Insects in relation to national defense


Material Information

Insects in relation to national defense
Series Title:
Its Circular no. 1-23. Feb. 1941-Jan. 1944
Added title page title:
Insects in relation to national defense, circular
Physical Description:
24 nos. in 1 v. : ill., photos., map, plans, diagrs. ; 23 cm.
United States -- Bureau of Entomology and Plant Quarantine
U.S. Govt. Print. Off.
Place of Publication:
Publication Date:


Subjects / Keywords:
Beneficial insects   ( lcsh )
Insect pests   ( lcsh )
Insecticides   ( lcsh )
Fumigation   ( lcsh )
World War, 1939-1945 -- Health aspects   ( lcsh )
serial   ( sobekcm )
non-fiction   ( marcgt )


General Note:
Reproduced from type-written copy.
General Note:
Includes bibliographical references.

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029081698
oclc - 09471812
lcc - SB931 .U44
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Full Text


NAT 1 0

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Circular 19



October 1943


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Digitized by the Internet Archive
in 2013


/arch Is/i nsectsi n relatio00u nit_


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Circular 19 Livestock Insects


Table of Contents


Insects Attacking Horses

Lice ............
Mange Mites ........
Sarcoptic ........
'Psoroptic ........
Chorioptic .......
Stablefly or Dogfly
Horse Bots .......
Horn Flies .........
Screwworms .........
Housefly Transmission
to Horses ........
Chicken and Bird Mites
and Pigeons ........
Insects Attacking Dogs
Fleas, Chiggers, and
Mange Mites ........


g e e
g e e
* g e
g e e
* O
* *




COO..0 Re *e 0.. 0@
* ee...... Cegeege...

Roundworm Parasite

Pests of Horses

ks ..... ...
e @O@g.... @ eg . g~@

*o eeo ge e* 0g..***o e # g*... e** *** .0

A Pest of Pigeons:
References .......

The Pigeon Fly
gee...... e@g....


Horses, dogs, and pigeons used in the
armed forces are subject to attack by a number
of insects which not only lower the efficiency
of animals but also may carry diseases to them.
Lice injure horses by sucking their blood, thus




Circular 19 Livestock Insects

lowering their vitality and in severe cases,
causing death. Several kinds of mange mites
live in or on the surface of the skin of horses
and produce a condition termed scabies or mange.
Animals are greatly annoyed by the intense itch-
ing caused by this disease and often break open
the scabs or nodules in their effort to secure
relief. In severe cases animals may succumb.
Mange in dogs is also caused by the presence of
mange mites. Lice suck the blood of dogs and
are a drain on the animals' nervous energy.
The vitality of pigeons used as messengers is
often lowered and their performance is handi-
capped by the presence of several different
insects. One such pest, the pigeon fly, sucks
the blood of these birds and in addition is
known to carry pigeon malaria to them. Mites
on pigeons are irritating and in some cases
cause deformities.


Lice, mites, dogflies or stableflies,
and horse bots are all common pests of horses,
while horn flies, screwworms, and chicken and
bird mites occasionally are annoying to these


Introduction.--Lice attacking livestock
are of two types--sucking and biting. Both are
wingless, have flattened bodies, and legs which
are somewhat adapted for clinging to hairs.
In general, the sucking lice may be distinguished
from the biting lice as follows: The heads of
sucking lice are long and pointed, being longer
than broad, the mouth parts are formed for suck-
ing and piercing, and the compound eyes are
indistinct. In contrast, the biting lice have
short, rounded heads, chewing mouth parts, and
a pair of simple eyes. The sucking lice are
the more injurious of the two as pests of mam-
mals, since they puncture the skin and suck
their blood. As a result the animal's vitality

Circular 19 Livestock Insects

is lowered, it loses weight, and occasionally,
if the infestation is very severe, th animal
may die. The biting lice generally attack birds,
but a number of species also live on mammals,
feeding on hair, dermal scales, and exudations
from the skin. The irritation is largely
caused, however, by the insects crawling on the
animals and their continuous gnawing on the
skin, rather than sucking blood. This produces
restlessness, failure to eat, and loss of weight,
and stunts the growth of young animals. In addi-
tion, infestations by either kind of lice make
animals vulnerable to attack by other insects.
Both sucking and biting lice are spread chiefly
by animals in direct contact with one another,
although infested equipment and premises are
further sources of infestation.

