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
Gall-inducing insect Gall-inducing insect A gall-inducing insect is any insect that can cause the growth of galls within plants. The term gall fly is also used to cover these species, although most are not true flies. There are several groups of insects that meet this description. They include the gall wasps, scales, gall midges, aphids, psyllids and certain species of leafminer flies. Galls are growth deformities induced in certain plants by various insects which are mostly species-specific. The gall's form or type depends on what organism is attacking the plant and where the plant is being attacked. Based on the form, there