Evaluation of the efficacy of X-ray irradiation on male testes of Mediterranean fruit fly using light and transmission electron microscopy

ABSTRACTThe present study evaluated the efficacy of X-ray irradiation for the sterilization of Ceratitis capitata. Pupae were exposed to doses of 0 (control), 60.7, 137, 156.9, 237.7, 300.59 and 344.46 Gy to determine which dose would not affect viability of irradiated fruit flies but would result in their sterilization. Doses of 60.7 and 137 Gy were suitable as males emerging from irradiated 7-day-old pupae were 100% sterile but were otherwise viable. Light and transmission electron microscopy were used to examine the structure of normal and treated male C. capitatatestes. The testes of males originating from non-irradiated pupae of C. capitataconsist of a single long follicle that looks like a sac and is full of germ cells at different stages of development. In testes of males originating from irradiated pupae, the presence of lysosomes, many vacuoles, and irregular distribution of spermatogonia and spermatocytes, led to an overall slowed rate of spermatogenesis. Apparent degeneration and abnormalities of the sperms resulted in the production of non-functional sperm or to a reduction in sperm production. This study concluded that X-ray is an alternative irradiation method for the sterile insect technique used to control Mediterranean fruit fly populations.