pecor, 1970, Coho Salmon Mortality and DDT in
Lake Michigan, Transactions of the Thirty-Fourth North American
Wildlife and Natural Resources Conference, 159-166.
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4.69 Burclick, G.E., E.J. Harris, H.J. Dean, T.M. Walker, J. Skea and
D. Colby, 1964, Accumulation of DDT in Lake Trout and the Effect on
Reproduction, Transactions of the American Fisheries Society, 93(2):
127-136.
4.70 Hopkins, C.L., S.R.B. Solly and A.R. Ritchie, 1969, DDT in Trout and its
Possible Effect on Reproductive Potential, New Zealand Journal of
Marine and Freshwater Research, 3(2): 220-229.
4.71 Lincer, J.L., J.M. Solon and J.H. Nair, 1970, DDT and Tendrin Toxicity
Under Static versus Dynamic Bioassay Conditions, Transactions of the
American Fisheries Society, 99(1): 13-19.
4.72 Macek, K.J., 1968, Growth and Resistance to Stress in Brook Trout Fed
Sublethal Levels of DDT, Journal of the Fisheries Research Board
of Canada, 25(11): 2443-2451.
4.73 Holden, A.V., 1962, A Study of the Absorption of 14C-Labeled DDT
from Water by Fish, Annals of Applied Biology, 50: 467-477.
4.74 Menzie, C.M., 1969, Metabolism of Pesticides, U.S. Bureau of Sport
Fisheries and Wildlife Special Scientific Report, Number 127, pp.
487.
4.75 Kallman, B.J. and A.K. Andrews, 1963, Reductive Dechlorination of
DDT to ODD by Yeast, Science, 141: 1050.
4.76 Wedemeyer, G-, 1966, Dechlorination of DDT by Aerobacter Aerogenes,
Science, 152: 647.
4.77 Johnson, B.T., 1968, Detoxification of Halogenated Hydrocarbon Insec-
ticides by Enteric Microorganisms, U.S. Bureau of Sport Fisheries
and Wildlife Research Publication Number 64 , pp 132.
4.78 Wedemeyer, G., 1968, Role of Intestinal Microflora in the Degradation
of DDT by Rainbow Trout (Salmo gairdneri), Life Science, 7: 219-224.
4.79 Greer, G.L. and U. Paim, 1968, Degradation of DDT in Atlantic Salmon
(Salmo salar), Journal of the Fisheries Research Board of Canada,
25: 2321-2326.
4.80 Cherrington, A.D., U. Paim and O.T. Page, 1969, In Vitro Degradation
of DDT by Intestinal Contents of Atlantic Salmon (Salmo salar),
Journal of the Fisheries Research Board of Canada, 26: 47-54.
4.81 Premdas, F.H. and J.M. Anderson, 1963, Uptake and Detoxification of
14c-labeled DDT in Atlantic Salmon, Salmo salar, Journal of the
Fisheries Research Board of Canada, 20(3): 827-837.
4.82 Spencer, D.A., 1967, Problems in Monitoring DDT and its Metabolites in
the Environment, Pesticide Monitoring Journal, 1(2): 54-57.
4-72 EQ-5025-D-2 (Vol. II)
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4.83 Boyd, C.E., S.B. Vinson and D.E. Ferguson, 1963, Possible DDT Resistance
in Two Species of Frogs, Copia, 2: 426-429.
4.84 Ferguson, D.E., D.D. Culley, W.D. Cottom and R.P. Dodds, 1964,
Resistance to Chlorinated Hydrocarbon Insecticides in Three Species
of Freshwater Fish, BioScience, 4(11): 43-44.
4.85 Connola, D.P., 1960, Airplane Spray Tests for the Control of Gypsy
Moth, Sta. to Sta. Res. News, 6(3): 1-4, Union Carbide Chem. Co., N.Y.
4.86 Doane, C.C. and P.W. Schaefer, 1971, Aerial Application of Insecticides
for Control of the Gypsy Moth, Bull. Conn. Agr. Expt. Sta. No. 724,
pp 23.
4.87 Hood, C.S., 1966, The 1965 Gypsy Moth Control Program on Cape Cod.
The Effects of Sevin on the Gypsy Moth, Pesticide Board, Common-
wealth of Mass. Pub. No. 547: 1-11.
4.88 Ide, P.P., 1956, Effect of Forest Spraying with DDT on Aquatic Insects
of Salmon Streams, Trans. Amer. Fish. Soc. 86: 208-219.
4.89 Gorham, J.R., 1961, Aquatic Insects and DDT Forest Spraying in Maine,
Maine Forest Serv. Cons. Found. Bull. 19: pp 49.
4.90 Graham, R.J. and D.O. Scott, 1959, Effects of an Aerial Application
of DDT on Fish and Aquatic Insects, in Montana, Montana Fish and
Game Dept. and the U.S. Forest Service, pp-35, Mimeo.
4.91 Flieger, B.W., 1970, Experiences with Large Scale Forest Insect
Control Programs, Sixth N.E. Aerial Applicators Conf., Ithaca, N.Y.,
79-86, Mimeo.
4.92 Hopkins, D.R., H. Benton, N.E. Johnson and A.T. Neale, 1966. Supplement
to the Status Report — 1963 Willapa Looper Infestation Control
Project - State of Washington, Department of Natural Resources,
Olympia.
4.93 Decker, G.C., 1966, Significance of Pesticide Residues: Practical
Factors in Persistence, 111. Nat. Hist. Survey, Biol. Notes No. 56,
PP 8.
4.94 Coutant, C.C., 1964, Insecticide Sevin: Effects of Aerial Spraying on
Drift of Stream Insects, Science, 146: 420-421.
4.95 Wells, Lewis F. Jr., 1966, Disappearance of Carbaryl (Sevin) from
Oak Foliage in Plots Aerially Sprayed for Control of Gypsy Moth on
Cape Cod, Massachusetts, in 1965, Pesticide Board, Commonwealth of
Mass. Pub. No. 547: 12-17.
4.96 Wells, L.F. Jr., C.W. Collier and R. Tardif, 1966, Analysis of Leaf
Duff Samples for Sevin, Pesticide Board, Commonwealth of Mass. Pub.
No. 547: 18-24.
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4.97 Tompkins, William A., 1966, Sevin Residues in Marine and .Freshwater
Aquatic Organisms, Pesticide Board, Commonwealth of Mass. Pub. No.
547: 37-42.
4.98 Boschetti, Mario M., 1966, Sevin Residues in Water and Topsoil
Following its use on a Watershed Area, Pesticide Board, Common-
wealth of Mass., Pub. No. 547: 52-62.
4.99 Felley, Donald R., 1970, The Effect of Sevin (1-naphthyl N-methyl-
carbamate) as a Watershed Pollutant, Unpub. PhD thesis. College
of Forestry, Syracuse.
4,100 Christie, A.E., 1968, Insecticides and Algae: Toxicity and Degradation,
Ontario Water Resources Commission Publication Number 27, pp 26.
4.101 Palmer, C.M. and I.E. Maloney, 1955, Preliminary Screening for
Algicides, Ohio Journal of Science, 55: 1-8.
4.102 Butler, P.A., 1965, Commercial Fishery Investigations, U.S. Fish
and Wildlife Circular, Number 167, pp 11-25.
4.101, Muncy, R.J. and A.D. Oliver, 1963, Toxicity of Ten Insecticides to the
Red Crawfish, Promcambarus dark ^Giard), Transactions of the
American Fisheries Society, 92: 423-431.
4.104 Parker, B..L., J.E. Dewey and C.A. Bache, 1970, Carbomate Bioassay
Using Daphnia Magna, Journal of Economic Entomology, 63(3): 710-714.
4.105 Haynes, H.L., H.H. Moorsefield, S.J. Borash and J.W. Keays, 1958,
Toxicity of Sevin to Goldfish, Journal of Economic Entomology, 51(4):
540.
4.106 Johnson, D.W., 1968, Pesticides and Fishes - A Review of Selected
Literature, Transactions of the American Fisheries Society, 97(4):
398-424.
4.107 Pressman, R., 1963, Pesticides. In: McKee, J.E. and H.W. Wolf (ed.),
Water Quality Criteria (2nd ed.), California State Water Quality
Control Board Publication Number 3-A, pp 355-404.
4.108 Henderson, C., Q.H. Pickering and C.M. Tarzwell, 1960, The Toxicity
of Organic Phosphorus and Chlorinated Hydrocarbons to Fish, Trans-
actions of the Second Seminar in Biological Problems in Water Pollution,
U.S. Public Health Service, pp 78-88.
4.109 Burdick, G.E., H.F. Dean, E.F. Harris, J. Skea and D. Colby, 1965,
Toxicity of Sevin (carbaryl) to Fingerling Brown Trout, New York
Fish and Game Journal, 12(2): 127-146.
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4.110 Abou-Donia, M.B. and D.B. Menzel, 1967, Fish Brain Chloinesterase:
Its Inhibition by Carbomates and Automatic Assay, Comparative
Biochemistry and Physiology, 21: 99-108.
4.111 Stewart, N.E., R.E. Milleran and W.P. Breese, 1967, Acute Toxicity
of the Insecticide Sevin and its Hydrolytic Product 1-naphthol to
Some Marine Organisms, Transactions of the American Fisheries
Society, 96: 25-30.
4.112 Menzie, C.M., 1969, Metabolism of Pesticides, U.S. Bureau of Sport
Fisheries and Wildlife Special Sciencific Report, Number 127, pp 487.
4.113 Lichtenstein, E.P., K.R. Schulz, R.F. Skrentney and Y. Tsukano, 1966,
Toxicity and Fate of Insecticide Residues in Water, Archives of
Environmental Health, 12: 199-212.
4.114 Crosby, Donald G., 1969, The Nonmetabolic Decomposition of Pesticides,
in, Annals N.Y. Acad, Sci., 160(1): 82-96.
4.115 Crosby, Donald G., E. Leitis and W.L. Winterlin, 1965, Photodecomposi-
tion of Carbamate Insecticides, Jour. Agr. and Food Chem. 13(3):
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4.116 Chisholm. R.D., and L. Koblitsky, 1947, Effects of Light on DDT
Residues, Agr. Chem. 2(9): 35-37.
4.117 Barthel, W.F., D.A. Parsons, L.L. McDowell and E.H. Grissinger, 1966,
Surface Hydrology and Pesticides, in, Pesticides and Their Effects
on Soils and Water, A.S.A. Special Pub. No. 8: 128-144.
4.118 Felley, Donald R. , 1970, The Effect of Sevin (1-naphthyl N-methyl-
carbamate) as a Watershed Pollutant, Unpub. PhD thesis, College of
Forestry, Syracuse.
4.119 Fleck, Elmer E. and H.L. Haller, 1944, Catalytic Removal of Hydrogen
Chloride from Some Substituted Trichloroethanes, Jour. Amer. Chem.
Soc. 66: 2095.
4.120 Fleck, Elmer E. and H.L. Haller, 1945, Compatability of DDT with
Insecticides, Fungicides and Fertilizers, Ind. Eng. Chem. 37: 403-405.
4.121 Fleck, Elmer E. and H.L. Haller, 1946, Stability of DDT and Related
Compounds, Jour. Amer. Chem. Soc. 68: 142-143.
4.122 Downs, W.C., E. Bordas, and L. Navarro, 1951, Duration of Action of
Residual DDT Deposits on Adobe Surfaces, Science, 114: 259-262.
4.123 Gunther, F.A. and L.R. Tow, 1946, Inhibition of the Catalyzed Thermal
Decomposition of DDT, Science, 104: 203-204.
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4.124 Eichelberger, James W. and J.J. Lichtenberg, 1971, Persistence of
Pesticides in River Water, Env. Sci. and Tech. 5(6): 541-544.
4.125 Alexander, H., 1966, Biodegradation of Pesticides, in, Pesticides and
their Effects on Soils and Water, A.S.A. Special Pub. No. 8: 78-84.
4.126 O'Brien, R.D., 1967, Insecticides, Action and Metabolism, Academic
Press, N.Y., pp 332.
4.127 Randall, A.P., 1965, Evidence of DDT Resistance in Populations of
Spruce Budworm, Choristoneura fumiferana (Clem.) from DDT-sprayed
Areas of New Brunswick, Canadian Ent. 97: 1281-1293.
4.128 Carolin, V.M. and W.K. Coulter, 1971, Trends of Western Spruce Budworm,
and Associated Insects in Pacific Northwest Forests Sprayed with DDT,
Jour. Econ. Ent., 64: 291-297.
4.129 Kaufman, D.D., 1966, Structure of Pesticides and Decomposition by Soil
Microorganisms, A.S.A. Special Pub. No. 8: 85-94.
4.130 Whitehurst, E.E., E.T. Bishop, F.E. Critchfield, G.G. Gyusco, E.W.
Huddelston, H. Arnold and D.J. Lisk, 1963, The Metabolism of Sevin
in Dairy Cows, Jour. Agr. and Food. Chem. 11: 167-169.
4.131 Knaak, J.B., M.J. Tallant, W.J. Bartley and L.J. Sullivan, 1965, The
Metabolism of Carbaryl in the Rat, Guinea Pig and Man, Jour. Agr.
and Food Chem. 13: 537-543.
4.132 Carpenter, C.F., C.S. Weil, P.E. Palm, M.W. Woodside, J.H. Nair III,
and H.F. Smith, Jr., 1961, Mammalian Toxicity of 1-naphthyl N-
methylcarbamate (Sevin Insecticide), Jour. Agr. Food Chem. 9: 30-39.
4.133 Pekas, J.C. and G.D. Paulson, 1970, Intestinal Hydrolysis and Conjuga-
tion of a Pesticidal Carbamate in Vitro, Science (Washington) 170:
3953: 77-78.
4.134 Dorough, H.W., N.C. Leeling and J.E. Casida, 1963, Nonhydrolytic
Pathway in Metabolism of N-methylcarbamate Insecticides, Science
140: 170-171.
4.135 Dorough, H.W. and J.E. Casida, 1964, Nature of Certain Carbamate
Metabolites of the Insecticide Sevin, Jour, Agr. and Food Chem.
12(4): 294-304.
4.136 Price, G.M. and R.J. Kuhr, 1969, The Metabolism of the Insecticide
Carbaryl (1-naphthyl N-methylcarbamate) by Fat Body of the Blowfly
Larva Calliphora erythrocephala, Biochem. Jor. 112: 133-138.
4.137 Kuhi:, R.J. and J.E. Casida, 1967, Persistent Glycosides of Metabolites
of Methycarbamate Insecticides Chemicals Formed by Hydroxylation in
Bean Plants, Jour. Agr. and Food Chem. 15: 814-124.
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4.138 Harris, C.R., 1970, Persistence and Behavior of Soil Inseticides,
in Pesticides in the Soil: Ecology, Degradation and Movement,
International Symposium on Pesticides in the Soil, Michigan State
University.
4.139 Dimond, John B. et al, 1970, DDT Residues in Robins and Earthworms
Associated with Contaminated Forest Soils, Canadian Entomologist,
V. 102, No. 9.
4.140 Yule, W.N., 1970 DDT Residues in Forest Soils, Bulletin of Environ-
mental Contamination and Toxicology, V. 5, No. 2.
4.141 Edwards, C.A., 1970, Persistent Pesticides in the Environment, in
Critical Reviews for Environmental Control (Richard G. Bond and
Conrad P. Straub, Ed) The Chemical Rubber Co., Cleveland, Ohio.
4.142 Heith, J.O. and E.L. Flickinger, 1965, Fate and Persistence of DDT
in a Forest Environment, in Effects of Pesticides on Fish and
Wildlife, U.S. Fish and Wildlife Service Circular 226.
4.143 Wurster, Charles F., Jr., Doris H. Wurster and Walter Strickland,
1965, Bird Mortality After Spraying for Dutch Elm Disease with
DDT, Science, V. 148.
4.144 The Effects of Pesticides on Fish and Wildlife, U.S. Department of
the Interior, Fish and Wildlife Service Circular 226, 1965.
4.145 Edwards, C.A., 1969, Soil Pollutants and Soil Animals, Scientific
American, 88-99.
