Define Morphology of Cockroach:
Tutors point offers Morphology of Cockroach Homework Help in biology. Cockroaches belong to the class Insecta of phylum Anthropoda. The scientific name of cockroach is Periplaneta americana. Cockroaches are 34-53mm long with wings that extend beyond the tip of abdomen in males. The body of cockroach is segmented, bilaterally symmetrical and triploblastic with organ level organization. The entire body is covered with hard chitinous exoskeleton. In each segment of the body, the exoskeleton has hardened plates called sclerites (tergites dorsally and sternites ventrally) which are joined to each other by a thin, flexible membrane known as arthrodial membrane.
The body of cockroach is divided into three major segments – head, thorax and abdomen. The head is triangular in shape and is fused together by six segments, thus showing mobility and flexibility of the neck. The head comprises of a pair of compound eyes and a pair of long, thread-like antennae arising from the membrane sockets present in the front of eyes. The antennae have sensory receptors used for sensing food, danger and stress environments. Appendages that can be used for chewing and biting are present in the anterior part of the head, thus forming mouth. The mouthparts comprise labrum (upper lip), a pair of mandibles, a pair of maxillae and a labium (lower lip). The mouthparts enclose a cavity within which median flexible lobe, called hypopharynx is found. It serves the purpose of a tongue.
A. Parts of head region B. Mouthparts
The thorax region consists of three parts – prothorax, mesothorax and metathorax. The prothorax region extends into a short neck which connects the head and the prothorax region. Each thoracic region bears a pair of legs. Two pair of wings is present – the forewings/tegmina arising from the mesothorax region and the hind wings arising from the metathorax region. The forewings are opaque dark and leathery, covering the hind wings when the body is at rest, whereas the hindwings are transparent, membranous and are required for flying.
In both male and females, the abdomen region is made up of 10 short segments. In males, the genital pouch lies in the hind end of abdomen dorsally bounded by 9th and 10th terga and ventrally by the 9th sternum. The male genital pouch consists of ventral male genital pore, dorsal anus and gonopophysis. Males bear a short anal-styles, which is absent in females. The females, the 7th sternum is boat-shaped, which joins along with 8th and 9th sternum to form a brood/genital pouch. This female genital pouch consists of female gonophores, spremathecal pores and collateral glands. A pair of joint filamentous structure called anal cerci is present in the 19th segment of both sexes.