Description and life history.--In the
United States the sucking horse louse (Haema-
topinus asini (L.)) (fig. 1) is the most impor-
tant of three species of lice attacking horses.
About one-quarter of an inch long, this louse
is similar to the biting species except that
it is much larger and has a long, pointed head.
The female attaches her eggs firmly to the hairs
of the animal where they hatch usually in 12
to 14 days. In about 10 or 11 days after hatch-
ing, females begin laying eggs. The remaining
two species which frequently annoy horses are
biting lice, Trichodectes pilosus Giebel, and
T. equi (L.) (fig. 2). These are generally
yellowish or reddish brown in color. They attach
their eggs in the same general w-." as the suck-
ing lice. Eggs hatch in about 10 days. Both
sucking and biting lice live only a few days
when removed from their host. During the summer
most of the lice disappear with the shedding of
the animal's hair, but a few remain and the
infestation builds up again during the next

Circular 19 Livestock Insects

Fig. 2.--Biting
horse louse.

Fig. 1.--Sucking horse louse.

Injury.--As a result of severe infesta-
tions of lice, the coat of the animal becomes
rough, and owing to frequent rubbing, patches
of hair are removed and abrasions are made in
the skin. In addition, the animal's vitality
is lowered.

Control.--In order to eliminate lice as
well as eggs, it is necessary to dip horses
twice, with an interval of 14 to 16 days. The
dips generally recommended are, in order of
their importance: arsenical solution, coal
tar creosote, and nicotine.

1. Arsenical solution: Proprietary
cattle dips used to control the cattle fever
tick are suitable for use on horses, mules, and
asses against lice. These dips should be mixed
and used at the strength recommended on the
container. Caution: Do not let animals drink

Circular 19 Livestock Insects

* dip, do not get clothing wet with dip, and
wash hands frequently.

2. Coal tar creosote: This material
is sold under many trade names and is satisfac-
tory when diluted with soft water. It should
not be used in hard or alkaline water as it may
not mix well with water and may injure the ani-
mals. The dip may be used warm or cold, but
if warm, should not exceed 95 F.

3. Nicotine: Nicotine dips may be pur-
chased under various trade names but should be
diluted with water in order to contain not less
than five hundredths (.05) of 1 percent nico-
tine. A solution of nicotine, if used much
stronger, may injure animals. This dip is used
warm but it should not be heated above 1100 FP,
and the temperature of the bath should be kept
at 90 to 95 F. Caution: Avoid using any
nicotine dip, the strength of which is not
given on the container. Follow instructions
on the label.

4. Dry treatment: In case dipping vats
are not available or if the season of the year
does not warrant dipping, dusting powders may
be applied. Powders are of value in holding
parasites in check but as a rule cannot be
relied upon to control sucking lice. Sodium
fluoride is effective in controlling biting
lice when.applied with a dust gun, shaker, or
by hand. Care should be taken not to apply this
material freely around natural body openings
or where the skin is very thin or hairless.
Sodium fluoride should not be rubbed into the
skin. Derris, cube, or pyrethrum powders are
reasonably effective against both biting and
sucking lice.