4.146 Hung, J.B., 1969, Mortality of the Earthworm Lumbricus Terrestris
Following Soil Applications of Insecticides to a Tobacco Field,
J. Economic Entomology, V. 62.
4.147 Thompson, A.R., 1971, Effects of Nine Insecticides on the Numbers
and Biomass of Earthworms in Pasture, Bulletin of Environmental
Science and Technology, V. 5, No. 6.
4.148 Barrett, Gary W., 1968, The Effects of an Acute Insecticide Strep
on a Semi-enclosed Grassland Ecosystem, Ecology, V. 49, NO. 6.
4.149 Barin, Ronald L. and Raymond K. Socke, 1970, Utilization of Cell
Culture Techniques in Carbaryl Metabolism Studies, Bulletin of
Environmental Contamination and Toxicology, V. 5, No. 4.
4.150 Fleck, Elmer E., 1966, Chemistry of Insecticides, in Pesticides
and Their Effects on Soils and Water, Madison, Wisconsin; Soil
Science Society of America.
4 151 Williams, C.H., 1969, Drug - Pesticide Interactions, FDA Papers,
3(7): 14-7.
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-4.152 McLean, A.E.M. and E.K. McLean, 1969, Diet and Toxic.ity,
Brit. Med. Bulletin, 25(3): 278-281.
4.153 Kwalik, D.S., 1971, Anticonvulsant and DDT Residues,
Journal of the American Medical Society, 215(1): 120-121.
4.154 Davies, J.E., W.F. Edmundson, C.H. Carter and A. Barquet, 1969,
Effect of Anticonvulsant Drugs on Dicophane (DDT) Residues on
Man, Lancet, 2(7610): 7-9.
4.155 Fishbein, L., H.L. Falk, J. Fawkes and S. Jordan, 1968,
Metabolism of Pesticide Synergists, Ind. Med. Surg. 37(7): 524.
(Abstract of paper presented at the Sixth Inter-American
Conference of Toxicology and Occupational Medicine,
Miami, Florida, August 26-29, 1968.)
4.156 Falk, H.L. and P. Kotin, 1969, Pesticide Synergists and Their
Metabolites, Annals of the N.Y. Academy of Science,
16(1): 299-313.
4.157 Wershaw, R.L., P.J. Burear and M.C. Goldberg, 1969,
•Interaction of Pesticides with Natural Organic Materials,
Environmental Science Technology, 3(3): 271-273.
4.158 Macek, K.J., C.R. Rodgers, D.L. Stalling and S. Korn, 1970,
The Uptake, Distribution and Elimination of Dietary 14-C-DDT
and 14-C-Dieldrin in Rainbow Trout, Transactions of the
American Fisheries Society, 99(4): 689-695.
4.159 Cain, S.A., 1965, Pesticides in the Environment, with Special
Attention to Aquatic Biology Resources, in: Report on
U.S.-Japan Planning Meeting on Pesticide Research, Honolulu,
Hawaii, pp. 12-18.
4.160 Ferguson, D.E. and C.R. Bingham, 19664 Effects of Insecticides
on Susceptible and Resistant Mosquito-Fish, Bulletin of
Environmental Contamination and Toxicology, 1: 97-103.
4.161 Dugan, P.R., R.M. Pfister and M.L. Sprague, 1 53, Evaluation
of the Extent and Nature of Pesticide and Detergent Involvement
in Surface Waters of a Selected Watershed, New York State
Report No. 10, Part 1.
4.162 Singh, J., 1968, Effect of Caffeine and Pesticide Carbaryl
(1-naphthyl-N-methyl-carbamate) on Female Albino Rats,
Ind. Med. Surg. 37(7): 544.
4.163 Sa^her, R.M., R.C. Metcalf and T.R. Fukuto, 1968,
Propynyl Naphthyl Ethers as Selective Carbamate Synergists,
Journal Agricultural Food Chemistry, 16(5): 779-786.
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4.164 Bakry, N., R.L. Metcalf and T.K. Fukuto, 1968,
Organothiocyanates as Insecticides and Carbamate Synergists,
Journal of Economic Entomology, 61(5): 1303-1309.
4.165 Hayes, W.J., 1969, Pesticides and Human Toxicity, Vol.160,
Arts 1-2, 40-54.
4.166 LaMotte, L.C., 1969, Pesticides and Human Health - A Query,
Entomological Society of America Bulletin, 15: 373-376.
4.167 Westermann, E., 1969, Accumulation of Environmental Agents or
Their Effects in the Body, Environ. Res. 2(5-6): 340-351.
4.168 Durham, W.F., 1971, Significance of Pesticide Residues to Human
Health, J. Dairy Science, 54(5): 701-706.
4.169 Kadis, V.W., W.E. Beitkreitz and O.J. Johasson, 1970,
Insecticide Levels in Human Tissues of Alberta Presidents,
Canadian Journal of Public Health, 61(5): 413-416.
4.170 Pol'chenko, V.I., 1968, DDT as a Health Hazard, Gigienai
Sanit. - Hyg. Sanit., (Translation), 33(3): 403-407.
4.171 Durham, W.F., 1969, Body Burden of Pesticides in Man,
Ann. N.Y. Academy of Science, 160(1): 183-195.
4.172 Kraybill, H.F., 1969, Significance of Pesticide Residues in
Foods in Relation to Total Environmental Stress,
Can. Med. Assn. Journal, 100(4): 204-215.
4.173 O'Leary, J.A., J.E. Davies and M. Feldman, 1970,
Spontaneous Abortion and Human Pesticide Residues of DDT and DDE,
American Journal of Obstet. and Gynecol. 108(8): 1291-1292.
4.174 Rappolt, R.T., D. Mengle, W. Hale, B. Hartman and B. Salmon, 1968,
Kern County: Annual Genetic Input; Blood Dyscrasias; p,p'-DDT
and p,p'-DDE Residues in Human Fat, Placentas with Related
Stillbirths and Abnormalities, Ind. Med. Surg. 37(7): 513.
(Abstract of paper presented at the Sixth Inter-American
Conference on Toxicology and Occupational Medicine, Miami, Florida,
August 26-29, 1968.)
4.175 Polishuk, Z.W., M. Wassermann, D. Wassermann, S. Larzarovici, and
L. Tomatis, 1970, Effects of Pregnancy on Storage of Organo-
chlorine Pesticides, Arch. Environmental Health, 20(2): 215-217.
4.176 Komarova, L.I., 1970, DDT Excretion with the Breast Milk and Its
Effect on the Body of the Mother and Child, Pediatr. Akusherstvo
Hinekol, 35(1): 19-20.
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4.177 Kontek, M., S. Kubacki, S. Paradowski and B. Wierzchowiecka, 1971,
Badanie Zawartosci Pestycydow Chlororganicznych w Mleku Kobiecym
(Study of the Level of Organochlorine Pesticides in Human Milk),
Pediat. Pol, 46(2): 183-188.
4.178 Phillips, W.E.J., W.R. Ritcey, T.K. Murray and K. Hoppner, 1971,
A Note on the Concentration of Organochlorine Pesticides in
Human Liver in Relation to Vitamin A Status, Bull. Environ.
Contain. Toxicol. 6(1): 17-19.
4.179 Paramonchik, V.M., 1968, The Functional State of the Liver in
Workers Engaged in the Manufacture of Certain Organochlorine
Poisonous Chemicals, Sov. Med. 31(3): 62-65.
4.180 Krasniuk, E.P., N.G. Loganovskii, E.I. Makovskaia and M.B. Rapporport,
1968, Functional and Morphological Alterations in the Kidneys
Following the Effect of DDT on the Organism, Sov. Med. 6: 38.
4.181 Paramonchik, V.M. and V.I. Platonova, 1968, The Functional State
of the Liver and Stomach in Persons Exposed to the Action of
Organochlorine Chemical Poisons, Gigiena Truda i Zabolevaniya,
12(3): 27-31.
4.182 Radomski, J.L., W.B. Dichman and E.E. Clizer, 1968, Pesticide
Concentrations in the Liver, Brain and Adipose Tissue Terminal
Hospital Patients, Food Cosmet. Toxicol. 6(2): 209-220.
4.183 Platonova, I., 1969, Some Indices of the Functional State of the
Stomach in Workers Under the Condition of Organochlorine
Poisonous Chemical Manufacture, Gigiena i Truda; Resp. Mezhved.
Sb. (Kiev), No. 1, i.e. No. 5: 135-137.
4.184 Krasniuk, E.P. and V.I. Platonova, 1969, Functional Disorders of
the Stomach Under the Prolonged Effect of Organochlorine Chemical
Poisons, Vrachebnoe Delo No. 9: 99-101.
4.185 Loganovskii, N.G., 1968, The Functional State of the Kidneys in
Workers Under the Prolonged Action of Organochlorine Chemical
Poisons, Vrachebnoe Delo No. 10: 82-86.
4.186 Loganovskii, N.G., 1969, The State of Gulmerular Filtration and
Tubular Reabsorption in the Kidneys in Persons Long Exposed to
the Action of Organochlorine Chemical Poisons, Gigiena i Truda:
Resp. Mazhved. Sb. (Kiev), No. 1, i.e. No. 5: 149-154.
4.187 Krasniuk, E.P., E.J. Makovskaia, M.B. Rappoport and V.M. Paramonchik,
1968, Changes in the Liver Under the Action of DDT: Clinical
Observations and Pathomorphological Studies, Gigiena Truda i
Prof. Zabolevaniya, 12(12): 20-22.
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4.188 Morgan, D.P. am! C.C. Roan, 1969, Renal Function in Persons
Occupationally Exposed to Pesticides, Arch. Environ, Health,
19(5): 633-636.
4.189 Edmundson, W.F., J.E. Davis and M. Cranmer, 1970, DDT and DDE in
Blood and DDA in Urine of Men Exposed to 3 % DDT Aerosol,
Public Health Report (U.S.), 85(5): 457-463.
4.190 Perron, R.C. and B.F. Barrentine, 1970, Human Serum DDT Concentra-
tion Related to Environmental DDT Exposure, Arch. Environmental
Health, 20(3): 368-376.
4.191 Edmundson, W.F., J.E. Davis, B.A. Nachman and R.L. Roeth, 1969,
p,p'-DDT and p,p'-DDE in Blood Samples of Occupationally
Exposed Workers, Public Health Report, 84(1): 53-58.
4.192 Krasniuk, E.P., 1969, Ballistocardiographic Changes in Those
Working with Organochlorine Compounds, Gigiena i Truda; Resp.
Mezhved. Sb. (Kiev), No. 1, i.e. No. 5: 203-207.
4.193 Greim, H., 1970, Toxicity and Therapeutic Utility of DDT and Its
Metabolites, Aerztl. Forsch. 24(7): 197-201.
4.194 Hayes, W.J., W.E. Dale and C.J. Pirkle, 1971, Evidence of Safety
of Long-Term High, Oral Doses of DDT for Man, Arch. Environmental
Health, 22(1): 119-235.
4.195 Hayes, W.J., 1960, Pesticides in Relation to Public Health,
Annual Reviews of Entomology, 5: 379-404.
4.196 Nichols, J.O., 1961, The Gypsy Moth in Pennsylvania — Its History
and Eradication, Pennsylvania Department of Agriculture Miscel-
laneous Bulletin No. 4404, pp. 1-82.
4.197 Carpenter, C.P., C.S. Weil, P.E. Palm, M.W. Woodside, J.H. Nair III,
and H.F. Smyth, 1961, Mammalian Toxicity of 1-Naphthyl-N-
Methylcarbamate (Sevin Insecticide), Agricultural and Food
Chemistry, 9(1): 30-39.
4.198 Farago, A., 1969, Suicidal, Fatal Sevin (1-Naphthyl-N-Methylcarbamate)
Poisoning, Archiv. Toxicol. 24(4): 309-315.
4.199 Main, A.B., 1969, Kinetics of Cholinesterase Inhibition by
Organophosphates and Carbamate Insecticides, Can. Med.-Assn.
Journal, 100(4): 161-167.
4.200 Anon., 1968, More Light on Carbamates, Food Cosmet. Toxicol. 6(3):
395-396.
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4.201 Kuzminskaya, V.A., 1968, Effects of DDT and Sevin on the Content
and Metabolism of Phospholipids in Warm-Blooded Tissues,
Farmak, Toksikol, 31(5): 609-612.
4.202 Anina, I.A., 1968, The Effect of Carbamic Acid Derivative Pesticides
on Nucleic Acid Metabolism in the Rat Liver and Spleen,
Byul. Eksperimem. Biol. Med., 66(10): 46-48.
4.203 Rybakova, M.N., 1968, The Effect of Certain Pesticides on the
Hypophysis and Its Gonadotropic Function, Gigiena i Sanit.
33(11): 27-31.
4.204 Boyd, E.M. and C.J. Krijnen, 1969, The Influence of Protein Intake
on the Acute Oral Toxic:' .y of Carbaryl, Journal Clin Pharmacology,
9(5): 292-297.
4.205 Strother, A., 1970, Comparative Metabolism of Selected N-
Methylcarbamates by Human and Rat Liver Fractions, Biochem.
Paramacol. 19(8): 2525-2529.
4.206 Smalley, H.E., J.M. Curtis and E.L. Earl, 1968, Teratogenic Action
of Carbaryl in Beagle Dogs, Toxicol. Applied Pharmacol. 13(3):
392-403.
4.207 Knaak, J.B. and L.J. Sullivan, 1967, Metabolism of Carbaryl in the
Dog, J. Agr. and Food Chem. 15(6): 1125-1126.
4.208 Knaak, J.B., M.J. Tallant, S.J. Kozbelt, and L.J. Sullivan, 1968,
The Metabolism of Carbaryl in Man, Monkey, Pig and Sheep,
J. Agr. and Food Chem. 16(3): 465-470.
4.209 Mrak, E.M., 1969, Report of the Secretary's Commission on Pesticides
and Their Relationship to Environmental Health, U.S. Department
of Health, Edurition and Welfare, GPO-0-371-074, pp. 667.
4-R?
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A-5
LAWS AND REGULATIONS CONCERNING THE USE AND SALE OF
PESTICIDES IN NEW YORK STATE
This section presents a description and distillation of the current
laws of New York pertaining to the use and sale of pesticides. While these
laws are necessary to prevent environmental damage, they are not totally adequate.
Specific inadequacies are identified in the first part of this Section; the
second part discusses a rationale for extending the scope of pesticide laws.
A-5.1 Current New York State Laws
The primary law in New York governing the use and sale of pesticides
is found in the Environmental Conservation Law, which became effective
1 July 1970. This law created a Department of Environmental Conservation and
transferred the responsibility for the control, sale and use of pesticides
from several agencies within the state government to the new department of
Environmental Conservation.
The Conservation Law, Public Health Law and the Agriculture and
Market Law were amended to transfer the authority governing the use and sale of
pesticides to the new Environmental Conservation Department.
Prior to the enactment of the Environmental Conservation Law, all of
the laws, rules, and regulations of the State of New York relative to the sale
and use of pesticides were directed towards safety and control, with only
implicit attention given to water pollution problems other than those resulting
from specific and identifiable sources. The broader question of pesticide runoff
to natural streams resulting from large area treatment was, for example, not
explicitly addressed until the enactment of the Environmental Conservation Law.
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This new law takes full cognizance of the entire problem of enviornmental
conservation and addresses solutions to the problems as well as regulations for
day-to-day control.
The following is quoted from the Environmental Conservation Law to
illustrate the concern of the law for the total problem.
Chapter 140, Laws of New York State, 1970, Article I, paragraph 14.
"Paragraph 14. Functions, powers and duties of department and commissioner
It shall be the responsibility of the department, in accordance
with such existing provisions and limitations as may be elsewhere set
forth in law, by and through the commissioner to carry out the en-
vironmental policy of the state set forth in section ten of this article.
In so doing, the commissioner shall have power to:
1. Coordinate and develop policies, planning and programs related
to the environment of the state and regions thereof.
2. Promote and coordinate management of water, land, and air resources
to assure their protection, enhancement, provision, allocation, and
balanced utilization consistent with the environmental policy of
the state.
3. Provide for the propagation, protection, and management of fish
and other aquatic life and wildlife and the preservation of en-
dangered species.
