Key to the known European species of subgenus Neocheilosia Barkalov, 1983

1. Males ................................................................................................................................................. 2

– Females ............................................................................................................................................. 4

2. Veins of wing brown or black; anterior eye angle ca 110–130°; lateral margin of tergite 1 and anterolateral corners of tergite 2 with black hairs ............................................................................. 3

– Basal half of wing with veins yellow; anterior eye angle ca 90°; lateral margin of tergite 1 and anterolateral corners of tergite 2 with yellow hairs ........................... N. barovskii Stackelberg, 1930

3. Sides of face with erect, black hairs; tergites entirely black-haired ...... N. morio (Zetterstedt, 1838)

– Sides of face without erect hairs; tergite 2 at least partly yellow haired, tergite 3 predominantly yellow-haired ................................................................................. N. luteicornis (Zetterstedt, 1838)

4. Veins of wing brown or black; scape and pedicel dark brown or black; tergites 3–4with yellow hairs…5

– Basal half of wing with veins yellow; scape and pedicel bright orange; tergites 3–4 with black hairs ................................................................................................. N. barovskii (Stackelberg, 1930)

5. Sides of face with erect, short yellow hairs [careful observation is necessary since hairs are occasionally inconspicuous]; hairs on scutum of about equal length, with only individual black hairs intermixed; body length 7–8 mm ........................................................... N. morio (Zetterstedt, 1838)

– Sides of face without erect hairs; hairs on scutum of unequal length, with numerous black hairs intermixed; body length 9.5–12 mm .............................................. N. luteicornis (Zetterstedt, 1838)