Effect of gamma irradiation on pupal stage of Ephestia calidella (Guenée)

Mature pupae of Ephestia calidella (Guenée) were irradiated at doses of 200-1000 Gy. Variations in the percentage of adult emergence and percentage of malformed adults were used as criteria to evaluate the radiation effects. A dose of 1000 Gy prevented the emergence of both sexes. Females and males were sterilized with a dose of 350 and 400 Gy, respectively. Adult longevity and mating ability varied with regard to the dose. Males irradiated with sub-sterile doses (100, 150, and 200 Gy) were more sexually competitive with normal males than those irradiated with the sterilizing dose (400 Gy).