Comparative Morphology of Insect Mandibulate Mouthparts and Larval Adaptations  Mouthparts are the head appendages of segments 3-6, surrounding the mouth. In omnivorous insects like, cockroaches, crickets and earwigs have a biting and chewing type or Mandibulate type of Mouthparts which are most closely resembling the basic design of ancestral pterygote insects . During insect evolution, an array of different mouthpart types has derived from the basic type. ( Knowledge of mouthparts is useful for taxonomic classification and identification, and for ecological generalisation .) Generally, mouthpart structure is categorised according to feeding method, but mandibles and other components may function in defensive combat or even make to male sexual contests. (Example: enlarged mandibles on certain male beetles, Lucanidae) The mandibulate mouthparts enable the insect to bite and chew hard substances, consume soft stuffs and lap up liquids. Mandibulate mouthparts are composed of h...