One-week-oldRlzyzopertha dominica(F,) adults were kept at 19, 25, 30, and 35°C following gamma irradiation with doses ranging from 5 to 80 kR given at 4200 R/minute. In general, the radiosensitivity of the beetle increased with elevation of the temperature following the treatment. A significant reduction in percent survival and duration of survival period occurred as the postirradiation temperature increased at all exposures. Furthermore, by lowering the temperature at which beetles were kept after irradiation, the onset of mortality was delayed by 5–10 days depending upon the exposure. In the control (unirradiated) group, beetles kept at 30°C lived longer as compared to any other temperature treatment.