Conops

1.b. Thorax without silverish stripe at the sides -> 10

2.a. Scutellum entirely yellow -> 3

2.b. Scutellum black, black with yellow on basis or entirely reddish brown -> 4

3.a. Frons with a longitudinal black stripe from antennal implant upwards. 11-12 mm. NL, B, D. -> Conops scutellatus Meigen

3.b. Frons with a black cross stripe from one eye to the other. 11-12 mm. Mediterranean. -> Conops silaceus Meigen

4.b. Face above antennal implant black, except the hill containing the ocelli, which has the same colour as the eyes -> 5

4.a. Face above antennal implant completely or partly yellow -> 7

5.b. Tergite 1-3 mainly black: yellow hind margin smaller than black front margin (if rather yellow, femora with large dark ring on middle) -> 6

5.a. Tergite 1-3 (and further) mainly yellow: yellow hind margin broader than black front margin (females darker than males); femur 2-3 not thickened, with at most a small brown patch at the centre. Female: theca semicircular, yellow-brown. 7-12 mm. Southern Europe. -> Conops vitellinus Loew

6.a. Femur 2 and 3 not thickened in the middle, uniformly pale with at most a small darkened, diffusely marked spot. Female: theca yellow, rounded. Male: tergite 5 black with broad yellow band at hind border. 10-15 mm. NL, B, D. Conops quadrifasciatus

6.b. Femur 2 and 3 somewhat thickened in the middle, with a large brown to black patch that (almost) forms a ring. Female: theca small and black. Male: tergite 5 yellow. 13 mm. D. Conops ceriaeformis Meigen.

Abdomen of, first, C. quadrifasciatus male and, second, C. ceriaeformis above male and below female.

7.a. Face above the antennal implant yellow, without black -> 8

7.b. Face above the antennal implant with a large black or a small brown spot in the yellow background ->9

8.a. Wing with well marked dark stripe; antennae yellow-red; scutellum reddish brown; abdomen: tergites 1-3 black on centre, reddish on side, tergite 4-6 densily dusted with golden dust. Female: theca reddish brown. 8-11 mm. Southern Europe, Africa -> Conops elegans Meigen -> 8

8.b. Wing hyaline to yellowish; antennae brown to black; scutellum black with reddish base; abdomen: females with first segment reddish brown and the others black with silverish hind border, males with all tergites yellow to red. Female: theca blackish. 8-11 mm. B, southern Europe -> Conops flavifrons Meigen

9.a. Face above the antennal implant yellow with a large black spot, black spot occupies more than half the frons width at the antennal implant; face between lower border of eye and mouth edge with a black spot; antennae black in male, more brownish in female; abdomen black with small yellow bands on hind margins of tergites; scutellum: black, sometimes with yellow basis. 10-12 mm. Europe -> Conops strigatus Wiedemann in Meigen

9.b. Face above the antennal implant yellow with a small brown spot, that is as wide as the antennal implant, leaving the majority of the frons yellow; face below eye without black spot; antennae reddish to dark brown; abdomen black with yellow dust bands, yellow band on tergite 2 covering almost entire tergite, with triangular black incision in the front margin. 10-13 mm. Southern Europe, Africa -> Conops insignis Loew

10.a. Body colour with reddish colour in addition to the black and yellow pattern; antennae, scutellum and femora reddish brown. Female: theca yellow with black tip. 14-18 mm. NL, B, D. -> Conops vesicularis Linnaeus