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| Insects of Britain and Ireland: the families of Diptera |
Adult insects. Very small to small (about 3–4 mm long); not stilt-legged. Antennae 10–14 segmented (ostensibly of two, terminated by a multi-segmented style-like appendage); ‘simple’ to ‘modified’ (the first and second segments stout, the remainder longer and more slender); not aristate. Ocelli absent. Eyes asymmetric, nearly or quite connected above the antennae (in both sexes). The maxillary palps 3–5 segmented (longer than the antennae); drooping. Thorax without a continuous dorsal suture (i.e., without the V-shaped suture of Tipulidae). Wing veins reaching the margin 6–8. Wings without a discal cell; without a sub-apical cell; without a closed anal cell. The costa extending around the entire wing. Sub-costa apparent; terminating blind (short). Wings with the lower calypter much reduced or absent.
Larvae and pupae. The larvae aquatic (generally in thin trickles of water over rocks and stones); eucephalic. The pupae without a puparium.
Comments. Sluggish, small, bare, drab brown or yellowish, small-headed flies.
Classification. Suborder Nematocera; Division Culicomorpha; Superfamily Chironomoidea.
British representation. 3 species in Britain. Genera 1; Thaumalea.
Illustrations. • Thaumalea testacea (from Walker). Thaumalea testacea, with details of antenna and mouth. From Walker (1856, Plate XXVI), with 2mm scale added.
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’.
