26 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 195 3 
When insecticides are applied uniformly to the entire surface area 
in the vicinity of an ant mound more lasting control is obtained. 
Chlordane at the rate of 2 pounds per acre will control ants for about 
1 year. Dieldrin at the same rate will keep the treated area free of 
ants for at least 2 years. 
The use of chlordane in combination with fertilizer, applied at the 
rate of 1 pound per acre, protected germinating seed corn from attack 
by the ants. m ..- , ^^ 
Heptachlor Effective Against Sand Flies in Florida 
Studies on sand flies in Florida showed 74 percent reduction of 
larvae after 2 weeks and 88 percent reduction after 14 weeks when a 
large area was treated with heptachlor at 2 pounds per acre in an oil 
solution. In a smaller test, 1 pound of heptachlor in 10 pounds of 
granulated bentonite per acre showed 81 percent control after 22 
weeks. At twice this dosage 93 to 100 percent control was achieved 
through 22 weeks. This work was supported in part by military 
funds and in part by the Florida State Board of Health and several 
mosquito control districts in Florida. 
Insecticides Tested Against Salt-Marsh Mosquitoes 
In extensive tests in Florida the most effective insecticides for use 
in mist sprayers and fog machines against adult salt-ma rsh mosquitoes 
were gamma BHC, heptachlor, DDT, dieldrin, and chlordane. There 
was little consistent difference between two commercial fog machines, 
a Japanese Kyoritu fog machine and a mist sprayer developed by 
Bureau personnel. This work was supported by funds made available 
to the Bureau from the Department of Defense. 
Orlando Facilities Expanded 
Six buildings at Orlando, Fla., were acquired under permit from 
the Department of Defense for the use of the Division of Insect s A f- 
fecting Man and Animals. This move, from other quarters at Or- 
lando, permits the use of more laud and building space and furnishes 
better facilities away from residential areas, Future costs to the 
Bureau will be for building maintenance only. 
INSECTS AFFECTING LIVESTOCK 
Various Insecticides Tested Against Livestock Pests 
A technique has been developed by which various insecticides and 
repellents Can be tested in a preliminary way for horn fly or stable tly 
control on cattle by t real ing an area about 6 Laches Bquare on the ani- 
mal. In this way as many as 12 or more formulations can he tested on 
a single individual. This technique reduces cost of maintaining and 
handling animals and permit- tests with small quantities of chemical 
Several experimental pyrethrum synergists have been shown by these 
test 3 ;i- w orthy of further t rials. 
CS "»" (,> . "Mi 1 of the new insecticides, was found to he :i- effective 
as methozychlor in controlling the horn fly on dairy cattle. 
