BIOLOGY AND CONTROL OF INSECT
AND RELATED PESTS OF BEEF CATTLE
John E. Lloyd, Professor of Entomology
Everett W. Spackman, Extension Entomologist
Rabinder Kumar, Research Associate
University of Wyoming
Laramie, Wyoming
This material was prepared under Inter-Agency Agreement EPA-78-D-f-0473
between the University of Wyoming and EPA Region VIII Denver.
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Table of Contents
Introduction 1
Insecticide Use 1
Precautions 1
Insecticide Formulations 2
Preparation of Correct Insecticide Concentration 2
Dilution Table 2
Formulas 2
Animal Systemic Insecticides 4
Methods of Insecticide Application 4
Dilute Spray 4
Mist Spray 5
Compressed Air Spray 5
Residual Wall Spray 5
Space Sprays or Aerosols 5
Dip Vats 5
Back Rubber 9
Pour-On 9
Dust 9
Dust Bags 9
Biology and Control of Insects and Related Pests of Beef Cattle 12
Biting and Nuisance Flies 12
Black Flies 12
Biting Midge 13
Mosquitoes 13
Horse Flies and Deer Flies 14
Stable Fly ] 5
House Fly 16
Horn Fly 17
Face Fly 17
Control of Flies 18
Cattle Crubs 19
Lice 20
Ticks 22
Rocky Mountain Wood Tick 23
Spinose Ear Tick 23
Control of Ticks 24
Mange Mites 24
Sarcoptic Mange 25
Psoroptic Mange 25
Chorioptic Mange 26
Control of Mange Mites 26
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BIOLOGY AND CONTROL OF INSECT
AND RELATED PESTS OF BEEF CATTLE
Prepared by
John E. Lloyd, Professor of Entomology
Everett VI. Spackman, Extension Entomologist
Rabinder Kumar, Research Associate
University of Wyoming
Laramie, Wyoming
Introduction
Management of arthropod pests
is important to the modern livestock
producer. Selection of the proper
preventive and control practices
contributes to efficient livestock
production and provides wholesome
livestock products to the consumer.
The large volume of insecticide
used in the United States today must
be applied with maximum benefit to
man and minimum danger to human and
animal health as well as to the
environment. When it becomes
necessary for the livestock producer
to use an insecticide, it Is important
that the most appropriate compound
be applied both safely and
ef fectively.
In order to achieve the objectives
of this manual, the user should learn
three things: (1) recognition of
insect problems; (2) biological features
of the insects important in their pre-
vention and control; and (3) appropri-
ate management techniques. Recommen-
dations of specific insecticides are
not presented. The reader is urged to
consult Agricultural Experiment Station
and Agricultural Extension Service
bulletins for current insecticide
recommendations.
Insecticide Use
Precautions
Insecticides must be handled with
care because most are toxic to man and
animals as well as to insects.
When it becomes necessary to use
an insecticide, the label of the
appropriate formulation should be read
and understood. Be sure that the
formulation is approved for your
intended use. Some insecticide formu-
lations are for crop use only and not
for use on livestock. When not in
use, all insecticides should be placed
in a proper storage area that can be
locked securely.
Before using the insecticide,
thoroughly familiarize yourself with
safe handling procedures, symptoms of
poisoning, if any, and what to do in
case of an accident.
Apply the insecticide in a manner
consistent with directions on the
insecticide label. If the compound is
rot ready-to-use, then it must be
diluted to give the correct concentra-
tion. Prepare only as much dilute
material as will be needed at one time.
1
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Observe label precautions
regarding treatment of animals
that for reasons of health, age,
condition or breed may be adversely
affected by the treatment. Also
observe precautions concerning use
in conjunction with other insecti-
cides or with medications.
Observe the required time inter-
val between treatment and slaughter
of animals. The purpose of this
waiting period is to avoid residue
levels that may exceed established
tolerances.
Insecticide Formulations
Several different kinds of
insecticide formulations are avail-
able. Some, such as dusts or oil
solutions are readv-to-use directly
from the original container, while
others, such as wettable powders (WP)
and emulsifiable concentrates (EC)
must be diluted prior to application.
Wettable powders are dry concentrates
that are formulated with wetting
agents so they will disperse in water.
Agitation of the diluted material is
necessary to keep the insecticide in
suspension. Emulsifiable concentrate
insecticides also contain a high
percentage of active ingredient and
must be diluted prior to use.
Preparation of Correct Insecticide
Concentration
Preparation of the correct con-
centration of insecticide is essential
for successful control. Errors in
determining the quantity of the
insecticide concentrate that must be
mixed with water or oil can result
in the use of excess toxicant thai
is costly, and may lead to toxicity
or residue problems.
The concentration of insecticide
in wettable powders or emulsifiable
concentrates is expressed on the label.
The concentration of a wettable
powder is expressed as a percentage,
for example, 25% malathion wettable
powder. The concentration of an
emulsifiable concentrate may be
expressed as percent active ingred-
ient, or pounds of active ingredient
per gallon of concentrate. For
example, 11.6% Co-Ral® emulsifiable
concentrate contains 1 pound of
coumaphos per gallon.
The problem of determining the
quantity of wettable powder or
emulsifiable concentrate that will be
needed to prepare a certain volume
of dilute spray or dip liquid can be
solved rather easily with the help of
either a dilution table or a formula
as presented below.
Dilution Table.
To prepare a spray or dip with a
desired percentage of active ingredient,
only the concentration of the formula-
tion need to known to use the Dilution
Table. The figures presented in
the Table represent the amount of
pesticide formulation for each 100
gallons.
For example:
A 0,_5% concentration of coumaphos
(Co-Ral'^) is recommended for cattle
grub control. To make a 0.5% spray
using a 25% wettable powder (WP), the
Table tells us to mix 16 lb. of the
wettable powder in 100 gallons of
water.
