Key to species of Chersodromia in the southern part of Primorsk Territory

1 Face between compound eyes narrower than frons (Figs. 50, 57)............................................... 2

- Face between compound eyes wider than frons (Figs. 20, 27, 34, 41)............................................. 3

2 Face between compound eyes narrower than median ocellus (Fig. 50); all setulae on head and thorax whitish................................................................................................. C. stenopsis sp. nov.

- Face between compound eyes wider than median ocellus (Fig. 57); all setulae on head and thorax brown or black............................................................................................... C. yamanei sp. nov.

3 In frontal view gena wider than one-third of maximum eye height (Figs. 34, 41); fore tibia with distinct tibial gland in basal part (Fig. 19); vein R1 meeting costa after midway of wing (Figs. 15, 16)......................................... 4

- In frontal view gena narrower than one-third of maximum eye height (Figs. 20, 27); tibial gland indistinct; vein R1 meeting costa at or before midway of wing (Figs. 13, 14)............................................................. 5

4 Larger species, more than 2.5 mm in body length; katepisternum with small polished area; male fore tibia with posteroventral row of curved setulae; left cercus of male terminalia spatulate (Figs. 45, 48)...................... C. nubifera Coquillett

- Smaller species, less than 2.0 mm in body length; katepisternum largely polished; male fore tibia without posteroventral row of curved setulae; left cercus of male terminalia oval (Fig. 40).................................... C. mohican sp. nov.

5 Outermost lobe of left surstylus of male terminalia rounded (Figs. 31, 33). Female unknown.............. C. leleji sp. nov.

- Outermost lobe of left surstylus of male terminalia elongated (Fig. 24). Female unknown........... C. gamoviensis sp. nov.