British Insects: the Families of Diptera
| British Insects: the Families of Diptera | |
Marsh-flies.
Life style parasitic (the larvae victimising slugs and snails).
Adult insects. Small to medium-sized. Antennae 3 segmented (second segment sometimes thickened or elongated); ‘modified’. Antennae aristate; the bristle dorsal (bare to plumose). The second antennal segment not grooved. Ptilinal suture clearly defined. Post-vertical orbital bristles present; parallel, or divergent. Mouthparts functional. The maxillary palps 1 segmented; porrect. Vibrissae absent. Thorax without a continuous dorsal suture; without well defined posterior calli. Wings with a discal cell; without a sub-apical cell; with a closed anal cell. The anal cell short. The costa unbroken. Sub-costa apparent; reaching the costa independently of vein 1. The leading edge veins not noticeably stronger than the rest. Vein 6 present; reaching the wing margin. Wings with the lower calypter much reduced or absent; patterned (sometimes with dark markings), or unpatterned. Tibiae with a dorsal pre-apical bristle. Hind tibiae without strong bristles in the basal 4/5.
Larvae and pupae. Larvae aquatic, or terrestrial; predatory, or parasitic (on slugs and snails, the terrestrial species parasitic and the aquatic species predatory); acephalic. Pupa enclosed within a puparium.
Comments. Head viewed dorsally as wide as, or wider than, the thorax. Small to medium sized flies of wet places, associated with snails.
Classification. Suborder Brachycera; Division Muscomorpha Schizophora Acalyptratae; Superfamily Scyomyzoidea.
British representation: Genera 23; 67 species.
Illustrations: • Pherbellia albocostata and Tetranocera ferruginea (from Walker). • Sepedon sphegea (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: 9th April 2007. http://delta-intkey.com’.