Circular 19 Livestock Insects


Mange of animals is a contagious skin
disease produced by tiny spider-like parasites
known as mites which live on or beneath the
surface of the skin. They are commonly known
as sarcoptic, psoroptic, and chorioptic mites,
all of which live at the expense of their hosts
by puncturing the skin and causing lesions or
wounds. Because of the infectious nature of
mites and their mode of living on or in the skin,
mange is considered as a communicable disease.
So far as is known these mites carry no organ-
isms which can be transferred to the blood stream
of their hosts, as does the tropical rat mite
which is capable of transmitting typhus. Al-
though the presence of mites may be recognized
by the general symptoms of each type of mange,
the only definite way of discovering their pres-
ence and species is to scrape thoroughly the outer
edges of the infected areas with a dull knife
and transfer these scrapings to a dark surface
such as black paper. The paper should then be
spread in the sun or near heat. The warmth will
cause the mites to become active and they can be
seen as tiny whitish objects moving about. As
a rule mites are transmitted from one animal to
another by direct contact, although they may
be spread by infested equipment. These mites
live only a short time away from their host,
three weeks being about the limit of their. exist-

Sarcoptic Mites

Of the three kinds of mites mentioned
above the most difficult to control are the
sarcoptic mites because of their habit of bur-
rowing into the skin. In equines sarcoptic
mange is caused by Sarcoptes scabiei Deg.
Mites of this genus are minute, yellowish or
whitish parasites which form galleries in the
skin where mating and egg laying take place.

Circular 19 Livestock Insects

Each female makes a separate burrow and dies
there after egg laying is completed. The entire
life cycle takes place in approximately 15 to
24 days.

S. scabiei equi (Gerlach) may infes+
man, carrying what is known as "cavalryman's
itch" among soldiers attending horses.

Symptoms of sarcoptic mange.--Lesions
or lumps are formed over the burrows, and scabs
or granules may appear as a result of the dis-
charge of serum from the lesions. These lesions
are usually found in early stages of the disease
on the neck, shoulders, or around the head, but
the disease may start on the breast, flanks,
sides, or other parts of the trunk. With the
advance of the disease, patches on the animal
become more or less bare. In severe cases
animals lose weight and may die.

Psoroptic Mites

Psoroptic mites, known as Psoroptes corn-
munis equi (Gerlach) produce psoroptic mange,
or common scab. Mites causing this disease
live in colonies on the surface of the skin
rather than in galleries in the skin. Visible
to the naked eye, oval in form, possessing a ta-
pering head which is longer than broad, and
larger than sarcoptic mites, these parasites
are best observed when they are placed against
a dark background. The complete life cycle is
spent on their host where the female deposits
15 to 24 eggs. After 4 to 7 days' incubation,
the eggs hatch. The young mites reach sexual
maturity, mate, and begin depositing eggs in
10 to 12 days from time of hatching.

Symptoms of psoroptic mange.--Psoroptic
mange usually starts on portions of the animal
more thickly covered with hair. Mites pierce
the skin and apparently introduce a toxin into

Circular 19 Livestock Insects

the wound. Vesicles are formed, and the serum
from these, caused to flow by scratching, be-
comes mixed with foreign matter including micro-
organisms. Yellowish or gray colored scabs
appear and the mites move to healthy areas
around the scab, thus increasing the extent of
injury. Some mites move to new regions of the
body until large areas of skin become denuded
of hair. Intense itching causes animals to bite
and scratch themselves, resulting in breaking
or tearing off the scabs. Very advanced cases
become emaciated and unless given proper treat-
ment may die.

Chorioptic Mites

Very similar to psoroptic mites, choriop-
tic mites live in groups on the surface of the
skin and make lesions which closely resemble
those of psoroptic mange. A characteristic
difference, however, in these two kinds of
mange is the location of the lesions which, in
the chorioptic mange, is confined chiefly to
the legs or tail, from which the common name
foot or tail mange is derived. In severe cases
lesions may spread to the abdomen. This disease
is produced in horses by Chorioptes equi (Hering).

