Males

1. In frontal view, presutural region of scutum without grey dust; haltere dark brown ........................ ................................................................................................................ S. hissarensis Hennig, 1959 ¯ In frontal view, presutural region of scutum with grey dust; haltere yellow or brownish-yellow .... 2

2. Fronto-orbital plates touching along the greater part of their length, narrower than diameter of anterior ocellus; distance between eye margins on upper part of frons about as wide as diameter of anterior ocellus; prementum shining but with a patch of light dust centrally on underside; presutural region mostly with whitish-grey dust; mid femur with 5–6 long and stout pv–v in basal half; hind femur with 5–6 av at apex .................................................................... S. platyfrons Sorokina, 2018

¯ Fronto-orbital plates touching only in upper part or separated by a narrow frontal vitta; distance between eye margins on upper part of frons as wide as or narrower than the distance between posterior ocelli; prementum completely shining, without any dust; extreme anterior half of presutural region with grey dust; mid femur with 2–4 stout pv–v in basal half; hind femur with 3–4 av at apex ....... 3

3. Notopleuron with some hairs in upper part, but not around posterior seta; fronto-orbital plates touching in upper part or separated by a very narrow frontal vitta; mid tibia without ad and v; dark marks on tergite 3 usually connected or narrowly separated; caudal margin of sternite 5 with dense setulae .............................................................................................. ...... S. imitatrix (Malloch, 1921)

¯ Notopleuron completely bare; fronto-orbital plates usually separated by a distinct frontal vitta, sometimes touching; mid tibia with 1 ad and sometimes a short v present; tergites with well separated marks; caudal margin of sternite 5 without dense setulae ................. S. nitidicauda (Schnabl, 1911)