Formulas
Emulsifiable concentrates. - Two
different formulas may be used to
determine the amount of emulsifiable
concentrate needed to prepare a spray
or dip containing a given percentage
of active ingredient. In the first,
the concentration of emulsifiable
concentrate is expressed as lb. of
2
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DILUTION TABLE
Percentage of actual chemical wanted
Formulation
0.0313%
0.0625%
0.12 5%
0.25%
0.5
%
1.0%
Wet table
Powder
(WP)
15% WP
1 2/3
lb
3
1/3
lb
6 2/3
lb
13
1/3 lb
26
2/3
lb
53
1/3 lb
2 5% WP
1
lb
2
lb
4
lb
8
lb
16
lb
32
lb
40% VP
5/3
lb
1
1/4
lb
2 1/2
lb
5
lb
10
lb
20
lb
50% wp
1/2
lb
1
lb
2
lb
4
lb
8
lb
16
lb
7 5% VP
1/3
lb
2/3
lb
1 1/3
lb
2
2/3 lb
5
1/3
lb
10
2/3 lb
Emulsifiable
Concentrate (EC)
1 lb actual/gal
(10-12% EC)
2
Pt
4
Pt
1
gal
2
gal
4
gal
8
gal
1.5 lb actual/gal
f s
h-1
U i
1
o
js.0
m
n
1 1/2
pt
3
Pt
6
Pt
1
1/2 gal
3
gal
6
gal
2 lb actual/gal
(25% EC)
1
Pt
?
Pt
4
Pt
1
gal
2
gal
4
gal
3 lb actual/gal
(33-35% EC)
3/4
pt
1
1/2
Pt
3
Pt
6
Pt
1
1/2
gal
3
gal
4 lb actual/gal
(40-50% EC)
1/2
pt
1
Pt
2
Pt
4
Pt
1
gal
2
gal
5 lb actual/gal
(57% EC)
7/16
Pt
7/8
pt
1 3/4
Pt
3
1/2 pt
7
Pt
1
3/4 gal
6 lb actual/gal
(60-65% EC)
3/8
Pt
3/4
pt
1 1/2
Pt
3
Pt
6
Pt
1
1/2 gal
;3 lb actual/gal
1/4
Pt
1/2
Pt
1
Pt
2
Pt
4
Pt
1
gal
lb = pounds
pt = pints
gal = gallons
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active ingredient per gallon. In the
second, the concentration is expressed
as % active ingredient.
gal
spray
wanted
X
% act j ve
ingredient
wanted
(8.3)
lb. active
ingredient/gal
of concentrate
X (100)
or,
% active ingredient in concentrate
% active ingredient wanted
number of parts of
finished spray or dip
that must contain 1
part of the concentrate
For example:
How many gallons of 25% lindane
(2 lb./gal) emulsifiable concentrate
are needed to make 100 gallons of
spray containing 0.25% lindane?
Using 2 lb. active ingredient/gal
(100) X (0.25) X (8.3) =
(2) X (100) 83
a spray or dip containing a given
percentage of active ingredient.
gal
spray
wanted
X
% active
ingredient
wanted
X (8.3)
(% active ingredient in WP)
For example:
How many pounds of lindane 25%
wettable powder are needed to make
100 gallons of spray containing 0.03%
lindane?
XI00) X (0.03) X (8.3)
25
1 lb.
Animal Systemic Insecticides
Some of the organophosphate
insecticides that are used to control
pests of beef cattle are systemicaily
active. That is, they are absorbed
and transported through the animal's
body by the circulatory system.
These compounds can be used for the
control of several internal and
external insect pests. These are not
the same as "plant systemic" insecti-
cides and must not be confused with
them.
or,
Using 25% active ingredient
25% = 100
0.25% 1
The dilution is one part 25%
lindane in 100 parts of f-inished spray
or dip. This would be equivalent to
1 gallon 25% lindane to 99 gallons
wa t e r.
Wettable powders. - The following
formula is used to determine the lb.
of wettable powder needed to prepare
Methods of Insecticide Application
Application techniques commonly
utilized in the control of several
different pests are discussed here.
More specific information is pre-
sented later along with the individual
pests. The purpose is to familiarize
the reader with common application
techniques and terminology.
Dilute Spray
This is a common method for
applying diluted insecticides to
livestock. Liquid insecticide is
applied by means of a livestock
A
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sprayer (Figure 1). The use of high
pressure, i.e., about 350 p.s.i., is
important in the use of systemic type
insecticides because wetting of the
skin is necessary. Lower pressures of
100 p.s.i. or less may be used to con-
trol those pests where merely wetting
of the hair coat is necessary. Sev-
eral animals may be sprayed at a time
by working them back and forth in a
small pen (Figure 2).
A spray gun that permits a vari-
able spray pattern is useful (Figure
3). A narrow spray stream may be
necessary under windy conditions or to
penetrate a dense hair coat.
It is important to calibrate the
sprayer. Determine the delivery in
gallons per minute for the particular
disc in the spray gun (usually a num-
ber 4, 5 or 6) and the pressure.
The amount of spray per animal will
vary with size of animal, and thickness of
hair coat due to time of year. For thorough
coverage of cattle in the winter, 1^ to 3
gallons of spray per cow and 1 to 2 gallons
per calf may be required.
Mist Spray
An electric or hand-operated
"mister" (Figure 4) may be used to
apply small quantities of relatively
concentrated insecticide spray to an
animal. A large nozzle opening is
desirable for a coarse spray that will
adhere to the hair coat of an animal.
Mist applicators are also used for
application of space sprays as dis-
cussed below.
Compressed Air Spray
An easy method of spraying a few
animals is with a hand-powered com-
pressed-air sprayer (Figure 5). These
sprayers make little noise and do not
frighten animals. They are also handy
for spot treatment of surfaces such as
walls and posts where flies tend to
congregate.