Control of sarcoptic, psoroptic, and
.chorioptic mange.--Animals should be dipped in
lime sulfur or nicotine solutions, proprietary W
brands of which are available. Lime sulfur
is known as liquid-lime sulfur, or in powder
form is known as dry lime sulfur. Nicotine
compounds are sold under various trade names
and when diluted with water the dip should con-
tain not less than 0.05 percent nicotine. Two
dippings, 10 to 12 days apart, are usually suf-
ficient for psoroptic and chorioptic mites,
but about 4 or more dips at intervals of 6 to 7
days are necessary for sarcoptic mites because
insecticides do not always penetrate the depth

Circular 19 Livestock Insects

of all burrows and contact the mites. Prepared
dips should be used warm and diluted or mixed
according to directions on the container. Com-
plete directions are given in Farmers' Bulletin
1017 of the United States Department of Agri-

Note: Animals having unhealed wounds
should not be dipped but should be treated with
dry lime sulfur. Animals should not be dipped
until several hours after feeding and should
be immersed completely. The liquid should be
kept at 95 to 1050 F. and animals kept in solu-
tion long enough to become fairly well soaked,
not less than two minutes for infested animals.
Horses infested with mites should be isolated
and stables as well as pens disinfected with a
strong coal tar creosote solution. Otherwise
stables should be vacated for three weeks so that
any mange mites present may die.


The stablefly, known as a vicious biter
in practically all parts of the world, is capa-
ble of transmitting a number of diseases to
livestock, such as anthrax, surra, and swamp
fever. Horses are particularly annoyed by
their presence. If fly infestation is severe,
the work efficiency of horses is lowered by
loss of blood and their vitality may be so re-
duced as to permit certain diseases to become
acute and cause their death. A detailed account
of the stablefly will be found in Defense Cir-
cular 17.


Larvae of botflies attach themselves to
the walls of the stomach and intestine of horses


Circular 19 Livestock Insects


and mules, thereby lowering their efficiency.
In addition, more feed is required to keep
an infested animal in condition. Aside from
annoying animals by depositing their eggs,
botflies, if present in numbers, may cause
horses to become uncontrollable. A light
infestation of horse bots in the digestive tract
is often unnoticed, but heavy infestations
may cause sore throats, emaciation, colic, and
even stoppage of the digestive tract, sometimes
resulting in death. For further discussion
on the habits and control of these pests, see
Defense Circular 16.


Although primarily a pest of cattle,
the horn fly (Siphona irritans L.) (fig. 3)
occasionally attacks
horses. It is about
h one half the size of
a a housefly, has a
pointed beak, and is
Ia fietce biter. Flies
of this species usually
Occur in clusters on
the animal. On warm
and cloudy days the
/adults are most preva-
lent, annoying animals
T by their presence and
by sucking blood. As
a result of this loss
of blood, the animal's
vitality is lowered.
Fig. 3.--Female horn fly.

Circular 19 Livestock In3ects

Life History
Eggs are laid in fresh manure where they
hatch out and become mature larvae in about
4 to 5 days. The larvae then crawl into the
lower part of the dropping or into the soil
to pupate. In 6 or more days after the pupal
case is formed the adult emerges. A minimum
of 9 to 12 days completes the life history
and the flies may live for about 7 weeks.


Two practical methods of controlling horn
flies are as follows

1. Destroy maggots by breaking manure
so that maggots may become exposed to the sun
and air and dry out quickly.

2. Kill adult flies on animals Dy apply-
ing livestock sprays preferably composed of ex-
tract of pyrethrum and kerosene oil. Do not
spray directly on the animal but generate a
fine mist around the animal, particularly
around the legs and under the belly.


Screwworms are a menace to livestock
in southern portions of the United States,
Central America, Mexico, West Indies, and
throughQut South America except the southern
portion. Horses and mules are usually at-
tacked in scratches, wire cuts, saddle and
harness sores, as well as in the sheath of the
penis owing to local irritation. Screwworm
flies are attracted to wounds of all kinds,
in which they lay their eggs and larvae develop.

