Generalised Male Reproductive System

diagram of the male insect reproductive system

The male reproductive system includes a pair of testes, each of which is comprised of testicular tubes, where sperm is produced. Germ cells at the distal (top) end of the testicular tube divide by mitosis to form spermatocytes. The spermatocytes divide again by meiosis to form haploid spermatids which increase in size as they are pushed down toward the base of the testicular tube by continual cell division. When they reach the base of the tube, the spermatids have developed into mature spermatozoa.

Mature sperm leave the testes via the vasa deferentia (sing. vas deferens) and accumulate in the seminal vesicles, which store the sperm until it is required during mating. During copulation sperm moves from the seminal vesicles to the ejaculatory duct and passes to the female via the intromittent organ, or penis (called an aedeagus).

The accessory glands have two major functions:

  1. Manufacture seminal fluid to nourish the mature sperm stored in the male reproductive system.
  2. Produce spermatophores, pouch like structures that encapsulate the sperm to protect them while being delivered into the female's body during copulation.