Residual Wall Spray
Wall sprays are applied at low
pressure, e.g. 80 p.s.i., to produce a
coarse spray. Spray may be applied
to fences, ceilings, and inside and
outside walls of buildings. Usually
animals should be removed from
buildings before spraying and one
should avoid spraying feed and water.
Space Sprays or Aerosols
This is a method for quickly
clearing spaces of flying insects. A
machine (Figure 7) is used that pro-
duces a finely directed mist or fog
that remains suspended in the air
for several hours. Usually the
application is most effective indoors
and must be repeated daily.
Dip Vats
Dipping is an excellent method
for obtaining thorough coverage.
Two popular types of dip vat can be
seen in Figure 8, the swim vat and
cage vat. The dip vat method
requires a relatively .large initial
expenditure for construction and
materials as well as chemicals.
However, there is no faster or more
thorough way of treating large numbers
of animals. Use of a community dip
vat is a good way to reduce the cost
to an individual rancher.
The dip vat may be located near a
convenient water source, but care should
be taken to avoid a location where
contamination of streams, ponds or
other water sources might occur.
Prior to charging, a dip vat
should be cleaned thoroughly. All
liquid, as well as solid material on
the bottom of the vat should be
removed and properly discarded. Check
with regulatory or extension personnel
for current regulations concerning
proper disposal.
The vat should lie charged immed-
iately prior to dipping. The volume
of the vat should be determined prior
5
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Fig. 1. A livestock sprayer.
Fig. 2. Application of an insecticide spray to cattle.
Fig. 3. Two different patterns of spray; a broad cone (3a) and a
narrow stream (3b).
6
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Fig. 4. A mist applicator.
Fig. 5. Small, hand-powered compressed
air sprayers.
Fig. 6. Residual wall spray.
7
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Fig. 7. An electric mist applicator (7a) and a gas-powered
fogger (7b).
Fig. 8. A swim-type dipping vat (8a) and a cage-type vat (8b)
8
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to charging. This can be determined
by pouring water into the vat from a
measured drum or tank, by metering
the water into the vat, or, if the
dimensions of the vat are known,
calculating the volume. Both emul-
sifiable concentrate and vettable
powder formulations should be sus-
pended in water in a premix tank before
being added to water in the vat.
If a vat is to be replenished
during dipping, it is advisable to
situate a tank or drum adjacent to
the vat. It should empty directly
into the vat. This container can
also be used in preparation of the
initial charge.
After filling or recharging the
vat, the contents should be mixed
thoroughly. Also, provision must he
made for mechanical agitation of the
vat to insure complete resuspension
of the contents after periods of non-
use. Compressed air or plunger boards
may be used for this purpose. A
plunger board is a board approximately
18 inches square with 1 inch holes
drilled on 3-inch centers. An up-and-
down plunger action with this mechanism
for approximately 15 minutes will
sufficiently agitate most vats.
Back Rubber
The back rubber (Figure 9) is an
inexpensive and effective self-treat-
ment device for cattle. It consists
of a 15 to 20-foot length of cable,
chain, or heavy wire around which
several layers of burlap are wrapped.
The back rubber is then suspended
between two posts, or one end is
attached to a post and the other is
anchored to the ground. The back
rubber, suspended between two posts,
should sag to about 18 to 24 inches
from theground at the center.
The back rubber is placed in an
area where cattle loaf, for example,
near water or a salt lick. The
selected insecticide should be mixed
with No. 2diesel fuel or furnace oil,
and applied at the rate of 1 gallon
for each 20 linear feet. The back
rubber should be recharged frequently
to keep it moist and effective.
Pour-On
The pour-on is a quick and simple
method of applying insecticides to
cattle (Figure 10). The method was
originally developed for application of
animal systemics for grub control. Now
it is used for some non-systemic
insecticides also. The pour-on solution
either an oil solution or a water
emulsion, is applied from a calibrated
dipper, evenly along the animals' back so
that none of the liquid drips off.
Usually the application rate is
between 4 and 1 oz per hundred lbs. of
body weight. Some newer formulations
designed for cattle grub or lice
control, are applied in even smaller
volume, and require special applica-
tion devices (Figure 11).
Dust
A small number of animals may be
individually treated with insecticide
dust. The dust may be applied by shaker
can or other means, then worked into
the hair coat (Figure 12).
Dust Bags
Dust bags are heavy (10 ounce
cloth) burlap sacks that are filled
with an approved insecticide dust
and suspended below backline height
in outdoor areas where cattle are
likely to pass (Figure 13). When an
animal bumps or rubs against the bag
a small quantity of dust sifts through
the fabric. Ready-made dust bags
can be purchased. These generally
consist of a grommeted burlap sack
with a plastic hood to protect the
hag from rain. A much less
expensive way is to purchase heavy
burlap sacks and insecticide dust
separately.
9
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Fig. 9. A cattle back rubber.
Fig. 10. A pour-on insecticide.
Fig. 11. Application devices for low volume (including spot-on)
pour-on type insecticides.
10
-------
Fig. 12. Hand dusting a single animal.
Fig. 13. Dust bags for cattle.
11
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Water tanks or salt blocks may
be fenced, and dust bags installed
in a gate so that cattle are forced
to use them. Frequently, cattle will
use the bags voluntarily after a
short period of adjustment if they
are suspended in a favorite loafing
place.
Biology and Control of Insects and
Related Pests of Beef Cattle
Biting Flies and Nuisance Flies
Adult flies are familiar to
everyone. Biting, blood-sucking
flies that are particularly bother-
some to cattle include horn fly,
stable fly, horse flies, deer
flies, mosquitoes, biting midges,
and black flies. The face fly and
house fly are. examples of nuisance
flies. They are bothersome even
though they do not bite and draw
blood.
Both biting and nuisance flies
affect the performance of cattle.
Flies will hinder grazing and resting,
and even force animals to run about
in order to be momentarily freed from
annoyance. In addition to annoyance,
some flies may be important in trans-
mission of organisms that cause cattle
diseases.
