Carbamate Insecticides: The Cross-Resistance Spectra of Four Carbamate-Resistant Strains of the House Fly After Protracted Selection Pressure1

Abstract

House fly (Musca domestica L.) strains maximally resistant to m-isopropylphenyl N-methylcarbamate and Isolan® (1-isopropyl-3-methyl-5-pyrazolyl dimethylcarbamate) were further selected routinely with these compounds to maintain resistance. Selection pressure over M generations resulted in maximal or near-maximal cross-resistance to DDT and methoxychlor, and in various levels of cross-tolerance or cross-resistance to organo-phosphorus compounds. A second strain selected with m-isopropylphenyl N-methylcarbamate showed a cross-resistance pectrum similar to those of the previous strains and demonstrated the induction of cross-resistance to lindane and dieldrin through selection with carbamate. The cross-resistance spectra of the carbamate-selected strains showed greater resemblance to the spectra of organophosphorus-than of chlorinated hydrocarbon-selected strains, thus suggesting relationships in esterases responsible for organophosphorus and carbamate detoxication.