Surveillance of the resistance of Musca domestica to insecticides in Dalian

Objective To understand the insecticide resistance of Musca domestica to 5 common insecticides in Dalian,and provide a reference for fly control.Methods The median lethal dose(LD50) of the drug on Musca domestica was determined by dropping method.Results The LD50values of deltamethrin,beta-cypermethrin,dichlorvos,chlorpyrifos and propoxur were 0.009 141 28(μg/♀),0.044 499 52(μg/♀),0.137 490 08(μg/♀),0.184 592 448(μg/♀),and 97.27(μg/♀),respectively.The resistance index of Musca domestica to propoxur,deltamethrin,beta-cypermethrin,chlorpyrifos and dichlorvos were 275.474 4,23.439 2,15.892 7,6.134 7,and 2.313 1,respectively.Conclusion The collected Musca domestica in Dalian presented obvious resistance to the five insecticides,and showed high resistance to propoxur,deltamethrin and beta-cypermethrin,middle resistance to chlorpyrifos,and low resistance to dichlorvos.