The sensitivity of 1-day-old eggs of Corcyra cephalonica Staint., to ionizing radiation has been investigated in view of a possible future application of sterile-insect technique to the control of this species. Further, the irradiation effects on subsequent developmental stages were evaluated. A dose of 5 krad prevented hatching of eggs, while a dose of 4 krad was the highest dose that allowed an adequate percentage of the irradiated eggs (28.23) to complete development to the adult stage. While the mating percentage and mating frequency of resultant adults appeared to be unaffected, the percentage of multiple mating was variable and no clear pattern emerged. Egg production and fertility of P1 adults was decreased significantly and all effects of the treatment were more severe for pairings of both sexes resulting from irradiated eggs than pairings of either sex with unirradiated partners. However, the results show that a dose of irradiation low enough to permit adequate numbers of adults to develop from irradiated eggs (4 krad) is insufficient to induce high levels of sterility. Therefore, irradiation of eggs for mass production of either sterile or partially sterile adults was found not to be feasible.