1. Wing with cell m 1 sessile, as in genus Nephrotoma (Alexander 1919, p 25, Pl. I, fig. 8)............................................. ..................................................................................................................................... A. parrioides (Alexander, 1919)
- Wing with cell m 1 long petiolate.................................................................................................................................. 2
2. Antenna with first flagellomere as long as second flagellomere (Alexander 1967, p 167, fig. 10).............................. ............................................................................................................................................... A. illustris (Doane, 1901)
- Antenna with first flagellomere much longer than second flagellomere...................................................................... 3
3. Tergites of abdomen with black or brown central stripe.............................................................................................. 4
- Tergites of abdomen uniform in color........................................................................................................................ 12
4. First flagellomere three times as long as scape; tergite 9 with lateral angles broadly rounded, posterior margin nearly straight (Savchenko, 1961, p 359, fig. 213)................................................................... A. rubzovi (Savchenko, 1961)
- First flagellomere subequal to scape in length; tergite 9 not as above......................................................................... 5
5. Flagellum uniform in color, brownish ochreous; R 3 curved, as in genus Holorusia (Edwards, 1926, p 51)............... .............................................................................................................................................. A. indica (Edwards, 1926)
- Flagellomeres 1–3 different from other flagellomeres in color; R 3 not curved........................................................... 6
6. Posterior margin of tergite 9 thickened, laterally expanded but not produced into process; clasper of gonostylus ventrally produced posteriorly, tip hook-like (Savchenko, 1961, p 355, fig. 211) ...... A. tumidicornis (Lundstrom, 1907)
- Characters not as above................................................................................................................................................ 7
7. Posterolateral margin of tergite 9 with a spine-like process......................................................................................... 8
- Posterolateral margin of tergite 9 without spine-like process..................................................................................... 10
8. Spine-like process on posterolateral margin of tergite 9 long; clasper of gonostylus ventrally produced into small spine-like process (Alexander, 1935, p 131, Pl. III, fig. 42; Savchenko, 1961, p 356, fig. 212)................................... ..................................................................................................................................... A. laetipennis (Alexander, 1935)
- Spine-like process on posterior margin of tergite 9 short............................................................................................. 9
9. Tergite 9 with a small obtuse process and a small spine-like process on posterolateral margin; lobe of gonostylus narrow, but distinctly narrowed at midlength (Fig. 15) ............................................................... A. biprocessa sp. nov.
- Tergite 9 with only a small spine-like process on posterolateral margin; lobe of gonostylus broad, not narrowed at midlength (Alexander, 1966, p 266, Pl. V, fig. 45) ..................................................... A. xuthoptera (Alexander, 1966)
10. Lobe of gonostylus long and narrow, the length about four and one-half times the diameter, parallel-sided, outer end narrowed and slightly curved, without protuberance on posterior margin (Alexander, 1966, p 263, Pl. V, fig. 43)..... .............................................................................................................................. A. snodgrassiana (Alexander, 1966)
- Lobe of gonostylus broad, outer end narrowed and curved, with protuberance on posterior margin....................... 11
11. Lobe of gonostylus with curved apex, posterior margin before apex with a tumid, setiferous lobe; clasper of gonostylus with beak slender and elongate, tip slightly expanded (Fig. 7)............................................... A. aspina sp. nov.
- Lobe of gonostylus with apex not curved, posterior margin just before apex slightly protuberant; clasper of gonostylus with beak stout, tip slightly expanded, broadly obtuse (Alexander, 1966, p 264, Pl. V, fig. 44)............................. ....................................................................................................................................... A. frommeri (Alexander, 1966)
12. Flagellomeres 1–3 yellow, first flagellomere three times as long as scape; tergite 9 with posterior margin gently emarginate, apex armed with two widely spaced, blackened conic processes; clasper of gonostylus with base of beak broad, ventrally with a long spine-like process, tip acuminate (Yang & Yang, 1995, p 335, fig. 4)............................. ......................................................................................................................... A. heilongjiangana Yang & Yang, 1995
- Flagellum uniform in color; first flagellomere subequal to scape in length............................................................... 13
13. Abdomen uniformly black; posterior margin of tergite 9 emarginate; lobe of gonostylus long rod-like; clasper of gonostylus medially depressed, beak long and stout (Yang & Yang, 1996, p 175, fig. 36)........................................... ............................................................................................................................... A. qinghaiensis Yang & Yang, 1996
- Characters not as above ............................................................................................................................................. 14
14. Femora dark brown except tips darker and bases slightly brightened; tergites of abdomen dark gray, lateral tergal borders narrowly paler gray; midposterior margin of tergite 9 slightly produced, more or less bilobed; lobe of gonostylus stout rod-like; clasper of gonostylus medially depressed, beak long and stout (Alexander, 1964, p 107, Pl. IV, fig. 41)....................................................................................................................... A. tokunagana (Alexander, 1964)
- Femora yellow except tips broadly blackened; tergites of abdomen dark brown, lateral tergal borders narrowly more yellowish (Alexander, 1935, p 133; male unknown) .................................................... A. altivolans (Alexander, 1935)