Evaluation of Pyrethroid Ear Tag and Spray Treatment of Cattle Against Horse Flies (Diptera: Tabanidae)

Abstract

Permethrin and fenvalerate ear tags, and fenvalerate sprays (0.01 and 0.02%) were evaluated against tabanids under field conditions in Louisiana. Residual concentration of insecticide in the hair from the head, side, back, abdomen, front and back legs of steers was measured after each fly collection period by gas chromatography. Mortality rates were reported relative to the feeding pattern of species of tabanids studied and insecticide concentration of different body regions. A total of 2,922 females belonging to three Tabanus species were collected. Mortality rates were 3% in controls, 9% in permethrin tag, 15% in fenvalerate tag, 67% in 0.01% fenvalerate spray and 79% in 0.02% fenvalerate spray treatments.