The genus Dolichocephala Macquart (Diptera: Empididae) is newly recorded from Tibet, which represents the first record of the subfamily Clinocerinae from this region. A new species, Dolichocephala tibetensis sp. nov., is described. Its relationships with other species in neighboring areas are discussed. A key to the species of the genus Dolichocephala from China is presented.
The genus Dolichocephala Macquart belongs to the subfamily Clinocerinae. It is characterized by the following features: neck arising high on occiput; head extending obliquely forward with distinct clypeus and gena; wing infuscate with clear spots; fore tarsomere 2 much longer than tarsomere 3 or 4; subepandrial sclerite extended beyond base of clasping cercus (Sinclair 1995; Yang et al. 2004). Detailed descriptions of the genus Dolichocephala are in Collin (1961) and Sinclair (1995). There are 39 known species in the world, of which 11 are distributed in the Afrotropical Region, 18 in the Palaearctic Region, 7 in the Oriental Region, 2 in the Australian Region and 2 in the Nearctic Region (Yang et al. 2007). According the previous study, 6 Dolichocephala species are known to occur in China (Fig. 3). The major references dealing with the Palaearctic and Oriental Dolichocephala are as follows: Horvat (1994); Wagner (1995); Wagner et al. (2004); Yang et al. (2004); and Yang (2008).
Tibet is a plateau region in Asia, located northeast of the Himalayas. It is the highest region on earth, with an average elevation of 4,900 m (16,000 ft). It supports a peculiar biodiversity. However, the dance fly fauna is poorly known (Yang & Yang 2004; Yang et al. 2007). Here we report that the genus Dolichocephala is newly recorded from Tibet with a new species (Fig. 3), which represents the first record of the subfamily Clinocerinae from this region. A key to the species of the genus Dolichocephala from China is presented. Type specimens are deposited in the Entomological Museum of China Agricultural University (CAU), Beijing. Morphological terminology generally follows McAlpine (1981). The following abbreviations are used for setae of the head and thorax: acr = acrostichal, de = dorsocentral, h = humeral, npl = notopleural, oc = ocellar, ph = posthumeral, psa =postalar, sa = supraalar, sc = scutellar, vt = vertical.
Key to Species of Dolichocepha from China [Modified from Yang (2008)]
1. Wing with more than 10 small white spots; clasping cercus rather wide, not finger-like 2
—. Wing with 6 or 8 large white spots; clasping cercus narrow, finger-like 4
2. Hypandrium with wide tuft of loose setae; dorso-apical corner of clasping cercus obtuse 3
—. Hypandrium with narrow bundle of compact setae at tip; dorso-apical corner of clasping cercus somewhat acute. Tibet D. tibetensis sp. nov.
3. Male cercus nearly quadrate, with a small inner process at base; epandrial lobe without anterodorsal process; hypandrium apically with wide-spaced row of long setae D. sinica Horvat
—. Male cercus somewhat triangular without inner process at base, but with nearly acute posterior corner; epandrial lobe with short antero-dorsal process; hypandirum with bundle of diverging setae D. irrorata Fallén
4. Wing with 6 large white spots 5
—. Wing with 8 large white spots D. cuiae Yang, Zhang & Yao
5. Thoracic pleuron with a blackish dorsal stripe; clasping cercus strongly curved inward and nearly geniculate; phallus narrow in dorsal view 6
—. Thoracic pleuron without dorsal stripes; clasping cercus weakly curved inward apically and not geniculate; phallus very wide in dorsal view D. orientalis Yang, Zhu & An
6. Mesonotum blackish; clasping cercus with a separate tubercle at base; basiphallus rather wide with angulate posterior process in lateral view D. guangdongensis Yang, Grootaert & Horvat
—. Mesonotum dark yellow with anterior and lateral portions blackish; clasping cercus without separate tubercle at base; basiphallus rather narrow without angulate posterior process in lateral view D. hainanensis Yang
Thorax black. Legs mostly brownish yellow; fore coxa brownish yellow, mid and hind coxae blackish. Wing with many small hyaline spots; 5 hyaline spots in cell r, 3 hyaline spots in cell rM. Clasping cercus thick, with short, somewhat acute anterior apex. Hypandrium with narrow bundle of compact setae at tip.
