Abstract
Radiosensitivity between phosphine (PH3)-resistant and -susceptible strains of the red flour beetle, Tribolium castaneum, to γ-ray was studied in the various stages of adults, pupae, larvae and eggs. Adults of the susceptible strain were completely killed by 150 Gy while 200 Gy was needed for those of the resistant strain. Radiotolerance also appeared in both stages of pupa and larva of PH3-resistant strain to some extent while eggs were quite similar in their radiosensitivity in both strains. Sterility of the beetles irradiated at adult stage were not different significantly in both strains except the irradiated female where the fertility of the resistant strain was in some cases much higher than that of the susceptible one.
