Metaterpna differens ( Warren, 1909 )

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 : 504-507

Metaterpna differens ( Warren, 1909)

Figs 2–4 , 18 , 23, 35

Terpna differens Warren, 1909 , Novit. zool. 16: 124. Holotype ♁, India (north): Kulu district. (BMNH) Metaterpna differens: Yazaki, 1992 , Tinea 13 (Suppl. 2): 8, pl. 3: 7.

Description. Head. Antenna in male shortly bipectinate, longest rami two to three times as long as shaft diameter of antenna, about 20 apical segments without pectination; female antenna slightly serrate in ventral view, flagellomers setose. Frons rather smooth-scaled, greyish-white, suffused with darker grey and black scales, the latter sometimes arranged band-like in upper half, lateral margins black; upper margin and vertex covered with larger, obliquely upright scales, white with a slight brownish or rarely greenish tinge. Labial palpus greyish-white, more or less suffused with dark grey or black scales, third segment rather short in male, considerably longer in female.

Thorax. Dorsal side covered with elongated or hair-like scales, darker than vertex, coloured greenish to blackish brown, mixed with greyish-white, with a distinct crest developed on metathorax; ventral side of thorax, including femora of legs, covered with long whitish hair-scales. Remaining parts of legs darker brownish-white, ringed black. Hind tibia in male not dilated, without hair-pencil, both sexes with two pairs of spurs.

Forewing length: 6 18–20 mm; ♀ 22–23 mm. Fore- and hind wings with outer margin slightly wavy. Forewing greenish-brown (dark brown mixed with yellowish green and a little pink, especially around transverse lines); apex blunt; basal, antemedial and postmedial lines black; basal line broken, extended to a short black streak on vein A1+2 basally; antemedial line oblique, often with small teeth on veins; postmedial line dentate and angled, starting from distal one-fourth of costa, then curved inwards to M3, forming large teeth on M3, CuA1 and CuA2, then deeply incurved to hind margin near dorsum; marginal area outside postmedial line with a diffuse, dull pinkish, subapical patch below M3, with dark brown (mixed with little dull pink) patches between veins; submarginal line often indistinct, whitish and dentate, when visible. Hind wing greyish, suffused with black scales until postmedial line, the latter narrow, black and dentate on veins, rather indistinct near costa; a second, broader, smooth line, probably the submarginal line, is running from apex to tornus of hindwing, touching the postmedial line at anterior half, but running distally of the latter between M3 and tornus, here often modified tooth-like; area outside postmedial line yellow-green suffused with black scales or shortly striated. Both wings with slender, streak-like, curved discal spots on both, upper and undersides (more strongly curved on forewing, less distinct on underside); marginal line black, slightly expanded between veins; fringe dark brown, much darker on vein ends. Underside: forewing much lighter grey than upperside up to postmedial line, the latter diffuse, broadened, without distinct teeth, its course not exactly following that on upperside; submarginal area more or less strongly suffused with black scales; hind wing completely paler than upperside, greyish-white, but submarginal line distinctly darker than on upperside, smoothly curved.

Abdomen. Dorsal side greyish to blackish brown, with crests of modified scales developed on segments 2-6 (crest on tergite 2 consisting of two smaller groups of scales); ventral side whitish, with a tuft of white hair-scales on sternite 1+2.

Male genitalia. Uncus stout, with apex slightly bifid, pointed. Socii with basal two-thirds broad, tapering apically. Gnathos with median region expanded, tongue-like and finely dentate; lateral arms irregularly expanded and strongly developed; basal lobe near uncus base indistinct. Valva broad at middle, tapering distally, apex blunt; costa convex and curved, strongly sclerotized, with a small, smooth lobe near base; sacculus a strongly sclerotized, rounded lobe, its posterior margin decorated with a row of long setae, medially with a curved ventral ridge forming a shallow pocket. Coremata absent. Transtilla developed as a pair of lightly sclerotized, narrow arms. Saccus projecting and rounded. Aedeagus slender, with a long, narrow, pointed apical process, vesica without cornuti.

