Mouth Parts of Cockroach The mouth parts are

Mouth Parts of Cockroach ü The mouth parts are the head appendages surrounding the mouth. ü These consists of Labrum (upper lip), a pair of mandibles, a pair of maxillae, the Labium (lower lip) and Hypopharynx. ü Because of its omnivorous habit, they enable it to bite & chew hard food stuffs. (1) Labrum: It is membranous flat lobe suspended below the clypeus. On its inner surface it bears a small sclerite called torma on each side. Its inner surface also bears two rows of sensory setae on each side.

(2) Mandibles: These are suspended from the side of the head capsule, one on either side of the mouth. § § § Each mandibles bears three tooth-like denticles a small smooth serrated molar area. Proximal to the molar area is a membranous lobe, the prostheca, with sensory hair. The denticles act as the interlocking structures whereas the molar areas are masticatory surfaces. Both mandibles shows sideways movement. Movement of mandibles is brought about by the action of the adductor and abductor muscles.

(3) Maxillae: These are two, one on either side of the head capsule behind the mandibles. § Each maxilla consists of a cylindrical stipes hinged to the basal cardo. § The stipes bears these processes (1) lacinula, (2) a galea which acts as a hood and (3) a maxillary palp which is five segmented & sensory in nature. § Maxillary palp is born on the basal projection, the palpifer.

(4) Labium: It is the lower lip lying behind the mouth. § It is formed by the fusion of two maxilla-like appendages. § The large basal part is submentum which supports the mentum. § The mentum supports the prementum and paired glossae & paraglossae together constitute ligula. § The prementum bears on each side, the labial palp. § The labium does not take active part in feeding.

(5) Hypopharynx: Between the maxillae and in front of the labium is a flat, cylindrical & tongue like structure, the hypopharynx. The common salivary duct opens at the base of the hypopharynx.