4. Provide for the care, custody, and control of the forest preserve.
5. Provide for the protection and management of marine and coastal
resources and of wetlands, estuaries and shorelines.
6. Foster and promote sound practices for the use of agricultural
land, river valleys, open land, and other areas of unique value.
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7. Encourage industrial, commercial, residential and community develop-
ment which provides the best usage of land areas, maximizes envir-
onmental benefits and minimizes the effects of less desirable
environmental conditions.
8. Assure the preservation and enhancement of natural beauty and man-
made scenic qualities.
9. Provide for prevention and abatement of all water, land and air
pollution including but not limited to that related to particulates,
gases, dust, vapors, noise, radiation, odor, nutrients and heated
liquids.
10. Promote control of pests and regulate the use, storage and disposal
of pesticides and other chemicals which may be harmful to man,
animals, plant life, or natural resources.
11. Promote control of weeds and aquatic growth, develop methods of
prevention and eradication, and regulate herbicides.
12. Provide and recommend methods for disposal of solid wastes, in-
cluding domestic and industrial refuse, junk cars, litter and
debris consistent with sound health, scenic, environmental
quality, and land use practices.
13. Prevent pollution through the regulation of the storage, handling
and transport of solids, liquids and gases which may cause or
contribute to pollution.
14. Promote restoration and reclamation of degraded or despoiled areas
and natural resources.
15. Encourage recycling and reuse of products to conserve resources
and reduce waste products.
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16. Administer properties having unique natural beauty, wilderness
character, or geological, ecological or historical significance
dedicated by law to the state nature and historical preserve.
17. Formulate guides for measuring presently unquantified environmental
values and relationships so they may be given appropriate con-
sideration along with social, economic, and technical considerations
in decision-making.
18. Encourage and undertake scientific investigation and research on
the ecological process, pollution prevention and abatement, recycling
and reuse of resources, and other areas essential to understanding
and achievement of the environmental policy.
19. Assess new and changing technology and development patterns to
identify long-range implications for the environment and encourage
alternatives which minimize adverse impact.
20. Monitor the environment to afford more effective and efficient
control practices, to identify changes and conditions in ecological
systems and to warn of emergency conditions.
21. Encourage activities consistent with the purposes of this chapter
by advising and assisting local governments, institutions, industries,
and individuals.
22. Undertake an extensive public information and education program to
inform and involve other public and private organizations and
groups and the general public in the commitment to the principles
and practices of environmental conservation and development programs
for the teaching by others of such principles and practices.
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23. Cooperate with the executive, legislative and planning authorities
of the United States, neighboring states and their municipalities
and the Dominion of Canada in furtherance of the policy of this
state as set forth in section 10 of article two of this chapter.
24. Exercise and perform such other functions, powers and duties as
shall have been or may be from time to time conveyed or imposed
by law, including, but not limited to, all the functions, powers
and duties assigned and transferred to the department, department
of agriculture and markets, and office for local government in
the executive department by a chapter or chapters of the laws
of nineteen hundred seventy."
While the new Environmental Conservation Law places the responsibility
for the sale and use of pesticides within the Department of Environmental Con-
servation, specific rules and regulations pertaining to pesticides are to be
found in the Agriculture and Markets Law, the Public Health Law and the
Conservation Law.
Portions of these relevant laws and regulations are abstracted and
discussed below.
Article 11 of the Agriculture and Markets Law
All pesticides, except those Federally registered, must be registered
with the State. The Commissioner of the Department of Environmental Conservation
may refuse to register a pesticide. Pesticides are registered on a restricted or
non-restricted use basis. The non-restricted use pesticides may be sold and
used without restriction providing such use is in accordance with the registration
and the label, whereas restricted use pesticides may be distributed and resold
only by holders of a Commercial Permit. The primary purpose of the Commercial
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Permit appears to be to maintain control of the pesticide in the distribution
chain since there is no requirement for the holder of the permit to have any
knowledge in the field of pesticides.
In addition, purchase permits are required for the purchase of all
restricted use pesticides. The primary purpose of this permit appears to be to
limit the sale of restricted use pesticide to qualified persons and to control
the application or use of such pesticides.
Article 11A of the Agriculture and Markets Law
Article 11A provides for the regulation of custom applicators. Custom
applicators must be registered by the Commissioner, Department of Environmental
Conservation, for any application of pesticides for others. This rule applies to
both non-restricted and restricted use pesticides.
The primary purpose of this regulation appears to be the registration
of all applicators so as to have records of usage, to control areas of application
and to set some standard of competence on the part of the applicator, although the
competence aspect of the regulation appears to be weak and not well defined.
Part 154.4 of Rules and Regulations
Part 154.4 of the Rules and Regulations (Ref. Circular #865, Department
of Environmental Conservation) is of particular interest to this study and is
quoted below.
"154.4 Restriction on the Application of Pesticides by Commercial
Application.
(a) Pesticide application to areas adjacent to crops,
pasturage, lands and waters shall be such that
contamination does not occur."
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Official Compilation of Codes, Rules and Regulations of the State of
New York
Under Part 155, "Rules and Regulations Relating to Restricted Pesticides,"
the restricted use pesticides are defined and listed. In addition, the conditions
under which these materials may be handled and used are delineated.
Environmental Conservation Law
Under Section 77 certain functions of the health department, air pollution
control board, and pesticide control board are transferred to the Department of
Environmental Conservation:
"All of the functions and powers possessed by and all the obligations
and duties of the department of health, commissioner of health, and
the air pollution and pesticide control boards pertaining to or
connected with sewage service in realty subdivisions; drainage of
sewage service into waters; water pollution control; air pollution
control; planning for collection, treatment and disposal of refuse;
and recommendations for controlling the use, transportation, storage
and disposal of pesticides, approval of marine toilet pollution control
devices and establishing effluent standards therefore, more particularly
described in titles two and three of article eleven, article eleven-A,
eleven B, and twelve C, sections thirteen hundred-a, and thirteen
hundred-B, title nine of article thirteen and article sixteen of the
public health law and section thirty-three-c of the navigation law,
including the administration of state aid for local expenditures therefor,
are hereby transferred and assigned to, assumed by and devolved upon
the department of environmental conservation."
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Another law of principal interest to this study is Article. 12,. "Water Pollutic
Control" of the Public Health Law. While Title 1 of Article 12, "General Provisions
and Public Policy" address the question of pure water, it is primarily concerned
with discrete inputs of waste materials to water bodies. It does not directly
address the question of runoff water into natural drainage systems which have
picked up pesticides or other potential pollutants which were applied to an area
for control over the area. However, the Department of Environmental Conservation
has taken a major step towards the effective control of pesticides or other
chemicals entering the waters of New York State with the issuance of three orders
as follows:
(1) Order Establishing Regulations Governing the Use of Chemicals for
the Control of Elimination of Aquatic Vegetation published as Part 609 of the
Official Compilation of Codes, Rules, and Regulations of the State of New York.
(2) Order Establishing Regulations Governing the Use of Chemicals
for the Control or Extermination of Undesirable Fish, published as Part 610 of the
Official Compilation of Codes, Rules and Regulations of the State of New York.
(3) Order Establishing Regulations Governing the Use of Chemicals
for the Control or Elimination of Aquatic Insects, published as Part 613, of
the Official Compilation of Codes, Rules and Regulations of the State of New York.
Each of these regulations requires permits for the treatment of water
and limits the choice of chemicals to those listed in the regulations.
However, the regulations do not require the holder of a permit to have any
special training or knowledge even though the permit holder is responsible for any
inaccuracies in the required registration data or any damage resulting from the
chemical treatment.
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Therefore, while the laws and regulations of New York relative to
pesticides and their use evidence design toward responsible use within the en-
vironment, we believe that the laws do not require sufficient proof of either
user competence or equipment applicability.
The discussion which follows presents some considerations relative to
the possible formulation of laws to amend this insufficiency.
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A-5.2 Considerations in the Formulation of Laws, Rules and
Regulations Pertaining to the Research, Development,
Handling and Use of Pesticides
Society, in general, requires laws, rules and regulations for the people
of that society to live in harmony with each other. Through law, the rights and
priviledges of the individual are protected, and, of equal importance, the less
fortunate members of society are assisted by the more fortunate members of
society.
The great majority of our laws, rules and regulations, hereafter
referred to simply as laws, are developed "after the fact". Hence, they are designed
to deter, stop, or control a practice, which is considered to be in discord with
the common good. Such laws are, therefore, addressed to a situation which has
advanced to a point where corrective action must be taken to protect the rights
and priviledges of the individual or to establish an equitable condition. In one
sense then, laws may be looked upon as disabling a segment of the society from
engaging in practices which are abusive to another segment of society, rather than
as enabling society in general to improve its posture in a truly anticipatory
fashion. Experience has shown us that our laws have considerable difficulty in
dealing with future conditions, except in the most general of terms, since our
technology and the environment in which we use the technology are subject to
constant change. It is difficult to generalize in this area, but it is probably
fair to state that most of our laws tend to relate to an existing situation and,
therefore, have great difficulty in providing adequate protection to new and
unforeseen situations.
The broad field of pesticides is most interesting in this regard. Laws
have been enacted to control the handling and use of pesticides only after
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considerable use of these materials has made clear that some level qf control
was needed. The laws appear to have been enacted in reaction to a situation and
as a result, may not serve to deter the development of new and hazardous situations
related to the current use of pesticides.
Laws can never be an effective substitute for competence, good judgment,
and a deep concern for the total impact of an act or procedure on the part of
personnel engaged in activities which are addressed by the laws. This statement
points to the need for examining and licensing personnel who wish to engage in
activities which are proven to have the potential for infringement on the rights
and priviledges of others. Licensing may be on the local, state and federal level
depending upon the nature and scope of influence of the activity.
We can find many examples of laws and licenses at all levels of govern-
ment. The laws, rules, regulations and licensing requirements of the Federal
Communications Commission (FCC) may serve to illustrate this point.
Among the responsibilities of the FCC is the control of the use of the
electromagnetic spectrum so as to achieve the maximum benefit to society from the
finite bandwidth which is available. Since electromagnetic radiation knows no
political boundaries, the FCC was structured on a national level and provided with
international agreements reached at worldwide conventions. The practical uses of
the electromagnetic spectrum, the equipment and techniques involved, and the
actual extension of the spectrum itself into ever shorter wavelengths, has required
truly visionary rules and regulations so as to protect the rights of all concerned
but which at the same time, do not stifle technological development.
The problems allied to the use of the electromagnetic spectrum parallel
the problems allied to the use of pesticides, namely,
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(1) Electromagnetic radiation and pesticides, once released,
propogate or disperse in accordance with natural law.
(2) The use of pesticides and the electromagnetic spectrum are con-
stantly on the increase.
(3) Research is constantly developing new pesticides just as research
is evolving new equipment and techniques for use in the electro-
magnetic spectrum
It is axiomatic that laws can be no more effective than the effectiveness
of personnel involved. Herein lies the great difference between the laws relating
to electromagnetic radiation and laws relating to pesticides.
The FCC has its laws as do the control agencies for pesticides, but, the
FCC requires the purveyors of the art to be thoroughly examined and qualified as
to fundamentals. These "user personnel" bear full and professional responsibility
to conduct all of their acts and operations within the intent of the law. In
addition, equipment is licensed for use only after it has been qualifed and a
determination made that it functions within the law. Normally, licensed equipment
must be under the direct supervision of a licensed operator.
These views on pesticide applicator licensing may be tempered to the point
where the requirement for a license could be dropped if it could be demonstrated that
no harm will result through irresponsible pesticide use. Again, let us look to the
FCC. A nonlicensed operator may purchase and use a 100 milliwatt radio transmitter
operating in the Citizen Band (CB). In this instance the band is very restricted,
the power very limited and the equipment is very carefully examined and qualified
for this use. Over-the-counter-pesticides which would present no hazard to the
user, which are very specific and which would have a very limited area of
influence can be seen to closely parallel the CB situation. The pesticide
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itself, as well as the packaging and dissemination mode must, of course,-be
thoroughly developed, tested, and qualified for this special case of use by a
nonlicensed operator.
In summary, we believe that the laws and regulations governing the use
and sale of pesticides, while comprehensive, are not sufficient to prevent envir-
onmental damage. This assertion is based on our belief that these laws and
regulations do not require sufficient proof of competence on the part of the
users of pesticides and do not require sufficient test, evaluation and licensing
of the pesticide, and the equipment used to apply the pesticides.
It is emphasized that our discussion has not been designed to explicitly
propose the national examination and licensing of pesticide applicators at the
expense of other alternatives. Rather, it has been advanced in the recognition
that the social and economic importance of pest control and the absolute magnitude
and characteristics of the problem are highly variable from state to state and
from time to time. As a result, approaches or techniques adopted by one state
can lead to direct conflict with approaches adopted by a neighboring state. Pest
control can be best studied and implemented on the basis of geographical areas
determined by the pest itself, rather than by state boundaries. Such pest
management procedures as quarantines, buffer zones, criteria for treatment and
materials to be used may be applied in a much more effective manner when specific
problems are treated on an area of involvement basis, and in consideration of
the national import.
Since a large percentage of the pesticides in use today are applied
by units of government, laws and licensing should be applicable to government as
well as nongovernment users. This has not always been the case in laws and
licenses. It bears special attention in this instance, and points to the
advisability of federal laws and licenses.
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A-6.
ALTERNATIVES TO CHEMICAL CONTROL
The objectives of this portion of the study were to identify and
analyze:
(1) feasible methods of forest pest control as an alternative to
the use of chemical pesticides and,
(2) chemical pesticide uses considered to be essential and for which
no suitable alternative is available.
Before considering specific alternatives to chemical control of forest
pests, it is important to recognize that different criteria are used to "define"
control. These criteria reflect not only differences in training (scientist
vs. layman) but also differences in expectations of profession-related gains and
most importantly, the differences in impact on individuals, states or agencies,
given a lack of pest control.
DeBach " defines control simply as the maintenance of a more or less
fluctuating population density within certain definable upper and lower limits
over a period of time by the action of abiotic and/or biotic environmental factors.
The upper and lower limits, or the density, will change appreciably only if the
actions of the regulatory factors are changed, or if certain ones are eliminated
or if new ones are added. This control may be natural or introduced.
Natural control (or other nonchemical alternatives) may or may not
regulate the population of a specific insect within a time frame consistent with
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man's interest and chemical pesticide measures may be invoked to counter this
situation.
Consider the case of forest insect defoliators. Reliance on a parti-
cular type of control will be largely dictated by the amount of tree defoliation
that can be accepted. This criterion considers not only the short-term loss
(lack of leaves) but also the time over which the concomitant loss has to be
accepted and, hopefully, the longer-term loss associated with tree mortality,
for example.
In this illustrative case, a nominal set of three criteria are out-
lined. These are that the criterion of control is:
(1) little or no defoliation,
(2) defoliation occurs and concomitant short-term (e.g., 3 years)
loss is accepted and,
(3) defoliation occurs and concomitant long-term (e.g., more than 3
years) loss is accepted.
Therefore, depending upon the criterion selected as being appropriate, both the
type of control and the degree to which the control is invoked will be dictated
by the impact that defoliation manifests. Consider the following examples:
(1) Little or no defoliation implies not only that the "trees must
remain green" but also that larvae (caterpillars) will not be present. In such
cases, rapid and relatively complete control is required and the use of chemicals
may be the only appropriate control agent. Examples where such a control criterion
could be considered as appropriate are resort areas, public camp and picnic areas
and forested urban communities. Since resort areas are dependent upon vacationers
for income, the lack of leaves on trees and/or presence of numbers of caterpillars
will have a serious impact on summer vacation business. The same can be said for
public campgrounds and picnic areas. In addition, however, it may be highly'desirabl
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to kill the larvae to preclude egg mass transport to uninfected regions by trailer
transport.
Forest-urban communities with susceptible tree types present a
particular problem in that the manicured conditions of the groundcover along with
the presence of household pets effectively destroys the habitat of beneficial
predators and parsites. Here, too, the high value placed on each tree and the
potential financial loss in removing and replacing lost trees demands rapid
protection. Further, the nuisance associated with larvae such as the gypsy
moth (frass, staining of house paint, and known human dermal reactions) aggrevate
the citizens to exert political pressures on those in charge of pest control
operations.
