Mecoptera (from the Greek meco = long, ptera = wings) are an order of insects with about 550 species worldwide. Mecoptera are sometimes called scorpionflies after their largest family, Panorpidae, in which the males have enlarged genitals that look similar to the stinger of a scorpion.
Mecoptera are small to medium insects with slender, elongated bodies. They have relatively simple mouthparts, with long mandibles and fleshy palps. Like many other insects, they possess compound eyes on the side of the head, and three ocelli on the top.
The wings are narrow in shape, with numerous cross-veins. The abdomen is cylindrical, and typically curves upwards in the male, superficially resembling the tail of a scorpion.
The female lays the eggs in close contact with moisture, and the eggs typically absorb water and increase in size after deposition. The larvae are usually quite caterpillar-like, with short, clawed, true legs, and a number of abdominal prolegs. They have a sclerotised head with compound eyes and mandibulate mouthparts.
The larva crawls into the soil or decaying wood to pupate, and does not spin a cocoon. The pupae are exarate, meaning that the limbs are free of the body, and are able to move their mandibles, but are otherwise entirely non-mobile.