British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Adult insects. Antennae 3 segmented (but the third segment strongly annulated, and thus ostensibly several-segmented); ‘modified’ (the first segment strongly developed); having the terminal segment annulated. The maxillary palps 1 segmented, or 2 segmented; porrect. Wing veins reaching the margin between the anal cell and the lower fork of vein 3 4. Wings with a discal cell; without a sub-apical cell; with a closed anal cell. The anal cell relatively long. Wings with the fourth posterior cell open. The costa extending around the entire wing. Wing vein 3 distally forked. The fork of wing vein 3 narrow, its lower branch reaching the wing margin near the apex. Wing vein 6 present; reaching the wing margin. Wing vein 7 present; falling short of the wing margin. Wings with the lower calypter much reduced or absent. Feet with a triple pad beneath the tarsal claws. Abdomen constricted basally.

Larvae and pupae. The larvae terrestrial; predatory (on other insect larvae, in decaying wood); hemicephalic. The pupae without a puparium.

Comments. Flies ichneumon-like, with long thorax and abdomen.

Classification. Suborder Brachycera; Division Xylophagomorpha; Superfamily Xylophagoidea.

British representation. 3 species in Britain. Genera 1; Xylophagus.

Illustrations. • Xylophagus (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.’.