Reproductive disorders in a laboratory colony of Glossana palpalis palpalis Robineau-Desvoidy (Diptera : Glossinidae)

Abstract

Reproductive disorders were used as a framework in assessing the loss in fecundity of a colony of G. p. palpalis. One thousand five hundred females at various stages of the pregnancy cycle were selected at random from the main colony and divided into 10 groups of 150 individuals each according to age, which ranged between 5-90 days. All the groups were observed for the next 30 days and then dissected. The result showed that abortions were the commonest form of disorder and the major source of loss of fecundity, closely followed by the pupariation of third instar larvae in utero. The incidence of ovular blockage, insemination failure and degeneration of embryo/egg follicles was low. No instance of atrophy of the ovary was seen. Aborted eggs and larvae were recorded from all the age groups studied, indicating that abortions occur at any stage of the female pregnancy cycle. With a total reproductive disorder of 3.0 %, losses in fecundity through reproductive abnormalities in the tsetse colony studied are minimal.