DIFFERENCE IN RADIOSENSITIVITY OF TWO COLONIES OF TOBACCO BUDWORMS, HELIOTHIS VIRESCENS (LEPIDOPTERA: NOCTUIDAE)

Abstract

Sterility induced by gamma irradiation of the adult male tobacco budworm, Heliothis virescens (F.), was studied in two colonies, one was reared in the laboratory for more than 60 generations (laboratory strain) and the other reared for fewer than 9 generations (wild strain). When irradiated males were crossed with untreated females, the percentage egg hatch for each dose was lower with the laboratory than with the wild strain. When laboratory and wild females were crossed reciprocally with irradiated males, the fertilities were similar to those of the laboratory and wild strains, respectively. When irradiated males were crossed with female progeny from reciprocal crosses, the percentage egg hatch was similar to that of the wild strain.Wild strain females were nearly monogamous for the first several generations, but F0 females mated nearly as frequently as females of the laboratory strain.