Black Flies
There are many species in the
black fly family Simuliidae,. and they
are among the smallest of the biting
flies that attack livestock. Fre-
quently, they are called buffalo gnats
because of their "humped back" appear-
ance. Black fly may be a misnomer,
because some species that attack live-
stock are frequently tan or yellowish
in color.
The four life stages of the black
fly are illustrated in Figure 14. The
duration of the life stages varies
Figure 14. Life stages of a black i
fly. The adult of this species is
approximately 3.5 mm.
considerably with the different
species. Several hundred eggs may be
deposited on or in the water by the
adult female. Larval and pupal black
flies spend their lives in running
water of rivers, canals or streams.
These aquatic stages are attached to
objects such as stones, logs and
submerged vegetation. After emergence,
adult flies are capable of moving great
distances from the waters of their
o rigin.
Female black flies are attracted
in large swarms to the host animal.
They fly about and get into the nose,
eyes, ears and mouth. They feed
either on exposed areas of skin or deep
within the hair coat. They lacerate
the skin and suck oozing blood. Strong
anticoagulants in the saliva prevent
coagulation of the blood for some time
after the bite. A large painful welt
may develop at the site of the bite.
12
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Some black fly species that are
serious pests of cattle prefer to
feed on animals. Significant losses
in weight gains and milk production
have been reported during black fly
outbreaks. During severe outbreaks,
death losses have been reported.
Biting Midge
The very tiny, bloodsucking midge
or gnat, Culicoides variipennis, is a
common pest of livestock (Figure 15).
Swarms of these midges may attack,
primarily in the evening. Large
numbers may be responsible for sores
and scabby areas along the belly of
livestock.
Figure 15. The life stages of
Culicoides variipennis, a biting
midge. The adult is approximately
2 mm.
In the United States, C. varii-
pennis is the primary vector of blue-
tongue, a virus disease of ruminants,
including cattle and sheep. It is
also a vector of epizootic hemorrhagic
disease of deer and cattle.
Ideal larval breeding sites for
C. variipennis usually consist of non-
vegetated, open areas of soft silty
mud, exposed to direct sunlight.
Such areas may be found in natural
marshy areas or along the margins of
alkaline bodies of water in the West.
Very dense populations of larvae can
occur as a result of pollution by
livestock or human wastes, e.g., near
feedlots or inadequate human sewage
facilities.
Mosquitoes
Adult mosquitoes are small (body
length about 6 mm or less) delicate
organisms with a conspicuous long snout
or proboscis. Mosquito life stages
are egg, larva, pupa and adult. The
eggs are laid on or near water. When
in contact with water the eggs hatch
and produce the aquatic immature
stages. The larvae or "wigglers", with
very few exceptions, are found in
standing water with relatively little
movement or wave action.
In the larval stage the mosquito
attains most of its growth. After four
larval stages of increasing size,
larvae molt to the pupal stage. The
pupa or "tumbler" moves about in the
water by a tumbling action. After a
few days, the pupa swims to the
surface of the water, and the adult
mosquito emerges from a slit in the
"back" of the pupa.
Usually, the adult male mosquitoes
emerge first and remain near the larval
habitat and fertilize females shortly
after their emergence. Most fertilized
female mosquitoes then require a blood
meal before egg-laying.
Female mosquitoes of the genera
Aedes and Culex are among the more
serious pests of livestock. Examples
of the two genera are presented in
Figure 16. Note that these genera
can be distinguished by the shape of the
tip of the abdomen.
Aedes, flood water mosquitoes are
extremely important pests of livestock
because there are many species, and
13
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Figure 16. Female mosquitoes of two
genera. The tip of the abdomen is
pointed in Aedes and blunt in Culex.
These specimens are approximately
5-6 mm.
they appear in tremendous numbers.
They are produced in vast inundated
areas such as marshes, flood plains,
snow pools and irrigated meadows.
The adult females are avid feeders on
man and his animals. While most
bites occur during the early morning
and evening hours, some species will
readily feed during the daylight hours.
The life cycle of a typical Aedes
mosquito is presented in Figure 17.
The eggs are laid on moist soil in areas
subject to reflooding, and where the
females are somewhat protected from
the wind. The eggs may survive for
several years before flooding. In
temperate areas, Aedes mosquitoes
overwinter in the egg stage, then hatch
in the spring due to spring runoff or
irrigation. Repeated flooding through
the warm months will produce additional
broods of some species.
r
j
Pieot o> i«rUeri
Law* o> mqgfen
0'-
-Vo'i
J
Larvoe
-------
Chr/tccs
Oeer fly
ToDanos
Hose Ity
Figure 19. Adult deer fly and horse
flies. These specimens range in size
from 9 to 28 mm.
The life stages of a horse fly are
presented in Figure 20. Usually, the
female flies lay their eggs, often
attached to vegetation, near the damp
or wet soil of streams, marshes, lakes
or ponds. After a short incubation
period of approximately 1 week, larvae
hatch, then develop in water or wet
soil. Later in the season, or possi-
bly the following year, full grown
larvae migrate to drier soil. Eacli
forms a pupal case, from which an
adult fly will eventually emerge.
Stable Fly
illustrated in Figure 19. Deer flies
are usually about the same size or a
little larger than the ordinary house
fly and frequently have distinct
patterns on their wings. Horse flies
are larger and darker than deer flies.
Some are quite large.
Adult horse flies and deer flies
usually appear in large numbers at
certain times during the season.
Females attack animals, and the bite,
which is extremely painful, causes
considerable flow of blood. Fre-
quently, clusters of other kinds of
flies will surround pools of blood
formed by the feeding of horse flies.
The stable fly, Stomoxys calcitrans
looks much like a house fly except that
it has a prominent beak (Figure 21).
Figure 20. Life stages of a horse fly-
Figure 21. The adult stable fly, and
enlarged side-view of head and piercing
niouthparts. The specimen is approxi-
mately 8 mm.
