Poultry Pest Management
Clifford E. Hoelscher
Professor and Extension Specialist
Special thanks is given to Dr. William F. Lyons, Extension Entomologist
(Retired) at Ohio State University, for assistance in developing this
publication. North Carolina Cooperative Extension Service provided the
line drawings used in the rodent control section.|
Under Texas' Pesticide Law, certain pesticides
are restricted and can be purchased and used
only by pesticide applicators and public operators
who are licensed by the Texas Department
Restrictions on the use of some of these pesticides
require the applicator to notify the occupants
of lands within 1,000 feet of the boundaries
of the area to be treated at least 24 hours
before the application is made. The applicator
should also inform the occupants of precautions
necessary for the safety of people and animals.
Any person who applies a pesticide on public
property must be licensed by the Texas
Department of Agriculture or be a trained applicator
working under the supervision of a
licensed applicator. This is true even if the pesticide
is not restricted. For application procedures
and more information, contact:
Texas Department of Agriculture
Austin, Texas 78711
Study materials to prepare for the license
exam are available from the Texas Agricultural
Extension Service. Call the Extension Agricultural
and Environmental Safety office at (409) 845-3849.
Current hazardous waste regulations went
into effect November 19, 1980. These regulations
require that waste pesticides and empty
containers of chemicals classified by EPA as hazardous
waste be disposed of in a designated hazardous
waste site, unless triple-rinsing and other
requirements are followed by commercial pesticide
applicators. Farmers or private applicators
are exempt from the new regulations, providing
they follow the instructions on the pesticide
label when they dispose of waste pesticides and
Triple-rinsing each emptied pesticide container
and using the rinse in the tank mix whenever
possible or disposing of the residue on the farm
are required. Triple-rinsed containers may be
recycled by the Texas country clean-up program.
This publication contains pesticide recommendations
that are subject to change at any time.
These recommendations are provided only as a
guide. It is always the pesticide applicator's
responsibility, by law, to read and follow all current
label directions for the specific pesticide
Because labels and product registrations constantly
change, some of the recommendations
given in this writing may no longer be legal by
the time you read them. If information in these
recommendations disagrees with the label, the
recommendation must be disregarded. The
label is the law.
No endorsement is intended for products
mentioned, nor is criticism meant for products
not mentioned. The author and The Texas A&M
University System assume no liability resulting
from the use of these recommendations.
Controlling Flies In and Around Poultry Houses
Texas ranks among the nation's leaders in
caged layer egg production.
One of the largest management problems facing
the poultry producer of today is filth fly control.
The shift from many small farm flocks to
fewer large poultry operations has greatly
increased fly problems by creating concentrated
breeding areas and large volumes of waste that
cannot be removed frequently. As urbanization
and rural non-farm residence increase, poultry
producers face increasing pressures to reduce fly
populations. Fly populations (manure-breeding
flies) may cause a public health nuisance, resulting
in poor community relations and threats of
litigation. A dedicated effort is necessary to
achieve an acceptable level of fly control.
Several kinds of flies are common in and
around caged layer houses in Texas. Probably
the most common flies are the house fly and the
little house fly. About 95 percent of problems
involve the house fly. Both of these flies can
move up to 20 miles from the site of development,
but normally no more than a mile or two
from the initial source.
House flies, Musca domestica L., about 1 /2
inch long, breed in moist, decaying plant material,
including refuse, spilled grains, spilled feed,
and in all kinds of manure. For this reason,
house flies are more likely to be a problem
around poultry houses where sanitation is poor.
These flies prefer sunlight and are very active,
crawling over filth, people, and food products.
This fly is the most important species because it
can carry and spread human and poultry diseases
and cause flyspecking problems of the
eggs. For example, house flies are the intermediate
host for the common tapeworm in chickens,
and they carry millions of bacteria.
The little house fly, Fannia canicularis (L),
about 3 /16 inch long, is somewhat smaller than
the house fly. This fly prefers a less-moist medium
than the house fly for breeding and reproduction.
The little house fly will choose poultry
manure over most other media. This fly also
prefers shade and cooler temperatures and is
often seen circling aimlessly beneath hanging
objects in the poultry house, egg room, and feed
room. It is less likely to crawl about on people
and food. However, it does cause people living
near poultry establishments to complain about
fly problems. The little house fly may hover in
large numbers in nearby garages, breeze ways,
and homes because it prefers shade.
The black garbage fly, Ophyra aenescens
(Wiedemann), is slightly smaller than the house
fly and shiny bronze-black in color. The wings
are held straight back. This fly tends to stay on
the food source at night rather than resting on
the ceiling or on outdoor vegetation, as does the
house fly. The female fly doesn't seem to fly
great distances, but has been found about 5
miles from its breeding area. Although black
garbage fly larvae have been known to exterminate
house fly populations, they should not be
considered entirely beneficial because these flies
can build large populations on the farm and disperse
as adults to nearby communities. All
stages are found throughout the year under suit-able
conditions, and they show rather good tolerance
to cold weather. The life cycle is similar
to that of the house fly.
Blow flies, sometimes known as green or
blue bottle flies, are slightly larger than house
flies and sometimes live in poultry houses. They
prefer to breed and reproduce in decaying ani-mal
and bird carcasses, dog manure, broken
eggs, and wet garbage. Generally, a good sanitation
program will hold these flies in check.
Other flies found on the poultry establishment
include soldier flies, small dung flies,
fruit flies, and rattailed maggots.
All flies develop through four life stages: egg,
larva, pupa, and adult. Adult flies lay small,
white, oval eggs on the breeding medium, and
creamy white larvae (maggots) develop in this
moist (wet) material. Mature maggots crawl out
of this material and move to a drier place for the
pupal stage. The brown, seed-like pupae finally
yield adult flies. Development from egg to adult
fly may take just 7 to 10 days under ideal conditions.
Adult house flies live about 3 to 4 weeks,
and females lay two to 20 batches of 75 to 200
eggs at 3- to 4-day intervals. At this rate,
a pair of flies beginning operation in April, if
all offspring were to live, would result in
191,010,000,000,000,000,000 (191 quintillion,
10 quadrillion) flies by August. Allowing 1 /8
cubic inch to a fly, this number would cover the
earth 47 feet deep. Of course, this does not happen
because beneficial predators and parasites
keep the populations under control.
Flies can be present in poultry houses year-round
if there are warm temperatures and no
Manure management is the most effective
way to control flies. As many as 1,000 house
flies can complete development in 1 pound of
breeding material. Fresh poultry manure contains
75 percent to 80 percent moisture, which
makes it ideal for fly breeding. You can practically
eliminate fly breeding in this material by
reducing the moisture content to 30 percent or
less or by adding moisture to liquefy it. Drying
manure is preferred because the product occupies
less space and usually has less odor.
Dry Manure Management
Frequent removal of manure (at least once a
week) prevents fly breeding because it breaks
the breeding life cycle. It is important to scatter
the manure lightly outdoors to kill the eggs and
larvae by drying. Avoid piles or clumps of
manure. You must have access to enough land
so the manure can be spread thinly; this keeps
excessive amounts of nutrients from building up
in the soil. Spread at an agronomic rate for your
In-house storage of manure requires drying it
to a 30-percent moisture level and maintaining
this level where sufficient storage space is available.
