Tests with a New Organophosphorus Compound (Dowco 109) against Cattle Grubs in Oregon

Abstract

A new organophosphorus compound, Dowco 109 (0-(4-tert-butyl-2-chlorophenyl)0-methyl methylphosphoramidothioate) was tested as a systemic against cattle grubs, Hypoderma lineatum and bovis. The treatments were made during the fall before the appearance of grubs and the results were based on the number of encysted grubs found during the following winter and spring months. Single oral treatments of approximately 5 to 15 mg/kg gave 67 to 94% control; rates of 20 or 25 mg/kg gave 94 to 100% control. Wettable powder sprays containing 0.75% active material gave 91 to 100% control when applied at an average of 2 quarts per animal and 99 to 100% control at 4 quarts per animal.