Examples include cockroaches and psocids, both of which have longer, many-segmented antennae, and some beetles, but these have fully hardened forewings which do not overlap.; "wing"), referring to the forewings of many heteropterans which are hardened near the base, but membranous at the ends.
Wings modified in this manner are termed hemelytra (singular: hemelytron), by analogy with the completely hardened elytra of beetles, and occur only in the suborder Heteroptera.
The oldest fossils are of the Archescytinidae from the Lower Permian and are thought to be basal to the Auchenorrhyncha.
Fulguromorpha and Cicadomorpha appear in the Upper Permian, as do Sternorrhyncha of the Psylloidea and Aleurodoidea. The Coleorrhyncha extend back to the Lower Jurassic.
The present members of the order Hemiptera (sometimes referred to as Rhynchota) were historically placed into two orders, the so-called Homoptera and Heteroptera/Hemiptera, based on differences in wing structure and the position of the rostrum.