Dry manure can be held for several years.
Any practice that limits moisture in the droppings
or aids in rapid drying is important for fly
Managing the water content of manure is
important in controlling flies. Following these
steps can help minimize water content:
- Prevent leaks in water troughs or cups.
Regulating water flow to an on/off cycle
may help eliminate moisture problems.
- Provide abundant cross-ventilation beneath
cages, especially during hot weather. Using
36-inch pit fans blowing across the manure
can be very effective. Placing a curtain
above the manure every 100 feet helps keep
air moving over the manure. Adequate
house ventilation is important at all times.
- If the water table in your area is high, or if
there is a danger of water running into the
house from the outside, adjust the floor-grade
relationship so that the house floor is
higher than the outside surrounding
ground. Have surface water run away from
the building. Drain and fill all low areas
around the houses.
- Prevent dysentery by keeping water clean.
Use recommended antibiotics if dysentery
- Prevent excessively high house tempera-tures,
which encourage the chickens to
drink abnormal amounts of water.
- Practice good husbandry by restricting
excess water consumption, but not to the
point of reducing egg lay.
- If your resources allow it, consider using a
new housing system designed to dry
manure in the pits.
Sanitation is the most important aid in successful
fly control. Often, certain conditions in
and around the poultry operation will encourage
fly outbreaks. These must be eliminated. Follow
these steps to improve sanitation:
- Quickly remove and dispose of dead birds
and broken eggs. Dispose of them far from
the poultry premises by burning in an
incinerator or other approved management
- Clean up and dispose of feed spills and
manure spills, especially if wet, immediately.
- Clean out weed-choked water drainage
- Install proper eave troughs and downspouts
on poultry houses to carry rain water far
from buildings. Provide proper drainage in
- Minimize the migration of flies from other
fly-infested animal operations close to the
Entomologists encourage the use of biological
control in poultry houses. If you are considering
biological control for your operation, be sure to
purchase beneficial insects (also called "beneficials")
adapted to the climate in your area.
These fly parasites, actually very tiny wasps,
are the naturally occurring enemies of manure-breeding
flies. They destroy flies in the pupal
stage. These wasps, Spalangia nigroaenea, are
about the size of the head of a house fly ( 1 /16 to
1 /8 inch) and live in the manure, depositing eggs
in fly pupae. Adult female wasps lay an egg on
the fly pupa within the puparium (the hard case
containing the pupa). Then the developing wasp
larva consumes the pupa and emerges as an
adult. These fly parasites are specific to flies and
attack nothing else. They are biteless and stingless
to people and usually go unnoticed by those
living near poultry operations. They self-propagate
in the process of controlling pest flies.
However, mass releases are needed. Also, the
wasp lays fewer eggs than the fly over the same
period, making it necessary to start with an initial
wasp release and follow up with weekly
supplemental releases. You should make these
releases before and during the fly season.
Whenever you use beneficial insects, you
must be very careful with insecticides. Chemical
sprays must be discontinued in areas of the
poultry house where these wasps are used. And
never treat the entire manure surface with
insecticides, with the exception of cyromazine
(Larvadex®); otherwise, beneficial insects as well
as the pest flies will be killed.
To improve the chances of successful biological
control with these wasps, you should also
follow a strict sanitation program, involving
manure management, water management, weed
mowing, etc. Keep the manure dry, since wet
manure promotes fly breeding and inhibits beneficial
insect breeding. Also, when you clean the
poultry house, leave areas of old dry manure to
provide a reservoir of beneficials to repopulate
the house as new flies occur.
According to the Cornell and Penn State
Cooperative Extension publication, "Pest
Management Recommendations for Poultry,"
other beneficials in poultry manure include
mites and beetles. Both are major predators in
caged-layer operations. The macrochelid mite,
Macrochelis muscaedomesticae, is reddish brown
and less than 1 /16 inch long. It feeds on house
fly eggs and first-instar larvae. These mites,
found on the outside layer of manure, can consume
up to 20 house fly eggs per day. Another
mite is the uropodid mite, Fuscuropoda vegetans,
which feeds only on first-instar house fly larvae
deeper in the manure.
A hister beetle, Carcinops pumilio, is black and
about 1 /8 inch long and feeds on house fly eggs
and first-instar larvae. This effective beetle
predator, common in both broiler and layer
houses, can consume 13 to 24 house fly eggs per
day. Both adult and immature hister beetles live
in the surface layers of manure. Another hister
beetle, Gnathoncus nanus, is present at lower
numbers on poultry farms.
Using fly parasites for biological control in
Texas would reduce chemical residues to people,
birds, eggs, and the environment. However, to
date, claims that wasps will provide long-term
fly control have not always been backed by scientific
research results. When using biological
control methods, remember to manage the habitat
for biological control by keeping the manure
dry. Accumulations of poultry manure left undisturbed
over long periods of time will support
large populations of native fly parasites (wasps
and mites) and fly predators (beetles). Be sure to
encourage the native strains of beneficials
already present in the dry manure to populate.
Remove manure only during the fly-free time of
the year and eliminate insecticide sprays in
Many types and styles of fly traps appear on
the market each year. These traps are usually
electrical, employing a black light with an electrically
charged grid to kill the insects. Some
traps are baited with a fly attractant material.
Traps do appear to be helpful in tight,
enclosed areas such as egg rooms-where there
is a breeding fly population, if good sanitation
practices are followed. However, in areas of
heavy fly populations, traps are not effective in
reducing fly numbers to satisfactory levels. Use
traps in the middle of the night away from doors
One should judge a trap by the population of
flies remaining in the area and not by the number
of flies caught in the trap. Most entomologists
feel that fly traps used alone are not effective
in controlling flies, especially in and around
livestock and poultry operations.
Use a fan to blow air through a screened
doorway from the egg room or other work area
into the main poultry house. Flies will not move
against the wind into the egg room or other work
area. There are commercial electric-powered air
curtain fans. However, certain state health
departments may require solid doors between
the egg room or other main work area into the
main poultry house.
Use sticky fly strips where appropriate.
It is important to monitor fly populations to
make wise control decisions. Visual observations
alone can be misleading. One needs to know the
fly's behavior patterns and history. Documentation
is very helpful in legal defense if needed.
Moving tape count. This is the best surveillance
method, taking about five minutes
each day walking on a 1,000-foot walk to catch
25 to 75 flies. Walking down and back in each
house is cheap and easy. Use the same walk pattern,
the same time of day, when carrying the
sticky fly tape.
Sticky fly tapes. Tapes that hang often tell
nothing. Tapes fill up fast during summer
months within a chicken house. However, one
can determine fly species. Some hang sticky fly
ribbons along aisles. Captured flies are counted
weekly and ribbons replaced. A weekly count of
100 flies per ribbon may indicate fly control is
required. Ribbons may become ineffective after
2 to 3 days because of dust and fly covering.
Tapes are messy to use and location is important.
Speck fly count. A 3- x 5-inch white file
card fastened flush against feed troughs, ceilings,
braces or other fly resting areas, left for a
period of several days to a week, will provide
documented evidence as to the number of "fly
specks" counted on a given date, over a period
of time within a given house. Place cards on
head rafters (three cards per house) and count
fly specks on one side. Change cards once each
day or week, depending on populations present.
