Insects of Britain and Ireland: the genera of Syrphidae (hoverflies)
Formerly Pipiza p.p.
Adult flies. The flies blackish tinted brownish, with golden hairs on the thorax and legs; small; 6–8 mm long. Wings 3.75–6.25 mm long.
The head about the same width as the thorax. The face flat or concave in the region between the antennae and the mouth; without a central knob (covered with long, drooping shaggy hairs); not elongated horizontally into a cone as long as the rest of the head. The frons not inflated. The eyes hairy; not rimmed along their facial borders for much of the height of the face. Antennae relatively short, drooping; with their bases well separated (seated on a prominant part of the frons); black. The third antennal segment ovoid or orbicular (somewhat elongate). The antennal bristle dorsal; about as long as the third segment to much longer than the third segment; simple (pubescent).
The humeri hairy, and readily visible behind the head. The thorax pubescent without stiff bristles interspersed; plain; without longitudinal stripes. The scutellum aeneous, or black. Wings plain (pale grey, somtimes with a large indefinite, very pale brown spot extending from the pale brown stigma to mid-disc); without a conspicuously dark stigma; incumbent and almost parallel 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 before the middle of the adjoining discal cell. Vein R4+5 without a conspicuous curve projecting into the cell R5; without a backwardly projecting, incomplete transverse veinlet. Vein R without bristles. The lower outer marginal vein markedly diverging from the posterior wing margin. The upper and lower outer marginal cross veins strongly stepped. The upper outer marginal cross-vein conspicuously bent near the base the base to conspicuously bent well above the base; bent at a sharp angle; joining vein R4+5 almost at right angles, so that cell R5 is not extended towards the wing tip; not re-entrant. The alula distinct. The hypopleuron exhibiting long hairs on its upper transverse ridge.
The abdomen slightly wider than the thorax to about the same width as the thorax; almost flat, narrowly obovate, or oval. The male abdomen with 4 visible segments. The abdomen with tergites 2, 3 and 4 all more or less well developed; not contrastingly patterned. The spiracles of the third abdominal segment borne at or near the anterior corner of each side.
Larvae and pupae. The larvae posteriorly blunt and tail-less; flattened (more so than those of Pipiza); dark brown, patterned; dorsally smooth, without projections; mouth with a triangular sclerite on either side; anal segments without lappets. The larvae predatory (aphidivorous, on the root aphids of umbellifers).
Classification. Subfamily Milesiinae; tribe Pipizini.
British representation. 3 species in Britain.
Illustrations. • P. virens (Verrall).
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’.