Investigation on the resistance of housefly in Huangshi city from 1996 to 2007

Objective To understand the resistance of housefly to common insecticides in Huangshi city.Methods The LD50(μg/head) of tested insecticides was determined by topical application.Results The resistance of housefly to ten kinds of insecticides was detected from 1996-2007.Of which,the toxicity of acetofenate to housefly was the weakest and its LD50 value was 0.0479-0.0898 μg/head. The resistance of housefly to pyrethroid tended to increase year after year, and for organophosphate insecticide,its resistance maintained a high level.For example,the LD50 of dichlorvos was 0.2116-0.8324 μg/head.Conclusion Housefly in Huangshi city had high resistance to dichlorvos,deltamethrin,alphacypermethrin and tetramethrin,and low resistance to permethrin P-dichlorobenzene,propylene permethrin and cypermethrin.However,it was more sensitive to acetofenate.In order to inhibit and delay the development of resistance,it should strengthen the research on control strategy of housefly resistance,and stop using the high resistance insecticides.