Key to species of Ypsolopha mucronella -group based on external characters

1. Forewing lanceolate, with four ocherous brown lines (Fig. 38)........................................... Y. longa

- Forewing not lanceolate, without ocherous brown lines...................................................... 2

2. Forewing with a streak at middle........................................................................ 3

- Forewing without streak at middle....................................................................... 6

3. Streak on forewing dark brown, broadened and darkened from base to apex (Fig. 37)................... Y. nigrofasciata

- Streak on forewing light-coloured, not broadened or darkened to apex.......................................... 4

4. Streak on forewing extending from base to middle (Fig. 34)......................................... Y. albistriata

- Streak on forewing extending from base to apex............................................................ 5

5. Streak on forewing yellowish white, not well-defined (Fig. 35)......................................... Y. strigosa

- Streak on forewing white, well-defined (Fig. 36).......................................... Y. paristrigosa sp. nov.

6. Forewing with streak on costa.......................................................................... 7

- Forewing without streak on costa....................................................................... 11

7. Streak on costa golden yellow.......................................................................... 8

- Streak on costa white................................................................................ 10

8. Streak on costa narrow, longer than half length of forewing................................................... 9

- Streak on costa wide, shorter than half length of forewing (Ponomarenko & Zinchenko 2013: Fig. 2)........ Y. costibasella

9. White stripe below fold extending to below apex (Fig. 42)........................................... Y. ulingensis

- White stripe below fold extending to 2/3 of fold (Fig. 47)..................................... Y. triangula sp. nov.

10. Streak extending to 1/2 length, fold with a black dot at middle (Fig. 40)........................... Y. umbrina sp. nov.

- Streak extending to distal 1/5, fold without dot (Fig. 39)................................................ Y. saitoi

11. Forewing with pale streak along dorsum................................................................. 12

- Forewing without pale streak along dorsum.............................................................. 16

12. Forewing with black dot below fold.................................................................... 13

- Forewing without dot below fold....................................................................... 15

13. Head, thorax and dorsum of forewing white (Fig. 44)......................................... Y. capitalba sp. nov.

- Head, thorax and dorsum of forewing not white........................................................... 14

14. Forewing with a short white line at end of cell (Fig. 46)............................................... Y. falcella

- Forewing without such a line as above (Fig. 45)..................................................... Y. yasudai

15. Head, thorax and dorsum of forewing yellowish white (Fig. 41)........................................ Y. dentella

- Head, thorax and dorsum of forewing gray or pale grayish brown (Fig. 43)...................... Y. varidentella sp. nov.

16. Forewing golden yellow, without strips along veins (Fig. 48)...................................... Y. aurea sp. nov.

- Forewing not golden yellow, with strip along veins........................................................ 17

17. Forewing with white strips along veins.................................................................. 18

- Forewing with brown strips along veins................................................................. 20

18. Forewing pale green, with a black patch below middle of fold (Fig. 50)........................... Y. chlorina sp. nov.

- Forewing not pale green, with a small black dot below middle of fold......................................... 19

19. Cell of forewing with black dot at middle on upper margin and at end respectively (Fig. 52)............ Y. bisticta sp. nov.

- Forewing without such dots as above (Fig. 49)..................................................... Y. blandella

20. Forewing with a large triangular black patch at end of cell (Fig. 53), CuA1 and CuA2 stalked (Fig. 102)........... Y. diana

- Forewing with a small black dot at end of cell (Fig. 51), CuA1 and CuA2 separated (Fig. 100)............... Y. nemorella