Metaterpna thyatiraria ( Oberthür, 1913 ), Oberthur, 1913

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 : 507-509

Metaterpna thyatiraria ( Oberthür, 1913)

Figs 5–9 , 19–20 , 24, 26–28, 30–32, 36–38

Hypochroma thyatiraria Oberthür, 1913 , Études Lépid. comp. 7: 290, pl. 173, fig. 1703. Holotype ♁, [China]: Tse-kou. (BMNH)

Dindica thyatiroides Sterneck, 1928 , Dt. ent. Z. Iris 42: 134. Syntypes 2 ♁, 1♀, [ China]: Tachien-lu [ Kangding ]. Synonymized by Sterneck (l.c.: 242) with D. thyatiaria [sic] Obth., 1913.

Metaterpna thyatiraria: Yazaki, 1992 , Tinea 13 (Suppl. 2): 8.

Description. Head. Antenna of male with basal three-fourths bipectinate, with short, rather stout rami (longest rami about two times the diameter of a flagellomer); in female antenna filiform, segments quadrate in ventral view, anteriorly angled, but not serrate. Frons rough-scaled, pale brown to grey brown or olive brown (there seem to be constant differences between the populations), with lateral margins black, and also more or less suffused with dark scales in the middle, with dorsal margin paler. Vertex pale olive-green. Labial palpus pale brown basally to black more distally, with third segment long (three fourths the length of second segment in male, even longer–reaching the length of the second segment- in female).

Thorax. Dorsal side with black hair-scales and narrow, elongated scales, the latter sometimes mixed with pale grey or more or less olive scales, with a distinct crest of differently shaped scales (shorter, distally broadened, curled) on metathorax; ventrally, thorax and femora of legs densely covered with whitish hair-scales, rarely there may be pink scaling on prothorax (only seen in specimens from Yunnan and Jiuzhaigou, Sichuan). Legs otherwise darker, tarsi ringed dark grey. Hind tibia in male not dilated, hair-pencil absent, both sexes with two pairs of spurs.

Forewing length: 6 19–23 mm; ♀ 24–26 mm. Fore- and hind wings with outer margin wavy. Forewing yellowish green (dark green in fresh materials) strongly suffused with dark brown or black striation; apex blunt; basal, antemedial and postmedial lines black; basal line short, rounded, indistinct, extended to a short streak basally on vein A1+2; antemedial line curved outwards near costa and in cell, inwards above vein A1+2, then bent outwards to hind margin near dorsum; postmedial line similar to that of M. differens , dentate at middle, but more deeply curved inwards above vein M3 and between CuA2 and A1+2, and occasionally forming a tiny tooth on the fold between the latter two veins; submarginal line white and wavy, distinct and visible only from costa to M2,forming the outer edge of a large, oval, pinkish-white subapical patch, located between postmedial and submarginal line and broadly reaching the costa anteriorly; a similar, but tornal patch present below CuA2 outside postmedial line; discal spot (discocellular line) dark and curved or angled. Hind wing with a very large, white basal area extended to the smooth, evenly rounded submarginal line, continuous from apex to tornus; hind margin dusted with black scales; postmedial line narrow, grey, strongly dentate, anteriorly reaching vein M2, strongly curved inwards between CuA1 and vein A1+2, often interrupted or partly absent; area outside postmedial line olive mixed with black scales and suffused with a little pink; discal spot absent. Marginal line on both, fore- and hind wings black, wavy; fringe brown, mixed with dark grey, notably at vein ends. Underside: forewing greyish, densely spotted dark brown, with exception of the large whitish patches agreeing with those on upperside, but less pinkish; markings similar to that of upperside, but postmedial line much broader; hind wing completely white, with a much darker and distinct submarginal line; postmedial line and discal spot faint or absent.

Abdomen. Dorsal side brown, mixed with black, with distinct crests developed on segments 2-6, brown or black and sometimes mixed with dull pink; there is a small white central patch, bordered by black patches, on the first segment. The crest on segment two is rather a pair of smaller, subdorsal crests, with a white patch in between. Underside of abdomen greyish-white.