Eggs of the stable fly are
deposited in wet and decaying organic
matter. Wet feed or hay contaminated
with manure, urine, and mud are parti-
cularly good media for development of
15
-------
of stable fly larvae or maggots. In
areas where large bodies of water occur,
stable fly may be abundant because
piles of decaying "seaweed" are good
larvae media.
Adult
Mi
IW*
Eggs
Pupa
/
Figure 22. The life stages of the
stable fly.
The life stages of the stable fly
are presented in Figure 22. After
egg hatching, the larvae pass through
three larval stages. After the final
larval stage a pupal or inactive
stage is formed. Eventually an
adult fly emerges from the pupal
case. Because of rapid development
from egg to adult, about 24 days,
stable fly can produce several genera-
tions per season.
Both male and female stable fly
are found abundantly on the legs of
cattle where they come to feed. They
have a stout proboscis with which they
pierce the skin and suck blood. The
bite is painful. Research has shown
that infestations of stable fly reduce
weight gains of feeder cattle and
reduce milk and butterfat production of
dairy cattle.
Stable fly is a particularly ser-
ious problem in areas where there is
considerable suitable medium for
production of larvae. Such conditions
frequently exist in and around live-
stock buildings and feedlots where
stable fly can be found indoors as well
as out.
House Fly
Figure 23. The adult house f.ly and an
enlarged, side-view of head and spong-
ing-type mouthparts. The specimen is
approximately 7 mm.
The house fly, Musca domestica,
is a wide-spread pest that is familiar
to everyone. Though it does not
inflict a painful bite because of the
nature of its mouthparts (Figure 23),
it is a very annoying insect and a
potential vector of many disease-
causing organisms of man.
The four life stages of the house
fly, egg, larva, pupa and adult are
presented in Figure 2^. The complete
16
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life cycle requires approximately two
weeks in warm weather.
Eggs
Pupa
3rd Stoge
Larva
Figure 24. The life stages of the
house fly'.
The house fly is a pest closely
associated with man's activities. It
is able to utilize many kinds of
organic matter, such as found in
garbage, as a larval medium. It is
also able to utilize all sorts of
excrement. Primarily, it is consid-
ered a pest in and around livestock
buildings and feedlots.
Horn Fly
The adult horn fly, Haematobia
irritans, is about half the size of
a house fly or stable fly (Figure 25).
Both sexes of the horn fly have beaks
which they utilize to obtain blood
meals. The horn fly may reach very
large populations on cattle, e.g.,
thousands of flies per animal.
Unlike most other flies, the horn
fly remains with the animal at all
times. Ordinarily the flies congregate
Figure 25.
horn fly.
4 mm.
The life cycle of the
The adult is approximately
on the shoulders and sides of the
animal. During extremely hot sunshiny
or rainy weather the flies congregate
on the underside of the belly.
The adult female leaves the animal
to deposit eggs in fresh cattle drop-
pings then returns. After hatching,
the three successive larval stages
develop in the dung pat. Larval
development is rapid and requires only
2^ to 3 days. Pupation takes place in
the soil beneath the dung pat or else
in the dung pat itself depending on
moisture conditions of the soil.
The pupal period lasts 5 to 6 days then
the adults emerge and seek out a host.
In some areas of the country the
horn fly is considered the greatest
pest of range cattle. It has been
estimated that 288,000 flies would con-
sume 1 quart of blood por day. Annual
losses due to horn fly attack have
been estimated at 150 million dollars.
Face Fly
The face fly, Musca autumnalis, is
an important, non-biting, nuisance-type
fly affecting cattle. The insect looks
very much like the house fly. In fact,
it is very difficult to distinguish the
17
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two except in the pupal stage which
is red-brown in the case of the house
fly and white for the face fly.
The face fly is primarily a
pest of cattle. It has the annoying
habit of landing on the face and prob-
ing the eyes and nostrils. Face fly
may be quite abundant with many, e.g.,
50 or more, on the face at one time.
Studies of the disease condition
known as "pink eye" have indicated
that face fly may play a role in
disease transmission and physical
abrasion of eyes.
Fig. 26. The life cycle of the face
fly. The adult is about 8 mm.
The life stages of the face fly
are egg, larva, pupa and adult (Figure
26). The adult female face fly lays
its eggs in fresh cattle droppings.
Development occurs only in fresh,
undisturbed droppings sucli as those
on pasture. The eggs hatch within
a day or two, and the larvae or
maggots grow rapidly within the
manure. After a period of four to
five days, including three molts to
permit body growth, the maggots seek
a drier location at the edge of the
dropping and form an inactive pupal
case. After a week or more the
adult fly emerges from the pupal case.
Due to the short life cycle, many face
Ely generations can be produced in one
season.
The face fly is a strong flier
and can travel several miles.
Individual face flies do not remain
with cattle at all times and, usually,
do not enter darkened barns or stables.
The adult face fly passes the winter
in the adult stage within shelters
and may be a household pest in the
spring when the flies emerge from
their indoor hibernation quarters.
Control of Flies
Insecticidal control of flies by
direct application to cattle is often
difficult and frequently unsatisfac-
tory with one exception. Because of
its constant association with cattle,
and its susceptibility to insectici-
cides, horn fly is relatively easy to
control by means of sprays, dips,
back rubbers, dusts and dust bags.
These methods may also provide relief
from annoyance by other biting and
nuisance type flies. Since fly popu-
lations usually build up again follow-
ing a single application of insecticide,
methods that permit frequent retreat-
ment, preferably self-treatment, are
preferred. Examples are oilers,
back rubbers and dust bags.
Protection of livestock from flies
is possible through frequent applica-
tions of fast acting insecticides or
insect ide-repellent combinat ions.
This is practical only if animals can
be handled frequently.