(2) Defoliation and concomitant short-term loss is accepted implies that
either the pest will disappear or will, as a minimum, stabilize to an acceptable
level of damage. Much of the northeastern forested lands are placed within this
category. Whether or not forested acreage is considered in this category will,
however, vary from state to state as the dependence upon a forest economy varies.
Natural control infers that there are a series of checks and
balances that regulate insect populations and explains why native insects only
periodically attain pest status. Even when this occurs, however, the infestation
of a native insect can be expected to collapse in a relatively short time (3 years)
due to the effects of starvation, and the buildup of disease, natural parasites
aau ^redators. Within such native pest infestations, certain recognized high-use
areas, such as a sugar bush, will be treated with chemicals to prevent serious
economic loss.
An introduced pest such as the gypsy moth presents a different
problem, since it arrives without its natural biotic control agents. Although
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there is considerable disagreement between authors on the subject of theory of
population control concerning the role that the various environmental factors
f\ 9 ft "}
play in controlling insect populations (Milne, ' Thompson, " and Andrewartha
& Birch, " to name a few) it is generally accepted that the introduction and
establishment of the natural enemies (.parasites, predators and pathogens) of an
introduced pest is a logical and beneficial control method. However, the ease
with which these natural control agents can be introduced and established is much
more difficult than with native pest outbreaks, and may not be consistent with the
period over which losses attributable to defoliation can be tolerated.
(3) Defoliation and long-term loss is accepted could include remote,
low value areas where the apparent value of the woodlands is not clear. Two
basic factors must be borne in mind: first, such areas may serve as a source
of infestion to land-use areas included under the preceding control criteria;
secondly, the apparent low value of a particular woodland plot today will not,
necessarily, have the same apparent low value at some future date. Increase in
woodland value could arise, for example, by increased pressures for recreational
facilities and/or watershed development.
The availability and use of nonchemical alternatives are different for
native and non-native pest infestations. Of singular importance is the ease with
which biological control can be invoked. Accordingly, the following discussion
on pest-control alternatives is presented in two parts identified as native and
non-native (i.e., introduced pest as the gypsy moth) forest pest infestations.
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A-6.1 Native Pest Infestations
In spite of the fact that there has been and is extensive use of
pesticides, evidence demonstrates that New York relies on natural processes to
combat and control native forest pest infestations.
In 1952, the Forest Tent Caterpillar defoliated about 3.5 million acres
of forested land. Of this total, 500,000 defoliated acres were noted as
"complete" ' . The following year about 7.5 million acres were defoliated. In
1954, about 15.3 million acres were measureably defoliated. No further defoliation
is mentioned for this pest until six years later, 1960. Table 6.1 lists these
figures, presents numbers of acres either completely or heavily defoliated, and
the number of acres that were chemically treated in response to this infestation.
Table 6.1
FOREST TENT CATERPILLAR DEFOLIATION AND
CONCOMITANT PESTICIDE TREATMENT
YEAR
1952
1953
1954
1955-59
1960
ACRES DEFOLIATED
TOTAL HEAVY
3,500,000 500,000
7,489,049 919,834
15,321,047 2,007,447
NOT MENTIONED
24,425 5,000
ACRES TREATED
WITH PESTICIDE
1,000
1,800
3,200
SOME IN 1955 ONLY
0
The demise of this infestation of Forest Tent Caterpillar was a com-
bination of factors as climate, starvation and the presence and buildup of
predators, parasites and pest disease. The important point is that chemicals
were not extensively used and that New York relied on biological control
mechanisms to halt the ravages of the pest. This reliance on biological control
is more than mere forest pest control philosophy; it is operational philosophy.
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The following is quoted from "Saddled Prominent".
"This pest often causes about three years of heavy defoliation before
such natural controls as insect parasites, predators, birds, and
rodents severely reduce their numbers. Starvation and disease
also bring an end to outbreaks. However, during outbreaks in
valuable stands such as sugar bushes, high-value commercial
woodlands, or high-use recreational areas, artificial control
may be necessary to prevent serious injury to trees."
In 1967, Saddled Prominent caused light-to-moderate defoliation of
39,000 acres of hardwoods; principally beech and sugar maple. In their annual
report, the Bureau of Forest Insect and Disease Control noted a "buildup coming".
The next year 763,955 acres were defoliated. Of this total, 89,195 acres were
classified as heavily defoliated. By 1969, 953,575 acres were defoliated. In
this same year, New York treated about 12,000 acres of high-use land. In regard
to this modest treatment, Risley " wrote:
"With any heavy infestiation of this magnitude a certain amount
of public pressure is expected. After a thorough analysis of
the situation the Conservation Department decided to treat sugar
bushes and State high-use areas. These areas were chosen because
the sugar bush industry stands to lose the most from this infes-
tation as well as State areas which received much public-use. All
areas to be treated in this control program were examined in the
spring of 1969 to make sure that they supported a pupal count of
0.5 per square foot. The sampling technique used in these ateas
was also developed by the Applied Forestry Research Institute. The
Department used this best biological information available in
determing whether the areas required chemical control".
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In 1970, 3 years after the outbreak, the Saddled Prominent defoliated
88,850 acres, which is less than 10% of the previous year. It was noted in the
annual report of the Conservation Department that 49,000 acres had been scheduled
for Sevin treatment, but that the treatment was cancelled due to population
collapse.
In the 1971 Spray Report issued by the Bureau of Forest Insect and
Disease Control, New York Department of Environmental Conservation, the following
quote is provided relative to Saddled Prominent Control:
"This year's spraying has been cancelled, because of natural
biological controls. Areas in District #12 and #1 are being watched
for buildup and defoliation. No spraying."
It is also interesting to note that the 1971 Defoliation Report issued
for New York State showed that the Cherry Scallop Shell Moth defoliated 166,500
acres. Of this total, all but 1,000 acres were 75 to 100 % defoliated, and no
chemical control treatments were used.
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A-6.2 Non-native Pests
It has been pointed out in earlier portions of this report that the
forest pest in New York receiving virtually all of the chemical pesticide
treatment is the gypsy moth, Porthetria dispar. Accordingly, the discussion which
follows reviews the various alternatives which have been used instead of chemical
pesticides. These alternatives include:
(1) silvicultural techniques,
(2) genetic controls,
(3) behavorial controls,
(4) traps control,
(5) biological controls, and
(6) direct controls.
An overview of these control techniques is presented. Following this overview, two
elements are discussed in somewhat greater detail. The first of these is a dis-
cussion of the current efforts being undertaken by the New Jersey Department of
Agriculture in the biological control program for gypsy moth in that state. The
second control element presented in detail, examines the historical use of man-
power in the direct control of this introduced pest during the late 1800's up
through the start of World War II. Presentation of this detail is warranted
since, during that period, there was less reliance on the use of chemical pesti-
cides. This was partly due to the lack of economic methods of pesticide appli-
.cation, i.e., aerial application, that we have availed ourselves of since 1945.
Since all of the discussion focuses on gypsy moth control, a capsule
of its history, life cycle and habits is initially presented to assist in under-
standing both the development and usefulness of the various control measures.
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A-6.2.1 Gypsy Moth - Porthetria Dispar
History
The gypsy moth is a foreign insect that was accidentally released near
Boston, Massachusetts in 1869. Without its natural effective enemies to contain
it, and finding an abundance of favored food trees, the moth has spread rapidly
and now inhabits most of New England, eastern New York and Pennsylvania, most
of New Jersey and threatens the vast oak forests of the entire eastern United States.
The moth was first discovered in the eastern part of New York State in
1911 and, in spite of repeated attempts at eradication, it is now found throughout
the eastern half of the state. As a matter of review, during this year this
pest defoliated about 480,000 acreas in New York. Further, an additional 250,000
acres that were infested were chemically treated.
Life Cycle
The gypsy moth goes through one generation a year in the four stages
shown in Figure 6.1.
FIGURE 6.1
LIFE CYCLE OF GYPSY MOTH
Egg
Larvae
Pupa
Adult
OCT. to MAR.
APRIL
MAY
JUNE
JULY
AUG.
SEPT.
The period of emergence and the length of time spent in each of the stages
depends on the locality, weather, pest population density and amount of available
food.
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a. Egg Stage The insect overwinters in the egg stage in flattened oval
clusters approximately 1" long by 0.5" wide and averaging about 400 eggs. The
cluster is covered with yellowish hair from the abdomen of the female and is
deposited near or on the ground on rubble, stones, walls, bark, etc. If deep,
moist, ground cover is not available, eggs are usually laid in protected spots
on the lower portion of tree trunks.
b. Larval Stage The eggs hatch with warm weather in the spring, usually
in late April or early May. Hatching may continue over a period of several
weeks but peak hatching usually occurs within a week. If weather is favorable,
newly hatched larvae forage; otherwise they stay around egg clusters until
conditions become favorable. Larvae seek food through random searching and can
live about a week without feeding.
Larvae up through the third instar feed by day and rest at night. With the
fourth instar this pattern reverses and larvae feed at night and descend to cool
protected places for rest during the day. (It is during this period that chemical
treatment is normally applied to the tree foliage.)
The male larve normally go through five instars while the female
goes through an additional or 6th instar.
During epidemic conditions, the feeding rhythm pattern of all instars
changes and larvae may feed continuously.
Fully grown caterpillars are from 1.5 - 2" long, with a brownish or gray
background color. There are three light stripes along the back. Each segment
except the first has a pair of tubercles; the first five pairs are blue; the last
six brick red.
c. Pupal Stage The gypsy moth pupa is a typical dark brown lepidopterous
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pupa that is never enclosed in a cocoon. It is attached to objects with a few
silken threads, usually on or near the ground if cool, moist cover is available.
On '..':, dry, open sites larvae normally pupate in the tree. Pupation lasts from
10 days to 2 weeks and occurs in late June and July.
d. Adult Stage Male moths have slender brown bodies with brown wings
irregularly crossed with dark lines. Wingspread is about 1.5". The female moth
has a heavy, stout body with white wings crossed with dark lines. The wingspread
is about 2.5".
Emergence of adults is at its height in mid-July and continues to mid-August.
The male emerges a few days before the female, is a strong flier, and normally
flies in a zig-zag pattern near the ground. The female, because of her heavy
body, cannot fly and deposits her eggs near where she emerged from the pupal
stage.
Oviposition begins soon after fertilization which occurs within a day or
two after emergence. Soon after egg laying, the female dies. The male
also lives for a short time (about a week) and neither adult take any food.
Dispersal
Inasmuch as female moths are unable to fly, natural dispersal is
through wind dispersion of newly hatched larvae. These are very small, light
and hairy and when disturbed spin down on silken threads and are easily dislodged.
b
Epidemic conditions generate continuous disturbance and fosters this dispersal.
There is also the possibility of older larvae-or bark with eggs attached
being distributed by major storms. Under epidemic conditions with its attending
food shortage, older larvae disperse by crawling but this movement is not great.
The principal means of artificial dispersal is transfer of egg masses
on such items as nursery stock, forest products, stones, junk etc. Caterpillars
have also been known to hitch-hike on cars, trucks, and/or campers passing through
infested areas. 6_H EQ-5025-D-2 (Vol. II)
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A-6.3 Alternative Control Methods
There are many methods of manipulating the forest environment and
insect behavior with the aim of controlling insect populations. Although all
the methods listed below are possible, many are not considered practical due to
constraints of manpower, money, and technical development. Some of the possibilities
6 8
of forest manipulation for insect control have been discussed by S. Graham ,
v ^ u 6-9 D A j 6«10 „ ^ t> u 6-1
K. Graham , R. Anderson and DeBach
A-6.3.1 Silvicultural Techniques
In a managed forest, it has been shown that it is possible to increase
the resistance of a forest to insect damage by regulating the composition, density,
vigor, age distribution, ground cover, and sanitation of that forest. These
actions are directed at manipulation of three main environmental factors: food,
microclimate and organisms antagonistic to the pests.
It is self-evident that stand resistance could be increased, if
economically feasible, by reducing or removing the favored species and/or by
replacing susceptible species with insect-resistant ones. Resistance will also
he increased by any measures that increase the vigor of susceptible trees since
this reduces chances of attack by secondary pests and ensures maximum recuperative
powers after an attack by defoliators.
It is also feasible to manipulate the population of insects in a
forest by silvicultural practice that provides an environment that is either ad-
verse to a pest, insect or is beneficial to the enemies of that insect-. For
examp.les a moiss s deep, ground cover encourages development of a complex of
mammal and insect predators that help control a potential pest that spends some
stage of its life cycle on or in the ground.
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Examples of silvicultural control of the gypsy moth are presented
in a paper by N. Turner ' excerpts of which follow.
"Control of Gypsy Moth by management of woodlands was proposed
by Clement & Munro (1917) and renamed silvicultural control by Behre, Cline,
and Baker (1936)."
"They advocated the removal of susceptible species, especially
those of low commercial value and encouragement of growth of resistant species.
On dry sites, the proportion of oaks, gray birch, and aspen would be reduced
sharply and growth of hemlock and white pine encouraged. On moist sites, the
percentage of favored species could be considerably higher without risking
heavy infestation".
"A large commercial forest has been under such management for
many years. During the course of two outbreaks of Gypsy moth in Norfolk, that
forest has remained relatively free from infestation. Several large tracts
in state forests have had similar management. One tract in an area of heavy
gypsy moth infestation escaped serious damage".
f 19
Nickols , in discussing gypsy moth work in Pennsylvania, notes
that while silvicultural control has held some promise in New England where
coniferous and mixed coniferous-hardwood forest types prevail, it would
not only be impossible but entirely impractical to attempt to change the
vast oak forest cover that predominates over most of the forested area south
OL We,. England. He concludes that silvicultural control will never play more
than a very minor part in the control program.
A-6.3.2 Genetic Controls
A promising alternative to the type of controls previously discussed
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f\ 1 *3
is exemplified by work reported by Knipling ' in using sterile-male technique
to eradicate screw worms.
During the past few years the federal'"'government has been mass rearing
gypsy moths to evaluate this control technique. While results on a laboratory
scale have been reported as promising, problems associated with rearing and
radiating millions of insects still have to be resolved. Then, too, radiated
males have shown a tendency to be less aggressive than normal males, reducing
their competitive efficiency in a natural habitat. Work is continuing to solve
these problems in the hope of providing a "clean" technique to handle infestations
in highly populated areas.
A-6.3.3 Behavioral Controls
In the past few years, the identification and synthesis of members of
the three major groups of hormones which"control insect development give rise to
the hope of developing a new generation of insecticides by disarranging an insect's
normal development, resulting in self-destruction. While this holds exciting
possibilities for the future, nothing, at present, has been done for control of
gypsy moth (Meltzer ' , Schneiderman * ).
In the field of pheromones, that is, chemicals secreted by insects which
influence the behavior of other members of the same species, synthesis of the
female gypsy moth sex attractant has played a major role in control programs
aimea at this pest.
The use of gypsy moth sex attractant provides a unique method of detecting
the presence of this pest in suspect areas. Used with a standard gypsy moth
trap (a hollow cardboard cylinder with hole in either end and lined with sticky
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material to capture the attracted moth), this has provided a relatively cheap
and effective method of scouting to asdettain spread of this insect.
To the present time, traps, as such, have not been widely used as a
direct control but have been the basis of surveys to locate new colonies and to
map the spread of infestion. Using such traps baited with a synthetic female sex
attractant, the federal government annually monitors suspect areas over a large
part of the eastern United States. Special attention is given to such areas as
camp or picnic grounds, and military installations because of the probabilities
that a visitor, arriving from the New England area, might bring gypsy moth eggs
or larvae attached to a house trailer. There is strong evidence that such a
"house trailer vector" was responsible for the recent introduction of this pest
.. . 6.16
into Alabama
The earliest techniques used such a trap baited with a virgin female
gypsy moth. This was soon replaced by the natural sex attractant obtained by
clipping the last two abdominal segments of virgin female moth, extracting
segments with benzene and processing the extract chemically to stabilize the
lure. This procedure entailed field collection of large numbers of female pupae
and allowing the female moth to emerge before segments could be secured. Not
only the expense involved but the difficulty of securing larvae during periods
of low gypsy moth population limited use of this sex attractant.