Male genitalia. Uncus stout, apex with a pair of diverging processes, dorsal side of the latter with a small, Vshaped, spinose cleft basally. Socii broad and rounded at base, tapering to a curved arm and an acute apex. Gnathos with median region expanded, tongue-like and finely dentate dorsally; lateral arms expanded and strongly developed, forming a short, triangular dorsal process near uncus base and sometimes a more basal lobe in addition. Valva broad, tapered but blunt apically; costa expanded, sclerotized, with a finger-like, distally spined process near base; sacculus sclerotized, with a curved ventral ridge forming a shallow pocket medially, and a wavy ridge at base, near lower margin. Transtilla built of a pair of lightly sclerotized, narrow arms. Saccus projecting and rounded. Coremata absent. Aedeagus slender, with a long and narrow, pointed apical process.

Female genitalia. Ovipositor lobes modified, strongly sclerotized and with a few ridges on the inner margin. Length of apophyses posteriores about 2–3 times the length of apophyses anteriores. Lamella postvaginalis a pair of large, transverse, triangular processes, with an oval, even more strongly sclerotized lobe with a crinkled surface at middle. Ductus and corpus bursae membranous, the first narrow and fairly long, the latter rather small, pyriform; signum absent.

Variation. There is some variation between the populations of different localities in M. thyatiraria . Wing pattern: The tornal patch on forewing of the holotype from Tsékou ( Fig. 5 ) and other specimens from Yunnan is curved much deeper and narrower basally, the posterior branch of this concavity is almost as long, of the same length or even a little longer than the anterior branch; therefore, the distal part of the tornal patch is rather small and it touches the hind margin of the forewing at a short distance only. The patch is larger, touching the hind margin at a longer distance, and the posterior branch of the concavity is very short in the specimens from Taibaishan ( Fig. 7 ). Specimens from other localities, e.g. from Sichuan, are more or less intermediate ( Fig. 8 ). The basal area of the forewing, reaching up to the antemedial line, is much lighter than the more distal part of the wing in specimens from Yunnan ( Fig. 6 ), including the holotype from Tsékou. This is rarely so in specimens from Sichuan and almost not seen in specimens from Taibaishan. There are some more external characters which distinguish the populations of the different localities (e.g. scaling of frons and thorax, colour of crests on abdomen, presence of white patches on tergite 1 and 2 etc.), but they are not yet studied sufficiently.

Male genitalia. Uncus: The V-shaped, spined cleft on uncus varies in depth: it is deepest in the males from Lijiang, Yunnan ( Fig. 26 ), shallower in specimens from Taibaishan, Shaanxi ( Fig. 27 ), and even slightly shallower in the material from Tatsienlou, Sichuan ( Fig. 28 ). Valva: The digitate basal process of the valve costa is rather slender and tapering towards tip in the specimens from Gansu ( Fig. 20 ), Ta-tsien-lou and Jiuzhaigou, but almost even in width, with an expanded tip in the specimens from Yunnan ( Fig. 19 ). Gnathos: The median region of the gnathos is much larger and more expanded in the material from Gansu ( Fig. 20 ), Taibaishan, Ta-tsien-lou and Jiuzhaigou, than in the specimens from Yunnan ( Fig. 19 ). The lateral arms of gnathos are -besides a basal (proximal) process near uncus of varying shape and size which is always present- smoothly expanded, swollen, and without a ventral (distal) process in the specimens from Taibaishan (Fig. 31) and Gansu; there is a trace of a process (slightly protruding) in the specimens from Ta-tsien-lou (Fig. 32), and in the specimens from Yunnan ( Fig. 30 ) there is a distinct process with similar length and shape or slightly shorter compared to the basal (proximal) process.

Morphological differences found between the populations seem to indicate that they are separated on specific or at least on subspecific level. This is notably the case for the nominate populations from Yunnan (including the holotype from Tsékou and a female specimen from A-tun-tse in coll. ZFMK) which also could be treated – considering the rather strong differences in the male genitalia- as a distinct species. Unfortunately, the barcoding studies have not been successful for thyatiraria - specimens from Yunnan, so we are not able to decide this question at present. Populations from Sichuan, Gansu and Shaanxi are genetically close to each other (see Fig. 40 ), even the externally quite different specimens from Taibaishan are clustering together with those from Gansu and Sichuan.

Diagnosis. M. thyatiraria is similar to M. batangensis on both, wing pattern and genitalia, but differences considered to separate both on specific level are present. They are summarized in the diagnosis of M. batangensis .

