Medetera triseta, 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 : 125-126

Taxon classification Animalia Diptera Dolichopodidae

Medetera triseta sp. n. Figs 3, 15, 32

Diagnosis.

Width of face approximately twice length of first flagellomere. Three pairs of long strong dc in same length, four hair-like biseriate acr. CuAx ratio 0.67. Legs mainly black. Ventral surstylus with one external bristle at apical 1/3 on ventral margin, one long apical bristles; dorsal lobe of dorsal surstylus dilated. Cercus strip-like, 2.5 times longer than wide, with blade-like bristles at apex and ventral apical 1/4 point. Phallus and hypandrium both normal in lateral and ventral view.

Description.

Male (Fig. 3). Body length 2.0-2.3 mm, wing length 1.75-1.9 mm. Head: vertex, frons and face dark metallic green with gray pollinosity; eyes separated, face nearly parallel, width of face nearly twice length of first flagellomere. Hairs and bristles on head black except postocular bristles and posteroventral hairs pale yellow. Antenna black, first flagellomere oval, 1.2 times longer than wide, shortly brown pubescent; arista apical, black, bare, with basal segment short, nearly 0.1 times length of apical segment. Proboscis black with black apical hairs; palpus black with black apical hairs and one black apical bristle.

Thorax dark metallic green with gray pollinosity. Hairs and bristles on thorax black except pp with three pale white spine-like bristles. Three pairs of long strong dc in same length, four hair-like biseriate acr, two sa. Scutellum with two pairs of sc (median pair long strong). Legs black except apical half of femora, middle 1/3 of fore tibia, mid tibia and main portion of hind tibia, basal half of fore and mid tarsomere 1 yellow. Hairs and bristles on legs mainly pale yellow. Fore coxa with row of 12 short dorsal bristles; mid and hind coxae each with one strong outer bristle at middle and one apical bristle. Mid and hind trochanters each with one spine-like outer bristle at middle. Hind femur with six dorsal bristles and eight short ventral bristles at basal 1/2. Fore tibia with three short apical bristles. Mid tibia with one paired black strong ad-pd at basal 1/5 and two black strong apical bristles. Hind tibia with row of six weak ad at apical 1/3 and two short apical bristles. Hind tarsomere 1 with row of short ventral bristles and two apical bristles. Hind tarsomere 2 with six short av. Relative length of tibiae and five tarsomeres of legs LI: 3.5: 2.0: 1.2: 0.8:?:?; LII: 5.0: 3.0: 1.5: 1.0: 0.7: 0.6; LIII: 5.0: 1.3: 3.0: 1.3: 0.5: 0.4 (fore tarsomeres 4-5 missing). Wing nearly hyaline, tinged brown; veins brown, R4+5 and M1+2 convergent apically. CuAx ratio 0.67. Squama pale white with long pale white hairs. Halter pale yellow.

Abdomen dark metallic green with thick gray pollinosity. Hairs and bristles pale white. Male genitalia (Figs 15, 32): Mainly black except epandrial lobes, surstylus, hypandrium and cercus dark yellow; phallus dark brown. Hairs and bristles yellow to pale white. Epandrium longer than wide; epandrial lobes forming two digitations each with one long thin apical bristle. Ventral surstylus nearly straight, slightly narrower at apical 1/6, blunt at tip, with one external bristle at apical 1/3 on ventral margin, one long and three short apical bristles; dorsal surstylus thin, dilated and U-shaped apically, straight and thin, with ventral lobe thin, sharp at tip, with one long apical bristle, dorsal lobe dilated with three normal apical bristles and one long apical bristle. Cercus strip-like, 2.5 times longer than wide, invaginated at basal 1/3 to apical 1/3 on ventral margin, thick at apical 1/4 to apical 1/3, with dense thin marginal bristles at dorsal margin, one long blade-like apical bristle, one blade-like bristle at apical 1/4 on ventral margin. Hypandrium thin and simple, sharp apically. Phallus thin and normal, 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: one male, same data as holotype (CAU); five males, CHINA, Inner Mongolia, keerqinhan, (N46°10'32.8", E122°03'20.5"), 460m, collected by sweeping nets in grass, 2008.VII.19, Gang Yao (CAU); one male, CHINA, Inner Mongolia, Xilinguole (N44°63'69.4", E117°54'35.7"), 1000.4 m, collected by sweeping nets in grass, 2014.VII.13, Yanan Lv (CAU); one male, CHINA, Inner Mongolia, Aergeqihamula (N48°46'42.3", E117°25'21.5"), 598.2 m, collected by sweeping nets in grass, 2014.VII.17, Yanan Lv (CAU).

Distribution.

Palaearctic: China (Inner Mongolia).

Remarks.

This new species is somewhat similar to Medetera turkestanica Stackelberg, 1926 because they both have three strong dc of similar length, their legs are both mainly black, their CuAx ratio are both 0.67 and their face both have gray pollinosity, but can be distinguished from the latter by the color of legs. In Medetera turkestanica , legs are all dark metallic green, nearly brown. There is no detailed description of male genitalia of Medetera turkestanica , but we are sure they are different species ( Negrobov and Stackelberg 1974: 349).

Etymology.

The species is named for the three claw-like bristles on the cercus.