Much can be done to alleviate
house fly and stable fly problems
around livestock buildings and feed-
lots through sanitation and proper
management of manure. Basically this
means either elimination of larval
habitat or modification in such a way
as to make it unsuitable for fly
production. Prompt and regular
removal and spreading of manure, soiled
bedding and spilled feed from live-
stock buildings is a good fly preventive
measure, as is elimination of wet areas
18
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in livestock pens. Some of these
areas can be prevented through proper
construction, while others can be
eliminated by periodically breaking
up and spreading the mixture oŁ soil,
manure, water, etc.
Insecticide-based control is
possible when a fly problem gets out
of hand around livestock housing
facilities. Residual sprays, applied
to walls, ceilings, fences and other
favored resting places are effective
and may last several weeks. For fly
control in buildings the various
insecticide baits are effective
against house fly if used properly.
For fast but temporary control of
flying insects in confined areas,
fogs, aerosols or mist applications
are effective.
Out-of-doors, mist applications
that involve a finely divided spray
will disperse quite rapidly. The dis-
persed droplets kill only the flies
they contact. This method, including
ground and aerial application, can be
used, however, for temporary relief
from a serious outbreak of biting
flies.
Many populations of the biting
midge, Culicoides variipennis are
produced inadvertently on farms and
ranches, and may be eliminated through
management or cultural practices.
Examples of such larval breeding
sites are: sites where water-borne
human sewage flows out onto the
ground; puddles contaminated with
manure such as those that occur near
water tanks and in livestock pens;
and dirt stock ponds where manure
has been trampled into the shallow
water along the edge.
Mosquito annovnm ni.-i-- be
reduced through "I in: in ii > "n ,
i.e., elimination of water thai,
provides a suitable habitat for
mosquito larvae. Mosquito larvae
can also be eliminated through the
removal of protective emergent vegeta-
tion from places such as drainage
ditches and the edges of ponds and
1agoons.
In several locations, communities
as well as smaller groups of farmers
and ranchers have organized for
mosquito control. Primarily these
programs have involved aerial applica-
tion of larvicides to vast areas of
flooded land.
Cattle Grubs
Two species of cattle grub are
important parasites in North America,
the common cattle grub, Hypoderma
lineaturn. and the northern cattle
grub, Hypoderma bovis. Losses' due
to these insects, which include hide
damage, carcass damage, and management
difficulties, have recently been
estimated as high as $10 per head.
The grub-like larvae which
appear in the backs of cattle in the
spring are familiar to almost every-
one who handles cattle. The adult
flies, which somewhat resemble bees,
are less familiar. Frequently, one
observes the reaction of cattle to egg-
laying attacks of the adult fly,
especially the northern species. This
reaction, which involves running
frantically with tails raised in
the air, is termed "gadding".
The life cycles of the two species
are similar, and that of the common
species is illustrated in Figure 27.
The adult flies appear in spring and
summer, with the common species the
first on the wing. The eggs are
attached to the hairs of the host, pre-
ferably on the lower parts of the body
(hence the term "heel fly"). They
lutcli in three or four days into
larvae or tiny grubs. The grubs
burrow into the skin of the animal
then migrate for several months
through body tissue until they reach
19
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,n the Host
Figure 27. The life cycle of the
common cattle grub. The adult is
approximately 14 mm.
the esophagus, in the case of the
common cattle grub, or the spinal
canal in the case of the northern
cattle grub. The grubs stay at these
locations for several weeks then
migrate to the area of the back
directly beneath the hide. They
then form breathing holes to the
outside and grow to full size. At
this stage they are called "warbles".
After reaching full growth, the
larva drops from the back and forms
an inactive pupa on the ground.
Adult flies emerge from the pupae
in the spring and summer when weather
is sufficiently warm. These flies
mate, then seek cattle for egg-laying
and the beginning of a new annua]
cycle. The adult fly does not feed.
Control of cattle grubs in beef
cattle is simple because of the avail-
ability of animal systemic insecticides.
These chemicals may be applied as a
high pressure spray, a dip, or a pour-
on. They should be applied after
cessation of adult fly activity in
late summer or fall.
It may be unwise to use animal
systemics at the rates recommended
for grub control late in the fall or
during the winter unless the cattle
were treated earlier for grub control.
Cattle may demonstrate a side reaction
due to the deaths of grubs in the
esophagus or spinal canal. Reaction
to the death of the common grub may
involve bloat and excessive saliva-
tion, whereas reaction to death of
northern grubs may be a paralysis of
the hind quarters. The safe time for
application of systemic insecticides
depends on the geographical location
of the cattle during the egg-laying
activity of the adult flies.
Lice
Lice are considered by many the
most serious insect pests of live-
stock on the North American continent.
Livestock producers' losses to lice
are estimated at over 6 million dollars
per year.
Two types of lice infest cattle,
biting or chewing lice and sucking
lice. The biting lice feed on the
outer layers of skin and crawl over
the skin and hair. The skin becomes
irritated and the animals will rub
themselves trying to relieve the
itching. Sucking lice may remove con-
siderable blood because they pierce
the skin and suck blood. Their
activities are also very irritating.
Lice can be extremely injurious
to animals. They help create open
sores which may provide entrance for
infectious agents. Animals may
become nervous and edgy, go off feed,
and fail to gain at their normal rate.
Lack of stamina may make them susceptible
to respiratory infections.
20
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Studies showing the effect of
cattle lice on weight gains of cattle
are available from many parts of the
world. The benefit derived from
spraying cattle for lice is from 0.10
to 1.20 lb. per animal per day depend-
ing upon the severity of the infesta-
tion and the condition of the cattle.
The most severely affected animals
are those under stress.
Heavy cattle lice infestations
are easy to recognize. Bluish colored
patches may appear on heads, necks and
shoulders of cattle. Lice may be seen
climbing about on the host's facial
hairs. Cattle scratch and rub against
objects and remove hair in an attempt
to relieve itching. All of these
signs may mean that the lice have
reached serious levels, and will cause
a substantial monetary loss unless
controlled.