Fifty or more spots per card per week may indicate
fly-control measures are required. Place
cards in the same position of each renewal. Fly
species cannot be determined from the spots.
The spot card method is very economical.
Baited jug trap. This is more expensive
than other sampling methods, but offers greater
sensitivity to fly population changes. A plastic
milk jug, with four access holes (2 inches in
diameter) around the upper part of the jug with
a wire attached for hanging about 3 feet above
the floor around the pit periphery, may indicate
need for control. The jug is baited with a commercial
fly bait (about 1 oz.) placed inside the
jug bottom. Use fly pheromone muscalure
(Muscamone) for effectiveness.
Larval sampling. It is most important to
walk the pits to determine "hot spots" where the
manure appears flattened and wet and contains
heavy populations of fly eggs and maggots.
Always take a hoe or trowel to sample the larvae
present. Keep pits walkable, clean, and water-free.
"Hot spots" usually appear where water
was standing in the manure. Some producers
may carry a knapsack sprayer to treat only the
"hot spots" to halt excessive fly larval breeding.
Treating manure widely and excessively will kill
beneficial agents. It is best not to treat with
chemicals in the manure pits. Pit manure should
appear tall, narrow, capped, and dry, perhaps
with beetles to assist in aerating the manure,
making it drier. (Manure will cone with proper
fly management.) Beneficial arthropods should
be monitored and establishment encouraged to
suppress fly populations.
Insecticides should be considered supplemental
to sanitation, and management measures
must be directed to prevent fly breeding.
Accurate records should be kept on insecticides
and dosage rates used.
Resistance to insecticides has developed at
different levels in various poultry house locations,
depending somewhat on prior exposure.
The use of a variety of different classes or families
of insecticides can minimize the development
of resistance. Rotate the use of
organophosphate, carbamate, pyrethroid, and
other classes of insecticides when necessary.
Residual sprays usually are the most effective
and economical method for controlling potentially
heavy populations of adult flies of any species
present. These sprays should be applied in
spring at the beginning of fly season. Application
after manure removal will reduce fly build-up
that usually follows house clean-out. A second
application should be made 5 to 6 weeks
later. (Two sprays are required.) Apply to surfaces
on which flies locate, such as poultry
house framework, the ceiling, walls, trusses,
wires supporting cages, electric light cords, and
other areas marked by fly specking. Also, treat
outside the poultry house around openings and
on shrubs and other plants where flies rest.
Apply coarse, low-pressure sprays to the point
of runoff at pressures of 80 to 100 pounds per
square inch, using a power sprayer or good proportioned-
type sprayer. Depending on the insecticide
used and the type of surface sprayed,
treated areas may remain toxic for 2 to 15
Avoid contamination of feed, water, and eggs
during spraying. Do not spray birds.
Any of these residual sprays are recommended:
1. Dichlorvos (Vapona®): Use 1 quart Vapona®
40.2% EC per 25 gallons of water. Apply
one quart of diluted mixture per 1,000
square feet as a coarse, wet spray. Birds do
not have to be removed from the building
before spraying. Follow label directions.
2. Malathion: Use 5 tablespoons of 57% EC
per gallon of water. Apply 1 to 2 gallons of
diluted mixture per 1,000 square feet as a
coarse, wet spray. Birds do not have to be
removed from the building before spraying.
Follow label directions.
3. Permethrin (Atroban®): Use 6.67 ounces
permethrin 25% WP per 5 to 10 gallons of
water. Apply 1 gallon of finished spray per
750 feet as a coarse, wet spray. Follow label
Permethrin (Insectaban®, Insectrin®,
Gardstar®, Insectrin X®, Hard Hitter®): Use
1 quart 5.7% EC per 10 gallons of water or
6 ounces 25% WP per 11 gallons of water.
Apply 1 gallon of finished spray per 750
square feet as a coarse, wet spray.
Permethrin (Expar®, Permaban®): Use 1 pint
permethrin 11% EC to 10 gallons of water.
Apply no more than once every 2 weeks.
Birds do not have to be removed from the
building before spraying.
4. Tetrachlorvinphos and dichlorvos (Ravap®):
Use 1 gallon Ravap® 28.7% EC per 25 gallons
of water. Apply 1 gallon of diluted
mixture per 500 to 1,000 square feet as a
coarse, wet spray. Birds do not have to be
removed from the building before spraying.
Follow label directions.
5. Tetrachlorvinphos (Rabon®): Use 4 to 8
pounds Rabon® 50% WP per 25 gallons of
water. Apply 1 to 2 gallons of diluted mixture
per 1,000 square feet as a coarse, wet
spray. Birds do not have to be removed
from the building before spraying. Follow
6. Lambda cyhalothrin (Grenade®) in a new
10% wettable powder formulation for
premise treatments: Apply 2 packets (0.2
ounce) in 1 gallon of water and spray to run
off. Each gallon should treat 750 square
7. Permethrin (Gardstar®) is a 40% permethrin
formulation: Apply 4 oz. to 10 gallons of
water. Apply 1 gallon of finished spray to
750 to 1,000 square feet.
Portable Mechanical Foggers and Misters
It is often impractical to treat large poultry
houses with residual sprays. Portable, light-weight,
mechanical fogging machines are convenient,
efficient, and labor-saving in caged bird
operations to quickly reduce adult fly populations,
providing quick fly knockdown with poor
residual action. Spraying with gasoline-powered
side-pack [Ultra-Low Volume (ULV)] aerosol generator,
using micron-particle-size spray droplets,
is a very effective contact application with little
or no residual effect. Space applications should
fill the room with fog or mist.
For indoor space application to kill flies, close
windows and doors. Natural pyrethrins, used
inside for adult fly control through a ULV
machine, are easy to use at 1% pyrethrin + 5%
piperonylbutoxide. The ration of 1:5 pyrethrin to
P.b. is most effective on fly control. When using
this equipment, adjust to deliver aerosol droplets
(30 microns or less), and apply 1 ounce of
pyrethrin per 1,000 cubic feet of space. Direct
spray toward upper areas of room. Leave room
closed for at least 1 hour. Do not remain in
treated areas, and ventilate before re-entry.
Repeat application as required.
To kill flies in open areas near buildings, use
an outdoor ground application, preferably when
the temperature is cool (75ºF or less) and wind
velocity is approximately 5 mph or less. Apply
at the rate of 4 ounces per acre in 50-foot
swaths. Allow spray drift to penetrate dense
foliage. Repeat application is required.
For additional information contact The
Lowndes Engineering Co., 125 Blanchard Street,
Valdosta, Georgia 31601, and Clarke Mosquito
Control Products, Inc., 159 N. Garden Avenue,
Roselle, Illinois 60172 (1-800-323-5727). They
have hand-held, backpack, 2-wheel, and 4-wheel
ULV sprays for adult fly control inside the poultry
house, as well as outside the building. Also,
a Hudson Model 98600 Porta-Pack ULV sprayer
is quite effective. Brand names are listed for educational
purposes only and must not be considered
as an endorsement. There are several brands of
machines on the market, producing various particle-
size sprays. Other treatments include using
one pint of dichlorvos (Vapona®) 1% oil base
(ready-to-use) per 8,000 cubic feet or permethrin
(Ectiban®) 5.7% undiluted at the rate of 4 fluid
ounces per 1,000 square feet or 1 pint (16
ounces) permethrin (Permectrin II®) 10% EC per
8,000 cubic feet. Rinse spray equipment after
application. Fly kill is good. Never retreat more
than once in 2 weeks. Follow label directions
and safety precautions.
