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| Insects of Britain and Ireland: the families of Diptera |
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. 1, Aulacigastridae: head of Aulacigaster leucopeza. 2a and 2b, Canacidae: wing and head of Canace nasica. 3, Diastatidae: head of a Diastata species. 4, Carnidae: Carnus sp., wing. 5a and 5b, Milichiidae: leg of Leptometopa latipes (5a), and head of Phyllomyza securicornis (5b). 6, Odiniidae: Odinia sp., wing. 7a and 7b, Tethinidae: Tethina sp., head and wing. 8, Periscelididae: Periscelis winnertzi, wing. From Colyer and Hammond (1951).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the families of Diptera. Version: 14th April 2022. delta-intkey.com’.
