British Insects: the Families of Diptera


L. Watson and M. J. Dallwitz


Cordyluridae, Scatophagidae, Scopeumatidae.


Life style parasitic (sometimes, in the larval stage?), or non-parasitic.

Adult insects. Medium-sized to large; slender-bodied to robustly-built; not stilt-legged. The back of the head rounded, with fine pale hairs below. Antennae 3 segmented; ‘modified’; aristate; the arista dorsal (pubescent or plumose). The second antennal segment distinctly grooved above. Ptilinal suture clearly defined. Ocelli present; 3. Eyes rounded, well separated. Mouthparts functional; adapted for piercing, or non-piercing. The maxillary palps 1 segmented (well developed); porrect. Vibrissae present (one or two, large). Thorax with the dorsal suture continuous across the middle; with well defined posterior calli. Hypopleural bristles absent. Wings with a discal cell; without a sub-apical cell (but the veins sometimes somewhat converging); with a closed anal cell. The anal cell short (never sharply pointed at the lower, outer corner). Sub-costa apparent; reaching the costa independently of vein 1. The leading edge veins not noticeably stronger than the rest. Wing vein 6 present; reaching the wing margin, or falling short of the wing margin. Wing vein 7 present (always detectable, but often only as a fold). Wings with the lower calypter much reduced or absent (smaller than the alar squama); patterned, or unpatterned (often tinged, clouded or spotted). Hind tibiae with strong bristles in the basal 4/5. Visible abdominal segments 5–7 (? - ‘at least 5 or six’). Predatory (on other insects), or neither parasitic nor predatory (notable dung-feeders).

Larvae and pupae. The larvae terrestrial; phytophagous (including some leaf miners), or saprophagous, or coprophagous, or predatory, or parasitic; acephalic. The pupae enclosed within a puparium.

Comments. Medium to large, often predatory flies. Winds never with a costal spine. Visible abdominal segments at least five or six.

Classification. Suborder Brachycera; Division Muscomorpha Schizophora Calyptratae; Superfamily Muscoidea.

British representation. 54 species in Britain. Genera 23; Anthocnema, Ceratinostoma, Chaetosa, Cleigastra, Conisternum, Cordilura, Cosmetopus, Delina, Ernoneura, Gimnomera, Gonatherus, Hydromyza, Leptopa, Megaphthalma, Microprosopa, Nanna, Norellia, Norellisoma, Parallelomma, Pogonota, Scathophaga, Spaziphora, Trichopalpus.

Illustrations. • Scathophaga scybalaria (Largest Dung-fly: B. Ent. 405). • Scathophaga scybalaria (detail: B. Ent. 405). • Scathophaga scybalaria (dissections: B. Ent. 405). • Scathophaga scybalaria: B. Ent. 405, legend+text. • Scathophaga scybalaria: B. Ent. 405, text cont.. • Hydromyza livens (Water-lily Cordylura Fly: B. Ent. 485). • Hydromyza livens: B. Ent. 485, legend+text. • Hydromyza livens: B. Ent. 485, text cont.. • Coniosternum, Cordilura, Scathophaga (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.’.