3. Face black, sometimes seems to be whitish or greyish from lateral view ... 4

– Face silvery white ... 9

4. Cercus bifurcated ... 5

– Cercus simple, long and narrow ... 8

5. Mid coxa without ventral spine, with several black setae only; femora black; surstylus acicular; 3.5-4.5. Fig. 168 ... nasutum (Fallén)

– Mid coxa with ventral setae forming spine ... 6

6. Fore basitarsus longer than rest tarsomeres combined, with several long setae at apex; legs mostly black; surstylus narrow, pointed at apex; 4.5-6.0. Fig. 177... commune (Meigen)

– Fore basitarsus shorter than rest tarsomeres combined ... 7

7. Fore and mid tibia dark; fore basitarsus straight, without strong setae; fore femur with black hairs; surstylus long and narrow, with short basodorsal projection; 4.5-5.6. Fig. 162... glaciale (Ringdahl)

– Fore and mid tibia yellow; fore basitarsus curved, with row of strong setae; fore femur with row of very strong black setae; cercus short and broad; surstylus narrow, pointed at apex; 4.5-4.9.Fig. 170 ... pectinatum (Loew)

8. Hind tibia strongly thickened at apex, whitish-yellow in basal half, black in distal half; fore tarsus simple; surstylus broad, triangular; 3.7-4.3. Fig. 160 ... fascipes (Meigen)

– Hind tibia not thickened or slightly thickened; 2^nd segment of fore tarsus flattened at base, slightly thickened at apex; surstylus bladelike, long, with strong seta at apex; 4.7-5.3. Fig. 167 ... nigribarbatum (Becker)

9. 5^th segment of mid tarsus strongly widened ... 10

– 5^th segment of mid tarsus weakly widened or simple ... 11

10. 4^th segment of mid tarsus not widened; 5^th segment of same tarsus widened and flattened; cercus triangular, moderately long; surstylus baculiform, curved; 4.4-5.1. Fig. 154 ... confine Zetterstedt

– 4^th and 5^th segments of mid tarsus widened; cercus bifurcated at middle; surstylus narrow; 4.4-5.2. Fig. 153 ... crassipes (Meigen)

11. Mid coxa with ventral setae forming spine ... 12

– Mid coxa without spine ... 17

12. Mid coxa with ventral spine of light setae; fore basitarsus widened; mid femur yellow; cercus foliaceous, with long hairs; surstylus baculiform; 4.8-5.7. Fig. 152 ... basale Loew

– Mid coxa with ventral spine of dark setae ... 13

13. Fore basitarsus simple, usually slightly longer than 2^nd tarsomere ... 14

– Fore basitarsus thickened, usually 1.5 times longer than 2^nd tarsomere ... 15

14. Postpedicel 3.5 times longer than high at base and longer than stylus; cercus elongate-triangular, reddish-yellow; surstylus spoon-like at apex, with apical setae; 3.1-4.4. Fig. 164 ... laticorne (Fallén)

– Postpedicel no more than 3 times longer than high at base, distinctly shorter than stylus; cercus bifurcated; surstylus narrow, slightly widened in distal half; 3-3.4. Fig. 173 ... rivale (Loew)

15. Cercus bifurcated; surstylus acicular; femora yellow; 4.3-4.7. Fig. 161 ... holmgreni (Mik)

– Cercus simple ... 16

16. Femora mostly black; stylus slightly thickened at apex; cercus long and narrow, bandlike, with apical seta; surstylus pointed at apex; 4.6-5.4. Fig. 169 ... patulum (Raddatz)

– Femora reddish-yellow; cercus long, gradually narrowing apicad; surstylus moderately long, baculiform; 5.6-6.9. Fig. 157 ... elegantulum (Meigen)

17. Fore femur with ventral row of strong setae, half as long as diameter of femur; fore basitarsus with short erect hairs; cercus short, triangular, with broad straight distal margin; surstylus lanceolate; 3.5-4.8. Fig. 155 ... discolor Zetterstedt

– Fore femur with ventral hairs only, without strong setae ... 18

18. Cercus trilobate; surstylus narrowing at middle, with basodorsal projection; femora mostly dark; 4.4-5.0. Fig. 175... tridactylum (Frey)

– Cercus simple ... 19

19. Cercus longer than epandrium; femora mostly dark; fore basitarsus thickened at apex; hind basitarsus with short dorsal spine; 4.5-5.5 ... gravipes Haliday

– Cercus shorter than epandrium ... 20

20. Cercus broad, spearlike; surstylus baculiform; femora mostly yellow; 4.3-5.5. Fig. 172 ... riparium (Meigen)

– Cercus narrower than surstylus, with bunch of long setae at apex; surstylus curved, with setae at apex; femora mostly black; 4.1-5.4. Fig. 171 ... penicillatum Loew

21. Scape higher than postpedicel; postpedicel long, thin, triquetrous; cercus long and broad; surstylus long and narrow, simple; 4.8-5.3. Fig. 165 ... longicorne (Fallén)

– Postpedicel higher than scape, flattened laterally ... 22

22. Fore basitarsus with ventral comb of strong setae, half as long as diameter of tarsomere; cercus long and narrow, broad at base; surstylus short; 3.8-4.8. Fig. 178 ... micans (Meigen)

– Fore basitarsus without comb of strong setae ... 23

23. Frons densely white or grey pollinose ... 24

– Frons metallic, without pollen ... 27

24. Postpedicel 2 times longer than high at base; cercus simple; surstylus widening distad, with distal emargination; 2.8. Fig. 176 ... viklundi Grichanov

– Postpedicel 5-7 times longer than high; cercus bilobate; surstylus without distal emargination ... 25

25. Four pairs of dorsocentral setae; femora partly dark; postpedicel 6 times longer than high; cercus with short and broad outer branch; surstylus securiform; 2.3-2.4. Fig. 149 ... albomaculatum Becker

– Five pairs of dorsocentral setae; femora yellow ... 26

26. Postpedicel 5 times longer than high; cercus with narrow branches; surstylus widened at middle; 2.4-2.7. Fig. 158 ... fissum Loew

– Postpedicel 6-7 times longer than high; cercus with broad branches; surstylus with small inner projection; 2.0-2.3. Fig. 148 ... albifrons Zetterstedt

27. Abdomen yellow laterally at base; cercus short, triangular; 2.0-2.5. Fig. 159 ... fasciatum (Meigen)

– Abdomen entirely dark, usually metallic green ... 28

28. Hind coxa with light external seta ... fissum Loew

– Hind coxa with dark external seta ... 29

29. Cercus elongate-triangular, with 1 long seta at apex; 2.5-3.3. Fig. 166 ... monotrichum Loew

– Cercus without long seta at apex ... 30

30. Surstylus with dense bunch of long setae at apex ... 31

– Surstylus without bunch of long setae at apex ... 32

31. Cercus long, bandlike; 2.4-3.1. Fig. 151 ... appendiculatum Zetterstedt

– Cercus short, irregularly triangular, widened at middle; 2.8-3.3... caliginosum Meigen

32. Postpedicel nearly 5 times longer than high; cercus narrow; surstylus broad, with distal comb of setae; 2.6. Fig. 174 ... umbripenne (Frey)

– Postpedicel approximately 4 times longer than high ... 33

33. Stylus 1/3 length of postpedicel; cercus elongate-triangular, longer than surstylus, with long sparse hairs; 3.3-3.5. Fig. 150... auctum Loew

– Stylus 2/3 length of postpedicel; cercus short, nearly equal in length to surstylus, with short dense hairs; 2.8-3.3. Fig. 163 ... lanceolatum Loew