Histology and Histochemistry of the Ovary during Oogenesis in the Autogenous Black-fly Simulium vittatum Zett.

Abstract

This research was designed to gain a better understanding of the oogenesis of the autogenous black-fly, Simulium vittatum and to compare it with studies on other Diptera. The autogenous character in S. vittatum showed only for the first gonadotropic cycle. Since the cytoblasts are first produced in the late larval period, the late larvae, early pupae, late pupae and adults of various ages were prepared separately for histological and histochemical examination. The adult female flies were fed only sugar and water. The changes in size, histology, and histochemistry of the oocyte, follicular cells and nurse-cells during oogenesis were described and the possible physiological role of these cells in oogenesis suggested. The amount and composition of larval fat-body remaining in females was compared with the stages of the oocyte development and the age of the flies.