Positional Relationships among Male Reproductive Organs in Insects

Abstract

The location, morphology and function of male internal reproductive organs in insects have been extensively studied, but the relative positioning of those organs is less understood. Position and morphology of the testis, vas deferens, seminal vesicle, accessory gland and ejaculatory duct determine the migration or ejaculation of sperm and other substances. In species where the testis is connected with the seminal vesicle directly or the seminal vesicle is lacking, males usually store complete sperm in the testis and thus can use them immediately for mating. In contrast, the testis of lepidopteran insects is separated from the duplex (sperm storage organ) via the vas deferens, and the sperm are not mature, requiring morphological development in the vas deferens. Here, we discuss the significance of various positional relationships of male reproductive organs and how this relates to their morphology and function with a focus on sperm.

Reproductive Biology of Muga Silk Moth <i>Antheraea assamensis</i> Helfer

“…In lepidopteran insects, sperms are not mature in the testis and change morphologically when passing through the vas efferens from the testis to the vas deferens. Hiroyoshi and Reddy (2021) discussed positional relationships of male reproductive organs and how this relates to their morphology and function with a focus on sperm maturation and transfer. However, Omura (1938b) reported that though spermatozoa attain full maturity in the testis in B. mori they remain inactive throughout the post testicular organs and become vigorously active only when get mixed with The female reproductive system consists of a pair of ovary, each with four ovarioles, paired lateral oviducts which joins to form a common oviduct which has a dorsal protrusion, the vestibulum, a bursa copulatrix, a spermatheca and a pair of female accessory glands or dorsal colleterial glands with their reservoirs (Fig.…”