Chersodromia

Grootaert, Patrick & Shamshev, Igor, 2010, A new Chersodromia Walker (Diptera: Hybotidae) from shore of the Sea of Azov (Russia), Zootaxa 2645, pp. 64-68 : 67

Key to Chersodromia from the coast of the Black Sea and Sea of Azov

1 Halters dark. Gena moderately wide, as wide as one-fifth to one-quarter of the eye height ....................................... 2

- Halters pale. Gena narrower ....................................................................................................................................... 4

2 Postpedicel pointed, with an apical stylus .................................................................................................................. 3

- Postpedicel ventrally rounded, with dorsoapical stylus .................................................................... caucasica Chvála

3 Wing brownish on costal half. Mid tibia with ventral spinules on apical third.......................... cursitans (Zetterstedt)

- Wing hyaline. Mid tibia with ventral spinules on apical two thirds ..................................... milanchvalai Beschovski

4 Wing at least as long as abdomen. Face broad, as broad as front of frons ................................................................. 5

- Wing greatly reduced in length, reaching just beyond tergite 2. Face narrower than front of frons .............................. .......................................................................................................................................................... curtipennis Collin

5 Postpedicel conical, with an apical stylus ...................................................................................... nigrosetosa Chvála

- Postpedicel ventrally rounded, with a dorsoapical stylus ............................................................................................ 6

6 Fore leg with tarsomeres 2–5 contrastingly darkened. Left surstylus with several long setae......... isabellae sp. nov.

- Fore leg with only tarsomeres 4 and 5 darkened. Left surstylus without long setae ................................................... 7

7 Upper basal cell (br) slightly longer than lower basal cell (bm). Right surstylus broadly forked ........ pontica Chvála

- Upper basal cell (br) as long as lower basal cell (bm). Right surstylus not forked, pointed ........ bureschi Beschovski