Nephrotoma xizangensis Yang & Yang, 1987 Figs 52-54, 55-59, 61

Nephrotoma xizangensis Yang & Yang, 1987: 129. Type locality: China: Xizang, Nyingchi Co.

Diagnosis.

Antennal scape yellow, pedicel pale brown, flagellum mainly dark brown, except first flagellomere pale brown (Fig. 52). Mid-longitudinal stripe of prescutum V-shaped. Scutellum with pale brown middle stripe and brown posterior margin. Mediotergite yellow (Fig. 53). Posterior extension of tergite 9 slightly depressed, with two pairs of short obtuse projections (Fig. 58).

Material examined.

2 males (CAU), China: Xizang, Yigong, 2017.VI.7, 2236 m, Qicheng Yang (light trap). 1 male (CAU), China: Xizang, Bayi, 2017.VI.4, 2955 m, Qicheng Yang (light trap).

Description.

Male (n = 3): body length 11.5-12.5 mm, wing length 11.5-12.5 mm, antenna length 3.5-4.0 mm.

Head (Figs 52, 53). Mainly yellow. Vertex with brown spot near inner margin of eye. Occipital marking brown, subtriangular. Dorsal part of rostrum including nasus brown. Head with black hairs. Antennal scape yellow, pedicel pale brown, flagellum mainly dark brown except first flagellomere pale brown; first flagellomere 1.5 times longer than second one. Proboscis yellow, with brown hairs. First palpal segment greyish brown, second one yellow, with brown hairs.

Thorax (Figs 52, 53). Mainly yellow. Pronotum yellow. Prescutum with three black longitudinal stripes; middle stripe V-shaped, anterior end of lateral prescutal stripe bent outward, outer curved part brown. Scutum yellow, with two black subtriangular spots. Scutellum with pale brown middle stripe and brown posterior margin. Mediotergite yellow. Pleuron pale yellow. Parascutellum yellow. Legs yellow, except tips of femora and tibiae brown, tarsi dark brown; hairs dark brown. Wing subhyaline, tinged with light brown; pterostigma brown; cell m1 sessile (Fig. 54). Halter brownish grey.

Abdomen (Fig. 52). Mainly yellow. Abdominal tergites with three longitudinal stripes, middle stripe brown, triangular; stripes on lateral side brownish grey. Abdominal segments 7 and 8 entirely dark brown to black; hypopygium mainly dark brown, tergite 9 black. Hairs on abdomen dark brown or golden.

Hypopygium (Figs 55-59) mainly black. Posterior extension of tergite 9 slightly depressed with two pairs of short obtuse projections; posterolateral margin with a pair of ventrad curved appendages each with two cusps (Fig. 58). Posterior margin of sternite 8 slightly depressed, middle part pleated, sclerotized, anterior part with long hairs (Fig. 55). Sternite 9 with a horn-like projection (Figs 55, 59). Outer gonostylus fleshy, widened at middle, narrowed toward tip (Fig. 56). Inner gonostylus with large concavity at base; beak sharp; outer basal lobe with hairy protuberance; posterior crest with a large membranous area (Fig. 57).

Distribution.

China (Xizang).

Remarks.

This species is similar to N. flavonota Alexander, 1914 from Japan (Honshu, Shikoku, Kyushu), China (Zhejiang, Fujian, Hainan), but the latter differs in the following characters: Sternite 8 sheathing very slightly narrowed outwardly, terminating in two broad lobes separated by a V-shaped emargination filled with pale membrane; lobes bearing abundant long yellow setae.