Cheilosia, Meigen, 1822

Bot, Sander, Mengual, Ximo, Meutter, Frank Van de & Skevington, Jeffrey H., 2025, Review of the genus Cheilosia Meigen, 1822 (Diptera: Syrphidae) from the Caucasus, with the description of 14 new species, European Journal of Taxonomy 1023, pp. 1-181 : 161-173

Key to the species of Cheilosia occurring in the Caucasus

The male of C. ( Cheilosia) atypica and the female of C. ( Taeniochilosia) ouwehandae sp. nov. remain unknown and are not included in the key.

Males

1. Eye bare ............................................................................................................................................ 2

– Eye pilose ........................................................................................................................................ 15

2. Protibia black .................................................................................................................................... 3

– Protibia yellow at base or yellow at base and apex .......................................................................... 8

3. Sternum II pruinose .......................................................................................................................... 4

– Sternum II shiny ............................................................................... C. ( T.) nigripes ( Meigen, 1822)

4. Parafacia pruinose ............................................................................................................................. 5

– Parafacia shiny ( Fig. 10B) ................................................... C. ( T.) bakurianiensis Kuznetzov, 1987

5. Postpedicel black .............................................................................................................................. 6

– Postpedicel orange ventrally ( Fig. 51B) ........... C. ( T.) ouwehandae Bot sp. nov. (female unknown)

6. Scutum shiny, at most slightly pruinose on the very anterior part of scutum ................................... 7

– Scutum slightly or distinctly pruinose in central part .................. C. ( T.) lukashovae Barkalov, 1993

7. Posterior margin of scutellum with few and thin setae, whose diameter is almost the same as scattered black pile on central disc of scutellum ( Fig. 2E); scutum with erect sparse long black pile and dense short erect golden pile ................................................................ C. ( T.) aenigmatosa Barkalov, 1993

– Posterior margin of scutellum with black setae, whose diameter is distinctly larger than diameter of scattered long black pile on central disc of scutellum ( Fig. 56E); scutum with erect sparse long black pile and dense short semi-adpressed pile, colour of short dense pile ranging from predominantly black to predominantly golden .............................................. C. ( T.) pollinifacies Stackelberg, 1968

8. Face in dorsal third along parafacia bare; pile on parafacia short .................................................... 9

– Face in dorsal third along parafacia covered with long whitish pile; pile on parafacia very long ( Fig. 25B) ....................................................................... C. ( Convocheila) laticornis Rondani, 1857

9. Wings with cross-veins infuscated; ventral part of face protruding ( Fig. 6B) ................................ 10

– Wings hyaline; ventral part of face not protruding ( Fig. 42E) ........................................................11

10. Face only slightly protruding ( Fig. 6B); haltere yellow; tarsi with tarsomeres dorsally brown or blackish; terga II–III shiny ........................................................ C. ( T.) armeniaca Stackelberg, 1960

– Face distinctly protruding ( Fig. 41B); haltere with dark brown or black capitulum; tarsi with tarsomeres 2–4 yellow; terga II–III medially pruinose ............................. C. ( T.) longifacies sp. nov.

11. Face black, at most with a brownish or brownish-yellow spot at mala ( Fig. 42E); basal third of wings with brown venation; trochanters black .......................................................................................... 12

– Face partly yellow ( Fig. 28B); basal third of wings with orange-yellow venation; trochanters at least partly yellow .................................................................................. C. ( E.) flavissima ( Becker, 1894)

12. Facial tubercle broad, semicircular in dorsal view ( Fig. 66E) ........................................................ 13

– Facial tubercle narrow, almost conical in dorsal view ( Fig. 52E) .................................................. 14

13. Anterior anepisternum with long pile on posterodorsal part; postpedicel usually bright orange ( Fig. 64B) ........................................................................................ C. ( E.) ruffipes ( Preyssler, 1793)

– Anterior anepisternum bare, without long pile on posterodorsal part; postpedicel variable, ranging from dark orange to dark brown ( Fig. 66B) .................................... C. ( E.) scutellata ( Fallén, 1817)

14. Arista with pile longer than diameter of arista at base; protarsus brown or black; lunule with reduced medial arm, antennal fossa present ( Fig. 10E) ............................ C. ( E.) longula ( Zetterstedt, 1838)

– Arista bare or nearly so; protarsus with central tarsomeres orange; lunule with distinct medial arm, acetabula separated ( Fig. 44D) ............................................. C. ( Cheilosia) pagana ( Meigen, 1822)

15. Face around facial tubercle pilose, pile as long as or longer than pile on parafacia ....................... 16

– Face around facial tubercle bare ..................................................................................................... 25

16. Scutellum without setae along posterior margin ............................................................................. 17

– Scutellum with setae along posterior margin .................................................................................. 18

17. A small species, body length ca 7–9 mm; parafacia broad; eye with sparse pile ( Fig. 40B) .......... ..................................................................................... C. ( Cheilosia) latifrons ( Zetterstedt, 1843)

– A large species, body length ca 12–13 mm; parafacia narrow; eye with long, dense pile ( Fig. 58B) .............................................................................. C. ( Cheilosia) pseudogrossa Stackelberg, 1968

18. Setae on posterior margin of scutellum long, longer than length of scutellum; colour of tibia ranging from black to yellow at both ends ................................................................................................... 19

– Setae on posterior margin of scutellum short, shorter than length of scutellum; tibiae black with basal part yellow, apex black ( Fig. 38C) ........................................... C. ( Cheilosia) lasiopa Kowarz, 1885

19. Wing base dark brown or black ...................................................................................................... 20

– Wing base yellow ( Fig. 70C) ................................ C. ( Cheilosia) transcaucasica Stackelberg, 1960

