Efficacy of Chlorfenapyr against Musca domestica (Diptera: Muscidae): A Laboratory Study

The housefly. Musca domestica L (Diptera: Muscidae), is a globally distributed synanthropic insect that must be controlled to maintain appropriate sanitary conditions for livestock and poultry. The efficacy of chlorfenapyr, a broad-spectrum insecticide, was tested against houseflies under laboratory conditions. In bioassays with a forced contact of adult flies with insecticide residues on the bottom of a glass cup, the chlorfenapyr contact toxicity was compatible to that of permethrin toxicity. When applied to surfaces, the chlorfenapyr contact toxicity was lower than that of pyrethroids and similar to neonicotinoids. In nonchoice feeding bioassays, chlorfenapyr demonstrated high intestinal toxicity to M. domestica: median lethal dose (LD50) was 4.18 mu g of active ingredient per gram of sugar. As a fly bait (3% and 6% wet powder), chlorfenapyr insecticidal efficacy was not less than 98% and 100% after 24 and 48 h of the exposure, respectively. The results indicate that chlorfenapyr, especially in the form of baits, may be recommended for fly control in livestock farms, and it may be useful for the development of insecticide resistance management strategies.