WARF Anti-Resistant: DDT Selection and House Fly Cross-Resistance123

Abstract

Continued selection pressure with a combination of DDT + WARF anti-resistant (N,N-dibutyl-p-chlorobenzenesulfonamide) on a laboratory strain of house fly, Musca domestica L., having relatively low resistance to various insecticides resulted in increased resistance to the selecting agent, and to diazinon, malathion, ronnel, dimethoate, Isolan (l-isopropyl-3-methyl-5-pyra-zolyl dimethylcarbamate), dimetilan, pyrethrins, and DDT. Although lindane resistance was not increased, further regression of resistance was prevented. Resistance to chlordane, dieldrin, and heptachlor regressed despite selection pressure. The results were comparable to those obtained when diazinon selection pressure was reapplied after many generations of no exposure to insecticides.