Nephrotoma evittata Alexander, 1935 Figs 26-28, 29-33

Nephrotoma evittata Alexander, 1935: 200. Type locality: China: Szechwan, Shin-Kai-Si, Mount Omei.

Diagnosis.

Antenna mainly dark brown except scape yellow, pedicel and first flagellomere brown; both ends of flagellomere with obvious expansion (Fig. 26). Scutellum dark yellow, with brown middle stripe. Mediotergite yellow with brown to dark-yellow middle stripe (Fig. 27). Tergite 9 semicircular, depressed at middle, with a pair of sharp short protuberances at posterior margin (Fig. 32). Inner gonostylus with flat lower beak bearing bristles (Fig. 31).

Material examined.

2 males (CAU), China: Xizang, Yigong, 2017.VI.7, 2236 m, Qicheng Yang (light trap). 2 males (CAU), China: Xizang, Yigong, 2017.VIII.5, 2183 m, Qicheng Yang (light trap). 1 male (CAU), China: Xizang, 80K, 2017.VI.13, 2023 m, Qicheng Yang (light trap). 1 male (CAU), China: Xizang, 106K, 2017.V.17, 2289 m, Qicheng Yang (light trap).

Description.

Male (n = 6): body length 11.0-12.5 mm, wing length 11.0-12.0 mm, antenna length 2.5-3.5 mm.

Head (Figs 26, 27). Mainly yellow. Occipital marking brown, faint. Frontal tubercle relatively high. Dorsal part of rostrum, including nasus, dark brown. Head with black hairs. Antenna dark brown except scape yellow, pedicel and first flagellomere brown; first flagellomere 1.2 times as long as second one; both ends of flagellomere obvious expansion. Proboscis mainly yellow, with black hairs. First palpal segment yellow, second one brown, with black hairs.

Thorax (Figs 26, 27). Mainly yellow. Pronotum yellow, pale brown on lateral side. Prescutum with three black longitudinal stripes; anterior end of lateral prescutal stripe bent outward, outer part brown. Scutum with four black spots. Scutellum dark yellow, with brown middle stripe. Mediotergite yellow, with brown to dark-yellow middle stripe. Anepisternum and katepisternum yellow; katepisternum with yellow lower part. Anepimeron pale yellow, lower part dark yellow. Anatergite and katatergite yellow. Parascutellum yellow. Legs yellow except tips of tibiae brown and tarsi dark brown; hairs dark brown except those on coxae dark yellow. Wing subhyaline, tinged with light brown; pterostigma slightly deepened; cell m1 shortly petiolate (Fig. 28). Halter with stem pale brown; knob pale yellow.

Abdomen (Fig. 26). Mainly yellow. Abdominal tergites with three brown longitudinal stripes. Abdominal segments 6-8 entirely dark brown to black; hypopygium mainly yellow; tergite 9 brown or yellow. Hairs on abdomen blackish or yellow.

Hypopygium (Figs 29-33) brownish yellow. Tergite 9 semicircular, depressed at middle, with a pair of sharp short protuberances on posterior margin (Fig. 32). Posterior margin of sternite 8 with dense bristles at middle (Fig. 33). Outer gonostylus fleshy, protruded at middle, narrowed toward tip (Fig. 30). Inner gonostylus flat, with large concavity at base; lower beak with bristles (Fig. 31).

Distribution.

China (Sichuan, Yunnan and Xizang).

Remarks.

First record for Xizang. This species is similar to N. impigra impigra Alexander, 1935 from China (Hubei, Sichuan, Zhejiang, Fujian, Guizhou, Jiangxi), but the latter differs in the following characters: occipital marking distinct; scutellum dark brown. The hypopygium of this species is consistent with holotype, and we found that its occipital marking is variable. We think the difference between the veins is caused by the origin, which is also variable.