Four different species of lice
are important parasites of cattle in
temperate areas of the United States
(Figure 28). Only one, Bovicola bovis,
(the cattle biting louseTi is a chew-
ing louse. This species is a little
red-colored louse about 1.5 mm-in
length. When present in great numbers
these lice produce skin lesions and
cause hair to fall out in clumps. The
chewing louse is primarily a pest
of cattle in confinement.
The three sucking louse species
are common on beef cattle. Haematopinus
eurysternus, the shortnosed cattle
louse, is about 4 mm long; Linognathus
vitull, the longnosed cattle louse, is
about 2 mm long; and Solenopotes
capillatus, the little bJue cattle
louse, is about 1.5 mm in length.
These lice derive nutrition from the
host animal by sucking blood, and
extremely heavy infestations produce
anemia in cattle.
All stages of cattle lice are
found exclusively on the host animal.
They are specific to cattle, and they
spread from one animal to the next
Figure 28. Four lice species that
commonly infest cattle: A, the cattle
biting louse (1.5 mm); B, the short-
nosed cattle louse (4 mm); C, the long-
nosed cattle louse (3 mm); and D, the
little blue cattle louse (1.5 mm).
by contact. All four lice species have
similar life cycles (Figure 29). The
eŁgs are glued to hairs, and in a
severe infestation, are very noticeable
The duration of the egg stage varies,
hut usually they hatch after one to two
weeks. The nymplial lice look very much
like the adults except that they are
smaller. There are three nymphal
instars which ]ast between two to three
weeks before maturing to adulthood.
Adults may live approximately two weeks
producing one to two eggs per day.
Although lice occur on cattle year
round, the most severe infestations
occur during the winter and early
21
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Figure 29. Life cycle of a louse.
spring months. Populations build up
in the fall and decline in late spring.
The reason for abundance in the winter
is unknown, but is probably due to a
number of factors.
Often one or two animals in a
herd appear to be much more suscep-
tible to infestations of lice. Some
ranchers believe that elimination of
these "carrier" animals from the herd
greatly reduces their problems with
cattle lice.
For best control using an insecti-
cide, a preventive treatment should be
applied early in the fall before cold
weather and while lice populations
are at a low level. Early treatment
also eliminates losses that are
known to occur before lice populations
are so heavy as to be visible. Con-
trol at this time can be coupled with
control of cattle grubs by means of
animal systemic insecticides. Sys-
temics applied as a dip or spray for
cattle grub control also control lice,
both by direct contact and systemic
activity. Certain of the pour-on
type systemic insecticides also pro-
vide lice control in addition to cattle
grub control.
Insecticides for lice control may
be applied in several different ways.
Depending on the compound selected, a
second application, two weeks following
the first, may be necessary to kill
lice that hatched from eggs that were
present at the time of the first
applica t ion.
The two conventional methods of
insecticide application are dips and
sprays. These give excellent con-
trol because of thorough coverage
of the animal and some effect against
eggs or against nymphs that hatch
shortly after treatment. More
laborious methods such as misting or
hand-dusting individual animals are
frequently suitable for use on just
a few animals.
One major drawback to lice control
has been the fact that control
measures may be needed at the time
of year when weather prohibits spray-
ing or dipping. New, "pour-on" type
insecticide formulations have been
developed specifically for lice control
and these products avoid the problem
of chilling the animals.
Cattle lice problems may also be
alleviated by providing self-treatment
devices such as back rubbers and dust
bags. Since the animals are inclined
to rub against things, these methods
are quite suitable.
Ticks
Frequently livestock become
infested with ticks. Ticks are not
insects, and do not resemble them.
Ticks as well as mites are more
closely related to spiders, scorpions,
etc. Ticks have four developmental
stages: egg, larva, nymph, and adult.
The larvae, nymphs, and adults can be
differentiated according to size.
Larval ticks possess six legs, whereas
adults and nymphs have eight.
Ticks are obligatory parasites and
require blood meals in order to
develop. The tick feeds by driving its
mouth parts into the skin of the host.
The feeding of ticks produces wounds,
and removes large quantities of blood.
22
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Some ticks transmit disease organisms
or cause paralysis in -livestock.
Rocky Mountain Wood Tick
Figure 30. The Rocky Mountain wood
tick. This adult, unfed female is
about 5.0 mm.
The Rocky Mountain wood tick,
Dermacentor andersoni (Figure 30),
attacks most domesticated animals. In
addition to being very pestiferous,
toxins secreted by the female tick can
paralyze many animals including
cattle, man, sheep, and horses.
Rocky Mountain wood ticks may
cause tick paralysis in livestock by
the feeding of females and their injec-
tion of a toxin into the blood stream
of the host. First symptoms ot afflic-
ted anima]s are weakness and staggers.
In a few hours they are incapable of
standing, and finally death ensues.
Animals can be saved by removing the
offending ticks. Recovery may bo rapid
(within an hour) or it may take a
couple of days. When recovery does not
occur within this time, it is an
indication that some ticks may have
been overlooked in the removal.
L
t Unftd „~m
f A' smell mowuM'
female I s
i
Adult T
le-noie I
'
Lar»0
or'Seefl T-Ck , . .
j smoll mommol
Blood enqcrqefl j
lemoie f
Egg most
Figure 31. Life cycle of the Rocky
Mountain wood tick.
The Rocky. Mountain wood tick is
a "three host tick" and has a com-
plicated life cycle (Figure 31) . It
is a problem in the spring of the
year when adults come out of hiberna-
tion. They climb upon vegetation, and
wait to attach to a suitable large
mammal host passing by. Mating and
feeding occur on the host, with the
female dropping off the host in about
one to three weeks. Egg-laying
takes place on the ground in a shel-
tered location. Over 6,000 eggs can
be produced by one female. The larval
or seed ticks hatch in a month. These,
if fortunate, attach to a small wild
mammal host where they feed for a
period of two to eight days, then drop
off. Nymphs appear three weeks after
the larvae drop. At this time they
may either hibernate that winter as
nymphs or find another small mammal
host. Tf another host is found, the
tick feeds, drops off, and molts; then
spends the winter as an unfed adult.
