How is the metamorphosis in cockroaches?


How is the metamorphosis in cockroaches?

Cockroaches belong to the group of insects with incomplete metamorphosis or hemimetábola. That is, from the egg hatch the larva that is called “nymph” identical to the adult insect but very small, without wings, without reproductive organs developed. The growth of the nymph and the development of the reproductive organs are made through the seedlings. In addition to the cockroach, bedbugs, grasshoppers, mantis, dragonflies, cicadas, crickets and other primitive insects have this type of metamorphosis and are called exopterigotos insects.

The process of metamorphosis is complex and regulated by effector hormones that are controlled by neurohormones in the brain. Cockroaches, like the rest of the arthropods, have the exoskeleton, the outer skeleton and very rigid. To grow the insect has to “remove” this exoskeleton that has already been “small” and form the new in the process of molting. Moulting takes place from one larval state to another.

Two types of hormone-releasing hormone-releasing hormone-releasing hormones (hormones) release the hormones: juvenile hormone (“winged bodies” and so-called juvenile hormone releasing glands) and ecdysone, or the hormone responsible for moult (the protaracic gland releases this hormone Type of hormone The juvenile hormone responsible for the maintenance of the larval characteristics in the insect and gradually decreasing with each molt and the ecdysone initiates and coordinates each molt.

During the motile ecdisotropin it inhibits the release of the juvenile hormone and stimulates the release of ecdysone. Ecdysone is responsible for stimulating the epidermal cells to synthesize enzymes that digest and recycle the components of the cuticle and the formation of the new cuticle. This causes the molting and formation of new exoskeleton.

With each molt the concentration of the juvenile hormone decreases but at the same time the characteristics of the adult insect appear more and more. Just after the molt is finished, the insect becomes pale and the exoskeleton soft, but within several hours it hardens and picks up the darker color.

In the last molt that is called metamorphic, the wings, the external genitals, the secondary sexual structures like eardrums are finished. From this moment the insect is prepared to lead the adult life.