Euryobeidia xuei Liu, Stüning & Han, 2025

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 xuei Liu, Stüning & Han sp. nov.

Figs 19 , 45 , 58

Type material.

Holotype. Vietnam – • ♂; North Vietnam, Cha-pa, Mt. Fan-si-pan; 22 ° 15 ' N, 103 ° 46 ' E; 1500–1800 m; 10 Jun. – 6 Jul. 1994; leg. V. Sinjaev & einh. Sammler; lux ( light trap); gen. prep. no. 2458 - DS; ZFMK . Paratype. Vietnam – • 1 ♂; same collection data as for holotype; ZFMK .

Additional material examined.

China – Yunnan Province • 1 ♂; Yuxi, Zhenyuan, Qianjiazhai , Ailaoshan ; 24.277 ° N, 101.264 ° E; 2200 m; 5 Aug. 2011; Kitching & Ashton leg.; KIZCAS, ARB 00027908 • 1 ♂ or ♀ (image only); Diqing, Weixi ; 27.358805 ° N, 98.965343 ° E; 2720 m; 01 Aug. 2024; Photographed by Fan Gao .

Diagnosis.

Euryobeidia xuei is generally similar to E. languidata ( Walker, 1862) in habitus, pattern, coloration and size, but can be distinguished from the latter on the basis of the shorter, less elongate wings, with apex and tornus more rounded and the compact, partly fused, very dark basal spotting, and a large, nearly fully fused, black discal spot forming a triangular shape in forewing which renders it more similar to E. ellipsoidea Xiang & Han, 2017 . It differs from the latter and also from languidata by the complete or almost complete absence of a large spot or a dense group of smaller spots in the middle of the hind margin of the forewing. This feature that rarely occurs in other species and the extreme reduction of spots in the hindwings are distinctive for E. xuei .

The structure of the male genitalia is quite similar to that of E. ellipsoidea , especially the shape of valva and the presence of a large, plate-like structure of the uncus, which indicates a rather close relationship of the two taxa. Distinguishing characters are the round, apical lobes of the valve costa which is markedly larger in xuei and the stalk connecting the central, beak-shaped part of uncus and the large dorsal plate is longer and narrower, the plate itself has a different shape. Moreover, the 3 % genetic distance based on molecular data separates this taxon from E. ellipsoidea , justifying its recognition as a distinct, but closely related species.

Description.

Forewing length 19–21 mm in males. Similar to E. languidata , but wing-shape different: wings shorter, broader, apex and tornus of forewing and hindwing more rounded.

