Medetera albens, Tang, Chufei, Wang, Ning & Yang, Ding, 2016

Tang, Chufei, Wang, Ning & Yang, Ding, 2016, New species of Medetera from Inner Mongolia, China (Diptera, Dolichopodidae, Medeterinae), ZooKeys 604, pp. 117-144 : 121-122

Taxon classification Animalia Diptera Dolichopodidae

Medetera albens sp. n. Figs 1, 11-12, 30

Diagnosis.

Width of face approximately twice length of first flagellomere. Arista of first flagellomere apical, becoming black to pale yellow from base to tip. Four pairs of dc (anterior one short, posterior three strong). Acr clear and regular. CuAx ratio 0.5. Legs mainly black. Cercus nearly white, strip-like, sharp apically, with one obvious dentation at basal 1/5, five times longer than wide, apical bristle somewhat claw-like.

Description.

Male (Fig. 1). Body length 2.2 mm, wing length 2.3 mm. Head: vertex, frons and face dark metallic green with gray pollinosity; eyes separated, face nearly parallel, width of face twice length of first flagellomere. Hairs and bristles on head black except postocular bristles and posteroventral hairs pale yellow. Antenna (Fig. 11) black, first flagellomere nearly triangular, almost as long as wide, shortly brown pubescent; arista apical, becoming black to pale yellow from base to tip, bare, with basal segment extremely short, less than 0.1 times length of apical segment. Proboscis brown with pale white apical hairs; palpus brown with pale white apical hairs.

Thorax metallic green with gray pollinosity. Hairs and bristles on thorax black. Four pairs of dc (anterior one short, posterior three strong), four clear regular biseriate acr at anterior portion, two sa. Scutellum with two pairs of sc (median pair long, strong). Legs becoming dark brown to brown from base to tip onward except tip of femora yellow. Hairs and bristles on legs mainly pale yellow. Fore coxa with six dorsal bristles on apical 1/2; mid coxa with three dorsal bristles and one outer bristle at middle. Hind coxa with one outer bristle at middle. Hind trochanter with one outer bristle at middle. Fore femur with two short ventral hairs apically. Mid femur with four ventral bristles at basal half, gradually becoming longer from base to tip onward. Fore tibia with two short black apical bristles. Hind tibia with five short strong apical spurs. Fore tarsomere one with row of 16 short ventral bristles; hind tarsomere 1 with row of 18 short dorsal and 18 short ventral bristles. Relative length of tibiae and five tarsomeres of legs LI: 2.7: 1.5: 0.8: 0.6: 0.5: 0.4; LII: 3.5: 2.0: 1.0: 0.7: 0.4: 0.4; LIII: 4.5: 1.0:1.5: 1.0: 0.5: 0.5. Wing nearly hyaline, tinged brown; veins brown, R4+5 and M1+2 convergent apically. CuAx ratio 0.5. Squama pale white with long white hairs. Halter pale yellow.

Abdomen dark metallic green with thin gray pollinosity. Hairs and bristles pale yellow. Male genitalia (Figs 12, 30): Mainly black except epandrial lobes, surstylus and cercus pale to yellow, phallus brown. Hairs and bristles pale yellow. Epandrium longer than wide, epandrial lobes small, fused at base, each with one slender apical bristle. Ventral surstylus long, wide, slightly wide at apex, with three short apical bristles; dorsal surstylus wide and rounded apically, with three short apical bristles. Cercus nearly white, strip-like, narrowed towards tip, with an obvious dentation at basal 1/5; marginal bristles present on weak digitations, five times longer than wide, apical bristle somewhat claw-like. Hypandrium tilted up apically, blunt apically. Phallus thin, hidden within hypandrium.

Female. Unknown.

Types.

Holotype male, CHINA, Inner Mongolia, Helan Mountain, Gulaben, Zhonggutian (N39°09'51.29", E106°05'82.66 '’), 1892 m altitude, collected by sweeping nets in grass, 2014.VII.13, Yanan Lv (CAU). Paratype: one male, same data as holotype (CAU).

Distribution.

Palaearctic: China (Inner Mongolia).

Remarks.

This new species is quite unique due to its special arista and the simple shape of the surstylus. It is easily distinguished from the other species of the Medetera apicalis group.

Etymology.

The specific name refers to the color of the arista, which becomes black to pale yellow gradually from base to tip.