Gonadal lesions in virus-infected male and female tsetse, Glossina pallidipes (Diptera: Glossinidae)

Ovaries and testes, dissected out and collected from wild Glossina pallidipes with virus-infected, hypertrophied salivary glands, were processed for routine electron microscopy and examined for pathological changes. Lesions in the male gonads were more severe than in their female counterpart and involved both testes in every case. Examination of the ovaries of the virus-infected females with hypertrophied salivary glands showed that although the occasional germarium appeared normal, the majority were affected by degeneration and severe necrosis. The degenerate ovarioles also showed virus particles within germarial cells. Sections of testicular follicles of adult males with hypertrophied salivary glands revealed a total arrest of spermatogenesis, depicted by complete absence of meiotic and postmeiotic stages. The follicles contained only sheets of undifferentiated premeiotic spermatogenic cells, i.e., spermatogonia and primary spermatocytes. In some testes, degeneration (characterized by diffuse vacuolation and exfoliation of degenerate cells leading to empty lumina) was superimposed on lack of sperm development. Testes of normal adult male G. pallidipes, on the other hand, showed swarms of entangled spermatozoa. The demonstration of virus particles within the germarium of the ovariole of females with hypertrophied salivary glands and the complete sterility observed in males with hypertrophied salivary glands identify the virus of G. pallidipes as a potential candidate for the biological control of the species.