Medetera bisetifera, 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 : 122-125

Taxon classification Animalia Diptera Dolichopodidae

Medetera bisetifera sp. n. Figs 2, 13-14, 31

Diagnosis.

Width of face about 1.5 times length of first flagellomere. Three pairs of long strong dc in same length, six biseriate acr. Legs mainly yellow, mid femur yellow except narrow blackish dorsal portion. CuAx ratio 0.3. Cercus strip-like, six times longer than wide, ventral margin with three bristles at apical 1/5; tip with two digitations each with one apical bristle. Phallus with distinct preapical lateral wings in ventral view.

Description.

Male (Fig. 2). Body length 1.8 mm, wing length 1.5 mm. Head: vertex, frons and face dark metallic green with gray pollinosity; eyes separated, face nearly parallel, width of face approximately 1.5 times length of first flagellomere. Hairs and bristles on head black except postocular bristles and posteroventral hairs pale yellow. Antenna (Fig. 13) black; first flagellomere flat, shortly brown pubescent; arista apical, black, bare, with basal segment extremely short, less than 0.1 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. Three pairs of long strong dc in same length, six hair-like biseriate acr, two sa. Scutellum with two pairs of sc (median pair long, strong). Legs mainly yellow but coxae, trochanters and all tarsomere 5 black, fore and hind femora dark yellow to yellow except mid femur with narrow blackish portion dorsally. Hairs and bristles on legs mainly pale white. Fore coxa with seven strong anterior bristles; mid coxa with three strong anterior bristles and one outer bristle; hind coxa with one outer bristle at middle and single apical bristle. Mid femur with 12 short dorsal bristles in a row. Mid tibia with one brown paired ad-pd at basal 1/3. Hind tibia with four ventral bristles in apical half and three black apical bristles. Relative length of tibiae and five tarsomeres of legs LI: 2.0: 1.0: 0.5: 0.4: 0.2: 0.3; LII: 2.5: 1.0: 0.5: 0.4: 0.3: 0.3; LIII: 2.5: 0.6: 1.0: 0.5: 0.3: 0.2. Wing nearly hyaline, tinged brown; veins light brown, R4+5 and M1+2 convergent apically. M1+2 somewhat curve. CuAx ratio 0.3. Squama pale white with short pale hairs. Halter pale yellow.

Abdomen dark metallic green with thin gray pollinosity. Hairs and bristles pale yellow. Male genitalia (Figs 14, 31): Mainly black except epandrial lobes, surstylus and cercus yellow. Hairs and bristles yellow to white. Epandrium longer than wide, epandrial lobes thin finger-like, each with single long thin apical bristle. Ventral surstylus widened towards tip, straight at apex, with row of eight short apical bristles; dorsal surstylus wide and U-shaped apically, straight and thin, ventral lobe with one short apical bristle, dorsal lobe with nine bristles. Cercus strip-like, long, narrowed towards tip, six times longer than wide, base slightly dilated; ventral margin with three bristles at apical 1/5, dorsal margin with dense marginal bristles, tip with two digitations each with one apical bristle. Hypandrium simple. Phallus with distinct preapical lateral wings in ventral view.

Female. Body length 1.9 mm, wing length 1.7 mm. Similar to male except the narrow blackish dorsal portion of mid femur is nearly indistinct.

Types.

Holotype male, CHINA, Inner Mongolia, Tongliao, Daqinggou (N42°49'16.6", E122°10'58.0"), 180 m alt., collected by sweeping nets in grass, 2014.VII.6, Ding Yang & Ning Wang (CAU). Paratypes: three females, same data as holotype (CAU).

Distribution.

Palaearctic: China (Inner Mongolia).

Remarks.

This new species is somewhat similar to Medetera gussakovskii Negrobov, 1966 because they both have three dc of same length, they both have two sa, their legs are both mainly yellow and their CuAx ratio are similar (in latter it is 0.32), but can be distinguished from the latter by the color of the antenna and the mid femur as well as the apical bristle of cercus. In Medetera gussakovskii , the scape and the pedicel of antenna are yellow and the mid femur is wholly yellow, the cercus has one strong peg-like apical bristle instead of the two digitations with bristles ( Negrobov and Stackelberg 1972: p 304, figs 555-557).

Etymology.

The specific name refers to the two digitations of the cercus which each has an apical bristle.