In 1960 Jacobson and co-workers synthesized gypsy moth sex attractant
sfrM.;ol) and reported its homolog (gyplure) was also a highly active gypsy moth
sex Attractant. When preparations Of these compounds by other workers were
reported as inactive, re-investigation showed these substances to be active
because of traces of another substance. This has been identified and synthesized
6.17
as disparlure . 6_15
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Activity of the disparlure was confirmed in a controlled field tests
in 1970 in Massachusetts. Male moths, reared in the laboratory, were released
periodically in the vicinity of eight traps; four were baited with lyU. g each
of the synthetic sex attractant and four with a potent extract of natural gypsy
moth sex attractant equivalent to ten abdominal tips, the amount used in survey
traps. In the 10-day test, the synthetic attractant caught 110 moths, the
6 1 R
natural attractant caught 3.
Synthesis of a gypsy moth sex attractant that "out-drew" the virgin
female moth made possible the investigation of two control techniques based upon
extensive use of the sex attractant.
Since the male gypsy moth depends upon the sex attractant to locate
the rather immobile female, it should be possible, by permeating the atmosphere
with the synthetic sex attractant to mask the virgin female and/or confuse the
male moth so that fertilization does not take place. Although several field
trials (including two trials in New York during 1971) have been conducted using
this technique but the results have been rather disappointing. This method is
still being investigated and further tests are planned for 1972.
Use of the gypsy moth sex attractant and for that matter any chemical
broadcast for control purposes will require that the material be registered for
gypsy moth control. This will involve a delay of 2 to 5 years while the material
undergoes the necessary toxicity tests.
A more recent use of traps is to distribute enough traps with sex
attractant to capture male moths in an area of light infestation. It is estimated
that this would require from 2000 to 5000 traps per square mile (at least as many
as there are female moths present). This method was tested in Pennsylvania during
1971 with unsatisfactory results; further tests on this technique are planned
for 1972t 6~16 EQ-5025-D-2 (Vol. II)
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Among several other possible methods of utilizing traps in a control
program are:
(a) Traps baited with sex attractant plus a sticky coating or an insecticide
would be a direct control if disseminated in sufficient quantities to remove a
significant number of males.
(b) Traps baited with sex attractant plus an infectious disease. In this case
the male would not be captured but attracted, infected and released to spread
the disease.
A-6.3.4 Direct Controls
This grouping includes those direct physical-mechanical efforts aimed
at collecting and/or destroying some life stage of the insect.
(a) Collection and Destruction The first almost successful attempt to
eradicate the gypsy moth in Massachusetts in 1890's relied mainly on the detection
and destruction by creosoting of the gypsy moth egg masses " . This was also
an effective major part of the federally funded CCC crew's attempt to combat the
gypsy moth in New York and New England in the 1930!s and early 1940's.
(b) Barriers Mechanical barriers are another type of direct technique that have
been successfully used as a part of early gypsy moth control efforts. Such barriers
are currently not used to any appreciable extent because the availability of in-
expensive chemical pesticides coupled with economic application techniques have
n,. 'e he manpower requirements associated with barriers-unattractive. This
apparent disadvantage is much less important in the protection of shade and
ornamental trees where the recognized value of the trees are high and the number
of trees per acre is low relative to the woodlands.
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Barriers are effective against an insect such as the gypsy moth
because of certain peculiarities in its life cycle, viz:
(1) Egg masses are normally deposited on rubble on or near the
ground and the newly hatched larval must climb the tree to reach
the foliage.
(2) Late-stage larvae feed normally at night and spend the day time
resting in the moist, cool undergrowth.
A barrier may be simply a band of burlap around the tree trunk
under which the larvae may seek shelter and be easily destroyed, or a band of
sticky material such as "Tree Tanglefoot" which they cannot cross during ascent
of the tree.
(c) Traps Traps as used in control programs against defoliating insects are
typically a small container baited with light, food or a sex attractant to lure
flying male adults. The trap is normally lined with a sticky material to capture
the insect once it enters the container.
A-6.3.5 Biological Controls
Biological control, defined here as the use of parasites, predators and
pathogens to regulate the population of another organism, dates from the early
18th century with the discovery of the nature of insect parasitism. ' ' "*^°
Its use as a valid tool in regulating insect populations is generally credited
to f;be spectacular success of the introduction of the vendalia beetle in
controlling the cottony-cushion scale that threatened the citrus groves of
California in 1889.
ft ?1
Balch ' notes that the mechanism of this control method is based
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on the theory, elaborated chiefly by Nicholson, that density-dependent factors
are the essential component of any regulating mechanism. Milne 6'2 holds that
their relationship is "imperfect" and while this "imperfection" allows natural
enemies to play an important part in maintaining low populations between outbreaks
they are unable to control rapid increases brought about by such environmental
factors as extremely favorable weather and/or extremely favorable forest types.
This is the reason that native insects occasionally escape control and reach
pest status.
Excluding the direct control exerted by CCC crews during the 1930's
and early 1940's and the use of chemical insecticides since that time, the field
of biological control has been the focus of control efforts against the gypsy moth
since the Federal Government, in cooperation with the State of Massachusetts,
undertook control measures in New England in 1906. Even before this time,
however, economic entomologists concerned with the gypsy moth were advocating
the importation of predators and parasites of the gypsy moth although only minimal
action was taken since Massachusetts was committed to a policy of total
6.19
eradication
During the winter session of 1904-5, Congress appropriated $2500 to
fund importation of parasites of the gypsy moth. This began a cooperative
biological control program between the Federal Government and the New England
States that lasted until 1929.
The first stage of this program, lasting until 1911, is reported by
Howard and Fiske 6'22. Table 6.II lists the known parasites of the gypsy
moth as well as those reared in this country. Table 6.Ill shows the status of
the introduced parasites in 1911 when the program was halted due to European
hostilities.
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After World War I, work was resumed and continued until 1927.
f O O
Burgess ' summarizes the work on the whole program. Table 6.IV lists all the
parasites and predators colonized, as listed by Burgess.
In discussing the results of this program, Burgess made the following
observations.
(1) From 1905 to 1916, the severity of forest defoliation showed
no decrease in intensity.
(2) Foreign natural enemies were being introduced in substantial
numbers with many species becoming established and increasing.
(3) From 1920 to 1924 the acreage defoliation gradually decreased until
only a few completely defoliated areas could be found.
(4) The combined percentage of parasitism increased and reached a
maximum in 1923 but decreased the following years.
(5) After 1929, the gypsy moth population increased rapidly in eastern
Massachusetts and reached its former severity over most of the
older infested area.
(6) The parasite population reached low ebb in 1925, made a slight
increase in 1926 and a noticeable increase in 1927.
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TABLE 6.II
KNOWN AND RECORDED PARASITES
HYMENOPTEROUS PARASITES OF THE GYPSY MOTH (Porthetria dispar L.)
BRACONIDAE
Reared at laboratory
Apanteles fulvipes (Hal.)
Apanteles solitarius (Ratz.).
Meteorus versicolor (Wesm.).
Meteorus pulchricornis (Wesm.)
Meteorus japonicus Ashm.3
Recorded as parasites
Apanteles fulvipes (Hal.).1'2
Apanteles solitarious (Ratz.).^»
Microgaster calceata Hal.1*2
Apanteles tenebrosus (Wesm.).1
Microgaster tibialis Nees.1
(Microgaster) Apanteles fulvipes
liparidis (Bouche).1»2
Apanteles glomeratus (L).1*^
Apanteles solitarius var.
melanoscelus (Ratz.).1
Apanteles solitarius? ocneriae
Svanov.
Meteorus scutellator (Nees).1
ICHNEUMONIDAE
PRIMARY
Pimpla (Pimpla) instigator (Fab.).
Pimpla (Pimpla) porthetriae Vier.3
Pimpla (Pimpla) examinator (Fab.)
Pimpla (Pimpla) pluto Ashm.3
Pimpla (Apechthis) brassicariae (Poda).
Pimpla (Piippla) disparis Vier.3
Theronia aLalantae (Poda).
Limnerium (Hyposoter) disparis Vier.
Limnerium (Anilastus) tricoloripes Vier.
Ichneumon disparis (Poda)
Pimpla (Pimpla) instigator (Fab.)1'2
Pimpla examinator (Fab.)1
Theronia atalantae (
Campoplex conicus Ratz.l
Casinaria tenuiventris (Grav.).1
Ichneumon disparis (Poda).l>2
Ichneumon pictus (Gmel.).l>2
Amblyteles varipes Rdw.2
Trogus flavitorius [sic.]
lutorius (Fab.)?l»2
(Cryptus) Aritranis amoenus (Grav.)1
Cryptus cyanator Grav.1
Recorded by the senior author in a card catalogue of parasites kept in the
Pureau of Entomology.
^Recorded by Dalla Torre in Catalogus Hymenopteroru.
Japanese species.
F 6~21 EQ-5025-D-2 (Vol. II)'
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TABLE 6.II (CONT)
PROBABLY SECONDARY BUT RECORDED AS PRIMARY
1 2
Mesochorus pectoralis Ratz. '
Mesochorus gracilis Brischke1'^
Mesochorus splendidulus Gray.1'
Mesochorus confusus Holmgr.
Mesochorus semirufus Holmgr.•*•
(Hemiteles) Astomaspis fulvipes (Grav.)1'
=A. nanus (Grav.) according to
Pfankuch.
Hemiteles bicolorius Grav.2
Pezomachus hortensis Grav.
Pezomachus fasciatus (Fab.)1=Pezomachus
melanocephalus (Schrk.).
CHALCIDIDAE
Eupelmus bifasciatus Fonsc.
Monodontomerus aereus Walk.
Chalcis flavipes Panz.
Chalcis obscurata Walk.^
Schedius kuvanae
Pteromalus halidayanus Ratz.l
Pteromalus pini Hartig.1
Dibrachys boucheanus Ratz.1 (Secondary)
Eurytoma abrotani Panzer^ >2=appendigaster
Swed. (Secondary)
Eupelmus bifasciatus Fonsc. »
Chalcis callipus Kby.-*
FOREIGN TACHINID PARASITES ON PORTHETRIA DISPAR
Blepharipa scutellata R. D.
Carcelia gnava Meig.
Compsilura concinnata Meig.
Crossocosmia sericariae Corn.
Dexodes nigripes Fall.
Parasetigena segregate Rond.
Tachina larvarum L.
Tachina japonica Towns.
Tricholyga grandis Zett.
Zygobothria gilva Hartig
6-22
Argyrophylax atropivora R. D.
Carcelia excisa Fall.
Compsilura concinnata Meig.
Echinomyia fera L.
Epicampocera crassiseta Rond.
Ernestia consobrina Meig.
Eudoromyia magnicornis Zett.
Exorista affinis Fall.
Historchaeta marmorata Fab.
Lydella pinivorae Ratz.
Meigenia bisignata Schin.
Parasetigena segregata Rond.
Phryxe erythrostoma Hartig.
Ptilotachina larvincola Ratz.
Ptilotachina monacha Ratz.
Tachina larvarum L.
Tachina nocturarum Rond.
Zenillia libatrix Panz.
Zygobothria gilva Hartiz.
Zygobothria bimaculata Hartig.
EQ-5025-D-2 (Vol. II)
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TABLE 6.Ill
THE PRESENT STATUS OF THE INTRODUCED PARASITES (1911)
PARASITES OF THE GYPSY MOTH
EGG PARASITES
ANASTATUS BIFASGIATUS Fonsc.
Received first in 1908. Colonized unsuccessfully in 1908 and successfully
in 1909. First recovered in immediate vicinity of colony in 1909. Increased
notably in 1910, but indicated dispersion is only about 250 feet per year. Arti-
ficial dispersion necessary. Apparently well established.
SCHEDIUS KUVANAE How.
Received first in 1907, dead, and in 1909, living. Successfully colonized
in 1909. Recovered in immediate vicinity of colony site in 1909. Doubtfully
recovered in 1910. Establishment very doubtful on account of climatic conditions.
HYMENOPTEROUS PARASITES OF CATERPILLARS
APANTELES FULVIPES Hal.
Received first in 1905, dead, and in 1908, living. Colonized unsatisfactorily
in 1908 and under exceptionally favorable conditions in 1909- Two generations
recovered in immediate vicinity of colony site in 1909. Not recovered in 1910
except from recent colony. Establishment doubtful on account of lack of proper
alternate hosts.
TACHINID PARASITES
COMPSTLURA CONCINNATA Meig.
First received in 1906 and colonized same year. Colony strengthened in
1907. Recovered doubtfully in 1907 from immediate vicinity of a colony site.
Certainly recovered and found to be generally distributed over considerable terri-
tory in 1909. Marked increase in 1910. Apparently established.
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TABLE 6.Ill (CONT)
CARCELIA GNAVA Meig.
Doubtfully colonized in 1906. Satisfactorily colonized in 1909. Not re-
covered from field. Establishment hoped for.
ZYGOBOTHRIA GILVA Hartig.
Doubtfully colonized in 1906. Satisfactorily colonized in 1909. Not re-
covered from field. Establishment hoped for.
TACHINA LARVARUM L.
First received in 1905 and colonized in 1906. Much more satisfactorily in
1909. Not recovered. Establishment doubtful on account of hybridization with
similar American species.
TACHINA JAPONICA Towns.
First received and poorly colonized in 1908. A better colony put out in 1910
Recovery doubtful on the same account as above.
TRICHOLYGA GRANDIS Zett.
Doubtfully received and colonized in 1906. Satisfactorily colonized in 1909-
Recovered from immediate vicinity of colony site in 1909. Not recovered in 1910,
but establishment hoped for.
PARASETIGENA SEGREGATA Rond.
First received in 1907 and colonized in 1910. Not recovered. Establishment
hoped for and expected.
iLEPHARIPA SCUTELLATA R. D.
First received in 1905. Colonized under very unsatisfactory conditions in
1907. Satisfactory colonization for first time in 1909. Recovered from immediate
vicinity of colony site in 1910. Establishment confidently expected.
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TABLE 6.Ill (CONT)
CROSSOCOSMIA spp.
First received in 1908 and colonized in 1910 under fairly satisfactory con-
ditions. Not recovered. Establishment rather doubtful on account of unsatisfactory
colony.
PARASITES OF THE PUPA
MONODONTOMERUS AEREUS Walk.
First received in 1906. Colonized in 1906. Recovered, generally distributed
over considerable area, in winter of 1908-9. Firmly established and dispersing at
a very rapid rate.
CHALCIS OBSCURATA Walk.
First received in 1908. Colonized in 1908 and 1909, but not satisfactorily.
Establishment doubtful on account of small size of colony.
CHALCIS FLAVIPES Panz.
First received in 1905. Colonized in 1908 and 1909 but in unsatisfactory
numbers. Recovered from immediate vicinity of colony site in 1909. Not re-
covered in 1910. Establishment doubtful on account of small colony.
PREDACEOUS BEETLES
CAOSOMA SYCOPHANTA L.
First received in 1906. Colonized same year. Recovered from immediate
vi ir.:ty of colony site in 1907. Found generally distributed over limited area
in 1909. Firmly established and increasing and dispersing rapidly.
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TABLE 6.IV
FOREIGN ENEMIES OF PORTHETRIA DISPAR AND NYGMIA PHAEORRHOEA LIBERATED
IN NORTH AMERICA
Species
Anastatus disparis
Ruschka
Apanteles lacteicolor
Vier
Apanteles liparidis
Bouche
Apanteles melanoscelus
Ratz
Apanteles solitarius
Ratz
Apanteles porthetriae
Muesebeck
Brachymeria intermedia
(Nees)
Brachymeria obscurata
(Walk.) (?)
