Abstract
The mechanism of DDT-resistance in the spotted root maggot Euxesta notata (Wiedemann), was found to be primarily attributable to decreased cuticular absorption ot DDT, with the resistant strain absorbing only half as much as a susceptible strain, rather than to increased detoxication. This finding is of interest since DDT resistance in this fly is due to a single genetic factor. The only metabolite produced from DDT was DDE, and the DDTsusceptible strain showed a high level of dehydrochlorinating activity.