Effect of high-temperature pre-irradiation on reproduction and mating competitiveness of male Sitotroga cerealella (Olivier) and their F1 progeny

Pupae of the Angoumois grain moth, Sitotroga cerealella (Olivier) were irradiated with substerilizing doses of 150, 180 and 210 Gy of gamma radiation. Inherited deleterious effects due to irradiation of P males irradiated as pupae were recorded for F1 progeny. The radiation damage increased when pupae were kept at high temperature (32.5 °C) for 24 h before irradiation, where a marked reduction in fecundity and egg hatch was obtained among P males and their F1 progeny. This reduction was significantly increased by increasing the dosage. F1 progeny were more sterile than the irradiated parent generation, though F1 males were more sterile than F1 females. Also, the combination of high temperature and irradiation applied to parental male pupae decreased larval survival and percentage of F1 female progeny, whereas it did not affect the mating frequency among P males and F1 progeny at the tested doses. Laboratory mating competitiveness indicated that parental males heat-treated with 32.5 °C and irradiated with 150, 180 and 210 Gy and their F1 progeny were fully competitive with their untreated siblings.