Fast-neutron Effects on Productivity of Young and Old Flour Beetles, Tribolium Castaneum. Herbst, and Alterations at Different Temperatures and after Exposure of Either or Both Sexes

Summary

Virgin day-old and three-week-old flour beetles, Tribolium castaneum, were given approximately 830 and 970 rads, respectively, of 4·6 MEV fast neutrons. Ten replicates of mating combinations in which neither sex, one sex, or both sexes were exposed were cultured at 25°c, 29°c and 32°c in 65–70 per cent relative humidity. Productivity, measured as adult progeny per reproducing female per day, was scored for 14 days.

Decreases in temperature progressively delayed reproductive onset. Further delay in reproductive onset occurred when young female beetles were irradiated, indicating a greater radiation sensitivity of immature oogonia.

Productivity of young beetles reached a plateau during the second week; that of old beetles after the first day. When one sex was irradiated, productivities were not significantly different within a temperature, but were less than when neither was exposed and more than when both sexes of a pair were exposed.