20. Scutum shiny on the central part; dorsal lobe of postgonite not sickle-shaped (cf. Fig. 55C); pro- and mesotibiae yellow at both ends ....................................................................................................... 21

– Scutum pruinose on central part; dorsal lobe of postgonite very long and slender, sickle-shaped (cf. Fig. 14D); pro- and mesotibiae black or only yellow at base .................................................. 22

21. Abdomen partly with black pile, at least tergum III in posterior half with black pile; parafacia narrow, about half the width of postpedicel; arista with pile, length equaling at least half the width of arista at base; dorsal lobe of postgonite slender ............................. C. ( Cheilosia) vulpina ( Meigen, 1822)

– Abdomen with yellow pile; parafacia broad, about two third as wide as postpedicel; arista nearly bare; dorsal lobe of postgonite broad basally, almost triangular in shape ( Fig. 55C) ........................ ......................................................................................................... C. ( Cheilosia) pogonias sp. nov.

22. Large species with slender abdomen, body length ca 11–12 mm; metafemur ventrally covered with short black setae; legs black ........................................................................................................... 23

– Smaller species with less slender abdomen, body length ca 10 mm; metafemur ventrally covered with short black pile; legs black or base of pro- and mesotibia dark yellow .......................................... 24

23. Scutum and scutellum with pile of two lengths, both long and short pile; procoxa usually with yellow pile and setae only; tergum IV medially with adpressed pile, widening in posterior half, covering ca one third of tergum surface .................................................. C. ( Cheilosia) variabilis ( Panzer, 1798)

– Scutum and scutellum with long pile of one length ( Fig. 14A); anterior part of procoxa with at least some black setae on apical half ( Fig. 14C); tergum IV covered with erect pile, adpressed pile absent or restricted to posteromedial area, covering distinctly less than one third of tergum surface .......... ........................................................................................................... C. ( Cheilosia) borjomi sp. nov.

24. Pile on arista at base almost as long as diameter of arista at base; apical half of posterior side of metatibia with yellow pile, basal half with black pile; long pile on dorsal margin of occiput behind dorsal margin of eyes black ( Fig. 46B); at most basal one third of anterior long and short pile on metafemur yellow ......................................................... C. ( Cheilosia) melanopa ( Zetterstedt, 1843)

– Pile on arista at base almost about as half as long as diameter of arista at base; posterior side of metatibia with yellow pile; long pile on dorsal margin of occiput behind dorsal margin of eyes predominantly or entirely yellow ( Fig. 60E); at least basal 60% of anterior long and short pile on metafemur yellow ............................................................................. C. ( Cheilosia) redi Vujić, 1996

25. Posterior margin of scutellum without setae ................................................................................... 26

– Posterior margin of scutellum with setae, usually black, sometimes yellow ................................. 43

26. Dorsal and ventral pile patches on katepisternum widely separated .............................................. 27

– Katepisternum continuously pilose ................................................................................................. 30

27. Basal three or four tarsomeres of protarsus yellow ........................................................................ 28

– Protarsus black ( Fig. 44A) ................................................. C. ( Cheilosia) megaclama sp. nov. [part]

28. Arista black ..................................................................................................................................... 29

– Arista with yellow or orange base ( Fig. 48B) ......................... C. ( Cheilosia) nebulosa Verrall, 1871

29. Postpedicel ca 1.5 times as wide as high ( Fig. 27B); angle of approximation of eyes less than 90°; frons not swollen, shiny, pruinose only narrowly along eye; usually very base up to basal one third of metafemur yellow ............................................................... C. ( Cheilosia) flavipes ( Panzer, 1798)

– Postpedicel ca two times as wide as high ( Fig. 16B); angle of approximation of eyes 100–110°; frons swollen and pruinose; base of metafemur black ............. C. ( Cheilosia) brunnipennis Becker, 1894

30. Wing hyaline, or with an indistinct blackish spot in the middle; if pile on mesonotum and abdomen bicoloured, then not in the form of alternating bands of black and yellow piles ........................... 31

– Wing with a distinct blackish spot in the middle ( Fig. 35C); large woolly species, mesonotum and abdomen with alternating pattern of black and pale (white and/or yellow and/or orange) pile bands ( Fig. 35A, C) .................................. C. ( Floccocheila) illustrata portschinskiana Stackelberg, 1960

31. Ventral part of eye bare or with sparse, shorter pile; large species, 12–15 mm............................. 32

– Eye entirely long pilose; large or smaller species ........................................................................... 34

32. Pile on posterior anepisternum with wavy apex; face slightly pruinose ........................................ 33

– Pile on posterior anepisternum with straight apex; face predominantly shiny ( Fig. 50B) .............. ........................................................................ C. ( Cheilosia) orthotricha Vujić & Claussen, 1994

33. Pile on arista about half the basal width of arista; apical segment of protarsus often darkened; for differences in genitalia see Stuke & Claussen (2000)..... C. ( Cheilosia) himantopus ( Panzer, 1798)

– Pile on arista longer than the basal width of arista; protarsus often completely yellow; for differences in genitalia see Stuke & Claussen (2000)......................... C. ( Cheilosia) canicularis ( Panzer, 1801)

34. Postpedicel black ............................................................................................................................ 35

– At least basoventral corner of postpedicel orange .......................................................................... 36

35. Metafemur yellow; eye with black pile ( Fig. 33B); sterna pruinose; scutum with yellow pile ............................................................................................ C. ( Cheilosia) grossa ( Fallén, 1817)

– Metafemur with black ring; eye with yellow or brown pile ( Fig. 11B); sterna predominantly shiny; scutum with black pile .................................................... C. ( Montanocheila) balu Violovitsh, 1966