Carabus arvenis Fab
Carabus auratus L
Carabus glabratus Payk
Carabus violaceus L
Carabus nemoralis L
Carcelia laxifrons Vill
Carcelia separata Rond
Calosoma chinense Kirby
Calosoma inquisitor L
Calosoma reticulatum Fab
Calosoma sycophanta L
Compsilura concinnati
Meig
Number
of indi-
viduals
of foreign
stock
liberated
138,680
55,000
76,702
23,476
222,546
12,065
20,798
394
108
478
63
136
9,742
317,061
140
259
b 83
2,711
25,134
Number subsequently liberated
By re- By repro-
produc- duction From New Total
tion from from es- England numbers
foreign tablished field col- of enemies
stock stock lections liberated
65,505,513 65,644,193
255,245 310,245
1 37,370 114,072
132,177 155,653
22,546
22,522 34,587
20,798
394
108
478
63
136
9,742
17,061
128 268
27 286
27 110
463,870 66,581
122,625 147,759
6-26
EQ-5025-D-2 (Vol. II).
-------
TABLE 6.. IV (CONT)
Soecies
Number
of indi-
viduals
of foreign
stock
liberated
Crossocosmia flavo-
scutellata
Schiner (?)
Crossocosmia
sericariae Corn
Ephialtes
(Ephialtes)
examinator Fab
Ephialtes
(Ephialtes)
instigator Fab
Eudoromyia
Magnicornis Zett
Eupteromalus
nidulans Foerst
Hyposoter disparis
(Vier.)
Lydella nigripes
Fall
Masicera sylvatica
• Fall
Meteorus japonicus
Ashrfi
Meteorus pulchri-
cornis Wesm
Meteorus veriscolor
700
402
--r ntotnerus
aereus Walk
Pales ..;avida Meig
fc'hcro.-Krf; a^ilis R.D
Procvuci'es coriaceus
Number subsequently liberated
By re- By repro-
produc- duction From New
tion from from es- England
foreign tablished field col-
stock stock lections
Total
numbers
of enemies
liberated
700
402
kuvanae How 1,703
4,568
5530,000
12,543
10,692
23
5 395
4 118
3,113
15,541
582
18,445 2,278
75
i 703 625,675,884
4,568
530,000
12,543
10,692
23
400
122
7,887 11,000
15,541
582
20,723
75
25,677,587
6-27
EQ-5025-D-2 (Vol. II).
-------
TABLE 6.IV (CONT)
Species
Number
of indi-
viduals
of foreign
stock
liberated
Number subsequently liberated
By re- By repro-
produc- duction
tion from from es-
foreign tablished
stock stock
From New
England
field col-
lections
Total
numbers
of enemies
liberated
Sturmia inconspicua
Meig.
Sturmia nidicola
Towns
Sturmia scutellata
R.D
Tachina japonica
Towns
Tachina larvarum L
Tachinids unclassi-
fied
Tachinids unclassi-
fied
Telenomus phalae-
narum Nees
Trichogramma spp
Tricholyga segregata
Rond
Xylodrepa quadripunc-
tata Schr
Zenillia libatrix
Panz
8
13,364
3,500
11,097
471
42,152
1 9,420
10,499
9,323
100
504
9
9
4,650
76,000
15
73,546
13,364
3,500
84,643
471
42,152
9,420
10,499
46,650
76,000
9,323
115
TOTAL
574,402
673,530 25,808,061 66,028,686 93,084,679
From a beginning of 288 individuals
2
Some doubt as to this species
3
Some of these Carcelia gnava Meigen
i
Some of this number were obtained by reproduction work with foreign and established
stock
Number of foreign stock received not known, but it was very many less than the
number given
r
Some reproduction from foreign stock but mostly from established stock
Includes some of multibrooded tachinids liberated from 1906 to 1907
'Mostly Tachina larvarum in 1926
Number of foreign stock received not known
6-28
EQ-5025-D-2 (Vol. II)
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The foregoing program was cited in some detail to underline the fact that
biological control of the gypsy moth is not a new concept. It has been used
rather extensively with varying degrees of success. It is not a panacea offering
an immediate and perfect solution to the gypsy moth problem but, apparently, can
have beneficial effects. The preceding tables should also serve to illustrate not
only the magnitude of early efforts, but also the need for patience in this type of
time-consuming effort.
6.24
Dowden ' states that it is generally believed that the gypsy moth is
as well controlled by biotic factors in North America as in Europe but that the
increased use of insecticides against the pest makes a definite appraisal very
difficult.
Biological control programs aimed at the gypsy moth received little
attention from 1930 through the 1960's being replaced by work of the CCC crews and
then by aerial application of chemical insecticides. Present day work in biologi-
cal control is exemplified by work being done by New Jersey and is discussed later.
Although biological control also includes the use of predators, both
vertebrate and invertebrate, little attention has been given until recently to
the role of vertebrate predators in controlling gypsy moth populations. While
vertebrate predators (both birds and mammals) can have only a minor effect in
regulating rapidly increasing host populations, they do have a significant effect
. . 6.8,6.9,6.1
in maintaining low population densities.
f 9 S
Bess, Spurr and Littlefield ' noted that both the short-tailed
shrew and the deer mouse, voracious feeders on larvae of the gypsy moth, were
most abundant and important in forest stands with moist, deep, forest floor.
Exposed, dry sites both restrict the presence of predators and inhibit the normal
descent of gypsy moth larvae to the ground to expose them to predation. Presently,
6-29
EQ-5025-D-2 (Vol. II).
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the United States Forest Service is conducting basic studies on the predation of
the gypsy moth by the deer mouse, as well as a fundamental elucidation of the pre-
dator life cycle.
The third aspect of biological control, namely pathogens, has long
been observed as causing sudden, dramatic collapse of epidemics of the gypsy
r o/:
moth. Doane ' among others, has identified this gypsy moth "wilt" as caused
by a nuclear-polyhedrosis virus (NPNV) and streptococcus faecilis. The epizoatic
of disease resulting in sudden collapse of host population appears to be dependent
upon high density of host larvae and the rapid spread of the pathogens enhanced
by behavior of larvae during the early instars.
r 97
Rollinson, Lewis and Waters " report a successful attempt to create
an epizootic of NPHV with a water spray from truck-mounted mist blower. Virus-
caused mortality occurred up to 34 days after application with peak kill at 19
days.
The possibility of using a microbial insecticide to control leaf-feeding
lepidopterous pests became a reality in the late 1950's with the commercial pro-
duction of Bacillus thuringiensis. In spite of successful use of this material
to control several agricultural pests, aerial application of this material against
f OQ
gypsy moth larvae has been disappointing " . With improved formulations and
application techniques, this bacterium may show promise as an effective biotic
, f t ,6.29,6.30.
control for the gypsy moth
At this time, Bacillus thuringiensis is the only pathogen commercially
produced and registered for used against the gypsy moth.
6-30
EQ-5025-D-2 (Vol. II),
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A-6.4 Control Alternatives
A-6.4.1 New York
Since the gypsy moth first invaded New York, continuous attempts to
eradicate this pest have been conducted. These included the use of pesticides,
sex lures, the introuduction of parasites and predators and direct physical
assault in destroying egg masses, banding of trees, purning infected trees and
the destruction of protected egg-laying habitat. This phase of the campaign
against this pest is treated more fully in a later section discussing the work of
the CCC crews during the 1930's and early 1940's.
While these early measures proved to be very useful, little effort has
been made in New York since 1945 to resort to these practices. Although the
State has cooperated with the Federal Government in experimental releases of
some parasites and predators and sex attractants, there is no evidence of a
concerted effort to use these agents in an active, integrated control program.
New York is not alone and while there is interest in the potentiality
of biological control agents in this and in all threatened states, New Jersey is
the only state that has manifested a commitment.
A-6.4.2 New Jersey
As long as DDT was being used, the gypsy moth in New Jersey was
effectively controlled and its range reduced. However, in 1963, the substitution
of Sevin for DDT, plus increased infestations along the northern borders of the
state, resulted in an "explosion" of the gypsy moth throughout the state.
Intrusion of the moth was so great, in fact, that the state abandoned its policy
of eradication for one of control - an integrated control program employing both
chemical and biological means to regulate populations of the gypsy moth.
6-31
EQ-5025-D-2 (Vol. II).
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Since New Jersey had long been active in the collection and rearing
of parasites to control introduced agricultural pests, it was a logical step to
adopt biological control measures as an important element of this program.
Accordingly, in 1963, work began with field collection of six of the nine
gypsy moth parasites that had become established in New England, with their
subsequent release in New Jersey. In addition, the other three parasites
were reared in New Jersey and also field released.
Since the remote forested areas of the northern part of the state
were so badly infested as to leave little hope of any economically acceptable
control, this area was selected as the focal point for establishment of
biological controls. Threatened high-value, forest urban areas were given
immediate protection through use of chemical insecticides (Sevin at 1 Ib/acre).
The main objective of the New Jersey program is to establish popu-
lations of various insect parasitoids throughout the distribution of the gypsy
moth in that state. It is anticipated that these efforts, part of an integrated
approach to managing this pest, will assist in maintaining gypsy moth populations
at a level where their impact on the forest and urban ecosystems can be
tolerated, both economically and ecologically.
Table No. 6.V listing all of the egg, larval, and pupal parasites
released under this program for each of the last 7 years, shows the variety
and numbers of parasites being handled. In addition to these, during spring of
1968, mass-rearing of gypsy moth larvae was initiated for use in both parasite
rearing and in male sterilization programs.
Figure 6.2 shows one of the exotic parasites being reared and released
under this program. This particular larval parasite, Exorista segregatta, is
shown depositing its eggs on a later instar gypsy moth larva.
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EQ-5025-D-2 (Vol. II).
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Table 6.V
GYPSY MOTH PARASITE RELEASES
STATE OF NEW JERSEY
PARASITE
Apanteles melanoscelus
Apanteles porthetria
Apanteles sp.
Brachymeria intermedia
Calosoma sycophanta
Compsilura concinnata
Ooencyrtus kuwanae
Hyposoter disparis
Parasetigena agilis
Exorista rossica
Exorista segregata
Exorista larvarum
Rogus sp.
Rogus indiscretus
Sturmia scutellata
Tricholyga segregata
TOTALS
YEAR OF RELEASE
1964-65
1,139
3,985,000
460
3,986,599
1965-66
137
338
5,235,000
2,359
5,237,834
1966-67
1,763
427
1,497,120
612
1,499,922
1967-68
400
53,315
3,028,500
1,620
1,826
3,085,697
1968-69
334,266
294
15,425,800
2,281
9,964
16,912
15,789,517
1969-70
17,497
145
393,060
247
18,664,500
12,505
35,616
45,877
1,127
14,184
19,184,758
1970-71
11,422
6,189
326,273
37,271,000
136
11,140
38,360
45,534
4,539
1,127
295
37,714,885
TOTALS
29,456
145
6,189
1,108,677
2,018
427
85,106,920
136
25,926
83,940
108,323
4,539
295
19,235
1,826
86,499,215
CO
CO
o
ro
"?
o
-------
?
COURTSEY: NEW JERSEY DEPT. OF AGRICULTURE
Figure 6.2 PARASITE EXORISTA SEGREGATTA OVIPOSITING ON GYPSY MOTH LARVAE
M
M
-------
The biological program is divided into two parts; insect rearing and
field evaluation. The insect rearing facilities and techniques used are well
organized, staffed and maintained. The rearing and releasing techniques developed
by New Jersey should serve as excellent models for the establishment of similar
facilities in other states.
The most critical part of the program, however, is the field evaluation
undertaken to determine the success or failure of the biological control effort.
It is too early at this time to critically review this part of the project, although
it is evident that the main interest is in determining whether or not populations
of various parasitoids had become "established" at the various release sites.
Establishment is considered successful if a particular species is recovered from
field collections after 3 years of releasing an individual parasitoid.
However, mere "establishment" of populations of various parasitoids in
the gypsy moth life system is not sufficient evidence for determining the success
or failure of the program. Unfortunately, basic research is lacking on both
the individual parasitoids that are being used, and the sampling techniques
employed for field evaluations. This is unfortunate and is a manifestation of
constraints of time and the need for additional scientific manpower. The importance
or potential of a particular parasitoid can only be determined, in most cases, by
a detailed examination of the biology, behavior, ecological adaptability, and
responses (functional and numerical) of individual species to changes in host
density.
It has been intimated that biological control efforts in New Jersey
have successfully reduced the duration of heavy defoliation from 3 to 2 years
in some areas. Also, field observations to date suggest that certain parasitoid
applications are playing a significant role in stabilizing gypsy moth populations
6-35
EQ-5025-D-2 (Vol. II)
-------
at tolerable levels, although, as noted above, sufficient information is not
available at this time.
However, it must be noted that biological control requires time to
become established. The results are not instantaneous as with chemical sprays
and losses must be both expected and accepted. The following table shows
mortality sustained in a 17,855-acre forest on the Newark watershed subjected
to heavy defoliation for 3 years before the gypsy moth infestation collapsed
from disease and parasitism.
Percent Oak Total No. Dead Oaks
Year Mortality in Affected Forest
1968 6.5 116,693
1969 14.3 257,112
1970 38.0 686,881
1971 57.7 1,033,269
A-6.4.3 Other Alternatives
In the Newark example cited the loss of over 1,000,000 oak trees may be
considered too high a price to pay for nonchemical control. The value of the
woodlands in one state is not necessarily the same in another state. This is, in
fact, the reason for different treatment philosophies within the northeastern
states.
Examination and study of historical and technical literature, coupled
with discussions with several individuals, have revealed that modern integrated
control procedures basically ignore the use of manpower as a central ingredient.
In the past personnel have, with minimal training, served as effective gypsy
moth control agents. Efforts have included scraping and creosoting of egg
masses, trapping and disposal of larvae> banding of trees, and the destruction
6-36
EQ-5025-D-2 (Vol. II)
-------
of protected egg-laying habitat. These measures have, in the past, been effective
in minimizing the ravages of this pest. Hundreds of personnel have been involved
in this work. Year-round efforts are possible in not only overt control but also
in the inspection and evaluation of woodlands for evidence of the pest. There is
no reason why this technique should not or could not be resurrected and relied
upon in integrated control efforts.
Once areas of infestations have been discovered through trapping, scouting
surveys conducted in these areas during the fall and winter will determine the
extent and intensity of the infestation. Then effective control measures of the
gypsy moth can be taken, including destruction of eggs and the destruction of
caterpillars. Methods used to destroy the pest are delineated in the following
paragraphs. The methods discussed herein as to how the destruction may be
accomplished do not include chemical spraying and introduction of parasites.
It should be noted that evidence indicates that no matter how effective
each method is, no one method can be depended upon for eradication of the gypsy
moth. Nature often upsets an attempt to exterminate by a single method by a single
process at a particular season of the year. The extermination program must proceed
day after day throughout the year in order to ensure success.
(1) Destruction of Eggs
Most of the life cycle of the gypsy moth is spent in the egg stage from
J'-y .r August until the following spring. The eggs are generally deposited on
trees and are of a conspicubus buff color and thus, provide an excellent
opportunity for scouting and locating gypsy moth colonies during the fall and
winter months when trees are devoid of leaves. Each egg cluster deposited upon
trees and other objects contains potentially 300 to 1400 caterpillars. It is
^6~37 EQ-5025-D-2 (Vol. II)
-------
apparent that destruction of the egg cluster eradicates the forthcoming hatch
of caterpillars, which would otherwise spread out and feed upon nearby foliage.
It appears to be more feasible to eliminate the insect when it is grouped and
stationary rather than after it has hatched and scattered in search of food.
In the late 1880's, when the gypsy moth had become well established
in the woodlands surrounding Medford, Mass., the Commonwealth of Massachusetts
appropriated funds to control the pest. In doing so, they consulted with
entomologists from European countries where the gypsy moth was the native pest.
The Europeans recommended egg-killing as the first and chief method of preventing
the spread and costly destruction of the pest.
Control of the gypsy moth by destruction of eggs was initiated in
Massachusetts * and later employed as a control measure in the States of New York
6 12
and Pennsylvania ' A review of the literature indicates that egg-killing was
employed as a chief method of control during the time period up through about
1944 when DDT was first experimented with to determine its value in gypsy moth
control and eradication work. It appears that egg-destruction as a method of
control is presently employed only on egg clusters found on materials being
shipped from quarantine areas. Because of the ban on use of DDT as a control
measure of the gypsy moth, it is recommended that consideration of a renewed
major effort be expended in egg destruction as a means of eradication of the pest.
During the past, egg killing has been accomplished by various methods,
namely:
1. Burning gypsy moth eggs.
2. Killing with chemicals.
3. Destroying by gases.
The methods are more fully described in the following discussion.