Circular 19 Livestock Insects

Bloody discharges, such as those from men suffer-
ing from nasal catarrh, also may attract the
flies. Larvae eat out the tissue in the wound
and if the infestation is severe and treatment
neglected, pockets may be eaten out beneath the
skin, and the animal or man may eventually dJW.
A discussion of the habits of the screwworm
and its control is given in Defense Circular


Although of minor importance to horses,
the housefly (Musca domestic L.) transmits a
roundworm, Habronema muscae, which is a stomach
worm of horses. In the adult housefly these
worms are usually found in the head, but they
may be found in other parts of the fly's body.
Horses accidentally swallow these infected flies,
or flies cluster around lips of horses, the
moisture stimulating the passage of the round-
worm larvae which then gain entrance to the

Since horse manure is one of the chief
media in which houseflies breed, the protection
of manure from oviposition of these flies is
one of the most important steps in their con-
trol. Further reference to the housefly and
its control will be found in Defense Circular
8, pages 2-14.


Several kinds of mites annoy birds,
chiefly poultry, but frequently pigeons and

Circular 19 Livestock Insects


livestock are affected by them. If horses are
kept in buildings where wild birds make their
nests, the animals may be annoyed by the mites.
In this case nests should be removed and the
surrounding area sprayed with a fly spray.
Birds' nests in trees should also be removed
if infestation of mites is coming from this
source. The two most common mites likely to
be encountered on pigeons and livestock are
the chicken mite (Dermanyssus gallinae Deg.)
and the feather mite (Liponyssus sylviarum
Canad. & Fanz.)


Hiding by day in cracks and crevices,
this mite usually attacks its victims at night.
Vitality of birds is lowered and sometimes even
death is caused. Development from egg to adult
requires about one week but the life span is
extended during cold weather.

Occasionally people who handle pigeons
are annoyed by these mites. Old buildings
used as barracks may harbor chicken and bird
mites if poultry or birds have been nesting
in these places.

,Boxes, boards, and trash all harbor
mites. Remove such equipment and burn nesting
material and litter. Spray roosts with crude
petroleum or creosote oil early in the day so
that materials may soak in before the pigeons
go to roost. Caution: Creosote oil should
be kept away from body and clothes as it iUS
somewhat caustic and will burn.

Circular 19 Livestock Insects


The feather mite attacks a number of
wild birds which may spread mites to pigeons
by contact with them. It is a severe pest
since it remains on the host most of the time.
The female lays her eggs among the feathers
and the mites complete their development on
the host. This pest causes a dirty appearance
on the feathers of birds. Heavy infestations
lower the vitality of birds, and a scabby con-
dition of the skin results.


Since this mite seldom leaves the host,
it is necessary to dip the birds rather than
treat the roosts. Each individual should be
dipped in a sulfur bath (2 ounces of fine sul-
fur and 1 ounce of soap to a gallon of water).
This should be done on a warm sunny day or in
a warm building. If this is not possible, birds
may be dusted with fine sulfur, or nicotine
sulfate may be sprayed on perches. Burning
nest material and litter while the pigeons are
being dipped is recommended. Nests of sparrows
and other wild birds should be pulled down and
burned if they are suspected of harboring mites,
and the area where they are located then treated
with a fly spray.


Since several insects and their close
allies, the mites and ticks, not only annoy
dogs by their presence, but cause loss of blood
and spread disease or parasites to animals

Circular 19 Livestock Insects

and man, it is of interest to keep dogs in a
healthy condition. Early diagnosis of such
sit.ltions will greatly aid in keeping up the
efficiency of dogs. Mange mites cause a dis-
ease of dogs that may easily be fatal. Present
on almost any dog are fleas which cause much
irritation and scratching. In addition the
cat, dog, and human fleas may act as inter-
mediate hosts for the double-pored tapeworm.
If dogs go through areas infested with chiggers,
many of these mites may be picked up and cause
sores to develop. Ticks not only are a drain
on the blood of dogs but may cause paralysis
and in some cases disease. Through the medium
of certain lice, tapeworms may be carried, to

Further information concerning fleas,
chiggers, and ticks may be found as follows:

Fleas---- see Defense Circular 13.
Ciggers--see Defense Circular 14.
Ticks---- see Defense Circular 12.


