; class Insecta, subclass Pterygota)
An order of insects with slender bodies, often brightly coloured, mouth-parts extended to form a beak, and in many species the tip of the abdomen curled upward so it resembles that of a scorpion (although scorpionflies do not sting). Most species have two pairs of membranous wings, held horizontally over the back when the insect is at rest. Larvae dwell in burrows, feed at the soil surface, and pupate in their burrows, undergoing complete metamorphosis. The pupa is exarate and moves to the surface prior to the emergence of the adult. Scorpionflies are mainly scavengers, as larvae and adults. Fossil mecopterans are known from the Permian, making them the oldest endopterygotes, and some extant species appear to have changed little since the Permian, making them living fossils. There are about 300 species, widely distributed, in three families: Panorpidae; Bittacidae; and Boreidae (snowflies or snowfleas).
Subjects: Zoology and Animal Sciences.