36. Wing hyaline; apical sclerite of distiphallus with wide and large anterior lobes, posterior lobes missing (subgenus Cheilosia ) ......................................................................................................... 37

– Wing with brown pattern in the middle; apical sclerite of distiphallus with two pairs (anterior and posterior) of lobes (subgenus Montanocheila ) ............................................................................... 39

37. Pile on eye yellow; pile on eye shorter than postpedicel width ( Fig. 4B) ...................................... 38

– Pile on eye black; pile on eye very long, as long as or longer than postpedicel width ( Fig. 9A) ................................................................................ C. ( Cheilosia) aurantia sp. nov. [part]

38. Pile on anepimeron with wavy apex; face narrow, below antennae about ⅔ as wide as an eye at the same height; parafacia pruinose; katepisternal pile patches connected by wide long pile ................. .................................................................................................. C. ( Cheilosia) albipila Meigen, 1838

– Pile on anepimeron straight or with bent apex; face wide, below antennae about as wide as an eye at the same height ( Fig. 44D); parafacia shiny ( Fig. 44D); katepisternal pile patches separated or connected by short pile ...................................................... C. ( Cheilosia) megaclama sp. nov. [part]

39. Surstylus long, approximately 3–5 times as long as wide ( Figs 20B, 24D) ................................... 40

– Surstylus at most two times as long as wide ( Fig. 63D) ................................................................. 41

40. Surstylus narrow, approximately five times as long as wide ( Fig. 20D); a smaller species, body length 9–11 mm................................................................................... C. ( M.) chrysocoma ( Meigen, 1822)

– Surstylus wider, approximately three times as long as wide ( Fig. 24D); a larger species, body length 12–13.5 mm............................................................................................... C. ( M.) contrasta sp. nov.

41. Larger species, ca 10.5–12.5 mm; face protruding ( Fig. 63A); facial tubercle less developed; facial tubercle shiny, the area directly around it pruinose; anterodorsal pile on metafemur long and dense, almost two times as long as diameter of metafemur in ventral view .............................................. 42

– Smaller species, ca 9.5–10 mm; face not protruding ( Fig. 32A); facial tubercle well developed; face shiny around facial tubercle; anterodorsal pile on metafemur not dense and at most just over diameter of metafemur in ventral view ................................................... C. ( M.) gorodkovi Stackelberg, 1963

42. Anterior part of procoxa with mixed black and yellow setae on apical half; dorsal lobe of postgonite erect and rectangular, as long as ventral lobe ( Fig. 68E) ...... C. ( M.) subpictipennis Claussen, 1998

– Anterior part of procoxa with only yellow setae on apical half; dorsal lobe of postgonite curved inwards and with black, widening, pointed apex, shorter than ventral lobe ( Fig. 63C) ..................... ............................................................................................................................ C. ( M.) rufa sp. nov.

43. Proleg black or partly yellow, if partly yellow not only middle segments of protarsus yellow ..... 44

– Proleg black except segments 2–4 of protarsus yellow ( Fig. 5A) .................................................... ......................................................................................... C. ( Cheilosia) albitarsis ( Meigen, 1822)

44. Wing base yellow and/or procoxa basolaterally with a knob-like projection ................................. 45

– Wing base dark brown or black; procoxa basolaterally without a knob-like projection ................ 46

45. Procoxa basolaterally without a knob-like projection ( Fig. 37B); scutum rough and densely punctured; postpedicel black or only dark orange in ventral half, seldom bright orange; tergum III pruinose in anterior half, pruinosity not reaching posterior margin; sclerite of the distiphallus asymmetric ( Fig. 37E) .................................................................... C. ( Cheilosia) inarmata sp. nov.

– Procoxa basolaterally with a knob-like projection ( Fig. 37C); scutum finely punctured; postpedicel often at least partly bright orange ( Fig. 65B); tergum III with pruinosity reaching posterior margin; sclerite of the distiphallus symmetric ..................................... C. ( Cheilosia) schnabli Becker, 1894

46. Sterna II–IV shiny or only very slightly pruinose .......................................................................... 47

– Sterna II–IV distinctly pruinose, at least anterior parts .................................................................. 60

47. Legs black ....................................................................................................................................... 48

– Legs partly yellow, at least tibiae yellow at both ends ................................................................... 51

48. Wings hyaline or with brown tinge; posterior anepisternum at least slightly pruinose .................. 49

– Anterior part of wing blackish ( Fig. 1A, C); posterior anepisternum shiny ................................... ......................................................................................... C. ( Cheilosia) abagoensis Skufjin, 1979

49. Face not elongated, face between antennae and facial tubercle short; katepisternal piles widely separated; frons not swollen; scutum usually with mainly black pile; scutum shiny; parafacia broad over full length; surstylus with field of microtrichia on dorsal part ............................................... 50

– Face elongated, with long straight part between antennae and facial tubercle ( Fig. 61B); katepisternal piles almost continuously pilose (only true for populations in the Caucasus, see species account for more information); frons swollen; scutum with long black and white pile; scutum at least in central anterior part slightly pruinose; parafacia slender, ventral part slenderer than dorsal part; surstylus without field of microtrichia on dorsal part ........................... C. ( Cheilosia) rhynchops Egger, 1860

50. Larger species, 8.5–11.5 mm; frons along eye margins broadly pruinose; arista not thickened in basal half and about three times as long as postpedicel ( Fig. 19A); sternum I pruinose; pile on dorsal part of eye short, ranging from whitish to dark brown ( Fig. 19A) ............................................................ .................................................................................................. C. ( Cheilosia) caucasi sp. nov. [part]

– Smaller species, 6.5–8.5 mm; frons along eye margins very narrowly pruinose; arista thickened in basal half and just over two times as long as postpedicel ( Fig. 30A); sternum I medially shiny or slightly pruinose; pile on dorsal part of eye black and very long ( Fig. 30A) ..................................... ......................................................................................................... C. ( Cheilosia) gemmula sp. nov.

