Lithostege stueningi Rajaei & Xue

Sh, Hossein Rajaei & Xue, Dayong, 2012, A new species of the genus Lithostege (Geometridae: Larentiinae) from China, Zootaxa 3478, pp. 399-402 : 399-402

Lithostege stueningi Rajaei & Xue , sp. nov.

Figs. 1–7

Material examined. Holotype, 3, CHINA: Sichuan, Ta-Tsien-Lou, 1899, Chasseurs indigènes; coll. ZFMK. Paratypes, 3 3: same data as holotype, leg & genitalia prep. 1810/ 2012 H. Rajaei; 1 3: Chasseurs indigènes, de Tá-Tsién-Loû. R.P. Déjean, 1901; coll. ZFMK. 1 31 Ƥ: same data as holotype, gen. prep. 35257, Ƥ 7695, in IZBE. 1 31 Ƥ: same data as holotype, female genitalia prep. Geom-01934/2012, coll. IZCAS. 10 35 Ƥ: Ta-tsien-Lou, 1899, Chasseurs indigènes, Ex. Oberthür Coll. Brit. Mus. 1927-3, gen. prep. Ƥ BMNH-24032, Han Hongxiang fec.; 2 3: Thibet, Chasseurs de Tâ-tsienlou, 1895, Ex. Oberthür Coll. Brit. Mus. 1927-3; 1 31 Ƥ: Ta-tsien-Lou, 1899, Chasseurs indigènes, Brit. Mus. 1964-454; 1 3: Tien-Tsuen, Yuin-Kin, 1899, Chasseurs indigènes, Ex. Oberthür Coll. Brit. Mus. 1927-3; all in coll. BNHM.

Description. Head. Antennae filiform, slightly flattened and finely and homogeneously pubescent in male, thinner, round and smooth in female. Frons slightly protruding in lateral view (about one-half of the eye diameters), speckled cream and brown. Surface beneath scales dark brown, rough, forming an edge around frons, centre slightly protruding. Labial palpi brown, rather long and narrow, reaching well beyond frons. Thorax. Foreleg tibia short and stout, 0.7 mm long, bidentate distally, with inner tooth-like projection only slightly shorter than tibia, outer one reduced (fig. 7). Wingspan 25–28 mm, length of forewings 16–17 mm. Forewings elongate, apex acutely angled, termen oblique, tornus evenly rounded. Hindwings moderately reduced in size, oval but slightly pointed at vein Rs. Forewing ochre to orange, areas between submarginal and postmedial and between antemedial and basal lines suffused with grey, thus darker than distal, medial and basal areas. Transverse lines distinct, cream. Basal line acutely angled in cell, antemedial line rather straight, but curved in cell, broadening towards costa. Postmedial line straight, but curved near hind margin and costa. Submarginal line strongly dentate (of a distinct zigzag-shape), projecting distad between veins R5 and M1, M1 and M2, M3 and CuA1 and CuA1 and CuA2, sharply angled in between (figs 1–3). Fringes white, interrupted dark brown at veins. Hind wing uniformly cream, with a faint, rounded medial band and a narrow, black marginal line reaching from apex to tornus. Fringes white, with only very weak brown streaks at the end of the veins. Underside of forewings dark reddishbrown, with only the postmedial and submarginal lines faintly visible (clearly visible and white near costa). Underside of hind wings light cream, with a distinct, rounded medial line, a darker shadow on basal area and a faint costal part of postmedial line (fig. 1b). Discal spot absent on upperside and forewing underside, but visible on underside of hind wing. Abdomen. Last abdominal (A8) tergite of male broad, terminally rounded.

Male genitalia ( Figs 4, 5 ). Valves broad, distally rounded and setose, with a strongly curved and sclerotized costa, terminating with a short, apical projection; a strongly sclerotized, dagger-shaped harpe at the centre of valve; juxta trapezoid; saccus short, proximally rounded; uncus elongated, apically wider than at base, lateral arms of gnathos strong. Aedeagus small (about 0.9 mm), apex curved ventrad, extended to a thorn-like projection.

Female genitalia ( Fig. 6 ). Ovipositor short and broad, with long posterior apophyses. Anterior apophyses very short, 8th segment broadly sclerotized laterally, ventrally narrow, with a small, semicircular protrusion at centre. Antrum short, ductus and corpus bursae continuous, pear-shaped, membranous, without appendix, signum or other decorations.

Diagnosis. Size, colour and wing pattern, especially the dentate submarginal line, are unique in the genus, easily separating the new species from other species of Lithostege . The other Chinese species of this genus are either distinctly smaller (e.g. L. mesoleucata , L. verbosaria and L. usgentaria ignorata ), or have wings without or with weak pattern elements ( L. narynensis and L. coassata mongolica ). Also the structures of male and female genitalia are distinctive from other species (e.g. shape of harpe, free subapical projection of the costa of valve in male, membranous ductus and corpus bursae in female). Similar structures in male genitalia are found in the buxtoni group (see Rajaei et al. 2011), but the long uncus and short saccus are important differences of the new species.

Distribution. China, Central Sichuan. So far only known from the type locality “Ta-Tsien-Lou” (today’s name: Kangding) and from “Tien-Tsuen” (Tianquan), about 70km NE of Kangding.

Etymology. The name of the new species is dedicated to Dieter Stüning, curator of the Lepidoptera & Trichoptera collection at ZFMK, Bonn, Germany.

Figures

FIGURES 1 – 3. Lithostege stueningi sp. nov., 1, holotype male, a. upperside, b. under side.; 2, paratype male (left: upperside, right: under side); 3, paratype female (Photo by Han Hongxiang). Scale bar: 10 mm.

FIGURES 4 – 7. Lithostege stueningi sp. nov., foreleg and genitalia structure; 4 – 5, male genitalia, gen. prep. 1810 H. R.: 4. genital capsule, 5: aedeagus, 6: female genitalia, gen. prep. BMNH 24032 (photo by Han Hongxiang); 7: left foreleg (paratype male, prep. 1810 H. R.), a, lateral view; b, frontal view (epiphysis not visible). Abbreviations: fe., femur; ti., tibia; ta., tarsus; ep., epiphysis; Scale bar: 1 mm (for genitalia only).