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| Insects of Britain and Ireland: the families of Diptera |
Petauristidae
Winter Crane-flies.
Adult insects. Medium-sized to large (of wing-span 10–12 mm); slender-bodied; stilt-legged. The legs not readily shed. Antennae 8–16 segmented; ‘simple’. Ocelli present; 2, or 3. The maxillary palps 3–5 segmented; drooping. Thorax with the dorsal suture continuous across the middle. The dorsal suture deeply V-shaped. Wing veins reaching the margin 9–12. Wing vein 7 reaching the margin. Wings with a discal cell; without a sub-apical cell; without a closed anal cell. The costa unbroken; extending around the entire wing. Sub-costa apparent; reaching the costa independently of vein 1. Wing vein 7 present; reaching the wing margin (but short and curved). Wings with the lower calypter much reduced or absent.
Larvae and pupae. The larvae terrestrial; saprophagous, or coprophagous, or consuming stored produce, or mycophagous; eucephalic. The pupae without a puparium.
Comments. Delicate-looking flies, habitually forming dancing swarms in winter.
Classification. Suborder Nematocera; Division Psychodomorpha; Superfamily Trichoceroidea.
British representation. 10 species in Britain. Genera 2; Diazosma, Trichocera.
Illustrations. • Trichocera hiemalis (from Walker). Trichocera hiemalis male, with detail of head in side view showing 16-segmented antenna. 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’.