51. Dorsal and ventral pile patches on katepisternum widely separated; pile on eye not very long .... 52

– Katepisternum continuously pilose; pile on eye very long, as long as or longer than postpedicel width ( Fig. 9A) ................................................................................ C. ( Cheilosia) aurantia sp. nov. [part]

52. Eye entirely pilose .......................................................................................................................... 53

– Ventral part of eye bare ( Fig. 12B) ................................ C. ( Cheilosia) bergenstammi Becker, 1894

53. Metatibia yellow at both ends; arista bare or with pile shorter than diameter of arista; postpedicel usually at least partly orange .......................................................................................................... 54

– Metaleg black or only base of tibia narrowly yellow; arista with pile as long as or longer than width of arista; postpedicel usually black ....................................... C. ( Cheilosia) mutabilis ( Fallén, 1817)

54. Postpedicel about as wide as high; if a small, slender species, postpedicel partly bright orange .. 55

– Postpedicel elongate, about 1.5 times as wide as height, usually dark brown or dark brown with dark orange basoventral corner ( Fig. 71B); small, slender species, 6–8 mm............................................. ................................................................................................ C. ( Cheilosia) urbana ( Meigen, 1822)

55. Sterna slightly pruinose .................................................................................................................. 56

– Sterna shiny .................................................................................................................................... 57

56. Base of claws yellow, apex black; frons densely pruinose; parafacia narrow, about half as wide as width of postpedicel ............................................................... C. ( Cheilosia) uviformis Becker, 1894

– Claws black; frons shiny or indistinctly pruinose; parafacia broad, about 0.8 times as wide as width of postpedicel ................................................................. C. ( Cheilosia) psilophthalma Becker, 1894

57. Scutum without blue shine; pile on scutum varying from yellow to black; parafacia pruinose or shiny ................................................................................................................................................ 58

– Scutum with blue shine; scutum covered largely with black pile; parafacia pruinose .................... .......................................................................................... C. Cheilosia ) cynocephala Loew, 1840

58. Mesotarsus with basal two segments black or orange; metatibia with short pile only, pile shorter than tibia width; pale pile on terga whitish or yellowish ........................................................................ 59

– Mesotarsus with basal two segments orange ( Fig. 15A); metatibia with individual long black pile, longer than tibia width; terga entirely golden pilose ( Fig. 15A) ........................................................ .................................................................................. C. ( Cheilosia) bracusi Vujić & Claussen, 1994

59. Body size 5–8 mm; frons not swollen; metasternum usually pilose; basal two tarsomeres of mesotarsus usually dorsally orange ........................................ C. ( Cheilosia) vernalis ( Fallén, 1817)

– Body size 8.8–9.5 mm; frons slightly swollen; metasternum bare; mesotarsus dorsally black ( Fig. 21A) ......................................................................................... C. ( Cheilosia) confusa sp. nov.

60. Dorsal and ventral pile patches on katepisternum widely separated .............................................. 61

– Katepisternum continuously pilose ................................................................................................. 64

61. Postpedicel at least at base brightly orange .................................................................................... 62

– Postpedicel black ............................................................................................................................ 63

62. Base of claws yellow, apex black; frons densely pruinose; parafacia narrow, about half as wide as width of postpedicel ............................................................... C. ( Cheilosia) uviformis Becker, 1894

– Claws black; frons shiny or indistinctly pruinose; parafacia broad, about 0.8 times as wide as width of postpedicel ................................................................. C. ( Cheilosia) psilophthalma Becker, 1894

63. Abdomen without distinct pruinose spots; scutum shiny ........... C. ( Cheilosia) caucasi sp. nov. [part]

– Abdomen with distinct pruinose spots ( Fig. 67C); scutum pruinose or with large pruinose parts .......... .............................................................................................................. C. ( P.) semifasciata Becker, 1894

64. Face not very wide, below lunule narrower than an eye; face along parafacia in dorsal one third bare ................................................................................................................................................. 65

– Face very wide, below lunule as wide as an eye; face along parafacia in dorsal one third covered with long pile ( Fig. 25B) .......................................................... C. ( Convocheila) cumanica Szilády, 1938

65. Anterior anepisternum without pile on posterodorsal part ............................................................. 66

– Anterior anepisternum with pile on posterodorsal part ............... C. ( Cheilosia) aerea Dufour, 1848

66. Scutum with long pile only, without field of short black pile on posterior part ............................. 67

– Besides long erect pile, scutum medially in posterior part also with field of short black pile ( Fig. 75A) .................................................................................... C. ( Cheilosia) vansteenisi sp. nov.

67. Legs black or at most base of protibia dark orange ........................................................................ 68

– Legs partly yellow, at least pro- and mesotibia yellow at both ends .............................................. 69

68. Large species, ca 11–13 mm; postpedicel ranging from blackish to orange ( Fig. 53B); pile on terga II–IV with distinctive alternating black and white pile: pile on terga on anterior part in center white and erect, in posterior part black and erect .................. C. ( Cheilosia) paragigantea Barkalov, 1993

– Smaller species, 9–10 mm; postpedicel black ( Fig. 69B); terga with erect white pile and adpressed black pile .......................................................................... C. ( Cheilosia) teberdensis Barkalov, 1993

69. Face in lateral view obviously concave between facial tubercle and postclypeus ( Fig. 31B); postpedicel usually black; scutum finely punctured ....................................................................... 70

– Face in lateral view almost flat between facial tubercle and postclypeus ( Fig. 78B); postpedicel usually with at least basoventral part orange; scutum coarsely punctured ......................................... .................................................................................................... C. ( Cheilosia) velutina Loew, 1840

70. Abdomen usually partly with black pile, usually at least sternum VIII with few black pile; facial tubercle well developed ( Fig. 31B) ................................................................................................ 71

– Abdomen (including sternum VIII) usually with yellow pile only ( Fig. 70A); facial tubercle poorly developed ( Fig. 73A) ................................................................. C. ( Cheilosia) ushguliensis sp. nov.

