Metaterpna batangensis Han & Stüning, 2016

Jiang, Nan, Stüning, Dieter, Xue, Dayong & Han, Hongxiang, 2016, Revision of the genus Metaterpna Yazaki, 1992 (Lepidoptera, Geometridae, Geometrinae), with description of a new species from China, Zootaxa 4200 (4), pp. 501-514 : 509-512

Metaterpna batangensis Han & Stüning , sp. nov.

Figs 10–17 , 21 –22, 25, 29, 33–34, 39

Description. Head. Antenna of male with basal three-fourths bipectinate, with short, rather narrow rami (longest rami about two times the diameter of flagellomer), simple filiform in terminal one-fourth. Antenna filiform in female, shape of flagellomers as in thyatiraria ; frons rough-scaled (with narrow, elongated, obliquely upright scales), pale to dark brown (dark olive brown in one specimen from Echu, Sichuan), with blackish lateral sides, often with dark scales arranged as a vague transverse band in upper third, upper margin white. Vertex rough-scaled, with larger, olive green or brown scales, mixed with a few black or dark brown scales. Labial palpus reaching beyond frons, dark grey or black on second and third segment, basal segment lighter, decorated with pink and black; second segment with long hair-scales, almost concealing the third segment; length of the latter about one third of second segment in male, about three-fourths in female.

Thorax. Dorsally black or brown, covered with narrow, elongated scales and hair-scales, a crest of differently modified, curled scales developed on metathorax. Ventral side of thorax and femora of legs with whitish hairscales, with pink scales on prothorax. Legs otherwise dark grey, tarsi ringed. Hind tibia in male light brown, not dilated, without hair-pencil, both sexes with two pairs of spurs.

Forewing length: 6 19–22 mm, ♀ 23mm. Fore- and hind wings with outer margin wavy. Forewing dull yellowish green mixed with dark brown; apex blunt; basal, antemedial and postmedial lines black; basal line indistinct, oblique and rather straight anteriorly, becoming a little broader at costa, extended to a short streak basally on vein A1+2; antemedial line slightly curved outwards near costa and in cell, shallowly arched above vein A1+2, then bent outwards to inner margin; medial line absent, the discocellular lines are narrow, black streaks, angled anteriorly; postmedial line dentate, starting from distal one-fourth of costa, then bent inwards to M3, forming large teeth on M3, CuA1 and CuA2, deeply bent inwards between CuA2 and A1+2. Submarginal line white, wavy or dentate between costa and M2, and indistinct below M2; a dull brownish pink or rarely whitish pink subapical patch present between submarginal and postmedial lines above M2, and another similar patch between CuA2 and the subtornal area. Hind wing with a large, whitish basal area; postmedial line narrow, greyish black, dentate, only visible below vein M2, curved inwards between M2 and tornus, often interrupted (indistinct in the specimens from Zhongdui, and Batang, which have a broad, band-like submarginal line, the latter otherwise narrow, smooth, evenly curved between apex and tornus); area distal to submarginal line suffused with dark brown scales. Terminal line on both wings black, wavy; fringe brown, mixed with dark grey. Underside: transverse lines similar to those on upperside, but postmedial line on forewing broader, not clearly defined, running more proximally; forewing otherwise greyish brown, with a large, basal part paler; hind wing with large basal part white, area outside submarginal line suffused with grey, but paler than on upperside.

Abdomen. Dorsally dark brown, mixed with light brown or olive scales, crests developed medially on segments 2-6 (crests on segments two and six small, the largest on segment three). A white dorsal patch on first tergite present. Ventral side of abdomen whitish.

Male genitalia. Uncus stout and short, apex with a pair of diverging processes, both with a truncate tip; cleft on the base of the processes absent, only with a trace of spines. Socii tapered, with dorsal margin almost straight. Gnathos small, with medial region slightly expanded, with little dentation only; lateral arms of gnathos, besides the small basal lobe near the uncus base, with another long, more ventral process. Valva broad, distally tapered, with a blunt and narrow apex; costa strongly convex, with basal lobe strong, stout, almost completely spinose; sacculus distinct and rounded at apex, with a membranous, densely setose lobe near base of valva . Transtilla consisting of a pair of lightly sclerotized, long and narrow processes, arising dorsally from the valve bases (hemitranstillae). Saccus protruding and rounded. Coremata absent. Aedeagus slender, with a long and narrow, pointed apical process.

Female genitalia. Ovipositor with papillae anales modified in shape, strongly sclerotized, tips rounded posteriorly and sharply angled anteriorly, central part deeply incurved and wrinkled on the inner margin. Length of apophyses posteriores about four times the length of the extremely short apophyses anteriores. Lamella postvaginalis a pair of short triangular processes, with a round, not very strongly sclerotized lobe in the middle. Ductus bursae narrow, corpus bursae pyriform, both membranous; signum absent.