Stationary Building Atomizers
Treatments are especially useful in closed egg
rooms or other work areas where there is little
or no air movement. Use pyrethrum oil-base
space spray (0.06% to 0.1% pyrethrins) plus
piperonyl butoxide as a mist or fog in the air
throughout the poultry house at the rate of 1 /2
fluid ounce per 1,000 cubic feet on an "as-needed"
basis for best fly control.
Baits are a supplement to residual and aerosol
sprays. Place baits outside cages upstairs in the
high-rise house. They can be effectively applied
on clean walkways by using a simple push-type
Scott's fertilizer spreader. (Baits falling into the
pit may destroy beneficial parasites.) These
selective adulticides suppress low fly populations,
maintaining them at a low level. Never
apply baits where they could accidentally be
eaten by the birds or mixed into feed. Dry sugar
baits of methomyl (Apache®, Fatal Attraction®,
Improved Golden Malrin®) are effective. To
reduce potential resistance, rotate the baits.
Methomyl is a carbamate insecticide, whereas
other baits, wet or dry, using dichlorvos
(Vapona®), trichlorfon (Dipterex®) and tetra-chlorvinphos,
(Rabon®) mixed with sugar are
Resin Strips and Fly Belts
Ready-to-use dichlorvos (Vapona®) 20% resin
strips can be used at the rate of one strip per
1,000 cubic feet of enclosed area. Strips will
need to be replaced as they lose their effective-ness,
or about every 3 months.
Methomyl (Golden Malrin®) fly belts can be
attached to surfaces out of the reach of food-producing
animals. The belt may be cut to any
desired length and attached to surfaces such as
walls and ceilings. Follow label directions.
Both resin strips and fly belts may become
dusty and dirty if used for long periods.
An insect growth regulator known as a cyromazine
(Larvadex®), when blended into a poultry
feed ration, will control manure breeding
flies in and around caged or slatted flooring in
layer chicken operations and breeder chicken
operations. Do not feed to broiler poultry.
Larvadex® 1% Premix kills fly larvae before
adulthood and does not adversely affect natural
predators and parasites. The 1% Larvadex®
Premix is blended into feed at the rate of 1
pound Premix per ton of feed. Larvadex® will
provide a high degree of fly control, and a feeding
program must be followed to prevent potential
fly resistance. Resistant flies have developed
in large poultry operations where label directions
have not been followed. Never feed continuously
throughout the year.
First, monitor adult flies in and near the poultry
house. When the population reaches a level
to cause concern, spray or fog with an adulticide
such as pyrethrins to reduce the breeding potential.
Spray adults for as long as possible. Then
check the manure first at "hot spots" in the pits
for maggot activity. If maggots are active, start
Larvadex® in the ration. Feeding could begin
March 15 or April 15, depending on maggot
activity. Feed Larvadex® continuously as direct-ed
for 4 to 6 weeks (minimum of 4 weeks) and,
if little or no maggot activity is observed in the
manure, discontinue Larvadex® feeding. This is
usually enough time to break the fly population
life cycle. Continue monitoring manure pits and,
if maggots become active again, repeat the procedure.
Use baits, sprays or fogs as needed during
and between Larvadex® feeding periods to
control flies. Do not spray manure pits.
During winter months or periods of low fly
pressure (October, November, December,
January, and February), discontinue Larvadex®
for at least 4 consecutive months per year.
Larvadex® use in poultry is limited to use as a
feed-through in chickens only and may not be
fed to any other poultry species.
To avoid illegal residues, Larvadex®-treated
feed must be removed from layers at least 3
days (72 hours) before slaughter.
Manure from animals fed Larvadex® may be
used as a soil fertilizer supplement. Do not
apply more than 3 tons of manure per acre per
year. Do not apply to small grain crops that will
be harvested or grazed, or illegal residues may
Larvadex® 2SL is a soluble concentrate, which
when diluted with water according to the
Directions for Use acts as a larvicide to control
fly species developing in poultry manure and
refuse. Larvadex® controls fly infestations by
breaking the life cycle at the maggot stage.
Larvadex® is labeled for fly control in and
around chicken layer and breeder operations
Do not apply this product in such a manner
as to directly or through spray drift expose
workers or other persons, except those knowingly
involved in the application.
For Housefly, Lesser Housefly, and
Soldier Fly Control in Poultry Operations,
Including Layer and Breeder Chickens
Fly control in poultry operations should
include appropriate sanitary and management
practices to reduce the number and size of fly
breeding sites. A successful sanitary and management
program may allow less than constant
use of insecticides. This, in turn, should prolong
the effective life of such control agents.
Controlling Other Pests
Northern Fowl Mite
The northern fowl mite, or feather mite,
Ornithonyssus sylviarum (Canestrini and
Fanzano), is a very important external parasite
of poultry with heavy populations capable of
reducing egg production 10 to 15 percent. Mites
can also annoy egg handlers and other persons.
Mites are often first noticed on eggs. Check for
mites first on the vent, then tail, back and legs
of layers. Feathers become soiled from mite
eggs, cast skins, dried blood from feeding, and
The entire life cycle is completed on the bird
and consists of the egg, larva, nymphal stages,
and adult. The eight-legged adult is about 1 /26
inch long and dark red to black in color. The
entire life cycle can be completed under ideal
conditions within a week.
With early detection, only some of the caged
layers may need to be treated. Monitor weekly
at least 10 randomly selected birds from each
cage row in the entire house. Mite populations
will increase in cooler weather.
The chicken body louse, Menacanthus
stramineus (Nitzsch), can reduce egg production
in caged layer hens. The skin of infested birds
becomes irritated and red, with formation of
localized scabs and blood clots. In addition to
feeding on skin fragments, feathers, and debris,
lice can attack young quill feathers, feeding on
blood. Although naturally infected with the eastern
encephalomyelitis virus, it is not considered
an important vector. Adult chicken lice are flat-bodied,
yellowish colored, and 1 /16 inch long
with chewing mouthparts.
The chicken mite, Dermanyssus gallinae
(DeGeer), sucks blood from poultry at night and
remains secluded during the day in cracks and
crevices. When mites are numerous, weight
gains and egg production can be reduced. These
red and gray mites are difficult to see without a
magnifying glass. The life cycle may be completed
in 7 to 10 days during warm weather with
inactivity during cold weather.
The common bed bug, Cimex lectularius L.,
occasionally attacks poultry. It hides in cracks
within the housing during the day and feeds
mostly at night on blood while the host is
asleep, causing small, hard, swollen, white welts
that become inflamed and itch severely. It is
rarely seen on poultry during daylight hours.
An infestation can sometimes be recognized by
blood stains and dark spots of excreta. The adult
is reddish-brown, oval-shaped, flattened and
about 1 /4 to 5 /8 inch long. There may be three
or more generations per year. There is no evidence
that they spread disease.
