Medetera flava, 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 : 126-129

Taxon classification Animalia Diptera Dolichopodidae

Medetera flava sp. n. Figs 4, 16-17, 33

Diagnosis.

Width of face about 1.7 times length of first flagellomere. First flagellomere somewhat rectangular, 0.4 times as long as wide. Four pairs of dc of which posterior three pairs long strong, Five hair-like biseriate acr. Pp with three pale yellow spine-like bristles in equal length. CuAx ratio 0.8. Legs almost entirely yellow. Basolateral bristle of epandrial lobe wholly feather-like. Cercus strip-like, tip depressed at middle, margin on invagination slightly raised at middle, with one short blade-like apical bristle.

Description.

Male (Fig. 4). Body length 2.8 mm, wing length 2.5 mm. Head: vertex, frons and face dark metallic green with gray pollinosity; eyes separated, face nearly parallel, width of face about 1.7 times length of first flagellomere. Hairs and bristles on head black except postocular bristles and posteroventral hairs pale yellow. Antenna (Fig. 16) black; first flagellomere somewhat rectangular, 0.4 times as wide as long; arista apical, black and bare, with basal segment extremely short, less than 0.1 times length of apical segment. Proboscis black with pale yellow apical hairs; palpus black with black apical hairs.

Thorax dark metallic green with gray pollinosity. Hairs and bristles on thorax black except pp with three pale yellow spine-like bristles in equal length. Four pairs of dc of which posterior three pairs long strong, five hair-like biseriate acr, two sa. Scutellum with two pairs of sc (median pair long, strong). Legs mainly yellow, but base of fore coxa, mid and hind coxae, extreme base of hind tarsomere 1, apical half of tarsomere 3 and tarsomeres 4-5 black. Hairs and bristles on legs mainly pale yellow. Fore coxa with three apical bristles; mid and hind coxae each with one strong outer bristle at middle and one outer bristle at apical 1/2. Mid femur with six pairs of weak av-pv. Hind femur with six dorsal bristles and eight short ventral bristles, all very thin. Mid tibia with one black ad-pd pair at basal 1/4 and two apical bristles. Hind tibia with eight short ad at apical 1/4 and three apical bristles. Fore and mid tarsomeres 2-4 each with three short black apical bristles. Hind tarsomere 2 with row of 12 short spine-like bristles. Relative length of tibiae and five tarsomeres of legs LI: 2.5: 1.3: 1.0: 0.5: 0.4: 0.4; LII: 3.5: 2.0: 1.0: 0.6: 0.5: 0.3; LIII: 4.0: 0.8: 2.0: 1.0: 0.5: 0.4. Wing nearly hyaline, tinged brown; veins brown, R4+5 and M1+2 convergent apically. CuAx ratio 0.8. Squama pale white with long pale hairs. Halter pale yellow.

Abdomen dark metallic green with thick gray pollinosity. Hairs and bristles pale yellow. male genitalia (Figs 17, 33): Mainly black except epandrial lobes, surstylus and cercus brown. Hairs and bristles yellow to pale white. Epandrium longer than wide, epandrial lobes forming one digitation with two long and slender apical bristles, of which basolateral bristle of epandrial lobe wholly feather-like. Ventral surstylus narrowed towards tip, almost straight except one wave near base, tip blunt, with row of six apical bristles; dorsal surstylus wide and U-shaped apically, thin, bent at middle, with one long bristle at apical 1/10, ventral and dorsal lobes each with one short apical bristle. Cercus strip-like, raised at middle on dorsal margin, three times longer than wide; dorsal margin with dense marginal bristles, tip depressed at middle, margin on depression slightly raised at middle, with short dense bristles and one short blade-like bristle apically. Hypandrium simple. Phallus thin, hidden within hypandrium.

Female. Body length 3.0 mm, wing length 2.5 mm. Similar to male.

Types.

Holotype male, CHINA, Inner Mongolia, Tumujinur Nur (N46°17'17.6", E122°10'58.0"), 220 m, collected by sweeping nets in grass, 2014.VII.23, Yanan Lv (CAU). Paratypes: 3 females, same data as holotype (CAU).

Distribution.

Palaearctic: China (Inner Mongolia).

Remarks.

This new species is somewhat similar to Medetera diadema Linnaeus, 1767 because they both have black antenna, yellow tibia and one ad, one pd on mid tibia, their bristles on pp are nearly in same length, but can be distinguished from the latter by the CuAx ratio and the color of legs and the bristles on epandrial lobe and cercus. In Medetera diadema , the CuAx ratio is 0.56, the coxae and the tarsi are brown, the bristle on epandrial lobe is normal, the cercus has a claw-like apical bristle and one long apical process ventrally ( Negrobov and Stackelberg 1972: 296, figs 505-506).

Etymology.

The specific name refers to the nearly entirely yellow color of the legs.