Neurosecretory Innervation of the Accessory Gland Region of the Male Stable Fly,Stomoxys calcitrans

Abstract

Summary The accessory gland region of the ejaculatory duct of the stable fly, Stomoxys calcitrans (L.) was found to be innervated by neurosecretory fibers that originate from a series of peripheral ganglia associated with the ejaculatory duct. An ultrastructural study of these ganglia revealed that they contain two neurosecretory cells that produce morphologically different secretory granules that release their products at different sites. Neurosecretory nerves extending from these ganglia form numerous branches that terminate on the basal surface of the gland cells and on the muscle fibers of the tunica muscularis of the ejaculatory duct. Since these ganglia as well as the median abdominal nerve were found to contain neurohemal areas, the accessory gland and the other reproductive organs of this species may be regulated by neurohemal as well as by neuroeffector mechanisms. The accessory gland of the male stable fly is the only internal reproductive organ reported thus far in insects in which the gland ce...