Occasionally the flea is found in the poultry
house. It is usually first noticed in the litter
where a wide range of hosts are attacked,
including rats, mice, chickens, humans, etc.
Bites annoying egg handlers occur primarily on
the ankles and legs, causing a raised (swollen)
itching spot. The adult flea, an excellent jumper,
passes through a complete life cycle consisting
of egg, larva, pupa and adult. The life cycle
varies from 2 weeks to 8 months depending on
temperature, humidity, food and species. The
most common flea found in Texas is the cat flea,
Ctenocephalides felis (Bouche). The adult is 1 /16
to 1 /8 inch long, dark reddish-brown, wingless,
hard-bodied; has three pairs of legs; and is flattened
vertically (bluegill fishlike).
The darkling beetle or lesser mealworm,
Alphitobius diaperinus (Panzer), is rapidly becoming
more of a nuisance in the poultry operation.
Large populations of beetles sometimes migrate
into nearby residence areas, especially during
litter clean-out time. Although beetles can fly up
to a mile, most crawl at night from litter disposed
in neighboring fields and homes.
Beetles are frequently associated with poultry
feed, preferring grain and cereal products that
are damp, moldy, and slightly out of condition.
Both adults and larvae consume poultry feed in
amounts costly to the producer. Larvae are
known as lesser mealworms.
Increased importance has been placed on control
of this beetle. Both adult beetles and larvae
act as reservoirs for many poultry pathogens
Scientists have been able to transmit the
causative agent of acute leukosis
(Marek's disease) in chickens with this
beetle. Positive confirmation of the
transmission has been made under
both laboratory and field research conditions.
Marek's disease usually affects birds between
3 and 4 months old. Symptoms are characterized
by various degrees of paralysis, most easily
observed in legs and wings. Droopy wings, gasping,
loss of weight, pallor, and sometimes diarrhea
are also symptoms. Birds severely affected
may be found lying on their sides with one leg
stretched forward and the other held behind.
The disease affects both broiler and egg-laying
types of poultry. Losses can reach 2 percent of
the flock per day, and mortality 30 percent of
the flock within a few weeks.
Acute leukosis is highly contagious and has
been shown to be airborne. Contamination may
persist in the environment because the darkling
beetle may serve as a reservoir for residual contamination.
Other diseases spread include the
causative agents of avian influenza, salmonella,
fowl pox, coccidiosis, botulism, and newcastle
disease. They also act as vectors of cecal worms
and avian tapeworms.
In the poultry house, the beetle can lay up to
800 eggs in litter during a 42-day period. Eggs
develop into larvae in 4 to 7 days. The life cycle
requires about 42 to 97 days, depending on temperature.
Beetles live up to 3 months to a year.
Adults are black or very dark reddish-brown,
and about 1 /4 inch long. Larvae are yellowish-brown
(wireworm-like), up to 3 /4 inch long, and
accumulate in dark corners of manure or litter,
especially under sacks, in bins, or in places
where feed is stored. Pupation occurs in the litter,
soil, and side walls of poultry houses. They
migrate frequently throughout the litter, generally
coming in soil contact.
Adult chickens and chicks are more likely
than poults or turkeys to eat beetles and their
larvae. Consumption of beetles and larvae,
rather than providing "extra protein" in the diet,
actually has a negative effect on feed conversion
and rate of gain, according to research.
Mature larvae of the hide beetle,
Dermestesmaculatus (DeGeer), have the habit of
boring into various hard surfaces to pupate, usually
preferring softwoods. Some may climb 24 to
36 feet and bore into wood posts, studs, and
rafters, seriously weakening and "honey-combing"
these structures. Larvae are especially troublesome
in poultry houses, damaging yellow
pine, foam insulation, Styrofoam air baffle
boards, paneling, drywall, and even PCP (Penta
Ready) chemically treated wood, in some cases.
Larvae emerge from the litter, climb the walls,
and bore into soft building material, often escaping
cannibalism during the pupation period.
Hide beetles are larger than darkling beetles,
about 1 /3 inch long, dark brown on top, with a
mostly white undersurface (belly). Each female
lays about 135 eggs, which hatch in 12 or more
days. The life cycle requires 40 to 50 days.
Larvae are thickly covered with long, brown
hairs, grow to about 1 /2 inch long, and have
two spines on top near the tail end, which curve
forward. Reasonable control has been achieved
by applying tetrachlorvinphos (Rabon®) 50% WP
in the dry form to building walls. Make treatments
with an electrostatic duster to negatively
charge the particles,
adhesion to the wall
surface. A distributor
for the duster
(model DM-9) is
Echo Inc., 3150
60062. Hide beetles
can be killed with a
Scaly-leg Mite, Knemidocoptes
mutans (Robin and Lanquentin)
The female is small with a round body and
short, stubby legs. These mites must be magnified
to be seen, because they are only 1 /50- to
1 /100-inch long. Young mites are at first six-legged,
then metamorphose through two eight-legged
Distribution and hosts. The scaly-leg mite
is distributed widely throughout the world, but
its exact range in Texas is unknown.
This mite attacks poultry, commonly chickens
and turkeys. The scaly-leg mite also has been
reported on pheasants, partridges, bullfinches,
gold finches, and many passerine birds.
Researchers suspect that wild birds transmit the
mites to domestic flocks.
Life history and habits. Little is known
about the life history and habits of this species.
Females burrow under scales on the feet and
legs of poultry and deposit eggs. They begin laying
a short time after they burrow under the
skin and continue to oviposit for about 2
months. Eggs hatch in about 5 days into six-legged
larvae that soon molt into nymphs.
Nymphs develop into mature males and immature
females. The immature female transforms
into a mature egg-laying female shortly after she
is fertilized. The cycle to egg-laying female probably
requires 10 to 14 days.
Importance and nature of damage.
Burrowing beneath scales on feet and legs
results in a powdery material that accumulates
and binds into a scab of serum discharge.
Affected feet and legs usually have red blotches.
Glands in the mouthparts of mites may secrete
an irritating fluid that causes the discharge and
blotches. Eventually, the feet and legs may be
covered with these crusts or scabs. Mites remain
beneath the crusts in small oval vesicles.
Irritation from mite infestation causes poultry to
pick at the crusty formations. As formations
extend over the feet and legs, they interfere with
joint flexion and cause lameness. Severe infestations
may cause loss of toes, loss of appetite,
lowered egg production, emaciation, and death.
Depluming Mite, Neocnemidocoptes
laevis gallinae var. gallinae (Railliet)
This mite is similar to the scaly-leg mite, but
is smaller and more oval.
Distribution and hosts. Infestation occurs
throughout the United States. Hosts include
pigeons, pheasants, geese, canaries, and chickens.
Many wild birds have been infested with
this species or with closely related, unidentified
Life history and habits. Development
stages include egg, larva, nymph, male adult,
and immature and mature female adult. Little is
known about the life history of this species, but
researchers believe transformation from immature
to mature female occurs after fertilization.
