s 



September 195^ ARS-33-2 



United States Department of Agriculture 

 Agricultural Research Service 

 Entomology Research Branch 



TESTS OF REPELLENTS AGAINST TABANIDS iJ ^^li 



By A. R. Roth, Entomology Research Branch, and Don C. Mote and Donald A. 

 Lindquist, ±/ Oregon Agricultural Experiment Station 



Horse flies and deer flies ( Tabanidae ) are difficult to control either 

 as larvae or as adults. Therefore, consideration has been given to the use 

 of repellent sprays for the protection of livestock from attack by these 

 I)ests. A large number of synthetic organic compounds, some of •which were 

 effective mosquito repellents, were obtained from the Orlando, Fla., 

 laboratory for testing at Corvallis, Oreg. Since only small qiiantities 

 (l to 5 grams) of "the materials were available, it was necessary to make 

 most of the tests on small animals in the laboratory. This paper reports 

 the results of laboratory tests on the deer fly ( Chrysops discalis Vill . ) 

 and limited field tests on cattle of a few materials against mixed popxila- 

 tions of tabanids at Siammer Lake, Oreg., during the stmmiers of 19^9 and 

 1950. 



Laboratory Tests 



White mice were used as the host animals in a technique similar to 

 that employed by Eddy and McGregor (19^9) in conducting tests against 

 Stomoxys calcitrans . Each mouse weighed approximately 25 grams and was 

 sprayed with 2.5 ml. of a 0.25-percent acetone solution of the chemical. 

 Application was made with a bulb -type hand atomizer that delivered coarse 

 droplets, so that the loss of chemical due to misting was minimized. Each 

 mouse was confined in a U-mesh hardware -cloth cage, approximately 1 inch 

 in diameter and k inches long, which was rotated by hand during the spraying. 

 After the spraying the mouse was placed in a small screen cage for about an 

 hoxir to permit the acetone to evaporate, axid then in a clean hardware -cloth 

 cage for testing. The cage containing the mouse was placed in a widemouthed 

 quart fruit Jar. About 30 to kO female deer flies that had been collected 

 with an insect net near the alkali flats of Summer Lake were introduced into 

 each jar. 



l/ Technical Paper No. 823, Oregon Agricult\iral Experiment Station. 

 Contribution of the Department of Entomology of this experiment station eind 

 the Entomology Research Branch. 



2/ Don C. Mote, formerly head of the Department of Entomology, Oregon 

 Agricultural Experiment Station, and Donald A. Lindqxiist, student in the 

 Department of Entomology, Oregon State College. 



