Cockroach: Mouth Parts

Cockroach mouth parts

1. The remaining three pairs of cephalic appendages are small and located around the mouth. Hence together with labrum of head capsule and hypopharynx, these appendages copmrise the mouth parts of the cockroach. These help in 'biting and chewing' its food.
    
2. Labrum: It is the broad, flattened terminal sclerite of the dorsal side of head capsule, movably articulated to the clypeus acts as upper lip. It has epipharynx (chemoreceptors) on its inner side.
    
3. Mandibles: Thick hard and triangular appendages beneath the labrum, on each lateral side of the mouth, which bear pointed, teeth like processes called denticles.
    
4. First maxillae: Located on each side of the mouth next to mandibles for cutting and chewing. They also bear olfactory receptors.
    
5. Labium: The second maxillae are fused together forming a single large structure which covers the mouth from ventral side, hence called the 'lower lip' or labium. It bears tacticle and gustatory sensory setae.
    
6. Hypopharynx: It is a small, cylindrical mouthpart, sand witched between first maxillae and covered by labrum and labium on dorsal and ventral sides respectively. It bears several sensory setae on its free end, and the opening of common salivary duct upon its basal part.