71. Basal two thirds of metafemur with the anterodorsal pile longer than the anteroventral pile; dorsal lobe of postgonite with a more or less distinct hook on its dorsal margin (see Vujić et al. 2013: fig. 3d) ............................................................................. C. ( Cheilosia) proxima ( Zetterstedt, 1843)

– Basal two thirds of metafemur with the anterodorsal pile as long as or shorter than the anteroventral pile; dorsal lobe of postgonite without distinct hook (see Vujić et al. 2013: fig. 3e) ......................... ......................................................................................... C. ( Cheilosia) gigantea ( Zetterstedt, 1838)

Females

1. Eye bare ............................................................................................................................................ 2

– Eye pilose ........................................................................................................................................ 23

2. Face around the facial tubercle bare ................................................................................................. 3

– Face around the facial tubercle pilose, pilosity as long as or longer than pile on parafacia ( Fig. 40D) ............................................................. C. ( Cheilosia) latifrons ( Zetterstedt, 1843) [part]

3. Protibia black .................................................................................................................................... 4

– Protibia yellow at base or yellow at base and apex ........................................................................ 10

4. Lunule with distinct medial arm, separating acetabula ( Fig. 45D) ................................................... 5

– Lunule with reduced medial arm, acetabula joined forming an antennal fossa ( Fig. 10E) .............. 6

5. Tarsomeres 2–4 of protarsus yellow or brown, paler than tarsomeres 1 and 5; veins yellow in basal half of wing ......................................................................... C. ( Cheilosia) albitarsis ( Meigen, 1822)

– Protarsus black; veins of wing black ....................................... C. ( Cheilosia) caucasi sp. nov. [part]

6. Scutum with erect pile ...................................................................................................................... 7

– Scutum with adpressed pile .............................................................................................................. 8

7. Face narrow, at level of antennal base narrower than eye; parafacia pruinose ( Fig. 43D) ................. ...................................................................................................... C. ( T.) lukashovae Barkalov, 1993

– Face broad, at level of antennal base as wide as an eye ( Fig. 10E); parafacia shiny ( Fig. 10E) ..... .......................................................................................... C. ( T.) bakurianiensis Kuznetzov, 1987

8. Sterna II–IV densely pruinose .......................................................................................................... 9

– Sterna II–IV shiny ............................................................................. C. ( T.) nigripes ( Meigen, 1822)

9. Posterior margin of scutellum with black setae ..................... C. ( T.) pollinifacies Stackelberg, 1968

– Posterior margin of scutellum without black setae .................... C. ( T.) aenigmatosa Barkalov, 1993

10. Lunule with reduced medial arm, antennal fossa present ( Fig. 10E) ..............................................11

– Lunule with distinct medial arm, acetabula separated ( Fig. 45D) .................................................. 16

11. Wings with cross-veins infuscated; ventral part of face protruding ( Fig. 6B) ................................ 12

– Wings hyaline; ventral part of face not protruding ( Fig. 42F) ........................................................ 13

12. Face only slightly protruding ( Fig. 6B); haltere yellow; tarsi with tarsomeres dorsally brown or blackish; terga II–III shiny ........................................................ C. ( T.) armeniaca Stackelberg, 1960

– Face distinctly protruding ( Fig. 41B); haltere with dark brown or black capitulum; tarsi with tarsomeres 2–4 yellow; terga II–III medially pruinose ............................. C. ( T.) longifacies sp. nov.

13. Pro- and mesofemur black, with narrow yellow apices; scutellum black or partly yellow ............ 14

– Pro- and mesofemur yellow; scutellum entirely yellow ................ C. ( E.) flavissima ( Becker, 1894)

14. Facial tubercle broad, semicircular in dorsal view ( Fig. 66E) ........................................................ 15

– Facial tubercle narrow, almost conical in dorsal view ( Fig. 52E) ................................................... ................................................................................................... C. ( E.) longula ( Zetterstedt, 1838)

15. Anterior anepisternum with long pile on posterodorsal part; postpedicel usually bright orange ( Fig. 64D) ....................................................................................... C. ( E.) ruffipes ( Preyssler, 1793)

– Anterior anepisternum bare, without long pile on posterodorsal part; postpedicel variable, ranging from dark orange to dark brown ( Fig. 66D) .................................... C. ( E.) scutellata ( Fallén, 1817)

16. Face in dorsal third along parafacia covered with long whitish pile; pile on parafacia very long ( Fig. 25D); postpedicel large to very large, orange, distinctly darkened in apical part ( Figs 25D, 39D); face with dense grey pruinosity ...................................................................................................... 17

– Face in dorsal third along parafacia bare; pile on parafacia shorter ( Fig. 27D); when postpedicel very large and orange, face shiny and postpedicel without darkened apical part ( Fig. 52D) ................. 18

17. Lunule bare and shiny mediodorsally; occiput with long yellow pile only ( Fig. 39D); scutellum on posterior margin with weak, yellow setae ..................... C. ( Convocheila) laticornis Rondani, 1857

