Key to species of the degeerella group in China based on external characters and male genitalia
1. Hindwing with a yellow spot at apex of CuA 2 (Caradja 1927: 63)..................................... N. syfaniella
- Hindwing without yellow spot.......................................................................... 2
2. Forewing with fascia separated.......................................................................... 3
- Forewing with fascia not separated....................................................................... 4
3. Forewing with black dots beyond outer fascia posteriorly (Fig. 22)............................ N. seorsifascia sp. nov.
- Forewing without black dot beyond outer fascia (Caradja 1927: 64).................................. N. disjunctella
4. Forewing with V-shaped pattern from beyond outer fascia to apex.............................................. 5
- Forewing without V-shaped pattern from beyond outer fascia to apex............................................ 6
5. Forewing with a streak along anterior margin of cell curved apically (Figs 20, 21)............... N. recurvatifera sp. nov.
- Forewing with a straight streak along anterior margin of cell (Küppers 1980: 277, fig. 78)............................................................................................................... N. ochsenheimerella
6. Forewing with four yellow stripes beyond middle of outer fascia (Fig. 14)............................. N. karafutonis
- Forewing without yellow stripes beyond middle of outer fascia................................................ 7
7. Forewing with a distally forked stripe from beyond outer fascia to apex (Fig. 5)................ N. bifurcifascia sp. nov.
- Forewing without forked stripe from beyond outer fascia to apex............................................... 8
8. Phallus with sclerotized belt............................................................................ 9
- Phallus without sclerotized belt......................................................................... 18
9. Juxta borne at middle of phallus, stalk swollen (Fig. 46)......................................... N. staudingerella
- Juxta borne near apex of phallus, stalk not swollen......................................................... 10
10. Tegumen with plate.................................................................................. 11
- Tegumen without plate............................................................................... 14
11. Transtilla broad rectangular; uncus reniform (Fig. 39).................................... N. latirectangula sp. nov.
- Transtilla narrowly banded; uncus not reniform............................................................ 12
12. Valva fused for basal 1/4; phallus without denticles (Fig. 35)............................ N. gaoligongshana sp. nov.
- Valva separated basally; phallus with denticles............................................................. 13
13. Valva rounded at apex, slightly sinuate on ventral margin (Fig. 41).......................... N. purpuratifera sp. nov.
- Valva pointed at apex, obliquely straight on ventral margin (Fig. 32)............................. N. borealis sp. nov.
14. Valva with three longitudinal ridges on ventral surface; phallus with two processes (Fig. 47)........... N. triuga sp. nov.
- Valva without longitudinal ridge on ventral surface; phallus without process..................................... 15
15. Valva with two triangular processes at basal 1/3 on ventral margin; transtilla with median process short digitate (Fig. 29).............................................................................................. N. augites
- Valva without triangular processes on ventral margin; transtilla with median process not digitate..................... 16
16. Tegumen with a median ridge (Fig. 38).......................................................... N. lapikella
- Tegumen without median ridge......................................................................... 17
17. Valva obliquely straight from basal 1/4 to middle on ventral margin; vesica with belts of short spines (Fig. 45)............................................................................................ N. spinatibaltea sp. nov.
- Valva vertically straight from basal 1/4 to middle on ventral margin; vesica without belts of short spines (Fig. 33)................................................................................................. N. chalybeella
18. Valva fused basally.................................................................................. 19
- Valva separated basally............................................................................... 23
19. Valva spatulate; vesica with two rows of spines (Hirowatari 2005: 323, fig. 8).......................... N. polychorda
- Valva not spatulate; vesica without spines................................................................ 20
20. Uncus triangular.................................................................................... 21
- Uncus not triangular................................................................................. 22
21. Phallus with a banded and two equally narrow processes (Fig. 31)............................. N. biprocessa sp. nov.
- Phallus without process (Fig. 42)....................................................... N. ravidifera sp. nov.
22. Phallus with a belt of short spines; sacculus subtriangular (Fig. 40)......................... N. parvaprocessa sp. nov.
- Phallus without belt of short spines; sacculus not subtriangular (Fig. 27)................................ N. amatella
23. Vinculum produced posteromedially; sacculus rectangular (Fig. 28)......................... N. apiciprocessa sp. nov.
- Vinculum not produced posteromedially; sacculus not rectangular............................................. 24
24. Sacculus reaching near apex of ventral margin; valva digitate (Fig. 34)......................... N. digitivalva sp. nov.
- Sacculus reaching basal 1/5 of ventral margin; valva subtriangular (Fig. 36)............................. N. japonica