1 Epiphallus each side with a spine-like projection near apical margin of dorsal surface.............................................. 2
- Epiphallus without any projection near apical margin of dorsal surface...................................................................... 6
2 Ectophallus parameres cystiform at apices; epiphallus each side with a short spine-like projection near apical margin of dorsal surface............................................................................................................................................................ 3
- Ectophallus parameres unlike above; epiphallus each side with a long spine-like projection near apical margin of dorsal surface................................................................................................................................................................ 5
3 Epiphallus distinctly narrowed apically, each side with a distinct spine-like projection on dorsal surface; endophallus narrow at apex, with round apical margin..................................................................................................................... 4
- Epiphallus slightly narrowed apically, each side with an indistinct spine-like projection on dorsal surface; endophal- lus wide at apex, with bilobate apical margin ................................................................................... N. hirsuta Ingrisch
4 Epiphallus parameres unidentated at apex; rami without any projection on outer sides .......... N. tranquilla Gorochov
- Epiphallus parameres multidentated at apex; rami each with a projection near apical one-third of outer side............. .................................................................................................................................................... N. denticulata sp. nov.
5 Epiphallus each side with a spine-like projection near apex of dorsal surface; endophallus with acute apex............... ...................................................................................................................................................... N. spinosa Gorochov
- Epiphallus each side with a spine-like projection at apical one-third of dorsal surface; endophallus with broadly rounded apex ...................................................................................................................................... N. glabra Ingrisch
6 Endophallus not bifurcated at apex, ectophallus parameres short................................................................................ 7
- Endophallus bifurcated at apex, ectophallus parameres very long............................................................................... 8
7 Epiphallus narrow at base, slightly narrowed apically; endophallus short, not reaching apex of epiphallus................. ...................................................................................................................................................... N. berezini Gorochov
- Epiphallus wide at base, distinctly narrowed apically; endophallus long, extending over apex of epiphallus............. ................................................................................................................................................... N. plurilingua Ingrisch
8 Head slightly wider than anterior margin of pronotum ................................................................. N. devexa Gorochov
- Head not wider than anterior margin of pronotum....................................................................................................... 9
9 Metanotal gland with large and slightly transverse concavity ......................................................... N. ardua Gorochov
- Metanotal gland with small and round concavity..................................................................... N. parardua Gorochov