Polyneoptera

The cohort Polyneoptera is one of the major groups of winged insects, comprising the Orthoptera (grasshoppers, crickets, etc.) and all other neopteran insects believed to be more closely related to Orthoptera than to any other insect orders. They were formerly grouped together with the Palaeoptera and Paraneoptera as the Hemimetabola or Exopterygota on the grounds that they have no pupa, the wings gradually developing externally throughout the nymphal stages; their metamorphosis is deemed "incomplete". Many members of the group have leathery forewings (tegmina) and hindwings with an enlarged anal field (vannus).

When Carl Linnaeus started applying binomial names to animals in the 10th edition of his Systema Naturae in 1758, he recognized relatively few animal species, and consequently relatively few groups that encompassed these species. As more and more new species were discovered, described and named, and importantly, their differences recognised and codified, the original groups proposed by Linnaeus were split up and/or expanded. The group of insects now recognized as being polyneopterans were, by Linnaeus, considered to belong within the genus Gryllus; the modern definition of this genus is restricted to species of closely related crickets, but in Linnaeus' original definition the genus contained crickets, grasshoppers, locusts, katydids / bush crickets (Tettigoniidae), stick insects, and praying mantises. These groups, along with the cockroaches, which Linnaeus considered as distinct, are all polyneopteran insects. The recently recognized order Mantophasmatodea is also included within Polyneoptera.