Dogs are subject to three types of mange--
the sarcoptic, ear, and demodectic--all of
which are caused by mites living in or on the
surface of the skin. Sarcoptic mange may occur
all over the body, while ear mange is generally
confined to the ears. Demodectic or red mange
occurs over the body. In the early stages of
this disease, the skin often appears red and
the hair falls out. A disagreeable mousy odor
is frequently evident in sarcoptic and red mange.

Circular 19 Livestook Insects

If dogs are not removed from premises
for about three weeks so that any mange mites
present may die, the premises should be treated
with a ho, strong coal tar creosote solution.
Kennels should be disinfected with this solu-
tion particularly if other dogs are present.
All bedding and litter should be burned if

Sarcoptic Mites

A mite, Sarcoptes scabiei canis Ger ,
is the cause of sarcoptic mange of dogs. Mites
of this species are barely visible to the naked
eye. Females make galleries in the upper layer
of the skin where 20 to 40 eggs are laid.
These hatch in 3 to 7 days, the larvae maturing
by molting. The entire life cycle from egg to
adult requires two to three weeks. Only the
females burrow into the skin, the larvae, nymphs,
and males living under crusts or scabs on the

Symptoms of sarcoptic mange.--Any age
or breed of dog is susceptible to sarcoptic
mange. Although the disease may become evi-
dent on any part of the body, it usually first
appears on the head, bridge of nose, around
eyes, or at the base of the ears. If control
measures are not applied, the whole body will
become involved.

The first symptoms of sarcoptic mange
are the red points whicn in a short time de-
velop into small blisters. Scabs are formed
by the exucdation or discnarge of serum by fe-
males. Intense itching follows and the ani-
mal, in attempting to ease his irritation,
may scratch the scab and secondary bacterial

Circular 19 Livestock Insects

infection may follow. The skin becomes %rin-
* kled and thickened. The hair mats and falls
out. If the disease is not checked, the dog's
digestion and other body functions may be im-
paired. Death may follow in a few months.
It is possible for humans to contract the dis-
ease through handling mangy animals.

Control of sarcoptic mange.--Dogs
should be clipped, bathed, and all crusts and
scabs removed before insecticides are applied.
After a complete course of treatment the dbg
should be bathed and the process repeated until
the animal is cured. Several control measures
are recommended:

1. Derris ointment, similar to that
used in ear mange, or a wash consisting of
4 ounces of derris powder (containing 5 per-
cent rotenone), 1 ounce of a nonalkali soap,
and 1 gallon of warm water may be used. This
mixture should be rubbed in well with a brush
and the surplus wash taken up with a towel.
The remainder should be left to dry on the ani-
mal. Two or three treatments are necessary
to cure the animal.

2. An ointment prepared by thoroughly
mixing 1 part flowers of sulfur with 8 parts
lard is a simple mixture that has given good

3. Two parts sublimed sulfur, 1 part
oil of tar, 1 part potassium carbonate, and
8 parts lard has been successfully used.

Ear Mites
The ear canal of dogs may be invaded
by ear mites, Otodectes cynotis (Hering), (fig. 4)

Circular 19 Livestock Insects


* A

Fig. 4.--Female ear mite of dogs.

which are responsible for a condition known
as ear mange. These are similar to sarcoptic
mange mites but are much larger and longer
legged. They may be seen with the naked eye
as tiny white creatures. TLd life cycle is
similar to that of the sarcoptic mites. They
obtain their food by puncturing the skin and
sucking the tissue juices of the ear canal
near the eardrum.

