Effects of Topical Applications of Dibrom upon Cattle Lice and Cattle Grubs1

Abstract

Dibrom®(1,2-dibromo-2,2-dichloroethyl dimethyl phosphate) sprays at a concentration of 0.5% produced useful levels of control in the cattle lice, Linognathus vituli (L.) and Solenoptes capillaus Enderlein. Control of populations of the cattle biting louse, Bovicola bovis (L.), was obtained with concentrations as low as 0.1%. The insecticide was applied to yearling beef cattle at a pressure of 400 p.s.i. at the rate of 1.5 gallons per animal. Marked mortality of larvae of Hypoderma lineatum (de Villers) and Hypoderma bovis (L.) in warbles in the backs of yearling cattle treated with Dibrom was noted. Animal systemic activity was not indicated. There was evidence of grub kill of both species for an extended period following treatment. This resulted in control for the balance of the warble season, which normally extends from December through May. Conccntrations of 0.25% to 0.5% Dibrom were considered effective. Application rates varied from 0,75 to 1.5 gallons per head at pressures of 400 p.s.i.