Arna bicostata Wang, Wang & Fan

Wang, Houshuai, Wang, Min & Fan, Xiaoling, 2011, Notes on the tribe Nygmiini (Lepidoptera: Erebidae: Lymantriinae) from Nanling National Nature Reserve, with description of a new species, Zootaxa 2887, pp. 57-68 : 58

Arna bicostata Wang, Wang & Fan sp. nov.

( Figs. 3–4 , 28 , 42 )

Diagnosis. Forewing length 10–14 mm. Forewing yellow, with two pale transverse lines medially; hindwing pale yellow.

Description. Male and female. Vertex covered with pale yellow scales. Labial palpus short, upturned. Thorax and tegulae yellow. Forewing yellow, with a deep yellow band between two pale transverse lines medially, the band shaded grey in some specimens; venation with R2, R3, R4 and R5 stalked, R2 branching off more distally than R5, M1 arising from upper angle of distal cell, M3 from under angle of distal cell, M2, M3 and CuA1 isolated, CuA1 parallel to CuA2. Hindwing paler yellow; venation with Rs stalked with M1 at basal 1/4, M2 arising from near under angle of distal cell, M3 and CuA1 short stalked. Male genitalia ( Fig. 28 ): Uncus broad, apically divided in the dorso-ventral plane, triangular at apex of dorsal part; valva narrowed from apex of sacculus to costa; saccus small; aedeagus straight. Female genitalia ( Fig. 42 ): Apophysis anterioris almost as long as apophysis posterioris, but thicker than the latter; ostium U-shaped; base of ductus inflated, lightly sclerotized; signum absent.

Type material: Holotype: 3, Nanling National Nature Reserve, Guangdong, 7.V.2009, leg. H.S. Wang. Paratypes: 4 3, 2Ƥ, same data as the holotype; 2 3, same locality, 1.VI.2006, leg. L.S. Chen, M. Wang.

Distribution. China (Guangdong).

Etymology. The specific name is derived from Latin, “bicostatus,” referring to the forewing with two pale lines medially.

Remarks. The genus Arna Walker was reviewed by Holloway (1999) who reported 12 species. A Chinese species Euproctis pentamaculata described by Chao (1984) should also belong to this genus according to the male genitalia illustrated in his Fig. 230, along with A. pseudoconspersa (Strand) and the new species. As a result, 15 species of the genus are now recorded. The new species is similar to Arna bipunctapex , but can be easily separated from the latter by the following characters: forewing yellow with two pale transverse median lines; hindwing pale yellow; uncus less acute at apex of dorsal part, valva with shorter protrusion at apex of costa; female with a smaller ostium.

Figures

FIGURES 1 – 26. Adults of Nygmiini species. 1 – 2. Arna bipunctapex, 1. male, 2. female; 3 – 4. A. bicostata sp. nov., 3. male holotype, 4. female paratype; 5 – 6. Somena scintillans, 5. male, 6, female; 7 – 8. Orvasca subnotata, 7. male, 8. female; 9 – 10. Artaxa angulata comb. nov., 9. male, 10. female; 11. Euproctis sakaguchii, male; 12. A. digramma, male; 13 – 14. Toxoproctis croceola comb. nov., 13. male, 14. female; 15 – 16. Nygmia uniformis, 15. male, 16. female; 17 – 18. Euproctis montis, 17. male, 18. female; 19 – 20. E. telephanes, 19. male, 20, female; 21 – 22. E. yunnanpina, 21. male, 22, female; 23 – 24. E. piperita, 23. male, 24. female; 25 – 26. E. flavotriangulata, 25. male, 26. female. Scale bar = 2 cm.

FIGURES 27 – 34. Male genitalia of Nygmiini species. 27. Arna bipunctapex; 28. A. bicostata sp. nov.; 29. Somena scintillans; 30. Orvasca subnotata; 31. Artaxa angulata comb. nov.; 32. Euproctis sakaguchii; 33. A. digramma; 34. Toxoproctis croceola comb. nov..

FIGURES 41 – 49. Female genitalia of Nygmiini species. 41. Arna bipunctapex; 42. A. bicostata sp. nov.; 43. Somena scintillans; 44. Orvasca subnotata; 45. Artaxa angulata comb. nov.; 46. Toxoproctis croceola comb. nov.; 47. Nygmia uniformis; 48. Euproctis montis; 49. E. telephanes.