Insect morphology least three different positions: prognathous, opisthognathous, and hypognathous. In species with prognathous articulation, the head is positioned vertically aligned with the body, such as species of Formicidae; while in a hypognathous type, the head is aligned horizontally adjacent to the body. An opisthognathous head is positioned diagonally, such as species of Blattodea and some Coleoptera. The mouthparts vary greatly between insects of different orders, but the two main functional groups are mandibulate and haustellate. Haustellate mouthparts are used for sucking liquids and can be further classified by the presence of stylets, which include piercing-sucking, sponging, and siphoning. The stylets are
Insect morphology a hard outer layer made mostly of chitin which protects and supports the body. The insect body is divided into three parts: the head, thorax, and abdomen. The head is specialized for sensory input and food intake; the thorax, which is the anchor point for the legs and wings (if present), is specialized for locomotion; and the abdomen for digestion, respiration, excretion, and reproduction. Although the general function of the three body regions is the same across all insect species, there are major differences in basic structure, with wings, legs, antennae, and mouthparts being highly variable from group to group.