Overwintering nymphs seek small
mamma] hosts the following summer, feed
for about a week, drop off the host,
molt and overwinter as unfed adults.
Spinose Ear Tick
The spinose ear tick, Otobius
23
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megnini, is a serious pest of many
species of domesticated and wild
animals. It is considered primarily
a pest in warmer climates, but has
become locally established in temper-
ate regions. The larvae and nymphs
of this species are found in the ears
of horses, cattle, sheep, dogs, cats,
deer, rabbits and numerous other
domesticated and wild animals. They
are quite abundant during the summer
months.
eggs that have been laid on the ground.
The larvae climb onto weeds, vegetation,
and feed troughs to contact host
animals. After attaching to the
host, the larval tick moves to the
ear where it attaches to the delicate
.lining of the ear and engorges. It
molts in one to two weeks to the
nymphal stages, which may remain in the
ear up to six months. Nymphs then drop
to the ground, molt to the adult, mate
and lay eggs.
Figure 32. Life cycle of the
spinose ear tick. The engorged larva
and nymph, which occur within the ear
are approximately 3.5 and 7.5 mm,
respectively.
The nymphs and larvae (Figure
32) of this tick cause injury by
puncturing the tender skin within the
ear and sucking blood. Wounds may
become Infected with bacteria. Plugs
formed by accumulation of ticks, their
excretions, and ear wax may block the
ear passage completely. A tendency
for the animal to rub and scratch
affected ears may result in extensive
lacerations.
The life cycle of the spinose ear
tick is complicated. It is a one-host
tick, meaning that all parasitic
stages of any individual tick remain
on one host. Larval ticks hatch from
Control of Ticks
Thorough coverage by means of
spray or dip is necessary for control
of the Rocky Mountain wood tick.
Several different insecticides are
approved for this purpose. For con-
trol of the spinose ear tick, approved
dust or oil solution formulations must
be applied into the ears of infected
animals, or'insecticide impregnated
car tags may be used.
Mange Mites
Several different mite species
produce a contagious disease of the
skin of domestic animals known as
mange. The type of mange is named
after the mite causing it, e.g.
sarcoptic mange, psoroptic mange, and
chorioptic mange which are caused by
Sarcoptes, Psoroptes, and Chorioptes
mites, respectively. Microscopic
examination is necessary for identi-
fication of the type of mange present,
because mites are barely visible to the
naked eye.
All of these mites have develop-
mental stages similar to those of ticks,
i.e. eggs, larvae, nymphs, and adults
(Figure 33). All stages are found on
the host animal and are spread by con-
tact between animals or with contami-
nated equipment.
The symptoms of the disease may be
obvious, and may consist of blisters
24
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Figure 33. The life stages of Chori-
optes bovis, a mange mite.
and small bumps in the skin, swelling
and inflammation of the skin, scabs
which consist of serum and scruf,
and, in advanced cases, a dry leathery
skin condition may follow. The
disease may be characterized by
intense itching.
Sarcoptic Mange
Figure 34. Sarcoptes scabiei, a
mange mite. These mites are micro-
scopic in size.
Adult sarcoptic mites (Figure 34)
burrow within the skin of the host and
cause severe irritation. The adult
female makes long channels within the
horny surface of the skin. The eggs
are laid within these burrows.
Development of the mite from egg to
reproductive adult takes approximately
two weeks. Lesions usually first
appear on the head, neck and shoulders,
then spread to other parts of the body.
As the host scratches to relieve
irritation, blisters and small bumps
or ridges develop. Further scratching
causes the blisters to break, forming
scabs. The skin may crack and ooze
blood and pus. Dandruff is abundant
and in advanced cases the affected skin
becomes dry, wrinkled, and hairless,
and remains so for some time.
Figure 35. Psoroptes ovis, the causa-
tive agent of scabies in cattle. These
mites are microscopic in size.
Psoroptic mange is common scabies
in cattle. Usually it is most severe
in winter, and it is caused by
Psoroptic Mange
25
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Psoroptes ovis (Figure 35). It is a
notifiable and quarantinable disease,
and when suspected should be
reported immediately to regulatory
officials.
Psoroptic mites do not burrow in
the skin of the host. Instead, by
pricking the skin to feed, they cause
serum to ooze from the wounds. Accu-
mulation of serum causes the formation
of scabs which usually start on the
withers then spread along the neck and
back, over the shoulders and brisket
to the belly and flanks. Psoroptes
infestations eventually may involve
large areas of skin all over the body.
In severe cases deaths of animals are
not uncommon.
The life cycle requires about two
weeks and the infestation can build
rapidly. Psoroptes mites occur
abundantly under the outer edges of the
the scabs. Cattle rub and scratch
because of the severe irritation, and
this results in rapid spread of the
disease to other animals.
Chorioptic Mange
This form of mange in probably the
most widespread in cattle, though
mangy skin lesions may be rare.
Chorioptes (Figure 36) infestations
start in the region of the feet and
lower hind legs or the tail. The
disease can then spread to other parts
of the body.
Control of Mange Mites
Dipping or thoroughly spraying
are the only treatments for mange
control in cattle. Current state and
federal regulations concerning treat-
ment of Psoroptes-infested livestock
must be followed. Vat dipping is
the preferred method for treating
cattle and most other species of
animals. Cattle may also be sprayed
using a spray-dip-machine.
Fig. 36. Chorioptes bovis, a mange
mite. These mites are microscopic
in size.
26
U.S. GOVERNMENT PRINTING OFFICE: 1981-680-148/74 Region No. 8
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