Insects of Britain and Ireland: the genera of Syrphidae (hoverflies)
Adult flies. The flies sphecid wasp-like (cf. Argogorytes mystaceus); patterned yellow and black; small to medium sized; 8–14 mm long.
The face ground-coloured at least part yellow (exhibiting four yellow spots behind the antennae); without a central knob. Antennae relatively long, porrect; seated on a long prominence on the frons that is as long as the first antennal segment. The antennal bristle apical; simple.
The thorax without longitudinal stripes. The scutellum at least partly yellow (with a yellow transverse band). Wings plain; divergent in repose. Wing veins R2+3 and R4+5 not forming a closed cell. The anterior cross vein R-M in cell R5 crossing it at or beyond the middle of the adjoining discal cell. Vein R4+5 with a conspicuous curve projecting into the cell R5; with a short, backwardly projecting, incomplete transverse veinlet located distally to the cross veinlet in cell R5 (originating from the curve). The lower outer marginal vein slightly diverging from the posterior wing margin. The upper outer marginal cross-vein not re-entrant. The alula distinct.
The abdomen somewhat clavate (cylidrical); contrastingly patterned. The tergite patterning involving 3, 4, and 5. The colour-patterned tergites marked with yellow. The tergite bands entire; narrow.
Larvae and pupae. The larvae tapering anteriorly and posteriorly from the middle, or tapering posteriorly; shortly tailed to the spiracular process; tailed (slightly so). The anal segment tapered gradually to the spiracular process. The larvae flattened; plain; without thoracic hooks; mouth without triangular sclerites; anal segments with lappets (the anal segment with 3 pairs). The larvae semi-aquatic, or non-aquatic (?); probably saprophagous; in sap runs and in rot-holes (in deciduous trees).
British representation. 1 species in Britain (C. conopsoides, probably adventive - omitted by Stubbs and Falk). Curtiss fine plate and description was hased on a specimen presented to the British Museum and purported to be indigenous by Dr. Leach, who was unable to give a locality!.
Illustrations. • Ceriana conopsoides (Long-horned Hover-Fly. Doubtfully British: B. Ent. 186). • Ceriana conopsoides: B. Ent. 186, legend+text. • Ceriana conopsoides: B. Ent. 186, text cont.. • C. conopsoides: Verrall. • 15 genera (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. Insects of Britain and Ireland: the genera of Syrphidae (hoverflies). Version: 28th July 2015. delta-intkey.com’.