Medetera transformata, 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 : 137-138

Taxon classification Animalia Diptera Dolichopodidae

Medetera transformata sp. n. Figs 9, 26-27, 38

Diagnosis.

Width of face about 2.5 times length of first flagellomere. Four pairs of long strong spine-like dc, seven short weak hair-like biseriate acr. CuAx ratio 1.0. Ventral surstylus nearly straight, wide at basal 1/3, sharp apically, with a small preapical protuberance, with one spine-like apical bristle; dorsal surstylus thin, but dilated and U-shaped apically. Cercus strip-like, with dense marginal bristles and three long external bristles at basal 1/4. Hypandrium slightly expanded preapically in ventral view.

Description.

Male (Fig. 9). Body length 2.5 mm, wing length 2.2 mm. Head: vertex, frons and face dark metallic green with gray pollinosity; eyes separated, face nearly parallel, width of face about 2.5 times length of first flagellomere. Hairs and bristles on head black except postocular bristles and posteroventral hairs pale yellow. Antenna (Fig. 26) black; first flagellomere nearly triangular, 1.1 times longer than wide, blunt at tip, shortly brown pubescent; arista apical, black, bare, basal segment short, nearly than 0.15 times length of apical segment. Proboscis black with black apical hairs; palpus black with black apical bristle.

Thorax metallic green with gray pollinosity. Hairs and bristles on thorax black except pp with three pale yellow spine-like bristles in same length. Four pairs of long strong spine-like dc, seven short weak hair-like biseriate acr, two sa. Scutellum with two pairs of sc (median pair long strong). Legs black except trochanters, tip of femora, mid tibia and basal half of mid tarsomere 1 yellow; hind tibia brown. Hairs and bristles on legs mainly pale yellow. Fore coxa with some short dorsal hairs and five-six short apical bristles; mid coxa with one strong outer bristle at middle and one relatively weak bristle at apical 1/3, hind coxa with one outer bristle at middle. Hind femur with five dorsal bristles and six short ventral bristles at basal 1/2. Fore tibia with two short brown apical bristles. Mid tibia with paired black strong ad-pd at basal 1/3 and two black strong apical bristles. Hind tibia with paired ad-pd at apical 1/6 and two short apical bristles. Fore tarsomere 1 with row of short ventral bristles. Hind tarsomere 1 with four short and thick black ventral bristles. Relative length of tibiae and five tarsomeres of legs LI: 2.5: 1.0: 0.8: 0.5: 0.3: 0.4; LII: 3.5: 2.0: 1.0: 0.7: 0.3: 0.4; LIII::3.5: 0.5: 1.7:?:?:? (hind tarsomeres 3-5 missing). Wing nearly hyaline, tinged brown; veins brown, R4+5 and M1+2 convergent apically. CuAx ratio 1.0. Squama pale white with long pale white hairs. Halter pale yellow.

Abdomen dark metallic green with thick gray pollinosity. Hairs and bristles pale yellow. Male genitalia (Fig. 22): Mainly black except epandrial lobes, surstylus and hypandrium dark yellow; cercus and phallus dark brown. Hairs and bristles yellow to pale white. Epandrium longer than wide; epandrial lobes forming one digitation with two long thin apical bristles. Ventral surstylus nearly straight, wide at basal 1/3, sharp apically, with a small preapical protuberance, with one spine-like apical bristle; dorsal surstylus thin, but dilated and U-shaped apically, ventral lobe short and wide, with six digitations each with one apical bristle, dorsal lobe dilated with one small digitation bearing one long apical bristles at basal 1/3 on dorsal margin and four preapical external bristles. Cercus strip-like, thick at basal 1/4 to middle on dorsal margin and apical 1/8 to 1/4 on ventral margin, with dense marginal bristles and three long external bristles at basal 1/4, two short bristles on the thick part of ventral margin and one short preapical bristle on ventral margin, and one apical blade-like bristle. Hypandrium thin and simple, sharp apically, slightly expanded preapically in ventral view. Phallus thin, hidden within hypandrium.

Female. Unknown.

Types.

Holotype male, CHINA, Inner Mongolia, Shuimogou (N49°34'44.8", E125°11'30.1"), 2130 m, collected by sweeping nets in grass, 2014.VII.5, Li Shi (CAU). Paratypes: two males, CHINA, Inner Mongolia, Helan Mountain, Xiangchizigou (N38°59'60.2", E105°70'23.0"), 1950 m, collected by sweeping nets in grass, 2013.VIII.30, Xiao Zhang (CAU); two males, CHINA, Inner Mongolia, Helan Mountain, Xilinguole, Dongwuqi (N46°23'42.8", E118°48'28.7"), 870 m, collected by sweeping nets in grass, 2014.VII.14, Yanan Lv (CAU).

Distribution.

Palaearctic: China (Inner Mongolia).

Remarks.

This new species is unique for the shape of the dorsal surstylus and easily separated from other known species. It is somewhat like Medetera murina Becker, 1917 as they have similar dc, the arista, the bristles on mid tibia, the color of legs and the CuAx ratio; but can be distinguished from the latter by the number of acr, the bristles on fore and mid femora and the shape of cercus. In Medetera murina , thorax has four-five pairs of acr, fore and mid femora each has one av, and the cercus has a deep apical incision. ( Negrobov and Stackelberg 1974: p 321-322, figs 693-695).

Etymology.

The species is named for the shape of the dorsal surstylus.