– Lunule pruinose mediodorsally; occiput, besides long yellow pile, also with few long black pile ( Fig. 25D); scutellum on posterior margin with robust black setae .................................................... .......................................................................................... C. ( Convocheila) cumanica Szilády, 1938

18. Postpedicel very large, bright orange ( Fig. 52D); sterna shiny; parafacia narrow .......................... ............................................................................................ C. ( Cheilosia) pagana ( Meigen, 1822)

– Without combination of postpedicel very large and bright orange, sterna shiny and parafacia narrow ............................................................................................................................................. 19

19. Femora black, only apices narrowly yellow ................................................................................... 20

– Femora yellow ........................................................................ C. ( Cheilosia) flavipes ( Panzer, 1798)

20. Arista bare or with short pile, pile shorter than width of arista at base; postpedicel predominantly orange ............................................................................................................................................. 21

– Arista with long pilosity, longer than or almost equal to the width of arista at base ( Fig. 47D); postpedicel black or only orange at basoventral corner ...................................................................... ..................................................................................... C. ( Cheilosia) mutabilis ( Fallén, 1817) [part]

21. Posterior margin of scutellum without black setae; parafacia very broad (cf. Fig. 45D); eye bare ..22

– Posterior margin of scutellum with black setae; parafacia narrow; eye with short sparse pile that can easily be overlooked .................................................... C. ( Cheilosia) uviformis Becker, 1894 [part]

22. Tibiae yellow with indistinct black ring in the middle; tarsi dorsally predominantly yellow ......... .................................................................. C. ( Cheilosia) atypica Barkalov, 1993 (male unknown)

– Tibiae yellow with distinct black ring in the middle ( Fig. 45C); tarsi dorsally predominantly black ( Fig. 45C) .................................................................................... C. ( Cheilosia) megaclama sp. nov.

23. Face around facial tubercle pilose, pile as long as or longer than pile on parafacia ....................... 24

– Face around facial tubercle bare ..................................................................................................... 33

24. Scutellum without setae along posterior margin ............................................................................. 25

– Scutellum with setae along posterior margin .................................................................................. 26

25. A small species, body length ca 7–9 mm; parafacia broad; eye with sparse pile ( Fig. 40B) .......... ........................................................................... C. ( Cheilosia) latifrons ( Zetterstedt, 1843) [part]

– A large species, body length ca 12–13 mm; parafacia narrow; eye with long, dense pile ( Fig. 58B) .................................................................................. C. ( Cheilosia) pseudogrossa Stackelberg, 1968

26. Setae on posterior margin of scutellum long, longer than length of scutellum; colour of tibia ranging from black to yellow at both ends ................................................................................................... 27

– Setae on posterior margin of scutellum short, shorter than length of scutellum; tibiae black with basal part yellow, apex black ( Fig. 38C) ........................................... C. ( Cheilosia) lasiopa Kowarz, 1885

27. Wing base dark brown or black ...................................................................................................... 28

– Wing base yellow ( Fig. 70C) ................................ C. ( Cheilosia) transcaucasica Stackelberg, 1960

28. Metatibia entirely with yellow pile; usually protibia and mesotibia yellow at both ends .............. 29

– Metatibia posterolaterally largely or entirely with yellow pile, anterolaterally with black pile; tibiae completely black, or with a yellow base, or both ends dark orange ............................................... 31

29. Tergum IV almost entirely or entirely with yellow pile ................................................................. 30

– Tergum IV centrally with black pile ..................................... C. ( Cheilosia) vulpina ( Meigen, 1822)

30. Occiput behind dorsal eye corners shiny or slightly pruinose; occiput with short and sparse long yellow pile behind dorsal margin of eye ( Fig. 60F); metafemur anteriorly and posteroventral with short yellow pile; pile on arista about half as long as width of arista at base ..................................... ........................................................................................................... C. ( Cheilosia) redi Vujić, 1996

– Occiput entirely pruinose; occiput with short yellow and sparse long black pile behind dorsal margin of eye ( Fig. 55B); metafemur anteriorly and posteroventral with long pile, at least as long as width of metafemur; pile on arista shorter than half the width of arista at base ........................................... ......................................................................................................... C. ( Cheilosia) pogonias sp. nov.

31. Posterior anepisternum pruinose ..................................................................................................... 32

– Ventral part of posterior anepisternum shiny ....................... C. ( Cheilosia) variabilis ( Panzer, 1798)

32. Scutum with short semi-adpressed pile, this pile usually predominantly black and with longer erect sparse black pile intermixed ( Fig. 14B); tibiae usually black or only very base dark orange to blackish ............................................................................................. C. ( Cheilosia) borjomi sp. nov.

– Scutum with short erect predominantly yellow pile and with longer erect sparse black pile intermixed; often base of tibiae dark orange .................................... C. ( Cheilosia) melanopa ( Zetterstedt, 1843)

33. Posterior margin of scutellum without setae ................................................................................... 34

– Posterior margin of scutellum with setae, usually black, sometimes yellow ................................. 47

34. Dorsal and ventral pile patches on katepisternum widely separated .............................................. 35

– Katepisternum continuously pilose ................................................................................................. 36

35. Arista black ..................................................................... C. ( Cheilosia) brunnipennis Becker, 1894

– Arista with yellow or orange base ( Fig. 48D) ........................ C. ( Cheilosia) nebulosa Verrall, 1871

36. Wing hyaline, or with an indistinct blackish spot in the middle; if pile on mesonotum and abdomen bicoloured, then not in the form of alternating bands of black and yellow piles ........................... 37

– Wing with a distinct blackish spot in the middle ( Fig. 35C); large woolly species, mesonotum and abdomen with alternating pattern of black and pale (white and/or yellow and/or orange) pile bands ( Fig. 35A, C) .................................. C. ( Floccocheila) illustrata portschinskiana Stackelberg, 1960

