Roeslerstammia tianpingshana, Hirowatari, Toshiya, Huang, Guo-Hua & Wang, Min, 2017

Hirowatari, Toshiya, Huang, Guo-Hua & Wang, Min, 2017, Review of the genus Roeslerstammia, with a new species from China (Lepidoptera, Roeslerstammiidae), ZooKeys 668, pp. 107-122 : 109-113

Roeslerstammia tianpingshana sp. n. Figs 4, 5, 6, 7, 8, 9

Type material.

Holotype male, "Tianpingshan (1,500 m)/ Badagongshan/ Hunan, China/ 26-27.v.2009/ G.H. Huang & M. Li", in HUNAU. Paratypes 3 males, same label as holotype, in HUNAU; 1 female, same label as holotype, in ELKU.

Diagnosis.

Distinguished from other Roeslerstammia species by the triangular white marking on the costa of the forewing. In the male genitalia, the uncus is triangular, apically narrow and bilobed; the valva has a blunt process on the median part of the costa; the phallus is long, its basal half straight, distal half strongly upcurved and sinuate. In the female genitalia, the ductus bursae is stout, the caudal part upcurved; the corpus bursae is ellipsoidal, with a thorn-shaped signum.

Description.

Male (Figs 4A, 5D).

Forewing length 7.3 mm in holotype, 6.7-7.1 mm in paratypes.

Wing expanse 15.3 mm in holotype, 13.5-14.3 mm in paratypes.

Head vertex, including between antennae, with raised blackish brown hairs anteriorly, yellow hairs posteriorly; frons smooth, ochreous with golden luster, laterally along eyes blackish brown with a metallic blue lustre (Fig. 5D). Eyes relatively large, interocular index ca 1.0. Antenna filiform, 0.8>(apical part lost) × as long as forewing; scales in flagellar segments near the middle of antenna somewhat raised (Fig. 7B); scape blackish brown with metallic blue lustre; flagellum dark brown on basal 1/3, white on distal 2/3 (apical part lost). Labial palpus slightly upcurved, relatively long ca 2.3 × as long as horizontal eye diameter, 3rd segment slightly longer than 2nd; entirely smooth and terminally acute, pale yellow (Fig. 5D).

Thorax tegula dark brown with metallic blue luster; mesonotum dark brown with metallic blue or golden luster. Foreleg dark brown, partly mixed with pale yellow; midleg pale yellow with dark brown tibial spurs; hindleg pale browish gray dorsally, tibia with pale yellow hairs ventrally. Forewing lanceolate, apex narrowly rounded, dark brown with metallic blue or golden luster; a clear triangular creamy white marking present at basal 2/3 of costa; fringe dark brown; veins R4 and R5 stalked, R5 reaching to costa (Fig. 6). Hindwing dark brown, darker near apex; fringe dark brown. Hindwing with frenulum consisting of a long bristle.

Abdomen dorsal part pale brown with golden luster, terminally with pale yellow tufts of long hairs. Ventral part similar to dorsal part, terminally with creamy yellow smooth scales.

Male genitalia (Fig. 8). Uncus triangular, apically narrow and bilobed. Tegumen broad, as long as uncus. Gnathos consisting of two slender arms united medially with a circular plate. Valva broad basally and narrowed distally, with a blunt process on median part of costa; sacculus short, about 1/3 length of valva, terminating in an indistinct projection; a small pad of long hair scales near the base ventrally. Vinculum narrow ventrally; saccus cylindrical, as long as dorsal part of tegumen. Phallus long, basal half straight, distal half upcurved and sinuate, with a band of minute spine-like cornuti.

Female (Fig. 4B).

Forewing length 7.6 mm. Wing expanse 15.8 mm.

Similar to male but differs as follows: antenna filiform, 1.1 × as long as forewing. Scales on antennal flagellar segments not raised; flagellum dark brown on basal half and apical 1/7, white on distal half to near apex. Hindwing with frenulum of two slender bristles.

Female genitalia (Fig. 9). Papillae anales narrow and apically pointed in ventral view, nearly triangular in lateral view. Apophysis posterioris slender, 0.7 × as long as papilla analis. Apophysis anterioris short and basally broad, 0.3 × as long as eighth tergite. Eighth tergite strongly sclerotized, dorsal posterior margin weakly emarginate at middle. Ostium bursae situated on anterior margin of eighth abdominal segment, posterior margin nearly straight. Ductus bursae stout, caudal part upcurved. Ductus seminalis attached to ductus bursae near ostium. Corpus bursae ellipsoidal, with a thorn-shaped signum.

Etymology.

The specific name, an adjective, is derived from the type locality.

Host plant.

Unknown. The larvae of Roeslerstammia are first leafminers and then become skeletonizers and mainly feed on plants of Betulaceae ( Alnus , Betula ) and Malvaceae ( Tilia ) (e.g., Kyrki 1983, Heppner 2005). Recently Hirowatari et al. (2012) recorded Facaceae ( Fagus ) as the hostplant. The type locality of R. tianpingshana is located in a deciduous forest where Fagus lucida Rehder & Wilson is the dominant tree species. Although we carried out a survey for immature stages of the new species, no information on the hostplant was obtained.

Distribution.

China (Hunan Province).

Remarks.

On 26-27 May 2009, a total of four males and one female of the new species were collected in a light trap at Tianpingshan (1,500 m), Badagongshan National Nature Reserve, Hunan Province, China. On 12-14 August 2014, we ran a light trap in the same locality, but did not obtain additional material. The adults of R. pronubella and R. erxlebella are known to fly in spring and summer ( Agassiz 1996, Huemer and Segerer 2001, Hirowatari et al. 2012) but we could not confirm the voltinism of the new species.