Some effects of gamma radiation on the oriental fruitfly dacus dorsalis Hendel

Irradiation of adult flies produced progeny with better inseminating capacity than those treated during the pupal stage. Increasing the dose from 5 to 10 krad hasten depletion of sperm supply by 6 days. However, 5 krad applied to mature pupae and 5 or 10 krad on 3-day old adults produced sterile but highly competitive male flies. Irradiation stopped the production of new sperm by inducing necrosis and pycnosis on early spermatogenic cells resulting in aspermia or sperm depletion in the male flies. On older cells, dominant lethal effect was induced by radiation such that fertility was reduced to less than 1%. In the female flies, total infecundity was achieved at 10 krad although at 5 krad a few eggs were laid but none of them hatched. The ovaries become atrophied due to necrotic effect on the oogonial cells and pycnotic condition induced among the nurse cells. Thus for sterility of D. dorsalis a dose of 5 Krad delivered to late pupae or 10 krad on 3-day old adults is recommended. (Auth.)