37. Ventral part of eye bare or with sparse, shorter pile; large species, 12–15 mm............................. 38

– Eye entirely long pilose; large or smaller species ........................................................................... 40

38. Pile on posterior anepisternum with wavy apex; face slightly pruinose ........................................ 39

– Pile on posterior anepisternum with straight apex; face predominantly shiny ( Fig. 50D) .............. ........................................................................ C. ( Cheilosia) orthotricha Vujić & Claussen, 1994

39. Pile on arista about half the basal width of arista; posterior margin of tergum III with thin incomplete adpressed pile; posterior third of tergum IV with scattered semi-erect pile; scutum centrally with white pile only ................................................................. C. ( Cheilosia) himantopus ( Panzer, 1798)

– Pile on arista longer than the basal width of arista; posterior margin of tergum III with dense band of adpressed pile; posterior third of tergum IV with dense adpressed pile; scutum centrally in posterior half with variable black pile ............................................. C. ( Cheilosia) canicularis ( Panzer, 1801)

40. Postpedicel black ............................................................................................................................ 41

– At least basoventral corner of postpedicel orange .......................................................................... 42

41. Metafemur yellow; eye with black pile ( Fig. 33D); sterna pruinose .................................................. ................................................................................................... C. ( Cheilosia) grossa ( Fallén, 1817)

– Metafemur with black ring; eye with yellow or brown pile ( Fig. 11D); sterna predominantly shiny ......................................................................................... C. ( Montanocheila) balu Violovitsh, 1966

42. Wing hyaline; femora orange .......................................................................................................... 43

– Wing with brown pattern in the middle; femora black except apices narrowly yellow ................. 44

43. Pile on anepimeron with wavy apex; pile on eye yellow ( Fig. 4D) ................................................. .............................................................................................. C. ( Cheilosia) albipila Meigen, 1838

– Pile on anepimeron straight; at least dorsal half of pile on eye dark brown or black ( Fig. 9B) ...... ............................................................................................. C. ( Cheilosia) aurantia sp. nov. [part]

44. Posterior margin of tergum V not rounded ..................................................................................... 45

– Posterior margin of tergum V rounded ..................................... C. ( M.) chrysocoma ( Meigen, 1822)

45. Face protruding ( Fig. 63B); pile on scutellum longer than diameter of metafemur; metafemur anteroventrally with pile longer than diameter of metafemur ........................................................ 46

– Face not protruding ( Fig. 32F); pile on scutellum shorter than diameter of metafemur; metafemur anteroventrally with pile shorter than diameter of metafemur ........................................................... .................................................................................................. C. ( M.) gorodkovi Stackelberg, 1963

46. Pile on terga III–V black ( Fig. 23C–D) ..................................................... C. ( M.) contrasta sp. nov.

– Pile on terga III–V yellow or orange ( Fig. 62C–D) ............................................................................ ......................................................... C. ( M.) subpictipennis Claussen, 1998 & C. ( M.) rufa sp. nov.

47. Wing base yellow and/or procoxa basolaterally with a knob-like projection ................................. 48

– Wing base dark brown or black; procoxa basolaterally without a knob-like projection ................ 49

48. Procoxa basolaterally without a knob-like projection ( Fig. 37B); scutum rough and densely punctured; postpedicel black or only dark orange in ventral half, seldom bright orange; pile on scutum short and adpressed ( Fig. 36D) .......................................... C. ( Cheilosia) inarmata sp. nov.

– Procoxa basolaterally with a knob-like projection ( Fig. 37C); scutum finely punctured; postpedicel often at least partly bright orange ( Fig. 65D); scutum with semi-adpressed short pile mixed with some longer pile ...................................................................... C. ( Cheilosia) schnabli Becker, 1894

49. Sterna II–IV shiny or only very slightly pruinose .......................................................................... 50

– Sterna II–IV distinctly pruinose, at least anterior parts .................................................................. 64

50. Legs black ....................................................................................................................................... 51

– Legs partly yellow, at least tibiae yellow at both ends ................................................................... 54

51. Wings hyaline or with brown tinge; posterior anepisternum at least slightly pruinose .................. 52

– Anterior part of wing blackish ( Fig. 1A, C); posterior anepisternum shiny .................................... ......................................................................................... C. ( Cheilosia) abagoensis Skufjin, 1979

52. Larger species, 8.5–11.5 mm; pile on scutum adpressed or semi-adpressed; arista not thickened in basal half and about three times as long as postpedicel .................................................................. 53

– Smaller species, 6.5–8.5 mm; pile on scutum long and erect ( Fig. 29C); arista thickened in basal half and just over two times as long as postpedicel ( Fig. 30B) ............. C. ( Cheilosia) gemmula sp. nov.

53. Face elongated ( Fig. 61D); katepisternal piles almost continuously pilose (only true for population in the Caucasus, see species account for more information); scutum with adpressed mainly golden pile; postpedicel dark orange in basoventral corner .............. C. ( Cheilosia) rhynchops Egger, 1860

– Face not elongated ( Fig. 19B); katepisternal piles widely separated; colour of pile on scutum variable; postpedicel black ..................................................................... C. ( Cheilosia) caucasi sp. nov. [part]

54. Femora predominantly black; dorsal and ventral pile patches on katepisternum widely separated ..... .............................................................................................................................................................55

– Femora yellow; katepisternum continuously pilose .............. C. ( Cheilosia) aurantia sp. nov. [part]

55. Eye entirely pilose .......................................................................................................................... 56

– Ventral part of eye bare ( Fig. 12D) ................................ C. ( Cheilosia) bergenstammi Becker, 1894

