DDT tolerance in diazinon-selected and DDT-selected strains of houseflies.

The following is virtually the authors' summary. Comparisons of the penetration and metabolism of DDT in a strain of house-fly [Musca domestica L.] selected with diazinon and resistant both to organophosphates and to DDT [cf. RAE B 51 5], a strain selected with DDT and resistant to it and a susceptible strain showed that the causes of resistance to DDT in the strains selected with diazinon and with DDT differ. Absorption was slower in the diazinon-selected strain than in the susceptible strain or the strain selected with DDT. As the dosage increased, the proportion penetrating in a given time decreased considerably in both the diazinon-selected and the susceptible strain but less in the DDT-selected strain. The DDT was changed to non-toxic metabolites faster in both the diazinon- and the DDT-selected strains than in the susceptible strain, but the strain selected with diazinon degraded DDE much faster and more completely than the one selected with DDT.