Head. Antennae filiform, agreeing with generic description, shaft dorsally covered with silvery-gray scales. Labial palpus dark gray, with a few yellow scales at base of first segment, the latter with moderately long, obliquely upright scales. Second joint rather smooth, third joint very small, tapering. Frons narrow, covered with dark brownish-gray scales, those on dorsal ½ smooth, slightly elongated, basal ½ with a brush of more strongly elongated scales, covering a small, rounded protrusion of the integument. Vertex small, consisting of large, dark gray, obliquely upright scales, forming a triangle. Posterior of it and around the head runs a conspicuous, yellow collar. Chaetosemata present, near eye-margin, consisting of a few sensillae only. Thorax. Dorsum as described in the generic description, anteriorly yellow, posteriorly grayish yellow, with two very large, almost black spots behind each other. Patagia yellow with large, dark gray spots, tegulae with a yellow transverse band, a basal dark gray spot and a second spot and lighter gray hair-scales posteriorly. Legs yellow and yellowish gray, with some black dots. Tibia of hind-leg not dilated, without scent pencil. Wings with ground color clear white. Pattern of very dark, rather large, round spots, compact and partly fused near base of forewing. The more internal dots are suffused with brown scales, while the large apical patch and narrow bands along costa and anterior ⅔ of termen are dark silvery gray. A large spot in the middle of the hind margin absent, resulting in a broad, white band stretching obliquely through the forewing from near apex to hind margin. This seems to be the most obvious distinguishing element and is present in all known specimens. There are small yellow streaks near tornus. Fringe almost entirely black. Spots on hindwing reduced in size or absent, rendering the white area the largest of all species. Discal dot round, rather large. Base of hindwing with a group of very small dots. Yellow band along hindwing termen narrow, only sparsely dotted, fringe yellow with black, almost round dots. Underside with pattern very similar, but much paler. Venation agreeing with generic description, except that CuP is represented by a very faint fold, without a weakly sclerotized basal portion. Pregenital abdomen. Ground color of proximal ¾ of dorsal side pale yellowish gray, distal ¼ deeply yellow. All tergites with spots or patches of different sizes, shapes, and colors: T 1 pale gray, with a deep incision proximally in the middle. Spots from T 2 to T 8 almost black. T 2, T 3 smaller, almost semicircular, T 4 - T 6 rectangular, transverse bands (T 6 smaller), T 7 a very small spot, T 8 a pair of rather large, quadrate patches (see Figs 19 , 58 ). Laterally a row of black, irregular spots, decreasing in size towards tip of abdomen. Lateral and ventral sides deep yellow, with moderately elongated scales and irregularly distributed black spots of different size and shape. Shape and number of these spots is due to ample variation. Integument without distinct variations, tergite 8 narrowly rectangular, sternite 8 much larger, laterally and distally rounded. Tympanal organs of moderate size, shallow, without lacinia. Setal comb on sternite 3 and sterno-tympanal process absent. Tergal phragma T 1 / T 2 long, strap-like.

Male genitalia. Uncus with a central, beak-shaped part, carried by a long and narrow “ neck ” which combines it with the forked base and the semicircular connection with the tegumen. From the central part, a long and narrow, spined stalk arises which supports a large plate of unknown function. It is rounded posteriorly and tapering to a slightly narrower end anteriorly (Fig. 45 ). The gnathos consists of tiny, sclerotized lateral arms, which are widely separated from each other. Valves long and narrow, with the costa smooth, slightly protruding on both sides. Apex of valva strongly curved back, with a large, round, transparent, sclerotized plate (but hardly visible). Sacculus with a large, oval, basal plate, its margin irregularly indented and covered with minute spines. Aedeagus moderately long, the sclerotized distal ½ flat and terminating with a short spine at the rather broad apex. Vesica with two cornuti of different shape which are fused at one end.

Female. Unknown.

Distribution.

Vietnam, China ( Yunnan).

Etymology.

The specific epithet is honoring the renowned Chinese taxonomist Prof. Dayong Xue for his outstanding contributions to the study of Geometridae .

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 44–49. Male genitalia of Euryobeidia species. 44. E. supercostata sp. nov., holotype, Hainan, China, IOZ-CAS slide no. Geom- 4140; 45. E. xuei sp. nov., holotype, male, Fansipan, Vietnam, gen. prep. no. 2458 - DS; 46, 47. E. tigratoides sp. nov., paratypes, Hainan Is., China, gen. prep. nos. CRICATAS 00247, CRICATAS 00243; 48, 49. E. tigratoides leopardiformis subsp. nov.: 48. Holotype, Sichuan, China, IOZ-CAS slide no. Geom- 04555: 49. Paratype, W. Hubei, China, gen. prep. no. 2449 - DS. Scale bars: 1 mm.

Figures 56–64. Living imagos of Euryobeidia species in resting position. 56. E. languidata (Walker), Fujian, China; 57. E. languidata incrassata Xiang & Han, stat. nov., Hainan, China; 58. E. xuei sp. nov., Yunnan, China; 59. E. largeteaui (Oberthür), Guizhou, China; 60. E. quadrata Xiang & Han, Hong Kong, China; 61. E. quadrata Xiang & Han, Anhui, China; 62. E. tigratoides leopardiformis subsp. nov. or E. largeteaui, Guangdong, China; 63. E. tigratoides sp. nov., male, Hainan, China; 64. E. tigratoides sp. nov., female, Hainan, China.