Diagnosis

Face with a distinct notch or carina on lower margin. Gena rather wide. First flagellomere subtriangular. Fore femur with only short weak ventral setulae, but without strong v. Fore tarsomere 2 much longer than tarsomeres 3 or 4. Phallus biarticulated (Sinclair 1995).

Distribution

Afrotropical, Palaearctic, Oriental, and Nearctic Regions.

Remarks

For detailed descriptions of the genus, we refer to Collin (1961) and Sinclair (1995).

Diagnosis

Pterostigma elongated, dark brown. Discal cell apically pointed, M₁ and M₂ basally convergent with short petiole; discal cell with a short apical appendage like a very short vein. Epandrial lamella with wide upper margin nearly truncate. Surstylus nearly strip-like, hidden below dorsal portion of epandrium. Distiphallus not swollen without spines at middle.

Male

Body length 5.9 mm, wing length 5.1 mm.

Head black with pale gray pollinosity. Setulae and setae on head black; upper occiput with a row of 7 strong postocular setae (uppermost being vt), lower half of occiput with minute pale setulae; ocellar tubercle weak with 2 long anterior oc and two pairs of very short posterior setulae. Antenna black; pedicel with circle of black apical setulae; first flagellomere subtriangular with short tip uniformly thin, 1.5 times longer than wide, indistinctly pubescent; arista weakly thickened, more or less uniform in thickness, 2.4 times as long as first flagellomere, indistinctly pubescent. Proboscis black with blackish setulae; palpus black with blackish setulae.

Thorax black with pale gray pollinosity. Setulae and setae on thorax black; biseriate acr short hair-like, 5 long dc, 1 long h, 1 long ph, 2 short npl, 1 long sa, 1 psa slightly shorter than sa; scutellum with 2 long sc and 4 short marginal setulae (2 setulae located between 2 sc). Propleuron with pale lower setulae mostly short. Laterotergite with several short pale setulae. Legs including all coxae black. Setulae and setae on legs black, but those on coxae pale except fore and mid coxae posteriorly with black setae. Fore femur with row of short hair-like av and pv distinctly shorter than femur thickness. Wing (Fig. 2) hyaline, slightly tinged grayish; stigma dark brown; veins dark brown; discal cell apically pointed, M₁ and M₂ basally convergent with short petiole; discal cell with a short apical appendage like a very short vein. Squama brown with pale setulae. Halter dark brown.

Abdomen black with pale gray pollinosity. Setulae on tergite blackish, on sternites dark yellow.

Male genitalia (Fig. 3). Epandrial lamella rather large, nearly trapezoid, distinctly higher than long, and with wide upper margin nearly truncate. Surstylus nearly strip-like, hidden below dorsal portion of epandrium. Cercal plate small, tubercle-like, with 5 long setae; clasping cercus rather large, lobate, nearly as long as height of epandrial lamella. Hypandrium somewhat trapezoid in lateral view. Basiphallus long, slightly thick, nearly straight, directed upward near level of upper margin of epandrial lamella; distiphallus long, nearly filiform, and with acute tip.

Female

Unknown.

Type Material

HOLOTYPE ♂, CHINA: Tibet, Nyingchi (N29°38′18″, E94°21′46″), Sejilashan, Zhongshan Station, 4200 m, 20.VIII-10.VII.2014, Malaise trap, leg. Baohai Wang & Zhaohui Pan (CAU).

Distribution

China (Tibet).

Remarks

Two Oriental species, Wiedemannia tibetensis sp. nov. from Tibet and W. glaucescens (Brunetti) from India and Nepal, are closely related and easily separated from the Palaearctic species by the discal cell apically pointed, M₁ and M₂ basally convergent with short petiole, clasping cercus nearly as long as height of epandrial lamella and apical portion wide and obtuse. They cannot be placed in any known species groups of Wiedemannia from the Palaearctic region. This new species may be easily separated from W. glaucescens by the wing with the dark brown stigma, discal cell with a short apical appendage like a very short vein, surstylus nearly strip-like and hidden below dorsal portion of epandrium, basiphallus moderately extended near the level of the upper margin of the epandrial lamella, and distiphallus not swollen without spines at middle. In W. glaucescens, the wing has no stigma, the discal cell has no apical appendage, the surstylus is lobate and exposed in lateral view, the basiphallus is much extended beyond the level of the upper margin of the epandrial lamella, and the distiphallus is swollen with several spines at middle (Brunetti 1917; Wagner et al. 2004).

Etymology

The specific name refers to the type locality Tibet.