Body length 2.0–2.8 mm, wing length 2.3–2.4 mm.
Head black with pale gray pollen. Eyes black, distinctly separated; face narrower than frons, narrowed downwards. Setulae and setae on head black; occiput with row of 5 strong postocular setae (uppermost one being vt), lower half of occiput with minute pale setulae; ocellar tubercle weak with 2 long oc and 2 pairs of very short posterior setulae. Antenna black; pedicel with a circle of black apical setulae; first flagellomere short, somewhat quadrate, 1.1 × longer than wide; arista upper apical, 5 × longer than first flagellomere, black, indistinctly pubescent. Proboscis blackish with black setulae; palpus black with black setulae and 2 apical setae.
Thorax black with pale gray pollen. Setulae and setae on thorax black; acr absent, 5 strong dc, 1 long h, 1 long ph, 1 short hair-like npl, 1 long sa, 1 slightly short psa; scutellum with pair of slightly short sc. Laterotergite with 4 short weak blackish setae. Legs mainly brownish yellow except mid and hind coxae are blackish, all trochanters brown, extreme tips of all tibiae brown, and tarsomeres 3–5 brown to dark brown onward. Setulae and setae on legs including those on coxae blackish to black. Fore femur with an erect, preapical anterior comb of short setae. Fore tibia apically with an anterodorsal serration, i.e., about 20 rows of short black setulae arranged in line. Apical 14 th of hind tibia, anterodorsally also with short black comb-like setae. Wing dark gray with many small hyaline spots, of which 5 hyaline spots are in cell r3 and 3 hyaline spots are in cell r2+3; veins dark gray. Squama dark brown with blackish setulae. Halter dark yellow with brown base.
Abdomen black with pale gray pollen. Setulae and setae on abdomen black. Tergum 1 very narrow, i.e. a triangular plate at both sides interconnected with a linear sclerotization. Anterior border of tergum 2 concave, leaving a distinct intersegmental space between terga 1 and 2. Terga 3–6 rectangular. Tergum 7 narrow with apical border concave. Tergum 8 narrow, strip-like; sternum 8 large and broad.
Male genitalia (Fig. 2): Epandrial lobe rather large and somewhat quadrate, with 5 long setae along dorsal margin. Cereal plate very small with 2 long setae; clasping cercus thick, with short, somewhat acute anterior apex curved forward (with apical tooth). Hypandrium nearly quadrate, with narrow bundle of compact setae at tip. Basiphallus rather long and thick, slightly curved; distiphallus rather short, strongly curved in lateral view.
Body length 1.9–2.1 mm, wing length 2.4–2.5 mm. External characteristics similar to male.
HOLOTYPE ♂, CHINA: Tibet, Bomi (N 29° 51′ 42.57″ E 95° 46′ 1.59″), Galonglashan, 2954 m, 2013.VII.9, leg. Xiaoyan Liu (CAU). Paratypes: 5♂, 2♀, same data as holotype (CAU); 1♂, CHINA: Tibet, Linzhi (N 29° 38′ 18″ E 94° 21′ 46″), Sejilashan, Lulangdong, 3260 m, 2012. VIII.18–25, Malaise trap, leg. Zeqing Niu, Huanxi Cao & Qingtao Wu (CAU).
The new species is similar to D. irrorata Fallén and D. sinica Horvat in the color pattern of the wing with many small hyaline spots, but may be separated from these 2 species by the hypandrium with a small bundle of compact setae at tip and dorso-apical corner of the clasping cercus somewhat acute and curved forward. In D. irrorata Fallén and D. sinica Horvat, the hypandrium has a large tuft of loose setae and the dorso-apical corner of the clasping cercus is obtuse (Collin 1961; Niesiolowski 1992; Horvat 1994).
The specific name refers to the type locality Tibet.
We are grateful to Mr. Xiao Zhang (Beijing) for his help during the study. Four 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 (No. 31272354) and the Ministry of Science and Technology of the Republic of China (2005DKA21402, Most Grant 2012FY111100, 2011FY120200).