Sciomyzidae - Snail-killing Flies

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Classification

BRACHYCERA, Muscomorpha Schizophora Acalyptratae, Sciomyzoidea

Number of British species: 68

Size: S-L

Difficulty: 1-2

Scheme: Covered by the Sciomyzid recording scheme

Characters

Small to large (2-14 mm), generally slender flies with a body colour varying from black lustrous to dull grey, brown, reddish or yellow. Antenna sometimes elongate; arista pubescent or with shorter or longer rays; ocelli present; Ocellar bristles usually present, rarely (Sepedon) absent; Postvertical bristles diverging to parallel, sometimes slightly converging in Pteromicra; 1-2 pairs of frontal bristles, curving backward, the lower pair sometimes curving inward; interfrontal bristles absent; interfrontal setulae sometimes present; vibrissae absent. Wing clear or with conspicuous markings; Costa continuous; vein Sc complete; crossvein BM-Cu present; cell cup closed. Tibiae almost always with dorsal preapical bristle.

Biology

The larvae of nearly all species feed on snails or slugs, some feeding on the eggs of snails. Most of the known larvae are semi-aquatic, some are aquatic; a number of species have terrestrial larvae. Larvae mainly prey on snails lacking an operculum; in general, aquatic larvae have to visit the surface frequently in order to breathe but some species preying on bivalves have adapted to breathing under water. The larvae of some species preying on terrestrial snails and slugs are parasitoids that develop inside a single snail or slug; in other terrestrial species the penultimate instar emerges from the snail or slug it developed in and are as last instar predatory on several snails. The adults are often found sitting on the vegetation, their heads down. Depending on the larval habitat, they are often found near water, in marshy vegetation, but also in woodland or even dry open habitats.

Identification

 
families/brachycera/acalyptrates/sciomyzidae.txt · Last modified: 2008/05/24 17:01 (external edit)     Back to top
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