[en] We investigated various effects of gamma radiation on the carob moth, Ectomyelois ceratoniae, treated with 200-600 Gy at different pupal ages. Irradiation resulted in a decrease of adult emergence. This effect was both dose and age dependent. At 500 and 600 Gy, no pupae developed into normal adults when treated at the age of 4-5 days. Only 6% normal adults emerged when the pupae were treated at the age of 6-7 days with 500 Gy. When 8-9 d old pupae were irradiated with 500 and 600 Gy, 30% and 10% normal adults emerged, respectively. Other emerged moths exhibited various malformations, mostly wing deformities. When pupae were treated with 400 or 500 Gy, fecundity and fertility of both untreated females mated with irradiated males or irradiated females mated with untreated males were drastically reduced. When 9-10 d old pupae were irradiated with 200, 250 and 300 Gy, adult morphology, fecundity, fertility and egg hatch were slightly affected. Mating behaviour of irradiated males also was affected. Competitiveness of males irradiated with sub-sterilizing doses varied depending on irradiation dose and number of insects present in the mating cages. A significant reduction of competitiveness was observed in males treated with ≤300Gy. (author)