Mecoptera (Scorpion Flies)
Slender, moderate or small-sized insects with elongate, filiform antennae, head usually produced into a vertically deflected rostrum, with biting mouthparts: ligula wanting. Legs long and slender. Wings similar and membranous, carried longitudinally and h
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MECOPTERA (SCORPION FLIES) Slender, moderate or small-sized insects with elongate, fi!tform antennae, head usually produced into a vertically deflected rostrum, with biting mouthparts: ligula wanting. Legs long and slender. Wings similar and membranous, carried longitudinally and horizontally in repose: venation primitive, Rs dichotomously branched, Cu, simple. Abdomen elongate with short cerci, male genitalia prominent. Larvae eruciform with biting mouthparts and three pairs of thoracic legs: abdominal feet present or absent. Pupae exarate, decticous: wings with reduced tracheation.
This small order comprises less than 400 species, the greater number of which belong to the genera Panorpa and Bittacus. The majority of the members of the group are easily recognized by the beak-like prolongation of the front of the head, and their often maculated wings. The 'scorpion flies' (sen. str.) belong to the Panorpidae, which include many species widely spread over the northern hemisphere (Fig. 430). Their vernacular name is due to the fact that the males carry the terminal segment of the abdomen upwardly curved, somewhat after the manner of scorpions. The Bittacidae are very slender Tipula-like insects with prehensile tarsi: they are found in most parts of the world excepting the northern portion of the Holarctic region. The Boreidae are characterized by their vestigial wings and occur in Europe and N. America. The order is represented in the British Isles by three species of Panorpa and a single species of Boreus (Hobby and Killington, 1934). The Mecoptera are essentially terrestrial insects undergoing their transformations in the soil: an exception is found in Nannochorista, of which the larva is aquatic. Both their larvae and imagines may be carnivorous, but the extent to which the Panorpidae prey upon living uninjured insects or other animals is doubtful. Brauer and Felt have reared larvae of Panorpa upon fragments of meat, but Miyake found wounded or dead insects more acceptable. Panorpodes and Brachypanorpa seem to be phytophagous (Byers, 1965). The adults are mostly found in shaded situations where there is a growth of O. W. Richards et al., Imms’ General Textbook of Entomology © O. W. Richards and R. G. Davies 1977
MECOPTERA (SCORPION FLIES)
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FIG. 430 Panorpa communis. A, male; B, female (from Photos by W.]. Lucas); C, apex of abdomen of male
After MacLachlan.
rank herbage. Bittacus rests suspended from grasses or twigs by its fore legs, and preys upon small Diptera, seizing them by means of its raptorial tarsi. Boreus lives among moss or beneath stones in autumn and early winter, appearing occasionally on the surface of snow; it feeds upon vegetable matter. External Anatomy (Fig. 431) The anterior region of the head (Heddergott, 1938; Hepburn, 1969b; Mickoleit, 1971a) is usually prolonged into a rostrum which is formed by the elongation of parts of the head-capsule together with the clypeus, labrum and maxillae. The compound eyes are well developed and there are usually three ocelli. The antennae a
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