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EQ-5025-D-2 (Vol. II)
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A. Burning of Gypsy Moth Eggs
The most effective method of egg killing employed by Massachusetts
in the early years of their eradication program was to scrape the egg clusters
from the trees and burn them. The eggs were scraped and cut away from the trees,
fences, buildings, etc., collected in cans and burned in large brush fires or
stoves. When exposed to a steady intense heat, the eggs burst with a popping sound
like corn in a corn popper.
Naptha burners (blow torch) were later employed against egg cluster
deposits as a more effective method than scraping and then burning egg clusters.
The flame reduced the egg clusters to ashes although occasionally some of the
clusters, exposed to intense heat, burst and scattered some of the eggs. Use of
the burner against clusters deposited on young trees caused damage to the tree
whereas a mature tree with thicker bark was not seriously affected. The burner
could be used effectively to destroy egg clusters deposited in cavities of trees
or rocks.
Where large deposits of egg clusters were found in underbrush and
wasteland, it was not feasible to scrape every bush and schrub so experiments were
conducted to destroy the eggs by more expeditious means. In one experiment, fire
was run through dead leaves and debris, but it was not found effective because the
heat was not intense enough. The hairy covering of the egg clusters apparently
acted as an insulator thus rendering the eggs insensitive for a time'to sudden
intense heat. It was found that it takes minutes of applied intense heat before
all the eggs are destroyed in a cluster. Heat from a running brush fire, at the
most, may scorch the outside of a cluster, killing those eggs in the outer layer.
6-39
EQ-5025-D-2 (Vol. II)
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In another technique, crude petroleum was sprayed over the ground
and vegetation and then ignited. The fire was violent enough to destroy most
of the eggs in the brush on the upper layer of leaves, but eggs under roots or rocks
were not affected. Also, there was considerable inefficiency since the oil soaked
into the ground and the flame fed from this oil was not as intense as that sprayed
on the brush.
As a result of the limited success in the experiments conducted in
undergrowth, investigations were made to devise a more efficient way of destroying
eggs in underbrush. After numerous experiments, an apparatus known as the
"cyclone burner", was* devised. It consisted of a 15-gallon tank, a Johnson
hand-pump, a length of hose and pipe at the end of which was attached a cyclone
nozzle. Crude oil and later "parrafin gas" oil was used as a fuel. Two men were
required to move and operate the apparatus; one to pump and one to direct the
nozzle. A fine spray, generated by the pumped oil passing through the nozzle,
was ignited and produced an intense flame that "destroyed every living thing in
its path". When an area was carefully covered, no eggs escaped destruction except
those hidden in ledges or holes in the ground.
This burner was also used in the destruction of gypsy moth egg clusters
deposited in stone walls. This was partially successful as those egg clusters
within reach of the flame were destroyed, whereas those clusters under the
lower stones of the wall were unharmed even though some of the stones were
cracked and broken by the heat.
In the 1930's, New York successfully used a large weed burner fueled
£ OO
with kerosene to destroy egg masses that were laid on or within stone walls
6-40
EQ-5025-D-2 (Vol. II)
-------
Fire was used in hollow trees wherein the eggs deposited by the moth
were destroyed by burning out the decayed wood. It was found that if judiously
done there was no injury to the tree. In fact, some of the old trees seemed to
\
benefit by such burning since the trees exhibited better growth in the following
season. To accomplish the burning, oil was poured into the top of the cavity
and a small opening was made at the bottom of the cavity to provide a draft
for the burning oil. Such work was done in the winter when the sap was dormant.
B. Killing with Chemicals
Early in the eradication program in Massachusetts it was found that it
was impossible to detach the egg masses by scraping without scattering and losing
some of the eggs. As a result, it was deemed that it would be more practical to
destroy the eggs without removal from the place of deposit. This led to an
extensive study of substances which might be advantageously used for this purpose.
The criteria for selection were that the substance:
(1) be effective wherever applied,
(2) leave a permanent stain or color thus enabling one to
distinguish treated egg clusters from untreated, and
(3) be low in cost.
A variety of liquid and gaseous materials were evaluated. Three types
of mixtures that were evaluated in the field are described.
Creosote
Of the many substances investigated it was found that application of
creosote to the egg clusters provided the most effective and economical method. The
creosote required no preparation nor complex application apparatus. It could
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EQ-5025-D-2 (Vol. II)
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be readily drawn from a can and applied with a brush. . The creosote rapidly pen-
etrated the egg clusters and killed all the eggs. Creosote has a tendency
to thicken in cold weather. During cold weather, a mixtrue consisting of 50 %
creosote, 20 % carbolic acid, 20 % spirits of turpentine and 10 % coal tar was
used. The coal tar was added to color the egg clusters when treated because
creosote alone often faded after application thus making it difficult to distinghish
treated egg clusters from untreated ones.
Where coal tar was not added to the mixture, a white circle was painted
around an egg cluster treated with creosote. For this purpose, a pocket receptacle
containing a tube of creosote and a tube of white paint (each of which had a
stopper with a small paint brush) was issued as standard equipment to workers in
Massachusetts.
Creosoting of eggs proved to be an effective method of gypsy moth control
in New York as shown in Table 6.VI. This table summarizes the eradication work in
New York State over the period from 1924 through 1942. New York State Legislative
Documents (LD) during the years 1925-1943 were used to develop this data compilation.
In this table, where numbers are separated by a slash, those preceding the slash
refer to egg clusters.
Careful examination of this table shows that in 25 of the 32 towns where
colonies and egg clusters were found, creosote treatment of the egg clusters re-
sulted in an eradication or reduction of egg count in subsequent years.
Acids
Another effective method of destroying egg clusters that was used early
in the Massachusetts control effort was the application of a 50-50 mixture of
carbolic acid and turpentine. When placed on an egg cluster it readily penetrated
and killed all the eggs. To ensure destruction, a jet of nitric acid was then
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EQ-5025-D-2 (Vol. II)
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Table 6.VI
GYPSY MOTH CONTROL BY DESTRUCTION OF EGG CLUSTER
LOCATION
NUMBER OF EGG CLUSTERS FOUND
DISCOVERY YEAR
SUBSEQUENT YEAR(S)
REMARKS
LD (1925)
Greenport
Patchogue
1000+(June '22)
1000+(June '22)
5 (1924)
15 (1924)
"... this year campaign has
further reduced, if not
completely eradicated, these
infestations."
LD (1927)
Chesterfield and
Morian, Essex Co.
Colonies (1925)
0 (1926)
"...gratifying to learn that
suppression campaign of 1925
had completely eradicated those
colonies."
LD (1928)
New York -
New England
Essex Co.
Long Island
328/15,583
(Jun'23-30 Jun'26)
(?) (1926)
1926 and previous
years
25/4,055
(Jul'26-30 Jun'27)
(None) (1927)
(None) (1927)
Scouting project in vicinity of
G.M. Colonies found previous. Year
revealed no additional colonies or
signs of G.M. were found.
Same as above except in Brooklyn
LD (1929)
Ulster Co.
Long Island
1927
1927
1928
1928
Survey within 1 mile radius of G.M.
colony found in 1927 revealed a
colony within short distance of 1927
colony.
Small colony found in immediate
vicinity of 1927 colony.
Notes: 1. G.M. denotes gypsy moth
2. 328/15,583 (example) denotes 328 colonies and 15,583 clusters
3. L.D. denotes N.Y. Legislative Documents.
-------
Table 6.VI (CONT)
LOCATION
NUMBER OF EGG CLUSTERS FOUND
DISCOVERY YEAR
SUBSEQUENT YEAR(S)
REMARKS
LD (1930)
New York State
Up to 1928
1929
The effectiveness of control
practices has been well proven.
On only very rare occasions has
any indication of re-infestation
been found at the colonies where
such control measures have been
properly applied.
LD (1931)
Southold -
Suffolk Co.
Douglas ton -
Queens Co.
1929 or earlier
1929 or earlier
(1930)
(1930)
Taken from "Summary of Checking
Work in Vicinity of where G.M.
have heretofore been found".
LD (1933)
Rye, Westchester
1/7 (1932)
1700 sq. miles of scouting
LD (1937)
Long Island
42/2282 (1935)
24/237 (1936)
"The size of actually infested
area is considerably less than
at any time since the control
program was inaugurated."
LD (1938)
Long Island
24/237 (1936)
14/94 (1937)
-------
Table 6.VI (CONT)
NUMBER OF EGG CLUSTERS FOUND
LOCATION
DISCOVERY YEAR
SUBSEQUENT YEAR(S)
REMARKS
LD (1938) (Cont)
Shawangunk,
Ulster Co.
Thousands (Jul'36)
(1937
"Present indications are that an
outstanding record with regard to
extermination was achieved. At
least it is positively known that
where thousands of G.M. egg masses
were in evidence last September not
a single one was seen in the same
locality this year".
LD (1939)
New York State
Putnam Co.
Mamaroneck and New
Rochelle,
Westchester Co.
Bronx
Ulster Co.
102,968 (1937)
73,000 (1937)
Small colonies
(1937)
12,527 (1935)
28,000+ (Sept.'36)
16,015 (1938)
308 (1938)
None (1938)
127 (1936)
19 (1937)
0 (1938)
15 (1938)
"Despite handicap of rugged terrain,
it is believed extermination program
has been very effective".
LD (1940)
Ulster Co.
Bronx
28,000
12,527 (1935)
20 (1939)
0 (1939)
"...good progress has been made
in the Ulster Co. G.M. extermination
program".
2nd consecutive year - no evidence
of G.M. found
-------
Table 6.VI (CONT)
LOCATION
NUMBER OF EGG CLUSTERS FOUND
DISCOVERY YEAR
SUBSEQUENT YEAR(S)
REMARKS
LD (1940) (Cont)
Newcastle
Westchester Co.
Putnam Valley
Warren Co.
(Trumbull Mt.)
New York State
(1938)
73,000+ (1936)
15,000+ (1937)
102,968 (1937)
87
1
163
(1939)
(1939)
(1939)
(1939)
Outbreak found in New Castle
in 1938 was completely eradicated
in 1939. This was revealed by
inspection.
Continuous extermination program
during the 3 years.
State Summary
LD (1941)
Yonkers
(Westchester Co.)
Putnam Valley and
Vicinity
Trumbell Warren Co.
Shawangunk, Ulster Co.
Wawarsing, Ulster Co.
147
(1939)
(1940)
73,000+ (Oct.'36)
15,244 (Fall137)
Thousands (Jul.'36)
Thousands (Jul.'36)
186 (1940)
60 (1940)
13
290
(1940)
(1940)
"Careful and frequent inspection of
burlap and larvalefood used
extensively in Yonkers area during
larvae season failed to reveal any
sign of G.M.,..."
Infestations has been reduced to a
few (15) small but isolated colonies.
Note a reduction for the time period
but up from the previous year.
"...control operations have been quite
successful; complete extermination
expected at an early date."
LD (1942)
Ticonderoga Essex Co.
(1939)
0 (1940)
3 (1941)
-------
Table 6.VI (CONT)
LOCATION
LD (1942) (Cont)
Warren Co.
Putnam Co.
Shawangunk, Ulster Co.
Esopus (Ulster Co.
Long Island
LD (1943)
Ticonderoga (Essex Co.)
Rampo (Rockland Co.)
Esopus (Ulster Co.)
NUMBER OF EGG CLUSTERS FOUND
DISCOVERY YEAR
15,000+ (1937)
21/380 (1940)
13 (1940)
4582 (1940)
3 (1941)
Small colony
508 (1941)
SUBSEQUENT YEAR(S)
77 (1941)
11/215 (1941)
1 (1941)
508 (1941)
5 (1941)
0 (1942)
0 (1942)
5/34-N, (1942)
34-0
REMARKS
Note up from last year.
Seven colonies found this year.
Majority of colonies consisted
of a single egg cluster, which
might indicate reinfestation was
originated through wind dispersion
from heavily infested New
England areas - no evidence of G.M.
has been noted in full work.
Believe complete extermination has
been attained.
-not expected that extermination has
been achieved.
Work of current year believes extermi-
nation is about achieved. Fall scouting
of area revealed no evidence of G.M.
infestation.
-------
directed on the treated egg cluster. The nitric acid alone will not penetrate egg
clusters, although it was sufficient to kill the eggs once they were devoid of the
hairy covering. Although the acids were effective, they were expensive and presented
a hazard to the men using the method. Clothes, ropes, tools and apparatus were
also affected by the acid fumes. This method gave way to the creosote method
described previously.
Gases
Many experiments with various gases were conducted to obtain a practical
method which would destroy the gypsy moth eggs deposited in hollow trees, stone
walls and other inaccessible places. The more effective gases were bromine or
chlorine. However, because of the difficulty of providing a tightly sealed chamber
or compartment about the egg deposits, the use of the gases was found to be only
partially effective.
(2) Destruction of Caterpillars
Gypsy moth eggs hatch in date April or early May following a period of
warm weather. The male larvae undergoes five instars or growth stages while the
female matures through six instars. The last instar of both occurs about mid-June.
The larvae emerge from the eggs and usually remain near the egg cluster
for several hours. If the weather is cold or stormy they will remain 2 or
3 days outside the cluster. The larvae find food by random movement since
no evidence has been found that they can select a favored tree from an unfavored
one without examining the foliage first. The newly hatched larvae can live about
a week without feeding and if cold, wet, weather is prolonged for this time period,
the initial mortality is very high. The young larvae, about 0.062" long
when grouped about the egg cluster can be quickly destroyed by the flame of a
6-48 EQ-5025-D-2 (Vol. II)
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naptha or propane burner or by applying creosote or kerosene. Methods of destroying
the larvae, once after they leave the egg-cluster and ascend the tree in search
of food, are discussed below.
A. Banding Trees
Banding of trees was employed in Europe and in Massachusetts, New York
and Pennsylvania as a means of combating the gypsy moth. Some bands consisted
of a sticky material which prevented larvae from ascending trees in search of
food and from descending in cases where larvae hatched in tree crevices above the
bands. Also some banding was employed as a cover to which the larvae retired
during the daytime. The specific details of the various types of bands are
described below.
Tarred Paper Bands
In 1891 and 1892 many of the large street trees in Maiden, Medford
and Somerville, Massachusetts were banded with strips of tarred paper. To
accomplish the banding about a 6" wide ring of bark of the tree was
scraped or planed to a reasonably smooth surface at a height about 6' above
the ground. A cotton waste band was placed on the scraped ring and then wrapped
with a band of tarred paper. The paper was then tightly tied with a cord.
Cotton waste was employed beneath the paper to prevent the first instars from
crawling under the band. The tarred paper was covered with the following mixture:
3 parts tree ink
1 part pine tar
1 part petroleum (residuum oil)
6-49 EQ-5025-D-2 (Vol. II)
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Several applications of the mixture was required to saturate the
paper. After the initial saturation of the bands, the mixture was applied at
least twice weekly during the larvae season on the trees that lined the dusty
streets. Those trees in the fields required less frequent applications.
Raupenleim Bands
Raupenleim, which translated from German means "caterpillar glue",
was introduced in 1892 in Massachusetts on the recommendation of Mr. B. Fernow,
Chief of the Division of Forestry of the U. S. Department of Agriculture.
Raupenleim rings had been used very effectively in Europe for about 10 years
prior to being introduced in the United States. It was used in the gypsy moth
work as a replacement of the tarred paper bands because, when properly placed upor
the tree, it remained soft and viscous for several months. When applied shortly
before the hatching clusters, it prevented the ascent of nearly all larvae.
Many different devices were devised for applying the Raupenleim to
the trees, namely the Eichhorn, Hochleim, Eck, Sertz and Hauenstein lime machines
Essentially these were extrusion-type devices in which the lime, as it extruded
from a wide nozzle, was applied to the tree trunk. The lime was also applied by
spades or trowels.
It was found that an effective lime band was one that was about
2.5" wide and varied in thickness from about 0.25" at the top to more than 0.5"
at the lower edge. The oil, which oozed from the mixture when exposed to direct
sunlight, would trickle down to the bottom edge and hang there forming an
impassable obstacle to the caterpillar.