The fertilized female begins depositing eggs
within a few hours after starting to burrow and
continues at 2- or 3-day intervals for about 2
months. Eggs hatch in about 5 days. The cycle
from egg to egg-laying female requires 10 to 14
days. Less than 10 percent of the eggs mature
Importance and nature of damage. The
depluming mite burrows into skin at the base of
the feathers on the back, on the top of the
wings, around the vent and on the breast and
thighs. It causes intensive itching, often resulting
in feather pulling. Fowls may lose feathers
over large areas of the body. Infestations, especially
noticeable in spring and summer, may dis-appear
Chigger, Trombicula (Eutrombicula)
splendens (Ewing), T. alfreddugesi
(Oudemans), T. batatas (Linne)
Chiggers also are known as red bugs, jiggers,
and harvest mites, and by other common names.
Adults usually are covered with dense, feathered
hairs that give them a velvety appearance. They
are often bright red with a figure-eight-shaped
body about 1 millimeter long. The parasitic larvae
are about 1 /150 inch long, reddish or straw-colored,
and not as densely covered with feathered
hairs as the adult. Larvae are barely visible
to the naked eye. More than 700 species are
known, but only three or four are important
parasites in the United States.
T. splendens is not as widely distributed as T.
alfreddugesi, but their ranges frequently overlap.
It is confined primarily to the eastern half of the
United States but ranges into Texas. It prefers
more moist habitations than the common chigger
(T. alfreddugesi), such as swamps, bogs, and
rotten logs. Its season pattern is also similar to T.
alfreddugesi. This species feeds on mammals,
birds, reptiles, and amphibians, but reptiles,
especially snakes and turtles, appear to be the
most common natural hosts.
T. alfreddugesi is the most common and wide-spread
species in the United States. It ranges
from New England and eastern Canada, west of
Nebraska to California, south to Florida and
Texas and extends into Mexico, Central and
South America, and West Indies. Larvae are
most abundant in transitional areas between
forests and grasslands and along the margins of
swamps. Berry patches and thickets are favored,
but chiggers have been collected in most habitats.
Larvae are active in the north from July to
September, but in southern semi-tropical areas
may be encountered throughout the year. This
species is found on a variety of hosts including
humans, fowls, reptiles, amphibians, and mammals.
T. batatas exists primarily in tropical areas and
ranges from the United States to Brazil. It
prefers open, sunlit, grassy areas, especially
where domestic animals are kept, but is not
abundant in jungles or wooded areas. It attacks
human beings, domestic animals and poultry,
but ground-inhabiting birds seem to be preferred
Neoschongastia americana americana
The range of this chigger extends across the
southern states from the Carolinas to California.
It is more abundant in areas with hard soils that
crack open during hot, dry summers and in
areas where rock outcroppings occur.
Populations begin to increase in late April or
May, peak in June, and decline in late July or
August. There may be an increase in September
or October, and by late October or November it
disappears from the host. Domestic hosts are
turkeys and chickens. Wild hosts include quail,
woodpeckers and other wild birds.
Chiggers differ from other mites in their life
cycle. The life cycle of most chiggers includes
these developmental stages: egg, deutovum (larvae
enclosed in a membrane in addition to the
eggshell); larval, nymphochrysalis (quiescent
stage that transforms to the nymph); nymphal,
imago chrysalis (quiescent stage that transforms
into the adult); and the adult stage. Eggs usually
are deposited singly in the soil. After a 4- to 6-
day incubation period, eggs hatch into the deutovum,
which remains in the eggshell fragments
for about a week before the six-legged larva
emerges. Larvae crawl around rapidly in search
of a host and may survive 2 weeks or more
without one. The larval chigger usually feeds
only once. It most often completes feeding in 1
to 4 days, but in some instances may require up
to a month. When feeding is complete, larvae
drop to the ground, burrow into upper layers of
the soil and become quiescent. Within the larval
skin the nymphochrysalis develops and, about a
week later, the eight-legged nymph emerges.
The nymph is larger, has a figure-eight-shaped
body, and is more hairy than the larva. It probably
feeds on insect eggs and early stages of other
After about a week, nymphs enter a quiescent
stage, the nymphochrysalis, and emerge as
adults in another week. Adults are larger, hairier,
and sexually mature. The sexes are similar in
size and appearance, but the appearance of the
genital opening differs. They have essentially the
same feeding habits as nymphs. Adults are
ready to deposit eggs within a week and egg laying
continues for several weeks, probably as
long as favorable conditions exist. Under laboratory
conditions, observers have counted as many
as 4,764 eggs deposited from a single female
within 23 days.
The minimum time for a complete cycle of
the common chigger, T. alfreddugesi, is 55 days;
for T. splendens, 50 days; and for T. batatas, 71
days. The time required to complete the life
cycle depends on the species, soil, temperature,
humidity, and food availability. From the three
species noted above, the minimum time
required to complete the life cycle appears to be
about 2 months, but under adverse conditions
12 months may be required. Number of generations
per year varies from one to three in the
temperate zones to continuous breeding in the
tropics. In temperate zones, hibernation probably
occurs during the adult stage.
Neoschongastia americana americana is the
most abundant external parasite on turkeys
grown on ranges with rocky outcroppings or
hard soils that crack during summer when they
become dry. Chiggers feed in clusters on the
thigh, breast, and underside of wings, and
around the vent. These clusters cause scabby
lesions that require about 3 weeks to heal after
engorged chiggers leave the host. These lesions
and scabs result in downgrading of turkeys, a
loss that may average more than $1 per bird.
Chiggers normally do not burrow into the
skin or suck blood. When the chigger is firmly
attached, it injects a digestive enzyme into the
wound that liquefies host tissue. It sucks up the
partially digested, liquefied host tissue, leaving a
tube called a "stylostome." The digestive enzyme
that hydrolyzes the host's tissues is probably
responsible for the severe irritation and raised
bump that results from chigger "tubes." The larval
stage is the only parasitic stage in the chigger
Several kinds of gnats attack poultry, including
black flies, buffalo gnats, and turkey gnats.
The most common is the turkey gnat, Simulium
spp., a vector of leucocytozoan parasites that
cause a malaria-like disease in turkeys and
Eggs are deposited on objects on the surface
of, or in, flowing water, usually at the edge. The
eggs must be kept wet or submerged to hatch
into larvae in 2 to 12 days. Larvae develop in
water 1 to 6 weeks before transforming into
pupae. Adults emerge after a 4- to 15-day pupal
period. Southern buffalo gnats appear during the
first warm period of late winter or early spring.
The turkey gnat usually appears later in spring.
Sticktight or Southern Chicken Flea
This flea, Echidnophaga gallinacea (Westw.), is
found in the southern United States from South
Carolina to California. It attacks poultry, cats,
dogs, horses, and humans.
Adult males and females are found on the
heads of fowl. Females remain attached by their
mouthparts in the same spot as long as 2 or 3
weeks. During this time, eggs are laid, being
thrown with considerable force from the
female's vagina. Eggs hatch on the ground in 2
days to 2 weeks. The slender white larvae feed
on excreta of the adult fleas, filth in cracks, or
litter on the poultry house floor or on the
ground in dry, protected places. After growing 2
weeks to 1 month, they spin silken cocoons and
change to the pupal stage. Adults attach to the
host in about a week and females feed approximately
1 week before females begin laying eggs.
