British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Life style non-parasitic.

Adult insects. Very small. Antennae 3 segmented (third segment long or short); ‘modified’; aristate; the arista dorsal (pubescent or short-plumose). The arista not forked at the tip. The second antennal segment not grooved. The third segment not elongated. Ptilinal suture clearly defined. Post-vertical orbital bristles present; convergent. Mouthparts functional. The maxillary palps 1 segmented; porrect. Vibrissae present (one pair). 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. Wings with a discal cell to without a discal cell (the cross-vein separating discal cell from basal cell incomplete); without a sub-apical cell; with a closed anal cell, or without a closed anal cell. The anal cell short. The costa with one break (near the end of vein 1), or with two breaks (sometimes also near the humeral cross-vein). Sub-costa apparent; joining vein 1 well short of the costa (visible and distinct only basally). Wing vein 6 present. Wings with the lower calypter much reduced or absent. Tibiae with a dorsal pre-apical bristle. Hind tibiae without strong bristles in the basal 4/5.

Larvae and pupae. The larvae acephalic. The pupae enclosed within a puparium.

Comments. Very small greyish or brownish-grey flies, with complete wing venation. The front orbital bristles are inset and upswept.

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

British representation. 6 species in Britain. Genera 1; Diastata.

Illustrations. • Diastata.

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.’.