Selection for DDT Resistance in a Beneficial Insect Parasite

Abstract
Expts. are in progress to see whether it is possible to produce by selective breeding appreciable DDT resistance in insect parasites of pest insects. Selection of DDT-resistant forms of Macrocentrus ancylivorus (Hymenoptera), an effective parasite of the larvae of the oriental fruit moth, was carried out daily for 9 mos. At the end of this period, DDT-resistance in females had been increased 4.35 times, and that of the males 3.72 times, as great as that of the original stock.