Euryobeidia yakushimensis Inoue, 1976

Liu, Bo, Stüning, Dieter & Han, Hongxiang, 2025, Further taxonomic studies of the mimetic genus Euryobeidia Fletcher, 1979 (Lepidoptera, Geometridae, Ennominae, Baptini), with descriptions of four new taxa and two status changes, ZooKeys 1260, pp. 313-343 : 313-343

Euryobeidia yakushimensis Inoue, 1976 stat. nov.

Figs 16 , 17 , 42 , 43 , 51 , 52

Euryobeidia languidata yakushimensis Inoue, 1976, Tinea 10 (2): 20. Holotype, Yakushima Isl., S. Japan ( NHMUK) [images examined].

Material examined.

Japan – Kagoshima Pref. • 1 ♂; Yakushima Island, Miyanoura, Siratani ; alt. 600 m; 18–20 Jun. 1993; M. Owada leg.; gen. prep. no. RS 7496; CRS / NIAES (shown by Sato 2011: pl. 1-015 - 12) • 1 ♀; Yakushima Island, Mt. Toimodake ; alt. 1016 m; 26 Jun. 2008; Y. Kubota leg.; gen. prep. no. RS 8879; CRS / NIAES (shown by Sato 2011: pl. 1-015 - 13) • 1 ♂; Yakushima Island, Yakusugi Land ; alt. 1000–1300 m; 12 Jul. 2008; Y. Kubota leg.; gen. prep. no. RS 7411; CRS / NIAES • 1 ♂; same locality and collector as for preceding; 16 Aug. 2009; gen. prep. no. RS 7407; CRS / NIAES • 1 ♀; same locality and collector as for preceding; 5 Jul. 2008; gen. prep. no. RS 7412; CRS / NIAES • 1 ♀; same locality and collector as for preceding; 5 Jul. 2009; gen. prep. no. RS 7808; CRS / NIAES .

Diagnosis.

This species is the only one with an almost unspotted wing pattern in the genus Euryobeidia , making it very easy to distinguish from other congeneric species. In terms of genitalia, this species is quite similar to E. languidata , indicating that they are rather closely related. However, there are still many stable differences between them, and they can be easily distinguished by the following characters: 1. Apex of the uncus is hardly dilated in E. yakushimensis , whereas it is distinctly inflated in E. languidata ; 2. Costa of the male genitalia, with a small process in the middle in E. yakushimensis , while it is smooth, without process in E. languidata ; 3. The triangular sclerite between the bases of the apophyses posteriores is distinctly narrower in E. yakushimensis than in E. languidata ; 4. Lamella postvaginalis is smaller in E. yakushimensis than in E. languidata ; 5. The spines on the posterior part of the bursa are sparser in E. yakushimensis than in E. languidata .

Redescription.

Wingspan 35–41 mm in males, 40–42 mm in females. Forewing almost entirely covered with large dark gray patches, the grayish-white ground color remaining only in narrow bands along the position of postmedial line or forming a few small, patches on discal cell or antemedial line. Hindwing similar to forewing, with a yellow marginal band intermingled with several small, dark gray transverse streaks and spots. Underside almost identical to upperside, but slightly darker. Male and female genitalia. The morphology of the genitalia is quite similar to that of Euryobeidia languidata (see description of E. languidata incrassata ), with the following different features: Uncus fine, stick-like, apex rounded, bent ventrad, dorsal apical portion barely dilated. Apical lobe-like protrusion and ventral notch of valva are more conspicuous. Costa exhibits a distinctive small protruding structure in the center. The triangular sclerite between the bases of the apophyses posteriores is narrower and the lamella postvaginalis is smaller compared to E. languidata . Basal part of apophyses anteriores weakly broadened. The spines on the posterior part of bursa are sparser than in E. languidata . Anterior part of bursa almost oval, the upper ⅔ with numerous spines inside and the lower ⅓ membranous (the membranous part is smaller in E. languidata , but probably variable in size).

Distribution.

Japan (Yakushima).

Remarks.

Sato (2011) proposed that E. languidata yakushimensis should be treated as a distinct species based on his comparative study of E. languidata languidata and E. languidata yakushimensis from Japan. In the present study, we additionally include specimens from continental China and Vietnam, as well as the new subspecies E. languidata incrassata from Hainan, in our comparative analysis. The results show that in addition to significant differences in wing pattern, there are also specific differences in male and female genitalia (see the previous diagnosis and description). We agree with Sato’s comments on E. languidata yakushimensis and elevate it to species rank.

Figures

Figures 2–19. Adults of Euryobeidia species. 2–8. E. languidata (Walker): 2. The holotype of Abraxas languidata, female, Nepal, NHMUK; 3. Female, Nepal, upperside, ZSM; 4. Ditto, underside; 5. Male, Khasi Hills, India, ZFMK; 6. Male, N. Vietnam, CKY; 7. Male, Tokyo, Japan, CRS / NIAES; 8. Female, Niigata, Japan, CRS / NIAES; 9. E. ellipsoidea, untypical pattern, female, Sichuan, China, ZFMK; 10–13. E. languidata incrassata Xiang & Han, stat. nov., Hainan Is., China: 10. The holotype of E. incrassata Xiang & Han, male, IZCAS; 11. Non-type, male, upperside, CRICATAS; 12. Ditto, underside; 13. Non-type, female, CRICATAS; 14, 15. E. supercostata sp. nov., holotype, male, Hainan, China, IZCAS: 14. Upperside; 15. Underside; 16, 17. E. yakushimensis Inoue, stat. nov., Yakushima Is., Japan: 16. The holotype of E. languidata yakushimensis Inoue, male, NHMUK; 17. Non-type, female, CRS / NIAES; 18. E. ellipsoidea, paratype, female, Sichuan, China, ZFMK; 19. E. xuei sp. nov., paratype, male, Fansipan, Vietnam, ZFMK. Scale bar: 10 mm.

Figures 38–43. Male genitalia of Euryobeidia species. 38, 39. E. languidata (Walker): 38. Fujian, China, gen. prep. no. CRICATAS 00283; 39. Tokyo, Japan, gen. prep. no. RS 8877; 40, 41. Euryobeidia languidata incrassata Xiang & Han, stat. nov., Hainan Is., China: 40. The holotype of E. incrassata Xiang & Han, IOZ-CAS slide no. Geom- 7235; 41. Non-type, gen. prep. no. CRICATAS 00220; 42, 43. E. yakushimensis Inoue, stat. nov., Yakushima Is., Japan, gen. prep. nos. RS 7407, RS 7411. Scale bars: 1 mm.

Figures 50–55. Female genitalia of Euryobeidia species. 50. E. languidata (Walker), Japan, gen. prep. no. 2460 - DS; 51, 52. E. languidata yakushimensis Inoue, Yakushima Is., Japan, gen. prep. nos. RS 7412, RS 8879; 53. Euryobeidia languidata incrassata Xiang & Han, stat. nov., Hainan Is., China, gen. prep. no. CRICATAS 00223; 54. E. tigratoides sp. nov., paratype, Hainan Is., China, gen. prep. no. CRICATAS 00244; 55. E. tigratoides leopardiformis subsp. nov., paratype, W. Hubei, China, gen. prep. no. 2450 - DS. Scale bars: 1 mm.