Insects of Britain and Ireland: the genera of hoverflies (Syrphidae)
Unless indicated otherwise, the following attributes are implicit throughout the descriptions, except where the characters concerned are inapplicable.
Adult flies. The face not extending below beyond the antennae; not elongated horizontally into a cone as long as the rest of the head. The frons not inflated. The eyes not rimmed along their facial borders for much of the height of the face. Antennae relatively short, drooping.
The thorax not exhibiting a skull-like figure. The thoracic striping not lateral only. Wings with a vena spuria. Vein R4+5 without a conspicuous curve projecting into the cell R5; without a backwardly projecting, incomplete transverse veinlet. The alula distinct.
The abdomen not petiolated; with tergites 2, 3 and 4 all more or less well developed; not conspicuously furry. The tergite patterning not comprising obliquely longitudial marks; not confined to one tergite. The dorsum of tergite 2 without golf-club shaped spots; without a wineglass-shaped black area. The dorsum of tergite 3 with neither a sunglasses-shaped nor a brassiere-shaped partially-interrupted pale band; not marked in the form of a moustache. The pale abdominal markings opaque.
Larvae and pupae. The larvae detectably segmented. The anal segment shorter than the rest of the body. The larvae not green; not longitudinally striped; not translucent; dorsally smooth, without projections; laterally smooth; anal segments without horn-like projections. The larvae non-aquatic.
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’.