Female genitalia. Ovipositor lobes modified, strongly sclerotized, irregularly papillate. Apophyses posteriores about 1.5 times the length of apophyses anteriores. Lamella postvaginalis well-defined, ovally rounded, with transverse corrugations; lamella antevaginalis not clearly defined, only slightly sclerotized. Ductus bursae narrow and short. Corpus bursae long, more than twice the length of ductus bursae; signum absent.

Diagnosis. M. differens can be distinguished from M. thyatiraria and M. batangensis on both, external and internal characters. Regarding wing pattern, the forewing postmedial line of M. differens is less concave below CuA2, and almost lacks the pinkish white or reddish brown patch near tornus present in M. thyatiraria and M. batangensis , and the forewing subapical patch is dull pinkish, not pinkish white as it is in M. thyatiraria .

In the male genitalia of M. differens the uncus is only slightly concave apically, while the other two species possess a pair of long, diverging processes. In addition, the basal lobe on the valve costa of M. differens is shorter, stouter and not spined, compared to the other two species. Moreover, a distinct process arising from the lateral arms of gnathos is lacking in M. differens .

In the female genitalia the ovipositor lobe has a different shape compared to the other two species. It has an irregular appearance and is strongly papillate which is not the case in M. thyatiraria and M. batangensis . Moreover, the sterigma is less sclerotized, lamella post-and antevaginalis are of a different shape, the bursa copulatrix is larger and more elongated and the ductus bursae shorter.

Type-material examined. Holotype 6 ( BMNH), Kulu distr. , Chas. Maries, Rothschild Bequest B.M. 1939-1 ( INDIA).

Additional material examined: CHINA ( IZCAS): Tibet: 3 6 , Tibet: Gyirong , 23–26.VI.1984, leg. Yan Zhaoxing . INDIA: 1 6 ( BMNH), Mussoorie, J.C.M. Gardner, 26.VI.1928, L.B. Prout Coll. B.M.1939-643 (figd Seitz Supp. IV. t. 6g); 1 6 ( BMNH), Mussoorie, J.C.M. Gardner, 13.VI.1926, Brit. Mus. 1928-402; 2♀ ( BMNH) , India Simla, 7000 ft, A.E. Jones, B.M, 1931-101; 1 6 ( ZFMK), Mussoorie, J.C.M. Gardner . 30.VI.1928, L.B. Prout Coll. B.M. 1939-643, ex B.M.; 2 6 1♀ (ZFMK), N-Indien, Uttar Pradesh Kumaon Himalaya Distr. Nainital Bhimtal, 1500 m, 15–30.V.1990, coll. A. Hauenstein, Museum A . Koenig Eing. Nr. 91/299; 1 6 ( ZFMK), same locality and date, H. Speidel leg., Museum A. Koenig Eing. Nr. 91/327 . NEPAL: 2 6 ( BMNH), Annapurna Himal, Thini , 1 km S Jomsom, 3000 m, 83˚44′E, 28˚46′N, 8.VII.1995, leg. G. Csorba, Gy . M.László and G.Ronkay, BMNH (E) 1999-98; 1 6 ( ZFMK), Kathmandu, Godavari 1600 m, 21.VI.1992, T. Haruta et al., Museum A. Koenig Eing. Nr. 93/383; 1 6 ( ZFMK), ibidem, 17.VI.1992; 1 6 ( ZFMK), Ganesh Himal., Syabrubesi , 1520 m, 12.VI.1993, leg. M. Hreblay, G. Csorba, Museum A. Koenig Eing. Nr. 94/415, genitalia prep. No. 2291-DS; 1 6 ( ZSM), Kathmandu Valley , Godavari , 1600–1800 m, 8.VI.1967, leg. Dierl-Forster-Schacht.

Distribution. China (Tibet), India (North), Nepal.

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.