Precaution: Pesticides used 
improperly can be injurious to 
man, animals, and plants.-Follow 
the directions and heed all pre- 
cautions on the labels. 
Do not treat horses that are to 
be slaughtered for food. 
External Treatment 
This treatment consists of apply- 
ing warm water to the animal to 
hatch the eggs of the common bot 
fly. The best time to give the treat- 
ment is about 30 days after the first 
frost, when adult bot flies have dis- 
appeared—about November in the 
North and December in the South. 
By this time most of the eggs of 
the throat and nose bot flies will 
have hatched, and most of their lar- 
vae will have passed to the stomach. 
The anmal may still harbor many 
eggs of the common bot fly, and lar- 
vae may be in the tongue. Unless 
these eggs are destroyed and 30 days 
are allowed for larvae in the tongue 
to pass to the stomach, heavy infes- 
tations may develop even after the 
larvae are killed in the internal 
treatment. 
The treatment for destroying 
common bot fly eggs: 
e Heat water to between 115° 
and 120° F. If you have no ther- 
mometer, test the water with your 
hand. It should be heated just to the 
point at which you can keep your 
hand immersed without discomfort. 
e Wet a sponge or cloth thor- 
oughly with the water and rub it 
firmly over the animal’s body where 
eggs of the common bot fly are seen. 
The firm rubbing provides the 
necessary heat and moisture to 
hatch the eggs quickly. The newly 
hatched bots will die soon after they 
hatch. 
COMMUNITY CONTROL 
PROGRAMS 
A number of communities have 
attempted bot control by a system- 
atic treatment of all donkeys, mules, 
horses, and colts. In only 1 year, 
such treatment has greatly de- 
creased the annoyance from bot 
flies and has improved the health of 
the animals. 
It appears possible to achieve a 
high degree of control of bot flies 
by 2 or 8 years of systematic com- 
munity effort. 
To arrange for a community con- 
trol program, consult your county 
agent, farm adviscr, or veterinarian. 
Prepared by 
Entomology Research Division 
Agricultural Research Service 
Washington, D.C. 
Revised September 1969 
Slightly revised July 1970 
For sale by the Superintendent of Documents, U.S. Government Printing Office 
Washington, D.C. 20402 - Price 10 cents 
U. S. GOVERNMENT PRINTING OFFICE : 1970 O - 388-883 
