The genus Wiedemannia Zetterstedt is recorded from China for the first time. One species is described from South Tibet: Wiedemannia tibetensis sp. nov. This new species can be separated from the related species Wiedemannia glaucescens (Brunetti) by presence of the pterostigma, discal cell apically with a short appendage, surstylus nearly strip-like and hidden below dorsal portion of epandrium, and distiphallus not swollen without spines at middle. A key to the species of the genus Wiedemannia from the Oriental Region is presented.
The genus Wiedemannia Zetterstedt is a larger genus in the subfamily Clinocerinae with 104 known species, of which 8 species are distributed in the Afrotropical Region, 90 in the Palaearctic, 1 in the Oriental, and 6 in the Nearctic (Yang et al. 2007). The major references dealing with the eastern Palaearctic and Oriental Wiedemannia are as follows: Brunetti (1917); Vaillant (1960); Collin (1961); Joost (1981, 1984); Wagner (1990); Niesiolowski (1992); Wagner et al. (2004).
Up to now only one species, Wiedemannia glaucescens (Brunetti), was known to occur in the Oriental region, recorded from India and Nepal of the Himalayas (Brunetti 1917; Smith 1965; Wagner et al. 2004). Tibet is a plateau region with an average elevation of 4,900 metres in Asia, located in the north-east of the Himalayas. It mostly belongs to the Palaearctic Region except that Southern Tibet is considered as Oriental. This region harbors a peculiar biodiversity, but the dance fly fauna is poorly known (Yang & Yang 2004; Yang et al. 2007). This genus is recorded from China for the first time with the description of a new species from South Tibet, which belongs to the Oriental Region.
Materials and Methods
Type specimen is deposited in the Entomological Museum of China Agricultural University (CAU), Beijing. Morphological terminology generally follows Cumming & Wood (2009), except male terminalia which follows Sinclair (1995). The following abbreviations are used for setae: acr—acrostichal, av—anteroventral, dc—dorsocentral, h—humeral, npl—notopleural, oc—ocellar, ph—posthumeral, psa—postalar, pv—posteroventral, sa—supraalar, sc—scutellar, v—ventral, vt—vertical.
Genus Wiedemannia Zetterstedt
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).
Afrotropical, Palaearctic, Oriental, and Nearctic Regions.
Key to species of Wiedemannia from the Oriental Region
1. Pterostigma present; 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; basiphallus relatively short, moderately extended upward near level of upper margin of epandrial lamella; distiphallus not swollen without spines at middle Wiedemannia tibetensis sp. nov.
—. Pterostigma absent; discal cell apically without short appendage; epandrial lamella with somewhat narrow upper margin nearly convex; surstylus lobate and exposed in lateral view; basiphallus very long, much extended upward beyond upper margin of epandrial lamella; distiphallus swollen with several spines at middle Wiedemannia glaucescens (Brunetti)
Wiedemannia tibetensis sp. nov. (Figs. 1–3)
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.
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.
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).
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).
The specific name refers to the type locality Tibet.
We are very grateful to Ms. Chufei Tang, Mr. Yuqiang Xi, and Mr. Xiao Zhang (Beijing) for their help during the study and to Dr. Zhaohui Pan (Nyingchi) for collecting specimens. Three anonymous reviewers are thanked for providing useful comments on an earlier draft of this paper. The research was funded by the National Natural Science Foundation of China (41301049, 31272354), Special Fund for Basic Scientific Research Projects in Central Scientific Research Institutes (Institute of Grassland Research of CAAS) (1610332014012), and the Ministry of Science and Technology of the Republic of China (MOST Grant 2013DFR30760, 2014FY210200, 2005DKA21402).