Mecoptera


Mecoptera (from the Greek: mecos = "long", ptera = "wings") is an order of insects in the superorder Endopterygota with about six hundred species in nine families worldwide. Mecopterans are sometimes called scorpionflies after their largest family, Panorpidae, in which the males have enlarged genitals raised over the body that look similar to the stingers of scorpions, and long beaklike rostra. The Bittacidae, or hangingflies, are another prominent family and are known for their elaborate mating rituals, in which females choose mates based on the quality of gift prey offered to them by the males. A smaller group is the snow scorpionflies, family Boreidae, adults of which are sometimes seen walking on snowfields. In contrast, the majority of species in the order inhabit moist environments in tropical locations.

The Mecoptera are closely related to the Siphonaptera (fleas), and a little more distantly to the Diptera (true flies). They are somewhat fly-like in appearance, being small to medium-sized insects with long slender bodies and narrow membranous wings. Most breed in moist environments such as leaf litter or moss, and the eggs may not hatch until the wet season arrives. The larvae are caterpillar-like and mostly feed on vegetable matter, and the non-feeding pupae may pass through a diapause until weather conditions are favorable.

Early Mecoptera may have played an important role in pollinating extinct species of gymnosperms before the evolution of other insect pollinators such as bees. Adults of modern species are overwhelmingly predators or consumers of dead organisms; they are the first insects to arrive at a cadaver, making them useful in forensic entomology.

Mecopterans vary in length from 2 to 35 mm (0.1 to 1.4 in). There are about six hundred extant species known, divided into thirty-four genera in nine families. The majority of the species are contained in the Panorpidae and Bittacidae families. Besides this there are about four hundred known fossil species in about eighty-seven genera, which are more diverse than the living members of the order.[9] The group is sometimes called the scorpionflies, from the turned-up "tail" of the male's genitalia in the Panorpidae.[10]

Distribution of mecopterans is worldwide; the greatest diversity at the species level is in the Afrotropic and Palearctic realms, but there is greater diversity at the generic and family level in the Neotropic, Nearctic and Australasian realms. They are absent from Madagascar and many islands and island groups; this may demonstrate that their dispersal ability is low, with Trinidad, Taiwan and Japan, where they are found, having had recent land bridges to the nearest continental land masses.[9]

The European scorpionfly was named Panorpa communis by Linnaeus in 1758.[11]The Mecoptera were named by Alpheus Hyatt and Jennie Maria Arms in 1891.[12] The name is from the Greek, mecos meaning long, and ptera meaning wings.[13]The families of Mecoptera are well accepted by taxonomists but their relationships have been debated. In 1987, R. Willman treated the Mecoptera as a clade, containing the Boreidae as sister to the Meropeidae,[14] but in 2002 Michael F. Whiting declared the Mecoptera so-defined as paraphyletic, with the Boreidae as sister to another order, the Siphonaptera (fleas).[15]


Male Panorpa dubia.
A, Body in lateral view; B–D. male genital bulb and gonostyli. B, dorsal view; C, ventral view; D, lateral view. ep, epandrium; gcx, gonocoxite; gs, gonostylus; hv, hypovalva; hyp, hypandrium. Scale bars represent 3 mm in A, 1 mm in B–D
A Panorpid scorpionfly feeding on a dead insect
Panorpa communis mating
Hangingflies have distinct mating behaviour.
The raised scorpion-like tail of the male has earned the scorpionflies a sinister reputation, but they do not sting.