Type-material examined. Holotype (by monotypy), 6 ( BMNH), Tsékou, 1900, R. P. J. Dubernard, Ex. Oberthür Coll., Brit. Mus. 1927-3, Geometridae genitalia slide No. 20794 ( China: Yunnan).

Additional material examined. China: Shaanxi: 1 6 ( IZCAS) , Shaanxi Ningshan Huoditang, 7.VIII.1979; 1 6 ( IZCAS), same locality , 1580 m, 26–27.VII.1998; 1 6 (IZCAS), Baoji Jialingjiang, 1620 m, 8–9.VIII.2014, leg. Xue Dayong and Ban Xiaoshuang; 1♂ ( ZFMK), Tapaishan [Taibaishan] im Tsinling , Sued-Shensi [Shaanxi], ca. 1700 m , 10.VIII.1936, H. Höne, genitalia prep. No. 2 296-DS; 7 6 1♀ ( ZFMK), South Taibashan [Taibaishan], 1900 m, Tsinling Mts. near Houzhenzi, 33o53′N 107o49′E , 1–12.VIII.1999, leg. Siniaev & Plutenko, incl. genitalia prep. No. 2297-DS. Gansu ( IZCAS): 1 6, Wenxian Qiujiaba , 2350 m, 21–22.VII.1999, leg. Wang Hongjian; 1 6, Wenxian Tielou, 1450 m, 24.VII.1999, leg. Zhu Chaodong; 1♀, Wenxian Baishuijiang , VIII.1986, leg. Wang Hongjian; 1 6, same locality and collector , VI.1986; 2 6 3♀, Wenxian Liziba, 1971 m, 22–23.VIII.2014, leg. Li Xinxin and Pan Xiaodan. Sichuan: 7 6 4♀ (IZCAS), Jiuzhaigou, 2045 m, 19–20.VIII.2014, leg Li Xinxin and Pan Xiaodan; 1♀ (IZCAS), Yajiangbingzhan, 3300 m, 24.VIII.1982, leg. Wang Shuyong; 1♀ ( IZCAS), same locality and date , 3800 m, leg. Chai Huaicheng; 1 6 (IZCAS), Yingjing Siping, 1100 m, 25.VI.1984, leg. Liu Dajun; 1 6 (IZCAS), Pingwu Wanglang, 2560 m, 9–11.VIII.1999, leg. Zhouxin; 1♀ (KIZCAS), Wolong , 21.VIII.1982, leg. Xiong Jiang ; 1♀ ( IZCAS), Miyaluo , 2700 m, 1.VIII.1983, leg. Niu Chunlai ; 1 6 (BMNH), Siao-Loû, Chasseurs Indigènes, du P. Déjean, 1903, Ex. Oberthür Coll., Brit. Mus. 1927-3; 1♀ ( BMNH), Frontière orientale du Thibet, Chasseurs indigènes du P. Déjean, 1906, Ex. Oberthür Coll., Brit. Mus. 1927-3; 1 6 ( BMNH), ibidem, 1905 ; 1♀ ( BMNH), Chasseurs indigènes de Tà-Tsién-Loû, R.P. Déjean, 1901, Ex. Oberthür Coll., Brit. Mus. 1927-3; 2 6 1♀ ( BMNH), Chasseurs indigènes de Tà-tsien-lou, Récolle de 1910, Ex. Oberthür Coll., Brit. Mus. 1927-3; 1 6 ( BMNH), Ta-tsien-Lou , 1899, Chasseurs Indigènes , Ex. Oberthür Coll., Brit.Mus. 1927-3; 10 6 ( BMNH) , China, Pr. Szechwan, Kunkala-Schan, Rothschild Bequest, B.M. 1939-1; 2 6 ( ZFMK), Chasseurs indigènes de Tà-tsienlou. Rècolte de 1910; 1 6 ( ZFMK), Thibet Oriental Chasseurs thibétains du P. Déjean, 1903; 1 6 ( ZFMK), Ta-tsien- Lou , 1899, Chasseurs indigenes; 1 6 ( ZFMK), Szetschwan Tatsienlu , Exp. Stötzner (genitalia prep. No. 2294-DS); 1 6 ( ZFMK), no data; 1 6 ( ZFMK), Ta-tsien-Lou , Chasseurs du P. Déjean, 1904; 1 6 ( ZFMK), Wolong, 2300 m, Qionglai Shan, W . Sichuan, CHINA, 10.VII.1994, G. C. Bozano; 2 6 ( ZFMK) , China, Pr. Szechwan, Kunkala- Schan , ex coll. Wehrli, 17/55 (incl. genitalia prep. No. 2295-DS); 12 6 1 ♀ ( ZSM), Kunkalaschan, Szetschwan; 1 6 ( ZSM), Sammlung Osthelder , China Oc. Szetshwan Kunkalashan; 1 6 ( ZSM) , China occ, Szetschan Kunkala- Schan. Yunnan: 1 6 ( IZCAS), Zhongdian Chongjianghe , 1800 m, 6.VIII.1984, leg. Liu Dajun ; 2♀ ( IZCAS), Lijiang Yushuizhai , 2680 m, 21.VI.2009, leg. Xue Dayong and Qi Feng ; 1 6 ( BMNH), Li-kiang ( China), Provinz Nord-Yuennan , 26.VII.1935, H. Höne, Brit. Mus. 1959-465 (det. Erwin Beyer 1958); 1 6 (BMNH), ibidem, 1.VII.1934; 15 6 ( ZFMK), Li-kiang, ( China), Provinz Nord-Yuennan , 27.VI–5.VIII.1935, H. Höne; 1 6 (ZFMK), ibidem, 19.VIII.1935, (genitalia prep. No. 3/C4); 1 6 (ZFMK), ibidem, 15.VII.1935 (genitalia prep. No. 2292-DS); 10 6 1 ♀ (ZFMK), ibidem, 29.VI–7.VIII.1934; 1♀ (ZFMK), A-tun-tse (Nord-Yünnan), Obere Höhe ca. 4500 m, 25.VII.1937, H. Höne.

