Penetration and excretion of effective ethoxychlor analogs in DDT-resistant and susceptible houseflies [Musca domestica, insecticides]

The penetration and excretion of six super(3)H-ring substituted ethoxychlor analogs with altered aliphatic moieties, and super(14)C p,p'-DDT were examined in susceptible and DDT-resistant strains of housefly Musca domestica Linnaeus. Within 24 hr, more than 85% of the applied dose of tested analogs penetrated into both strains except the nitropropane analog and there was no correlation between the rate of penetration and their toxicities to houseflies. The isobutane, chloropropane, and dichloroethane were eliminated rapidly. Qualitative and quantitative analyses of excretory products in feces indicated that chloroalkane analogos were primarily metabolized to corresponding dehydrochlorinated products. The isobutane, nitropropane, and neopentane were oxidized to benzophenones, There was a strong correlation between the Taft ( delta *) values for the aliphatic moieties of ethoxychlor analogs and LD sub(50) resistant/susceptible houseflies (R/S) ratio). The results indicate that rates and extent of metabolism resulting in detoxication of these analogs play an important role in their toxicity to DDT-resistant houseflies.