RESPONSES TO PROSTEPHANUS TRUNCATUS (COLEOPTERA: BOSTRICHIDAE) AND TRIBOLIUM CASTANEUM (COLEOPTERA: TENEBRIONIDAE) TO GAMMA RADIATION FROM 60Co

Abstract The radiosensitivity of Prostephanus truncatus (Horn) and Tribolium castaneum (Herbst) to 60Co radiation was determined at doses of 5 to 100 krad. P. truncatus was more radiosensitive than T. castaneum at 5, 15, and 25 krad (P < 0.05) at 8 and 16 days after irradiation but after 24 days all individuals irradiated at 15 and 25 krad were dead. At 50 or 100 krad all individuals of both species died in 16 or 12 days, respectively. Dose rates of 1.07 to 12.84 krad/min for a total delivered dose of 25 krad had no effect on the speed of lethal response. The results indicate that on economic grounds alone, it may not be justified to use 50 or 100 krad to accelerate the onset of death by 8 or 12 days, respectively.