Taxonomic notes. In Oberthür’s very short original description (“ Hypochroma Thyatiraria, Obthr. (Pl. CLXXIII, fig. 1703), de Tse-kou, rapellant, par les taches roseés de ses ailes supérieures, notre Thyatira Batis.”), only the type-locality “Tse-kou” (N. Yunnan) is given, all other information (date of collecting, number of specimens) is missing. Today, Oberthür’s collection is partly deposited in BMNH (the larger part) and partly in ZFMK (mainly Palaearctic Geometridae , as a part of the Wehrli-collection). We studied both collections, but in fact only one male specimen from Tse-kou was found in BMNH, none in ZFMK, though in both large collections several thyatiraria -specimens from other localities (Tatsienlu, Siaolou etc,. see list above) are stored, definitely originating from Oberthür’s collection and all collected earlier than the description of thyatiraria . It is not clear to us why he did not mention them in the description. There were no labels attached to the single Tse-kou specimen designating it as holotype or as one of a series of syntypes. Therefore, we consider this specimen as holotype (by monotypy), obviously being the only one on which Oberthür based his description.

Sterneck (1928) described this species very detailed, but without figuring it, as Dindica thyatiroides again, based on two males and one female from Sichuan (Tatsienlu, 11.8.). However, he synonymized it in an appendix of the same paper, referring to information he got from L. B. Prout on this matter before. This is probably also the reason why we did not find any specimens labelled as types (Sterneck’s Geometridae types are kept in the collection of the “Senckenberg Naturhistorische Sammlungen, Museum für Naturkunde, Dresden” and have been studied by D.S.).

Distribution. China (Shaanxi, Gansu, Sichuan, Yunnan).

Figures

FIGURE 40. Neighbour-Joining (NJ) tree, Kimura 2 - parameter model.

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.

FIGURES 26 – 30. Dorsal view of the uncus of M. thyatiraria and M. batangensis sp. nov. 26 – 28. M. thyatiraria. 26, from Likiang, Yunnan; 27, from Taibaishan, Shaanxi; 28, from Tatsienlou, Sichuan; 29, M. batangensis. 30 – 34. Lateral view of uncus and gnathos of M. thyatiraria and M. batangensis sp. nov. 30 – 32. M. thyatiraria. 30, from Likiang, Yunnan; 31, from Taibaishan, Shaanxi; 32, from Tasienlou, Sichuan. 33 – 34. M. batangensis sp. nov. 33, from Batang; 34, from Echu.