Effect of selection for dichlorodiphenyltrichloroethane (DDT) resistance on the uptake and breakdown of DDT in Aedes aegypti L.

Abstract

Aedes aegypti larvae and adults were selected to high levels of resistance with dichlorodiphenyltrichloroethane (DDT) along separate lines. The larval-selected line showed three responses associated with larval resistance: (i) increased detoxication of DDT by dehydrochlorination to dichlorodiphenyldichloroethane DDE (demonstrated both in vivo and in vitro), (ii) increased tolerance to unmetabolised ("residual") DDT and, (iii) a reduction in uptake of DDT. Larval selection caused very little change in adult resistance or the uptake of DDT by adults, but there was an increase in dehydrochlorination. In the adult-selected line dehydrochlorination was increased by selection and was significantly correlated with resistance.Key words: DDT, DDE, resistance, Aedes aegypti.