Effects of gamma radiation on reproduction, Mating competitiveness and sperm activity of Callosobruchus chinensis (l.)

Abstract

The effects of gamma irradiation at different doses on the adult stage of Callosobruchus chinensis L. were studied. Adult fecundity and fertility decreased by increasing the radiation dose and effects of the treatment were more severe when both sexes were irradiated and mated together than matings of either sex with unirradiated partner. The dose required to sterilize males and females was about the same: 120 Gy was sterilizing to both sexes. Fractionation of sterilizing dose did not reduce perrcent sterility of irradiated adults, and there is no clear effect on fecundity or adult longevity. Irradiated males were full sexually competitive with unirradiated males at all doses of ratios used. Males irradiated with a sterilizing dose (120 Gy) were able to negate previous insemination by unirradiated ones, sperms of the sterile males could compete with sperms of the normal males. These results indicated that sterile males give good results in controlling a population of Callosobruchus chinensis in an autocidal control programe.