Autosterilization of the house fly, Musca domestica (Diptera: Muscidae) in poultry houses in north-east India

Autosterilizing devices, composed of 20 x 50 cm rectangles of white polyester cloth, baited with 50% w/v sucrose and impregnated with 10% suspension concentrate of the chitin synthesis inhibitor triflumuron, were suspended in two caged-layer poultry houses on a 6 ha farm near Bhubaneswar, Orissa Province, in north-east India. Populations of Musca domestica Linnaeus declined significantly over 6 weeks in houses in which the triflumuron-treated targets had been deployed. Following the removal of the targets from these houses, the M. domestica populations subsequently increased. No comparable changes were observed in a control poultry house in which an equal number of targets, dosed with 50% w/v sucrose only, were suspended. Laboratory evaluation of the sugar-baited triflumuron targets confirmed that exposure of the strain of M. domestica present in the poultry manure to triflumuron-treated targets reduced egg hatch to less than 1%. There was no decline in the quantity of triflumuron present on targets during their 6 week exposure in the poultry houses, as shown by gas chromatography. Furthermore, a laboratory bioassay demonstrated no decrease in the potency of the chemical over the exposure period. However, the quantity of sugar present on targets decreased significantly after only 3 weeks exposure. However, populations in the treatment houses were not eliminated and immigration from surrounding houses may have reduced the effectiveness of the technique. The results are discussed in relation to the use triflumuron-treated targets as a practical autosterilizing system for house fly control in livestock production systems.