56. Metaleg black or only base of tibia narrowly yellow; arista with pile as long as or longer than width of arista; postpedicel usually black ................................................................................................. 57

– Metatibia yellow at both ends; arista bare or with pile shorter than diameter of arista; postpedicel usually at least partly orange .......................................................................................................... 58

57. Abdomen medially with predominantly black pile; sterna II–IV shiny ........................................... ................................................................................. C. ( Cheilosia) mutabilis ( Fallén, 1817) [part]

– Abdomen with yellow pile; sterna II–IV pruinose on anterior half, shiny on posterior half .......... ....................................................................... C. ( Pollinocheila) semifasciata Becker, 1894 [part]

58. Postpedicel about as wide as high; if a small, slender species, postpedicel partly bright orange .....59

– Postpedicel elongate, about 1.5 times as wide as height, usually dark brown or dark brown with dark orange basoventral corner ( Fig. 71D); small, slender species, 6–8 mm............................................. ................................................................................................ C. ( Cheilosia) urbana ( Meigen, 1822)

59. Sterna slightly pruinose .................................................................................................................. 60

– Sterna shiny ..................................................................................................................................... 61

60. Base of claws yellow, apex black; eye almost bare ( Fig. 74D) ........................................................ .................................................................................. C. ( Cheilosia) uviformis Becker, 1894 [part]

– Claws black; eye with distinct pile ( Fig. 59E) ............... C. ( Cheilosia) psilophthalma Becker, 1894

61. Scutum without blue shine; pile on scutum varying from yellow to black; parafacia pruinose or shiny; wings brownish without blackish cloud ......................................................................................... 62

– Scutum with blue shine; scutum covered largely with black pile; parafacia pruinose; usually wings brownish with a faint, blackish cloud ................................. C. ( Cheilosia) cynocephala Loew, 1840

62. Mesotarsus with basal two segments black or orange; tibiae with distinct black rings ................. 63

– Mesotarsus with basal two segments orange; tibiae entirely orange, or only with traces of black rings ......................................................................... C. ( Cheilosia) bracusi Vujić & Claussen, 1994

63. Body size 7 mm; pile on scutum semi-adpressed; posterior anepisternum shiny; metasternum pilose; basal two tarsomeres of mesotarsus usually dorsally orange ............................................................. ................................................................................................. C. ( Cheilosia) vernalis ( Fallén, 1817)

– Body size 8 mm; pile on scutum erect; posterior anepisternum lightly pruinose; metasternum bare or with one or two pili only; mesotarsus dorsally black ( Fig. 21C) ...... C. ( Cheilosia) confusa sp. nov.

64. Dorsal and ventral pile patches on katepisternum widely separated .............................................. 65

– Katepisternum continuously pilose ................................................................................................. 67

65. Postpedicel at least at base brightly orange .................................................................................... 60

– Postpedicel black ............................................................................................................................ 66

66. Scutum with mixed black and yellow or predominantly black semi-adpressed pile ( Fig. 18C); Sterna II–IV shiny or only slightly pruinose ....................................... C. ( Cheilosia) caucasi sp. nov. [part]

– Scutum with erect golden pile; sterna II–IV at least on anterior part distinctly pruinose ............... .......................................................................................... C. ( P.) semifasciata Becker, 1894 [part]

67. Anterior anepisternum without pile on posterodorsal part ............................................................. 68

– Anterior anepisternum with pile on posterodorsal part ............... C. ( Cheilosia) aerea Dufour, 1848

68. Scutum not with short semi-adpressed almost exclusively yellow pile; frons shiny or only pruinose in anterolateral corner ..................................................................................................................... 69

– Scutum with short semi-adpressed almost exclusively yellow pile ( Fig. 75C); anterior part of frons, i.e., above lunule, pruinose .......................................................... C. ( Cheilosia) vansteenisi sp. nov.

69. Legs black or at most base of protibia dark orange ........................................................................ 70

– Legs partly yellow, at least pro- and mesotibia yellow at both ends .............................................. 71

70. Large species, ca 11–13 mm; postpedicel ranging from blackish to orange ( Fig. 53D); pile on scutum black ............................................................................. C. ( Cheilosia) paragigantea Barkalov, 1993

– Smaller species, 9–10 mm; postpedicel black ( Fig. 69D); scutum with short mainly yellow pile and longer black pile .............................................................. C. ( Cheilosia) teberdensis Barkalov, 1993

71. Face in lateral view obviously concave between facial tubercle and postclypeus ( Fig. 31D); postpedicel usually black; scutum finely punctured ....................................................................... 72

– Face in lateral view almost flat between facial tubercle and postclypeus ( Fig. 78D); postpedicel usually with at least basoventral part orange; scutum coarsely punctured ......................................... .................................................................................................... C. ( Cheilosia) velutina Loew, 1840

72. Tergum III medially and anterior part of tergum IV pruinose; pile on scutum often partly black and semi-adpressed ................................................................................................................................ 73

– Terga III–IV shiny, except pruinose along anterior margin of tergum III; scutum with erect golden pile ( Fig. 72A) ........................................................................... C. ( Cheilosia) ushguliensis sp. nov.

73. Metafemur without anteroventral pile, occasionally with few individual pile anteroventrally which are shorter than, or rarely as long as, the diameter of the metafemur; apex of the metafemur ventrally most often without black setae ....................................... C. ( Cheilosia) proxima ( Zetterstedt, 1843)

– Basal two thirds of metafemur with the anteroventral pile long, usually obviously longer than diameter of metafemur; apex of metafemur ventrally with some black setae .................................... ......................................................................................... C. ( Cheilosia) gigantea ( Zetterstedt, 1838)