The influence of mature males on the neurosecretory control of ovarian development in the desert locust

Abstract

ABSTRACT The ovaries of the desert locust are made up of about 100 ovarioles. When females are reared with mature males, the terminal oocytes in the ovarioles develop very much more rapidly than the terminal oocytes of females reared without males. In addition, the percentage of terminal oocytes which are resorbed during development increases more rapidly in females reared without males than in females reared with mature males. This results in a significantly larger percentage of mature eggs being produced by females reared with mature males. The neurosecretory system contains little stainable material in females whose terminal oocytes are developing rapidly in the presence of mature males, but contains a large amount when the terminal oocytes are mature. In females reared without males, whose terminal oocytes either develop slowly or remain undeveloped, the neurosecretory system shows a precocious accumulation of stainable material. It is concluded that the neurosecretory system is actively extruding secretion when the amount of contained material is small, and that material is accumulating and not being released when it is present in large amount. The presence of mature males somehow brings about the release of material from the female neurosecretory system, with consequent rapid development of terminal oocytes and the production of a larger number of eggs.