Feed Additives for Control of House Fly Larvae in Livestock Feces1

Abstract

There was no reduction in the numbers of house flies (Musca domestica L.) completing development from egg to adult in feces from a steer fed up to 100 gm./day of Polybor 3, (containing 98% of disodium octoborate tetrahydrate (Na2B8O13-4H20)). When mixed directly with cattle manure, Polybor 3 was an effective larvicide; a possible explanation for relatively higher rates in a steer ration not controlling larvae in feces is discussed. Bacillus thuringiensis Berliner spores containing 25 billion/gm. mixed directly with cattle feces at rates of 0, 50, 100, 200, and 300 mg./kg. and inoculated with 100 house fly eggs resulted in an average of 43, 41, 9, 5, and 0 adult house flies completing development, respectively. Feeding 20 gm. B. thuringiensis/day to a steer prevented development of house flies in manure, and 0.125 gm. B. thuringiensis/kg. ration greatly reduced the number of adult flies emerging from hen droppings. The presence of aureomycin did not decrease the effectiveness of this pathogen.