Diagnosis. Regarding the wing pattern, M. batangensis is close to M. thyatiraria , also having clear subapical and tornal patches on forewing. M. batangensis has, however, much darker and smaller (oval), dull pinkish brown or pinkish white patches, which are always pinkish white and rounded in the latter. In addition, the submarginal lines on the hind wings are broader than those of M. thyatiraria . In the male genitalia, M. batangensis also has distinctive characters, e.g., the uncus of M. batangensis is much broader and shorter than that of M. thyatiraria , the diverging processes are much longer and have truncate ends, and a dorsal cleft between them is absent. Another distinctive character of M. batangensis lies in the quite shorter gnathos, possessing a long, ventral process on the lateral arms, which is much longer than the basal lobe close to the uncus base, while in M. thyatiraria the lateral arms have a smaller ventral process or a trace of a process, or they are only slightly expanded, and if a process is present, it is never longer than the basal lobe close to the uncus. In the female genitalia, M. batangensis has the ovipositor lobes more strongly wrinkled than that of M. thyatiraria on the inner margin and a distinctly different shape (see figs 36, 39).

Type-material examined. Holotype, 6 ( ZFMK), CHINA: Batang (Tibet), Untere Urwaldzone (Ca. 3800 m), 22.IX.1936, H. Höne.

Paratypes: China: Sichuan: 7 6 ( ZFMK), Batang (Tibet), Untere Urwaldzone (Ca. 3800 m), 2.IX., 17.IX. (2 males; including genitalia prep. No. 2299-DS), 26.IX., 27.IX., 3.X. (genitalia prep. No. 2298-DS), 5.X.1936, H. Höne; 1 6 ( BMNH), Batang (Tibet), Untere Urwaldzone (Ca. 3800 m), 6.X.1936, H. Höne; 1 6 1♀ ( IZCAS) , Sichuan Batang Yidun, 3350–3370 m, 16.VIII.1982, leg. Zhang Xuezhong ; 2 6 ( IZCAS), Sichuan Daocheng Zhongdui, 3290 m, 25.VII.2014, leg. Li Xinxin and Pan Xiaodan ; 4 6 ( IZCAS), Sichuan Daocheng Echu, 2880 m, 24.VII.2014, leg. Li Xinxin and Pan Xiaodan . Yunnan ( IZCAS): 1 6, Lijiang Yuhu , 2768 m, 11.VII.2014, leg. Li Xinxin and Pan Xiaodan ; 1 6, Lijiang Yuhu , 2700 m, 27.VII.1984, leg. Liu Dajun .

Remarks. The forewing subapical and tornal patches are dull brown pink in seven specimens from Batang, three specimens from Echu and two specimens from Zhongdui, and pinkish white as in M. thyatiraria in two specimens from Yidun, one specimen from Echu, one specimen from Yuhu, and two specimens from Batang. The width of hind wing submarginal line is variable, e.g., it is wide and band-like in a part of specimens from Batang and two specimens from Zhongdui, but very narrow in other specimens from Batang and Echu, and that of the specimen from Yuhu is moderately wide. In consideration of the fact that even the specimens from the same locality (such as Batang and Echu) have above external variations, that they all have the same genitalia, and that the NJ tree clustered them together as one species, we consider all these variations as intraspecific.

Etymology. The new species is named after the type locality.

Distribution. China (Sichuan, Yunnan). All the type specimens of M. batangensis were collected in a rather small area, the distance between the southernmost (Yuhu, Yunnan) and the northernmost locality (Batang, Sichuan) being less than 700 km.

Figures

FIGURES 2 – 17. Moth of Metaterpna. 2 – 4. M. differens. 2, ♁, holotype, BMNH, upperside; 3, underside; 4, female, ZFMK; 5 – 9. M. thyatiraria. 5, ♁, holotype, from Tsekou, Yunnan, BMNH; 6, ♁, from Likiang, Yunnan, ZFMK; 7, ♀, from Taibaishan, Shaanxi, IZCAS; 8, ♁, from Wolong, Sichuan, ZFMK; 9, ditto, underside; 10 – 17. M. batangensis sp. nov. 10, ♁, holotype, upperside, from Batang, ZFMK; 11, ditto, underside; 12, ♁, paratype, from Batang, ZFMK; 13, ♁, paratype, from Zhongdui, IZCAS; 14, ♁, paratype, from Echu, IZCAS; 15, ♁, paratype, from Echu, underside, IZCAS; 16, ♁, paratype, from Yuhu, IZCAS; 17, ♀, from Batang, IZCAS. Scale bar = 1 cm.

FIGURES 18 – 21. Male genitalia of Metaterpna. 18, M. differens; 19 – 20. M. thyatiraria. 19, from Yunnan; 20, from Liziba, Gansu; 21 – 22. M. batangensis sp. nov. 21, paratype, from Batang, IZCAS; 22, paratype, from Echu, IZCAS. FIGURES 23 – 25. Aedeagus of Metaterpna. 23, M. differens; 24, M. thyatiraria; 25, M. batangensis sp. nov. Scale bars = 1 mm.