– Pale species, with thorax reddish yellow ... 4

3. Sternites and tergites concolorous dark brown; bristles on thorax and abdomen ochreous yellow; palpi mainly brown, yellowish in basal half; small, stout species with relatively short legs; average wing length 2.3 (male) – 2.5 (female).Fig. 4 ... cinereus (Haliday in Walker)

– Sternites whitish yellow, clearly contrasting with darker tergites; bristles on thorax and abdomen dark brown; larger, slender species with relatively long legs; average wing length 2.8-2.9.Fig. 8 ... thalhammeri Lichtwardt

4. Entire body pale reddish yellow; antennal segments mainly whitish yellow; postpedicel triangular; female 9^th abdominal segment with 6 spines; very small, stout species with average wing length 1.9 (males) – 2.1 (females).Fig. 3 ... bimaculatus Pollet

– At least some abdominal segments brownish; scape and pedicel at least partly infuscated and when entirely pale, then postpedicel with acute shape; female 9^th abdominal segment with 8 spines ... 5

5. Mesonotum dorsally with dark brown elongate central spot on prescutellar depression; hind tibia with 2 anterodorsal bristles; very small and stout species with average wing length 1.8-1.9.Fig. 7 ... nigropunctatus Pollet & Brunhes

– Mesonotum without central dark spot; hind tibia always with 3 (strong or minute) anterodorsal bristles; larger species with average wing length over 2 ... 6

6. Palpi usually yellow to whitish yellow; antenna mainly dark brown; sutural bristles mostly absent; male cerci long and tapering, with distinctly curved bristles on apex; slender species; average wing length 2.1 (male) – 2.3 (female).Fig. 5 ... flavicollis (Meigen)

– Palpi brown to dark brown; antenna mainly yellow; palpi infuscated at least partly, or brown to dark brown in females; sutural bristles mostly present; male cerci shorter, about as long as other genital appendages, with blunt apex; wing 2.4.Fig. 9 ... vaillanti Brunhes