British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz



Stilt-legged Flies.

Adult insects. Small; slender-bodied; stilt-legged. The face in lateral view not deeply excavated between the antennae and the edge of the mouth. The back of the head rounded. Antennae 3 segmented (third segment short and rounded); ‘modified’; aristate; the arista dorsal. The second antennal segment not grooved. Ptilinal suture clearly defined. Ocellar bristles absent. Post-vertical orbital bristles present; parallel, or divergent. Mouthparts functional. The maxillary palps 1 segmented; porrect. Vibrissae absent. Thorax without a continuous dorsal suture; without well defined posterior calli. Wing venation complete, in the sense of exhibiting 1st and 2nd basal, anal and discal cells, or incomplete, in the sense of lacking one or more of the cells. Wings with a discal cell, or without a discal cell (i.e., no vein separating it from the second basal cell); with a subapical cell; with a closed anal cell (not apically convex). The anal cell short. The costa unbroken. Sub-costa apparent; reaching the costa independently of vein 1. The leading edge veins not noticeably stronger than the rest. Wing vein 4 extending far beyond the end of the first basal cell. Wing vein 6 present; reaching the wing margin. Wings with the lower calypter much reduced or absent. The hind femora not thickened with spines beneath as in Megamerinidae. Tibiae without a dorsal pre-apical bristle. Hind tibiae without strong bristles in the basal 4/5. Predatory (on other insects).

Larvae and pupae. The larvae terrestrial; saprophagous (in decaying wood and vegetable matter); acephalic. The pupae enclosed within a puparium.

Comments. Extraordinarily long and thin, narrow-winged flies of streamlined appearance.

Classification. Suborder Brachycera; Division Muscomorpha Schizophora Acalyptratae; Superfamily Nerioidea.

British representation. 9 species in Britain. Genera 5; Calobata, Cnodacophora, Neria, Micropeza, Raineria.

Illustrations. • Calobata and Micropeza (from Walker).

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the families of Diptera. Version: 1st January 2012.’.