Although mating is a necessary prerequisite for the induction of ovulation in the tsetse fly, Glossina morsitans morsitans, neither the accessory gland substance from the male nor any testicular component is responsible for causing ovulation. Experimental evidence suggest that two neural factors, one originating from the uterus during mating act as an afferent stimulus, and the other originating from the ovary during oocyte maturation regulate a cerebral hormonal factor which controls the event of ovulation. It is probable that one successful copulation removes an inhibition for the release of an ovulation stimulating hormone from the neurohemal organ into the circulation. The rate of synthesis and/or transport of the hormone from the neurosecretory cells to the neurohemal organ is probably regulated by the rate of oocyte development.
(Received May 12 1980)