One to five eggs are laid at one time. The life
cycle may be completed in 1 to 2 months. This
pest thrives in dry, cool weather, and under
these conditions adults may live several months.
In the South and Southwest, fleas sometimes
embed themselves in clusters about the face,
eyes, ear lobes, comb, and wattles of poultry so
that they cannot be brushed off. Young fowls are
often killed; egg production and growth are
reduced by loss of blood and irritation caused
A new insecticide labeled for control of darkling
beetles, hide beetles and flies, known as
orthoboric acid (SafeCide®), provides long residual
control up to 9 to 12 months or longer. Both
adult beetles and larvae are killed by contact or
Usually a quick-kill insecticide is used prior
to SafeCide® to kill beetles away from the litter.
A 99% IC and/or 30% bait formulation is
applied directly to the manure. For poultry
houses where birds are grown on litter, remove
birds before applying the bait uniformly to the
floor or to old litter by fertilizer or seed spreader
at the rate of 1 to 2 pounds per 100 square feet,
in bands along feeder lines. Spread fresh litter at
least 4 inches uniformly over all treated areas
(floor or old litter), then introduce birds.
Reapply after each grow-out, if needed.
For poultry houses in which birds are grown
in cages (layer or high-rise "pit type" houses),
birds do not have to be removed prior to application
For control of beetle adults and larvae in poultry
houses using SafeCide IC, remove birds
before dry and wet applications. Use 1 to 2
pounds for each 100 square feet of treated surface
for dry application, dusting side walls, top
plates, posts and framing. For wet application,
mix dust at the rate of 1 to 2 pounds per 3 gallons
of water to apply over 100 square feet of
House fly resistance is genetic in nature,
developing more quickly under heavy doses of
pesticide or very frequent application. Insects
resistant to one insecticide can be cross-resistant
to other insecticides of the same class or even
having a similar mode of action. The only
proven solution to resistance problems is
to rotate the use of different classes of
It is unusual to find a poultry farm that does
not have at least a few rats or mice, and, more
often than not, the population is much larger
than suspected. In addition to eating and contaminating
a great deal of food, rodents do considerable
damage to buildings. They undermine
foundations, destroy curtains and insulation,
damage equipment, and cause fires by gnawing
electrical wiring. In rare cases, rats have been
known to kill poults and young chickens.
Finally, since they are able to carry a variety of
diseases and ectoparasites, rodents can affect
flock health and performance.
Two species of rodent, the Norway rat and
the house mouse, are common pests on most
poultry farms (Figure 1). The following descriptions
provide information on their biology and
behavior that is useful in their managing these
Norway Rat (Rattus norvegicus)
Adults are up to 46 cm (18 inches) long from
head to tail. The tail is hairless and shorter than
the body; the fur is reddish, grayish brown, or
black with the underside gray or yellowish
white. (Varicolored forms may occur.) Common
names are brown rat, house rat, barn rat, sewer
rat, and wharf rat.
- Rats burrow under and along foundations
and feed bins, and in secluded spots near
poultry houses (fields, trash piles, and
banks of ditches and lagoons). They may
also burrow into manure under slats or
cages. Their burrows are large, often with
conspicuous piles of dirt nearby.
- They are active at night. If they are seen
above ground during the daytime, it indicates
a large population.
- Capsule-shaped droppings about 13 mm
( 1 /2 inch) long may be seen along walls and
areas where rats move or congregate.
- Rats prefer fresh food when available.
- They are cautious. They may not take baits
immediately unless placed directly in their
path. They may pass up baits even when
correctly placed if a better food source is
- They are excellent climbers, able to enter
buildings by a variety of routes.
House Mouse (Mus musculus)
Adults are between 13 and 18 cm (5 and 7
inches) long from nose to tail. Their hairless tail
is as long as their body. They have light brown
to black fur with a white underside.
- Mouse burrows are small, ranging from 6
to 13 mm ( 1 /4 to 1 /2 inch) in diameter. They
are found along foundations, under boards,
near feed bins, in manure under slats and
cages, and in other similar areas. They also
nest in walls, ceilings, and curtains left
down for extended periods.
- Mice feed throughout the day, with greatest
activity at dawn and sunset.
- Droppings are smooth and about 6 mm ( 1 /4
inch) long. They may be seen along interior
walls, on sills, and in secluded areas where
mice move and congregate.
- Mice are very curious and will investigate
bait stations and bait placed in their path.
- They are excellent climbers, able to enter
buildings by a variety of routes.
In general, rodents have three basic requirements:
food (Figure 2), water, and harborage
(places to hide and nest; Figure 3). If one or
more of these items is missing from the area,
rodent populations will remain low.
Unfortunately, all three are usually abundant in
and around poultry houses.
An adult rat eats about 1 to 2 ounces of food
each day, whereas a mouse will eat far less,
about 0.1 ounce per day. Individually, this is not
a lot of feed, but a large population can account
for several tons of food each year.
Although both rats and mice need water to
survive, mice are often able to get what little
moisture they need from the food they eat. This
ability allows them to nest and feed in locations
where water is not abundant. Rats are not so
adaptable. They cannot extract enough moisture
from their food and must be relatively close to a
source of water.
Rats and mice are both burrowing animals,
but mice also build nests above ground in hidden,
secluded areas such as walls and ceilings.
Rats, on the other hand, generally nest almost
exclusively underground and come out only to
find food or water.
The reproductive capacity of rats and mice is
quite high. Both breed throughout the year, producing
4 to 8 litters annually. Rats are sexually
mature at 3 to 5 months of age and have 6 to 12
young per litter. Mice reproduce when younger
(1 to 2 months) and deliver 5 to 6 young per litter.
Based on reproductive potential alone, a single
pair of rats could produce 1,500 offspring in
a single year. Fortunately, other factors such as
predation, food availability, and population density
limit reproduction and survival in nature.
Even so, rat and mouse numbers can rise quickly
Three elements make up a good rodent management
program: sanitation, rodent proofing,
and rodent killing (Figure 4). Sanitation
and rodent proofing, the first lines of defense,
include a number of cultural practices easily
incorporated into the overall management of the
Successful management of rodent infestations
also involves some method of killing rats and
mice. Rodenticides (baits, concentrates, tracking
powders, and fumigants) are the most efficient
method of rodent control but should be selected
and used carefully to be effective.
Sanitation is nothing more than a combination
of cultural practices that deny rodents harborage
and food. Rats and mice are most troublesome
where there is a good cover to hide their movements
and provide sites in which to nest. A
well-maintained poultry facility not only exposes
them to predators but also makes it easier to
spot any burrowing activity. This last point is a
big help when using rodenticide.
The following items are important to the success
of a good sanitation program:
- Keep the area around poultry houses
mowed. Maintain a clear zone of not less
than 50 feet from field borders and fence or
- Remove old equipment, lumber, and trash
from around buildings. Lumber may be
stacked near buildings if it is elevated 1 or
2 feet above the ground.
- If side curtains are dropped for the summer,
raise and lower them twice a week to
stop mice from nesting in the folds.
- Clean up feed spills inside poultry houses
and at feed bins.
Completely rodent-proofing a poultry house is
impractical, if not impossible. However, sealing
up obvious entry points makes it a little more
difficult for rodents. Even small cracks and
holes in walls, foundations, and screens should
be patched. Mice need only a 1 /4-inch hole to
gain entry into a building.
