Explain the morphology of cockroach.

Explanation

The body of cockroach is compressed dorso-ventrally, bilaterally symmetrical and segmented. The body is divisible into head, thorax and abdomen. The entire body is covered by a hard, brown, chitinous exoskeleton. In each segment, exoskeleton has hardened plates called sclerites which are joined by a delicate and elastic articular membrane or arthrodial membrane. The sclerites on the dorsal side are called tergites, and those on the ventral side are called stemnites and those on the lateral sides are called pleurites.
Head: Head is small, triangular lies at right angle to the longitudinal axis. The mouth parts are directed downwards so it is hypognathous. The head has a pair of large, sessile and reniform compound eyes, a pair of antennae and appendages around the mouth part. Antennae have sensory organs. The cockroach has a biting and chewing type (mandibulate or orthopterus type) of mouth parts. It includes a labrum, a pair of mandibles, a pair of maxillae, a labium and a hypopharynx or lingua
Thorax: The thorax consists of three segments, prothorax, mesothorax and metathorax. The head is connected with thorax by a short neck or cervicum. Each thoracic segment has three pairs of walking legs. Each leg consists of five segments, coxa, trochanter, femur, tibia and tarsus. The tarsus has five movable joints or podomeres or tarsomeres. A pair of forewings arises from the mesothorax called elytra or tegmina. It protects the hind wings when at rest. The second pair membranous wings arises from the metathorax and are used in flight.
Abdomen: The abdomen has 10 segments. Each segment has a dorsal tergum, ventral sterum and between them a narrow membranous pleuron. In female the 70 segment is boat shaped and together with the 8th and 9th sterna forms a brood pouch or genital pouch. Its anterior parts contain female gonopore, spermathecal pores, collaterial glands and the posterior parts constitutes the oothecal chamber in which the cocoons are formed. In males, the genital pouch lies at the hind end of the abdomen bound dorsally by `9^(th) and 10^(th)` terga and ventrally by the `9^(th)` sternum. It contains dorsal anus and ventral male genital pore. In both sexes, genital apertures are surrounded by sclerites called gonapophysis.
Male has a pair of short and Fitom slender anal styles in the `9^(th)` Compound eyesternum which are absent in Prohoracks og female. In both sexes, the `10^(th)` Prontum Monathan segment has a pair of jointed Melhor filamentous structures called anal cerci which is a sense organ Mosaic that is receptive to vibrations in Mutahoraciethe air and land. The `7^(th)` sternum of male has a pair of large and oval apical lobes or gynovalvular plates which forn a keel like structure which distinguishes the male from female.