none Pupae of the oriental fruit fly, Dacus dorsalis Hendel, which had been exposed as larvae to the parasitoid, Biosteres longicaudatus (Ashmead), were subjected to 10 krad gamma radiation in nitrogen atmosphere on the eleventh day after parasitization. The irradiation treatment caused sterility in the adult parasitoids of both genes. Gamma irradiation slightly enhanced longevity of treated females when compared with untreated parasitoids. However, longevity of treated males decreased significantly.