- Seal openings around water pipes, drain
spouts, and vents with concrete or heavy
mesh (Figure 5).
- Cover openings and floor drains with mesh.
- In new structures with corrugated siding,
use flashing to seal both top and bottom of
the siding. Be sure that corner seams are
Killing Rodents (Using Rodenticide)
Glue-boards and traps are devices that can be
used to control rodent populations. In small
areas, these devices can be efficient; in a 12,000-
to 20,000-square-foot house, however, baits are
often more practical.
A wide variety of rodenticidal compounds and
formulations are available. The selection of the
right material for a specific situation is important.
(See listings under multiple-dose and single-
dose rodenticide later in this section.) An
understanding of the basics is necessary to know
how to use a particular compound and formulation
Rodenticides are formulated as pellets, bar
baits, tracking powders, and concentrates.
Pellets are formulations of poisons mixed with
grain products and a binder. They may be packaged
loose or in individual pitch packs. Bar
baits are formulated with rodenticide, grain
products, and a binder with a high wax content
to withstand moisture for long periods.
Tracking powders are compounds formulated
with talc or other inert material. They are
intended for use along rodent runways. Rodents
pick up the poison on their fur, tails, and feet
and ingest it during grooming. Concentrates
are designed to be mixed with feed or water.
The most important thing to know about a
rodenticide is that the type of active ingredient
determines how the material is to be used.
Failure to use a particular rodenticide correctly
will result in poor control and may present a
hazard to nontarget animals.
In general, rodenticides can be classified as
either multiple- or single-dose poisons. All of the
multiple-dose and two of the single-dose products
affect the rodent's nervous system or other
Multiple-dose poisons must be eaten every
day for 7 to 21 days in order for the rodent to
accumulate a lethal dose. Any interruption of
exposure breaks the cycle, and, although rodents
may become ill, they will not die. In such cases
rodents may learn to avoid the bait.
Active Ingredients in Multiple-Dose
Single-dose poisons have a decided advantage
over multiple-dose rodenticides in that rats and
mice receive a lethal dose after only one or two
Active Ingredients in Single-Dose
Once a rodenticide has been selected, it must
be used properly to be effective. Random placement
of bait or tracking powder around a poultry
facility is rarely successful. Always remember
that rodents will not go out of their way to
eat poison bait if they have other food readily
available. Similarly, tracking powders will not
work as intended if rodents do not run through
the material on their way to and from their feeding
or nesting areas.
Since baits are the most efficient and economical
way to deliver rodenticide, we will limit our
discussion to the proper use of baits to control
rats and mice. Because baiting methods differ
for rats and mice, they will be discussed separately.
Rats are much easier to bait than mice. Their
burrows are conspicuous and, once located, can
be baited by placing the rodenticide directly in
the burrow. The following method is called
pulse baiting and is an effective way to kill
1. Locate and mark all burrows.
2. Seal all burrows with newspaper or soil.
3. Inspect burrows the next day and place a
packet of bait well inside each open bur-row.
It is not necessary to open the packets.
4. Bait all open burrows for 2 consecutive
days if using a single-dose product and 10
to 14 days if using a multiple-dose rodenticide.
5. Close all burrows and wait 1 week.
6. Repeat step 4.
7. Close all burrows and monitor for activity.
Bait all new burrows when they first
Where rat burrows are located in inaccessible
areas such as the manure under slats and along
steep banks, bait stations should be used (Figure
6). Place stations against walls or on rodent run-ways
with the first station as close to the burrows
as practical. Orient the entry holes along
the wall or path. Well-used runways are easy to
spot (by the large amounts of droppings, rodent
tracks, greasy looking rub marks, etc.) and are
the best place to locate bait stations. Position
stations at 15- to 10-foot intervals to cover a
large area and give rats ample opportunity to
find the bait before reaching their normal feeding
sites. Put one or two stations around feed
bins as well. Inspect the stations every few days
and add 1 ounce of fresh, loose bait as needed.
If the bait has not been taken within several
days, place the station at a new location.
Large numbers of mice will often nest in the
walls and ceilings of poultry houses. Consequently,
mouse baiting is a matter of quantity
and persistence. Bait bars or stations baited with
an ounce of loose bait should be placed at 5- to
10-foot intervals throughout the house. Sill
plates and horizontal wall braces are often good
locations to place bait in breeder, turkey, and
other open-floor houses. Bait stations may also
be placed along alleyways in facilities where
birds are caged or penned. Egg rooms, offices,
and attic spaces should also be baited.
As with rat baiting, placement is important.
Bait stations and bar baits should be placed next
to walls or on the horizontal surface of sills and
braces. Corners are good locations, as are cool
cells and housings for exhaust fans. In all cases,
care should be taken to attach stations firmly
and in such a way that birds cannot reach the
Once bait has been placed, inspect the locations
frequently and replenish the bait as needed.
Inspection intervals depend on the severity
of the mouse infestation and type of bait used.
Where multiple-dose baits are used or the infestation
is heavy, check locations daily for the first
week. Try increasing the amount of bait placed
in each station if mice have eaten it all. This
will allow for less-frequent inspections. In time,
it will be necessary to inspect stations only once
a week. Bar baits are partially useful in locations
such as sill plates that are near the ceiling.
Most bars have a hole in the center that allows
the bait to be nailed in place (Figure 7). Bar
baits generally last much longer than loose baits
because mice cannot carry them to their nests.
It is not uncommon for bar baits to last several
months. Evidence of feeding is also easier to
gauge by noting the condition of the bar bait.
Bait stations are easily made from a variety of
materials. One of the simplest consists of an 18-
to 24-inch section of 1-inch polyvinyl chloride
(PVC) pipe (use 2- or 3-inch for a rat station) or
plastic drain tile (Figure 8). More elaborate stations
that fit nicely into corners or behind materials
in storage can be made with PVC pipe and
a variety of T-U joints. Plastic pails with lids
also make good bait stations (Figure 9). Cut 3- or
4-inch-diameter holes (use 2-inch holes for rats)
at the base of the pail.
Poison Control Office in Texas
The Texas State Poison Control Center can be
reached by calling 1-800-764-7661. The Austin
office works as a dispatcher system as calls
Be sure your doctor has this number and the
"note to physicians" printed on dangerous pesticide
labels. If you plan to use a hazardous pesticide,
it is a good idea to notify your physician in
advance so he or she can relay the right chemical
name to the poison information center in
case of emergency. Treatment for pesticide poisoning
The information given herein is for educational purposes
only. Reference to commercial products or trade names is made
with the understanding that no discrimination is intended and
no endorsement by the Cooperative Extension Service is implied.
Educational programs conducted by the Texas Agricultural
Extension Service are open to all people without regard to race,
color, sex, disability, religion, age or national origin.
Issued in furtherance of Cooperative Extension Work
in Agriculture and Home Economics, Acts of Congress of May 8,
1914, as amended, and June 30, 1914, in cooperation with the United States
Department of Agriculture. Zerle L. Carpenter, Director,
Texas Agricultural Extension Service, The Texas A&M University
3M-6-97, Revision ENT
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