Nemacerota sejilaa Pan, Ronkay, Ronkay & Han

Pan, Zhao-Hui, Ronkay, Gábor, Ronkay, László & Han, Hui-Lin, 2014, A new species of Nemacerota Hampson, [1893] (Lepidoptera, Thyatiridae) from Tibet, China, Zootaxa 3754 (1), pp. 97-100 : 97-100

Nemacerota sejilaa Pan, Ronkay, Ronkay & Han sp. n.

( Figs 1–2, 5–7, 9 )

Material examined. Holotype. Male, Autonomous Region Xizang, Linzhi, Kadinggou, altitude 3000m, 31 VII 2013 (leg. HL Han, ZG Wu). Paratypes. 1 male, Autonomous Region Xizang, Linzhi, 28–30 VIII 2012 (leg. Zhaohui Pan), slide no. hhl-2785-1; 2 females, Autonomous Region Xizang, Linzhi, Mt. Sejila, altitude 3400m, 2 VIII 2013 (leg. HL Han, ZG Wu), slide no. hhl-2838-2; 1 male, Autonomous Region Xizang, Linzhi, Mt. Sejila, altitude 4300m, 4 VIII 2013 (leg. HL Han, ZG Wu). Type material is deposited in the collection of the Northeast Forestry University ( NEFU), Harbin, China.

Diagnosis. This new species is externally close to N. igorkostjuki Laszlo, Ronkay, Ronkay& Witt, 2007 and N. decorata (Sick, 1941) , but can be distinguished by the light gray and broad forewing; postmedial line smoothly incurved above vein M2, then slightly straight to inner margin without curving out towards tornus which is typical of both N. igorkostjuki and N. decorata . In N. igorkostjuki ( Figs 3–4 ) and N. decorata , the postmedial line runs from the costa inward straight to M1, cambered outward between M1 and Cu2, then outward to tornal area. In addition, the reniform stigma of N. sejilaa is long, narrow and kidney-shaped, whereas in N. igorkostjuki it is short and more broadly round. The male genitalia of the three species are rather similar, but display several clearly recognizable differences. The socii of N. sejilaa ( Fig. 7 ) are much thinner and longer than in N. igorkostjuki ( Fig. 8 ) and N. decorata ( Laszlo et al 2007: gen. fig. 93); the sacculus has a weakly sclerotized process, which is reduced in N. igorkostjuki and differently shaped in N. decorata ; the fultura superior of the new species is considerably more slender than in N. igorkostjuki (especially in its ventral section) and narrower although less conspicuously than in N. decorata ), and the saccular margin is almost straight which is somewhat concave in N. igorkostjuki . The aedeagus of N. sejilaa is slenderer than in the two related species, slightly curved medially, and the basal part of the carinal hook has sclerotized lateral lobe which is missing in N. igorkostjuki . In the female genitalia, the size and sclerotization of the ostium bursae is different in the three species: that of N. sejilaa ( Fig. 9 ) is larger and more cup-shaped than in N. igorkostjuki ( Fig. 10 ), but smaller and more flat than in N. decorata ( Laszlo et al 2007: gen. fig. 93). The tubular part of the corpus bursae of the new species is similar to that of N. decorata , but considerably shorter and less coiled than that of N. igorkostjuki ( Fig. 10 ).

Description. External appearance ( Figs 1–2 ). Wingspan 42–46 mm. Antennae bipectinate in male, comparatively thin in female; head, palpi and thoracic pubescence generally gray, mixed with whitish and blackish scales; thorax with black dorsal lines on tegulae; abdomen gray-brown. Ground colour of forewing silvery ash-gray; basal band thin and black; subbasal line double, waved, dark grey filled with ground colour; antemedial line sharply defined and less sinuous, black, defined by red scales, double with interior line stronger; median line rather indistinct, shadow-like, grey. Outer half of basal field suffused with dark brownish grey, median area bright grey; postmedial line black, double, with indistinct interior line; termen with dark blackish-grey subapical patch followed with whitish-grey costal spot of subterminal line; marginal area with fine dark lines on veins; subterminal line pale whitish-grey, waved, gradually tapering from costa to inner margin; terminal line deep black; fringes as ground colour, chequered with black patches at veins. Reniform stigma elongate, more or less kidney-shaped; orbicular stigma obsolescent, small and rounded, whitishgrey. Hindwing lighter than forewing, pale whitish-grey with fine ochreous-pinkish hue; transverse line broad, diffuse, darker grey; marginal area deeper grey with ochreous shade along black terminal line; fringes whitish, chequered with blackish; inner margin with long ochreous-brown hair-scales. Male genitalia ( Fig. 7 ). Uncus long, strong and straight, twice as long as socii; socii thin, finely arched inwards. Tegumen broad and rather short; fultura superior sclerotized, cuneate-lanceolate with narrow basal (ventral) portion; dorsal part of juxta reversed triangular with V-shaped marginal sclerotisation; vinculum U-shaped with well-developed saccus. Valvae rather broad, with apex rounded; sacculus narrow, thick, shorter than half length of valva, with small and sclerotized process of harpe; costa with broad triangular sclerotisation. Aedeagus slightly curved at middle, long and narrow, with strongly sclerotized, thick, falcate hook of carina; vesica broadly tubular, tapering distally, everted dorsad and recurved ventrad, without cornuti band. Female genitalia ( Fig. 9 ). Papillae anales short, broad, loose-bodied apically. Apophyses posteriores relatively shorter, ca 2/3 as long as apophyses anteriores. Ductus bursae short, membranous; cervix bursae narrow, weakly screwy at anterior part; tubular distal part of corpus bursae with one full coil; proximal part of corpus bursae oblong, with weakly sclerotized signum.

Etymology. The species name “ sejilaa ” refers to the type locality, Mt. Sejila.

Distribution and Bionomics. The new species occurs in China, Xizang: Mt. Sejila ( Fig. 5 ). Bionomics ( Fig. 6 ). It inhabits the coniferous forest zone with high montane shrubby regions dominated by Rhododendron stands above 3000 m in the Southeast part of the Autonomous Region Xizang (Tibet) in the south-eastern Himalayas ( Fig. 6 ). Adults are on the wing from late July to late August.

Figures

FIGURES 1 – 6. Nemacerota spp., adults. 1. N. sejilaa sp. n., male, holotype, China (NEFU); 2. N. sejilaa sp. n., female, paratype, China (NEFU); 3. N. igorkostjuki, male, holotype, Nepal (MWM); 4. N. igorkostjuki, female, paratype, Nepal (MWM); 5. collecting sites of N. sejilaa sp. n.: a. Auto. Reg. Xizang, Linzhi, Kadinggou, b. Auto. Reg. Xizang, Linzhi, Mt. Sejila; 6. collecting site close to timberline with shrubs, deciduous and coniferous forest patches.

FIGURES 7 – 10. Genitalia of Nemacerota spp. 7. N. sejilaa sp. n., genit. prep. hhl- 2785 - 1 (male); 8. N. igorkostjuki, genit. prep. LG 1121 (W 5884) (male); 9. N. sejilaa sp. n., genit. prep. hhl- 2838 - 2 (female); 10. N. igorkostjuki, genit. prep. LG 1921 (W 7142) (female).