Periacma Meyrick, 1894

Wang, S. X. & Li, H. H., 2006, Review of the genus Periacma Meyrick (Lepidoptera, Oecophoridae) from China, with descriptions of four new species, Journal of Natural History 40 (41 - 43), pp. 2371-2393 : 2373-2375

Key to the Chinese species of Periacma Meyrick based on male genitalia (excluding P. isanensis Moriuti, Saito & Lewvanich )

1. Uncus somewhat trapezoidal or elongate, but not conspicuously dilated... 2 Uncus with distal portion conspicuously dilated.......... 9

2. Unucus trapezoidal.................. 3 Uncus elongate.................... 4

3. Valva nearly parallel-sided from base to distal 2/3, then gradually narrowed, dorsally with a spine at apex; aedeagus with four apex-blunted processes distally ( Figure 36 )............... spinivalvula sp. nov. Valva wide basally, narrow medially, dilated distally, without spine at apex; aedeagus with one pointed process distally ( Figure 37 )... rectignatha sp. nov.

4. Gnathos with ventral plate pointed distally; aedeagus distally divided into two longer branches................... 5 Gnathos with ventral plate concave inward or rounded anteriorly..... 6

5. Aedeagus without process in both branches ( Figure 33 )...... plumbea Aedeagus with two processes in dorsal branch and several processes in ventral branch................... acutignatha

6. Gnathos with ventral plate concave inward anteriorly........ 7 Gnathos with ventral plate rounded anteriorly........... 8

7. Aedeagus with three short processes apically......... tridentata Aedeagus with two long processes apically......... simaoensis

8. Aedeagus distally produced into two large hairy parts; valva with ventral margin projected outward at about 3/5............ equivalvata Aedeagus distally pointed, not divided into two parts; valva with ventral margin gently arched.................. ferialia

9. Uncus with one or two small tooth-like processes caudally...... 10 Uncus without such process............... 13

10. Uncus with one small tooth-like process caudally; sacculus without distal process................... acriuncata Uncus with two processes caudally; sacculus with distinct distal process.. 11

11. Gnathos with anterior margin slightly concave at middle; sacculus with ventral margin smooth dorsally............... novella Gnathos with anterior margin rounded; sacculus with ventral margin toothed dorsally..................... 12

12. Aedeagus with two pointed processes at apex........ sacculidens Aedeagus with a spiniform process medially........ qujingensis

13. Gnathos with ventral plate spinulate in anterior portion....... 14 Gnathos with ventral plate not spinulate........... 23

14. Gnathos with ventral plate not roundly dilated......... 15 Gnathos with ventral plate roundly dilated........... 17

15. Gnathos with anterior margin concave at middle; sacculus without any process.................... siamensis Gnathos with anterior margin rounded; sacculus with processes distally.. 16

16. Aedeagus distally produced into two processes...... angkhangensis Aedeagus distally rounded, not produced into distinct processes... weishana

17. Sacculus with distal process............... 18 Sacculus without distal process.............. 20

18. Valva expanded distally; aedeagus laterally with process at about middle.. 19 Valva parallel-sided in distal 3/5; aedeagus without process at middle... sinica

19. Uncus with caudal margin rounded; aedeagus with several minute tooth-like spines in medial portion............ iodesma vienamica Uncus with caudal margin somewhat straight; aedeagus without tooth-like spines in medial portion................. iodesma

20. Uncus projected caudally................ 21 Uncus blunt caudally................. 22

21. Gnathos with anterior margin blunt; sacculus with apex truncate... absaccula Gnathos with anterior margin rounded; sacculus with apex curved upward ( Figure 35 )................ latizona sp. nov.

22. Sacculus dorsally with a small process at apex directing upward; aedeagus with basal portion narrowed ( Figure 34 ).......... leyensis sp. nov. Sacculus dorsally without process at apex; aedeagus with basal portion about same thickness as remainder............... orthiodes

23. Gnathos with ventral plate broad and somewhat semicircular..... 24 Gnathos with ventral plate narrow, extended outward laterally..... 27

24. Valva with dorso-proximal process short and hairy, somewhat rounded.. 25 Valva with dorso-proximal process long, roundly dilated distally.... 26

25. Sacculus distally expanded; aedeagus with three pointed, spine-shaped processes apically................... immaculata Sacculus distally pointed; aedeagus without process apically..... delegata

26. Sacculus with distal portion bifurcate; aedeagus irregularly triangular.. bifurcata Sacculus with distal portion gradually narrowed; aedeagus somewhat long, distally with one side dentate............... tianshuiensis

27. Costa with a digitate process at basal 1/5........ binchuanensis Costa without any process............... 28

28. Sacculus with a process near end dorsally........... 29 Sacculus without process dorsally............. 30

29. Aedeagus with a band-like process at middle, apex serrate.... ziyangensis Aedeagus with a small process near apex, apex pointed..... zhouzhiensis

30. Gnathos with ventral plate straight anteriorly; valva with dorso-proximal process distally dilated................. fengxianensis Gnathos with ventral plate arched anteriorly; valva with dorso-proximal process not obviously dilated distally............ kangdingensis

Figures

Figures 33–37. Male genitalia of Periacma spp. (33) P. plumbea Meyrick; (34) P. leyensis Wang & Li, sp. n.; (35) P. latizona Wang & Li, sp. n.; (36) P. spinivalvula Wang & Li, sp. n.; (37) P. rectignatha Wang & Li, sp. n.