British Insects: the Families of Diptera
British Insects: the Families of Diptera |
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Robber-flies.
Non-parasitic.
Adult insects. Medium-sized to large; slender-bodied to robustly-built; not stilt-legged (the legs powerful, prehensile, used for grasping the prey). Antennae 3 segmented (third segment not annulated); ‘modified’; terminal segment not annulated. Antennae aristate, or not aristate (Laphria); the bristle apical. Ocelli present; 3. Eyes not meeting. Mouthparts strong and horny, adapted for piercing (in both sexes). The maxillary palps 1 segmented, or 2 segmented; porrect. Vibrissae absent. Wings without a sub-apical cell; with a closed anal cell. The anal cell relatively long. Wings with 8 cells between vein 3 and the anal cell. The costa extending around the entire wing. Sub-costa apparent; reaching the costa independently of vein 1. The leading edge veins not noticeably stronger than the rest. Vein 3 distally forked. Vein 6 present; reaching the wing margin. Vein 7 present; falling short of the wing margin. Wings with the lower calypter much reduced or absent. Feet without a triple pad. Predatory (on insects, which are often caught on the wing, and the females often consuming the males).
Larvae and pupae. Larvae terrestrial; saprophagous, or predatory; hemicephalic. Pupa without a puparium.
Comments. Medium to large flies, usually of narrow build, with strong, bristly legs; face below the antennae strongly produced, bearing a ‘moustache’ of hairs and bristles; wings folded over abdomen when at rest. Including some wasp mimics.
Classification. Suborder Brachycera; Division Asilomorpha; Superfamily Asiloidea.
British representation: Genera 15; 29 species.
Illustrations: • Asilus, Choerades, Dioctria, Leptarthrus (from Walker). • Leptarthrus brevirostris (Slender-legged Robber-fly: B. Ent. 153). • Leptarthrus brevirostris (detail: B. Ent. 153). • Leptarthrus brevirostris (dissections: B. Ent. 153). • Leptarthrus brevirostris (B. Ent. 153, legend+text). • Pamponerus germanicus (White- and Black-winged Robber-fly: B. Ent. 046). • Choerades marginatus (Black Robber-fly: B. Ent. 094).
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: 9th June 2008. http://delta-intkey.com’.