Circular 19 Livestock Insects

Symptoms of ear mange.--Irritation by
these mites may result in interference with the
normal production of ear secretions. Inflam-
mation causes accumulation of exudates and
modified wax in the ear. Dogs often hold their
heads to one side and in advanced cases run
around in a circle. The intense itching causes
the animal to scratch and rub its ears as well
as shake its head.

Control of ear mange.--Since ear mites
live on the surface of the skin, this type of
mange is the most easily controlled. The dog
should be held so that the ear canals may be
treated without damaging the eardrum. After
cleaning out the ear, the canal should be swabbed
with any one of the following insecticides:
1 percent phenol (carbolic acid) in glycerin;
5 percent phenol in castor oil or olive oil;
or a mixture of 1 part carbon tetrachloride
and 3 parts castor oil. Treatment should be
given daily until all traces of infestation
have disappeared.

Demodectic Mites

The most common of the parasitic skin
diseases of dogs is red mange. A wormlike
mite (Demodex canis Leydig) is the cause of
this type of mange. This mite lives in the
* hair follicles and sebaceous glands, but the
facts concerning its life history are not well-
known. Females deposit e-r-s which, on hatching,
are similar to adults. Larvae molt as do other
mites, but the time required to complete the
life cycle is unknown. The disease is usually
found in young dogs, particularly short-haired
dogs, but it may attack animals of any age.

Circular 19 Livestock Insects

Symptoms of demodectic or red mange.--
The first symptom of this disease is the appear-
ance of red spots on the skin where the hair
has fallen out. This is usually around the
eyes, elbows, hocks, toes and other places
on the body. Some itching may be present as
the disease advances, but it is not as intense
as in sarcoptic mange. Later when more hair
drops off, the skin presents a copper color from
which the name "red mange" originated. The
skin may develop a gray or bluish color in
cases of heavy infestations. The hairless type
of the disease is complicated through lowered
resistance and by the presence of pus-forming
bacteria. Poisons formed in the pustules by
the bacteria are liberated in the animal's
system and as a result body functions are im-
paired. Emaciation, weakness, and an unpleasant
odor develop, and unless treatment is given,
the animal dies.

Control of demodectic mange. Dogs should
be clipped, bathed, and all crusts and scabs
removed before control measures are applied.
After bathing, repeat this process until animal
is cured. Treatment of this disease is very
difficult, but the most promising insecticide
appears to be a 1 percent solution of rotenone
in alcohol or oil. Dissolve the rotenone in
a small amount of acetone and add the proper
proportions of alcohol or a bland oil, depend-
ing on the type of solution desired. An oil
solution is usually preferred since it tends
to keep the skin soft and pliable. Apply the
insecticide daily with moderately rough massage
to affected parts or entire body, depending
on extent of lesions. Continue treatment daily
for two weeks to effect a cure. The derris
wash suggested for sarcoptic mange has been
responsible for a number of cures. Apply this

Circular 19 Livestock Insects

wash every other day for two weeks, then once
a week for 4 weeks.

Of the two species of lice found on dogs,
one is a sucking louse, Linognathus piliferus
(Burm.), and the other a biting louse, Tricho-
dectes canis Deg. The sucking lo'ise is less
than one twelfth of an inch long, is pale yel-
low, and has a long slender head, while the
biting species is a clear yellow, is smaller,
and has a wide blunt head. Sucking lice feed
on the serum and the blood, while biting lice
live on scales, scurf, and superficial portions
of the skin. T. canis is an intermediate host
of the tapeworm.


Intense itching causes animals to scratch
and rub themselves against objects. This action
may create sores and constitute a drain on their
nervous energy. Pups, old dogs, and long-haired
dogs are much more susceptible to infestation
than dogs of mature age and short-haired vari-

6 Several measures have been found effec-
tive for controlling lice on dogs:

1, Coal tar creosote dips may be used
2 or 3 times at intervals of 8 to 10 days.
This insecticide should be diluted according
to directions on the container.

Circular 19 Livestock Insects

2. A pyrethrum dust may be applied to
animals. In order to destroy all lice on an
animal, treatment should be repeated a number
of times.