The insect lime had the disadvantage of being messy, e.g., oil
exuded from the mixture in hot sunlight; cattle and horses rubbing against the
6-50 EQ-5025-D-2 (Vol. II)
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bands plastered their coats; cats having come in contact with the lime in climbing
trees tracked the lime over carpets in the home.
Dendrolene Bands
Dendrolene was invented by Professor F. L. Nason as a result of
experimenting to obtain a domestic product similar to Raupenleim. It, as well
as Raupenleim, was made of a crude petroleum base. Dendrolene was applied to
trees in the same manner as Raupenleim. It appeared that Dendrolene remained soft
longer than its counterpart, which in some cases required two or three applications
because of hardening. Both types of bands installed near dusty areas required
occasional renewal in windy weather. No injury to trees was observed as a result
of banding with Dendrolene or Raupeleim.
Tree Tanglefoot
fi Q
Tree Tanglefoot " was developed around 1920 by the Gypsy Moth Labora-
tory of the U. S. Department of Agriculture, and proved to be a very effective
banding material against larval ascent. It was extensively used in gypsy moth
control in New York and Pennsylvania during the 1930's.
Other Methods of Viscous Banding
Viscous banding of trees other than the types just described was
employed in Europe. Bands of pitch or tar were frequently used in Russia,
but these soon became dry and required replacing. In Crimea, a banding material
made of two parts of boiled tar and one part rope oil, thoroughly heated together,
v as used a';out 1893. Another Crimean banding mixture of 10 Ib of lard, 20 Ib
f hemt>-seed oil and 80 Ib of coal tar was recommended for use in Massachusetts.
Evidently this mixture remained soft a long time since, after applying it directly
to the tree, it required renewal only, twice a year.
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Dr. Richard Hess in "Der Forstscnutz" published in Leipzig in 1887
and 1890 recommended that orchard trees should be smeared with a mixture of lime,
black soap, potash and cow dung to prevent larvae from ascending to the foliage.
Burlap Bands
Burlap bands were used on trees as early as 1891 in Massachusetts
and also were used in the gypsy moth control in New York and Pennsylvania. The
purpose of the bands was to assemble the larvae so that they could be readily
found and then destroyed.
Observation of the gypsy moth revealed that before the larvae reached
half their growth, they daily leave the foliage which they fed upon during the night
and cluster in sheltered places, such as cavities in the bark and underneath
limbs. As the larvae grow larger, search for shelter during the day became more
apparent. The caterpillars often leave the trees upon which they were feeding,
if the tree offers no shelter, in search of a hiding place such as stone walls,
rubbish heaps, etc. It was also observed that they would cluster during the day
under a piece of cloth left in a tree.
As a result of these observations an investigation was launched
to devise an inexpensive, durable shelter which could readily be examined and
serve as a trap. It was found that inexpensive 8-oz burlap, was the best
material for the purpose. The burlap, cut into 1-ft wide strips, was wrapped
around the trunk of the tree and held in place by twine. The upper half
of burlap, above the twine, was folded over to provide a double thickness of
burlap around the tree. If the trunk and/or branches offered no hiding places
for the larvae, they would climb down, morning after morning, crawl under the
burlap and remain there during the day. The burlap bands were tended daily
at which time the assembled caterpillars were killed by crushing or cutting.
6-52 EQ-5025-D-2 (Vol. II)
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To ensure that each band was examined every day the following plan
was utilized. When the burlap was checked the first time, the folds were
turned up, the next day the folds were left down. Thus, by this method any band
that was missed during a particular day could be readily identified. Whether the
folds of the bands were left up or down did not affect the number of caterpillars
trapped.
The use of burlap bands is an effective method for collecting
the larvae so that they can be killed easily. In one experiment, a medium
sized apple tree upon which caterpillars were feeding was burlap-banded and fenced
off. The tight board fence enclosed an area 18-ft square and 5-ft high. A
Raupenleim band was placed on the inside of the fence thereby confining all the
caterpillars within the area. Observations were made daily over a 10-day period
on the location of the caterpillars. Although the number of caterpillars varied
on the tree, the number found each day in the same place and position was found to
be quite constant. The number found under, the burlap band varied between 52 % to
72 % whereas those found on the underside of branches constituted about 29 % of
those on the tree; the number on leaves and on the trunk constituted less than 3 %.
Other Methods
Experiments were conducted in 1895 to determine the resistance of
caterpillars to water. The results showed that the gypsy moth larvae are able
to live in water for 2 or 3 days. Thus, water would not be an effective
means of killing collected larvae; rather a liquid such as a petroleum distillate
or turpentine should be used. This experiment points out that the ability to live
' water for this time period enables it to be transported long distances in
swiftly moving water and thus establish colonies distant from known infested
area.
6-53 EQ-5025-D-2 (Vol. II)
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A-6.4.4 Control Personnel Used
An attempt was made to correlate manpower loading and the efficacy
of various control measures. Records pertaining to forest pest control ' in
New York during the 1930's did not categorize the manpower use with the control
method and efficacy although creosoting the egg masses apparently was effective
(see A-6.4.2). In addition, during the mid-to-late 1930's, thousands of trees
were banded. For example, in 1938 over 400,000 trees were so treated. Throughout
this period, 100-200 men/month were utilized. It should be remembered, however,
that many of these personnel were utilized in scouting operations.
A more interesting account of manpower use has been presented by
Forbush and Fernold ' . The manpower loading per month during 1890-1894 inclusive
are plotted in Figure 6.3; a schematic representation of the gypsy moth life cycle
is also presented. This chart shows that the employment peaks occurred during
the larvae, pupa and adult stages of the life cycle of the gypsy moth. A
summary of early gypsy moth control within the state for the above time period
is presented in Table 6.VII. Use of this table in conjunction with Figure 6.3
gives some indication of manpower used for specific methods of gypsy moth control.
In 1891, the peak employment period occurred during the larval stage, where control
measures available at that time period were burlapping and spraying. Since spray-
ing methods in 1891 utilized cumbersome equipment and required considerable man-
power and since a large number of trees (177,415) were sprayed as compared to
subsequent years, it may be concluded that a high percentage of the manpower was
utilized in spraying. Further for 1891, the banding of 12,000 trees would have
occurred during April, before the emergence-of the larvae, and would have required
an average of about 120 men to accomplish this task. The remainder of the year,
6-54 EQ-5025-D-2 (Vol. II)
-------
Ul
o
to
f
<
O
00 111
EGG
EGG
LARVA
H
Figure 6.3 GYPSY MOTH LIFE CYCLE AND WEEKLY EMPLOYMENT FOR GYPSY MOTH
CONTROL IN MASSACHUSETTS
-------
TABLE 6-.VII SUMMARY OF EARLY GYPSY MOTH CONTROL IN MASSACHUSETTS
Trees (fruit, shade and forest):
Inspected
Found to be infested with caterpillars,
pupae, moths or eggs
Cleared of eggs
Cemented
Banded (insect lime or tree ink)
Burlapped
Sprayed
Trimmed
Scraped
Cut
Acres of brush land and woodland cut
and burned over
Buildings :
Inspected
Found to be infested
Cleared of eggs
Wooden fences :
Insected
Found to be infested
Cleared of eggs
Stone walls :
Inspected
Found to be infested
Cleared of eggs
Number of each form of the moth destroyed
by hand
Caterpillars
Pupae
Moths
Hatched or infertile egg clusters
Unhatched and probably fertile egg clusters
1891
3,591,982
213,828
212,432
19,296
12,000
68,720
177,415
-
-
-
120
87,536
3,647
3,574
53,219
6,808
6,570
-
-
•—
-
—
—
—
"
1892
2,109,852
108,428
99,989
12,172
21,251
110,108
7,372
-
-
395
115
22,102
1,557
1,427
24,936
2,365
2,159
2,213
672
354
935,656
80,021
9,338
40,954
99,790
1893
4,108,494
44,716
2,068
4,583
19,453
419,434
5,145
1,906
2,406
4,055
184
8,828
348
232
15,092
713
541
814
225
93
1,173,351
77,029
5,655
6,868
46,101
1894
6,828,229
48,752
2,176
7,844
-
624,673
14,857
8,618
6,068
10,296
336
27,430
508
55
35,276
798
99
1,620
423
44
1,153,560
92,225
18,084
18,036
94,706
6-56
EQ-5025-D-2 (Vol. II)
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August through December, would have been devoted to inspection and destruction
of eggs. Here, most likely the fences, stone walls and trees would have been in-
spected and cleared of eggs after mid-September, when the vegetation would be
clear of foliage. During this time period the average manpower requirement was
about 55 men.
This rationale can be applied to the years subsequent to 1891.
Further, it should be realized that the life cycle, indicated on Figure 6.3, would
vary and shift, one way or another due to weather and amounts of food available,
the time and length of stages. A shift in the larvae stage from May and June to
July and mid-August in 1894 is indicated by reference to Figure 6.3 and Table 6.VII
because employment peaked to about 265 men during this period and 624,673 trees
(the most of any of the 4 years) were burlapped.
A word of caution in viewing Table 6.VII, Forbush and Fernold note
that: the vast number of gypsy moth destroyed by wholesale methods as spraying,
fire and, presumably, banding, are not included in the table. Even so, the
destruction of the pest is significant when it is remembered that each egg cluster
or mass contains about 400 eggs.
A-6.5 Summary
Many pest control alternatives can be used either in conjunction
with chemical pesticides or as a substitute for them. However, there is no
obviously apparent, practical rationale1 by which chemical pesticides can be
totally abandoned. The recipe by which chemical pesticides and their alter-
natives are invoked must depend on a thorough assessment of the impact that lack
of pest control will manifest. Such an assessment should include not only the
6-57 EQ-5025-D-2 (Vol. II)
-------
economic losses associated with reduced timber supply, recreational opportunity
and watershed development, but also the overt impact of pest depravation on the
environment itself. Within this context, however, it is demonstrable that
useful alternatives to chemical pesticides do exist.
Biological control shows promise although it is clearly not rapidly
invoked. Further, these methods appear to have minimal short-term impact on
epidemic pest populations.
There do appear to be other alternate methods that have worked in
the past and, while not as efficient as chemicals, will provide significant
impact on pest populations. Foremost among these methods is the collection
and/or destruction of egg masses. While these and other methods can be useful,
the requirement for relatively much manpower has apparently mitigated against
recent consideration in integrated pest control. Therefore, it appears prudent
to examine current economic feasibility relative to the use of manpower as a
central ingredient in integrated gypsy moth control on the basis that technical
feasibility has been established and that manpower can potentially bridge the
gap between the short-term efficiency of broadcast chemical treatment and the
long time associated with the establishment of biotic control agents of acceptable
efficacy.
6-58 EQ-5025-D-2 (Vol. II)
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A-6.6 References
6.1 DeBach, Paul (Ed.), 1965, Biological Control of Insect Pests & Weeds,
Reinhold Public Corp., N.Y.C.
6.2 Milne, A., 1957, The Natural Control of Insect Populations, The Canadian
Entomol. Vol. LXXXIX, No. 5, pp. 193-213.
6.3 Thompson, W.R. , 1956, The Fundamental Theory of Natural & Biological
Control, Ann. Rev. of Entomol. Vol. 1, pp 379-402..
6.4 Andrewartha, H.G. and Birch, L.C., 1960, Some Recent Contributions to
the Study of the Distribution and Abundance of Insects, Ann. Rev. of
Entomol. Vol. 5, pp 219-241.
6.5 N.Y.S. Conservation Dept. Annual Report to Legislature - 1952-1960.
6.6 "Saddled Prominent" New York State Tree Pest Leaflet F-24.
6.7 Risley, J.H., The Saddled Prominent, The Conservationalist. August-
September 1969.
6.8 Graham, S.A., 1939, Principles of Forest Entomology, McGraw-Hill Book
Co., N.Y.C.
6.9 Graham, K., 1963, Concepts of Forest Entomology, Reinhold Publish
Corp. N.Y.C.
6.10 Anderson, Roger F., 1966, Forest and Shade Tree Entomology, John Wiley
& Sons, Inc., New York.
6.11 Turner, N., 1969, The Gypsy Moth in Connecticut, Conn. Agric. Exp. Sta.
Circ. #231, August 1969.
6.12 Nickols, J.O., 1961, The Gypsy Moth in Penn. - its History and
Eradication, Penn. Dept. of Agric., Misc. Bull. 4404.
6.13 Knipling, E.J., 1955, Possibilities of Insect Control or Eradication
through the Use of Sexually Sterile Males, J. of Econ. Entomol.,
Vol. 48, pp 459-62.
6.14 Meltzer, Y.L., 1971, Hormonal & Attractant Pesticide Technology, Noyes
Data Corp. Parkridge, New Jersey.
6 15 Schneiderman, H., et al., 1969, Endocrinological & Genetic Strains in
Insect Control, Symp. on Potentials in Crop Protection. N.Y.S. Exp.
Sta. Cornell Univ.
6 16 McQueen, F., Personal Communication, Auburn Univ. Dept. Agric.
29 Oct. 1971.
6-59 EQ-5025-D-2 (Vol. II)
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6.17 Jacobson, M., Schwartz, M., Waters, R., 1970, Gypsy Moth Sex Attractantsr
A Reinvestigation, Jour, of Econ. Entomol. Vol. 63, pp 943-5.
6.18 Bierl, B.A., Beroza, M., and Collier, C.W., 1970, Potent Sex Attractant
of the Gypsy Moth, Its Isolation, Identification and Synthesis, Science -
Volume 170, No. 3953, pp 87-89.
6.19 Forbush & Fernald, 1896, The Gipsy Moth, Porthetria dispar, Wright &
Potter, Boston, Mass.
6.20 Turnbull, A.L., & Chant, D.A., 1961, The Practice and Theory of
Biological Control of Insects in Canada, Canada Jour. Zool. Vol. 39,
pp 697-753.
6.21 Balch, R.E., 1960, The Approach to Biological Control in Forest
Entomology, Canadian Entomology V. 92, pp 297-310.
6.22 Howard, L.O., Fiske, W.F., 1961, The Importation into the United States
of the Parasites of the G. M. and the Brown-tail Moth, U.S.D.A. Bureau
of Entomol. Bulletin #91.
6.23 Burgess, A.F., 1929, Imported Insect Enemies of the Gypsy Moth and the
Brown-tail Moth, U.S.D.A., Tech. Bull. #86.
6.24 Dowden, P.B., 1957, Biological Control of Forest Insects in the United
States and Canada, Jour, of Forestry, Vol. 55, pp 723-726.
6.25 Bess, H.A., Spurr, S.H., Littlefield, E.W., 1947, Forest Site Conditions
and the Gypsy Moth, Harvard Forest Bulletin 22, pp 56.
6,26 Doane, C.C., 1970, Primary Pathogens & their Role in the Development of
a Epizootic in the G.M., J. of Invert Path., Vol. 15, pp 21-33.
6.27 Rollinson, W.D., Lewis, F.B., Waters, W.E., 1965, The Successful Use of
a Nuclear-Polyhedrosis Virus Against the Gypsy Moth, J. of Invert. Path.,
Vol. 7, pp 515-7.
6.28 Doane, C.C., & Hitchcock, S.W., 1964, Field Tests with an Aerial Applica-
tion of Bacillus thuringiensis, Conn. Agric. Exp. Sta. Bull. #665.
6.29 Doane, C.C., 1966, Field Tests with Newer Materials Against the Gypsy
Moth, Jour, of Econ. Entomol., Vol. 59, pp 618-620.
6.30 Secrest, J.P., McLane, W.H., Henderson, J.A., 1971, Field Trials of
Insecticides, Cape Cod, Mass., 1971, Chem. Test Section Gypsy Moth
Method Dev. Lab., Otis AFB, Mass.
6.31 N.Y.S. Conservation Dept. - Annual Report to Legislature - 1924-1944.
6.32 Risley, J.H., Personal Communication to R. Klingaman, September 17, 1971.
6.33 Baker, W.L., 1941, Effect of Gypsy Moth Defoliation on Certain Forest
Trees, J. of Forestry, Vol. 39, pp 1017-1022.
6-60 EQ-5025-D-2 (Vol. II)
* U.S. GOVERNMENT PRINTING OFFICE : 19730-502-143
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