The female system

The main functions of the female reproductive system are egg production, including the provision of a protective coating in many insects, and the storage of the male's spermatozoa until the eggs are ready to be fertilized. Transport of the spermatozoa to the female's storage organ and their subsequent controlled release requires movement of the spermatozoa, which in some species is known to be mediated by muscular contractions of parts of the female reproductive tract.

The basic components of the female system (Fig. 3.20a) are paired ovaries, which empty their mature oocytes (eggs) via the calyces (singular: calyx) into the lateral oviducts, which unite to form the common (or median) oviduct. The gonopore (opening) of the common oviduct usually is concealed in an inflection of the body wall that typically forms a cavity, the genital chamber. This chamber serves as a copu-latory pouch during mating and thus often is known as the bursa copulatrix. Its external opening is the vulva. In many insects the vulva is narrow and the genital chamber becomes an enclosed pouch or tube, referred to as the vagina. Two sorts of ectodermal glands open into the genital chamber. The first is the spermatheca, which stores spermatozoa until needed for egg fertilization. Typically, the spermatheca is single, generally sac-like with a slender duct and often has a diverticulum that forms a tubular spermathecal gland. The gland or glandular cells within the storage

Table 3.2 The corresponding female and male reproductive organs of insects.

Female reproductive organs

Male reproductive organs

Paired ovaries composed of ovarioles (ovarian tubes)

Paired testes composed of follicles (testicular tubes)

Paired oviducts (ducts leading from ovaries)

Paired vasa deferentia (ducts leading from testes)

Egg calyces (if present, reception of eggs)

Seminal vesicles (sperm storage)

Common (median) oviduct and vagina

Median ejaculatory duct

Accessory glands (ectodermal origin:

Accessory glands (two types):

colleterial or cement glands)

(i) ectodermal origin

0 0

Post a comment