3. Derris may be used as a dust in the
proportion of 1 part derris to 2 parts flour,
cornstarch, or talcum. The mixture should
be dusted into the hair.


A pest cf carrier pigeons, the pigeon
fly (Pseudolynchia canariensis Macq.) (fig. 5)
is not much smaller than the housefly, is flat,
brownish, and crawls
rapidly among the
J \feathers to blood
of both squab-, ..nd
*adults. The f1.y trans-
Sj-- J mits an organism which
I causes pigeon malaria,
la disease the exact
effect of which on
birds has noT yet been
I determined.

./ y "- Life History and Habits
\ Often pigeon
flies will bite man
when pigeons are being
handled and irritation
Fig. 5.--The pigeon may continue for sev-
fly. eral days. No marked

Circular 19 Livestock Insects

evidence of their bites is apparent on pigeons,
however, but the birds seem to be greatly
annoyed by them. Both irritation and loss of
blood prove injurious to squabs as well as
adults. In warmer parts of the country the
flies are active on pigeons through the winter,
but in the spring, the number of flies dimin-
ishes. Female flies deposit mature larvae
in pale yellow pupal cases (fig. 6) singly
among the feathers
of the pigeon. These,
in about three hours,
become shiny black.
Although they may hang
for a short time in
the feathers, they
soon drop into the
e nest and usually fall
sinc to the bottom of the
nest boxes. t ults
emerge about -:_ days
p s b later when e temper-
ature is high, but
in about 31 days or
longer when the
weather is cold.

Fig. 6.--Group of
pigeon fly pupae. Cleaning of
nests.--Nests should
* be cleaned thoroughly
every 25 days and the trash burned. Pupae may
be brushed out of the cracks of nests, and
since a number of pupae roll to the bottom of
the nest boxes, it is easy to pick up the nest
and clean it from the top downward. Falling
pupae should be collected on paper and burned.

Circular 19 Livestock Insects

Pyrethrum, derris, and cube.--One to
3 pinches of fresh pyrethrum powder may be
applied to squabs for killing adult flies.
The amount varies with the size of the bird.
Derris or cube powder (containing 3 to 5 per-
cent rotenone) is almost as effective as pyre-
thrum and should be used in the same way.

Fly sprays.--Pupae may be killed by thor-
oughly wetting them with one of the standard
fly sprays. This may also be used in a light
spray on the pigeons themselves as the feathers
are lifted. Great cre should be taken in
spraying the birds, \ver, because the eyes
may be made sore or thp skin burned, especially
that of squabs. Pireo:nJ used as messengers
should be kept free o7 the flies as their per-
formance is handicapped by the parasites.


Dove, W. E., and Simmons, S. W. 1941. Control
of dog fly breeding in peanut litter.
U. S. Dept. Agr., Bur. of Entomology
and Plant quarantine. E-54.2.

Hall, Maurice C., Price, Emmett W., and Wright,
Willard H. 1934. Parasites and
parasitic diseases of dogs. U. S.
Dept. Agr. Cir. 338, pp. 3-17.
Revised 1934.

Schwartz, Benjamin, Trues, Marion, and Wright,
Willard K. 1942. Parasites and
parasitic diseases of horses. U. S.
Dept. Agr. Cir. 148. Revised 1942.

Simmons, S. W. and Blakeslee, E. B.- 1942.
The prevention of dog fly and house-
fly breeding in waste celery. U. S.
Dept. Agr., Bur. of Entomology and
Plant Quarantine. E-583.

Circular 19 Livestock Insects

Simmons, S. W., and Dove, W. E. 1941. Con-
trol of dog fly breeding in beach
deposits of marine grasses. U. S.
Dept. Agr., Bur. of Entomology and
Plant Quarantine. E-541.

U. S. Dept. Agr.

1942. Keeping livestock
1942 Yearbook of Agricul-

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