Rhaphium tianshuiense, Qilemoge,, Wang, Mengqing & Yang, Ding, 2019

Qilemoge,, Wang, Mengqing & Yang, Ding, 2019, Three new species of Rhaphium from China, with an updated key to Chinese Rhaphium (Diptera, Dolichopodidae, Rhaphiinae), ZooKeys 840, pp. 87-99 : 87

Rhaphium tianshuiense sp. n. Figures 2, 8, 9

Diagnosis.

First flagellomere about 1.8 times longer than wide; arista with basal segment 0.1 times as long as apical segment. Legs mainly yellow; fore coxa mainly yellow, black basally, mid and hind coxae mainly black, yellow apically; fore femur black dorsally, hind femur black apically; hind tarsus entirely black. Fore coxa with two black bristles, mid coxa with one black bristle at apical half, apically with a bunch of black bristles, hind coxa with one black outer bristle. CuAx ratio 0.52. Surstylus basally thick, apically sharp, with one protuberance. Cercus bifoliate, outer lobe long strip-like, apical curlily with one long strong bristle; inner lobe short, 1/4 as long as outer lobe.

Description.

Male (Fig. 2). Body length 3.8-4.0 mm. Wing length 3.1-3.3 mm.

Head metallic green with pale gray pruinescence. Frons with white pruinescence. Face dark metallic green with silvery white pruinescence, not as wide as first flagellomere (length). Upper postocular bristles black, middle and lower postocular bristles yellow. Two oc, two vt, two pvt. Antenna (Fig. 8) black; first flagellomere elongated, about 1.8 times longer than wide, apically sharp; arista black, apical position, basal segment 0.1 times as long as apical segment. Proboscis black with black hairs, palpus black with black apical bristle and hairs.

Thorax metallic green with pale gray pruinescence. Mesonotum without dark spot. Hairs and bristles on thorax black. Five strong dc, four irregular pairs of acr, two strong npl, one strong sa, two strong pa; scutellum with two pairs of sc, medial pair pubescent, lateral pair strong.

Legs mainly yellow; fore coxa mainly yellow, black basally, mid and hind coxae mainly black, yellow apically; fore femur black dorsally, hind femur black apically; fore tarsus black from tip of tarsomere 2 onwards, mid tarsus from tip of tarsomere 3 onward black, hind tarsus entirely black. Hairs and bristles on legs black. Fore coxa with two bristles, mid coxa with one black bristle at apical half, apically with a bunch of black bristles, hind coxa with one black outer bristle. Mid and hind femora each with one black preapical bristle. Fore tibia with two ad, three pd, and two apical bristles, av absent,; mid tibia with three ad, four pd, one av, and three apical bristles; hind tibia with two ad, three pd, and three apical bristles, av absent. Relative lengths of tibia and 5 tarsomeres of fore leg 2.2: 1.3: 1.2: 0.5: 0.5: 0.3; mid leg 3.2: 1.7: 1.0: 0.7: 0.5: 0.3; hind leg 4.2: 1.2: 1.3: 1.0: 0.7: 0.4. Wing hyaline, veins black; M bent medially, M and R4+5 parallel apically; CuAx ratio 0.52. Squama yellow with black hairs. Halter yellow.

Abdomen entirely metallic green with pale gray pruinescence. Hairs and bristles on abdomen black. Male genitalia (Fig. 9): epandrium black, nearly as long as wide. Surstylus yellow, basally thick, apically sharp, with one protuberance, without distinct bristles. Cercus bifoliate, outer lobe long strip-like, curled apically with one long strong bristle; inner lobe short, 1/4 as long as outer lobe, apically sharp with strong bristles.

Female. Unknown.

Types.

Holotype male, CHINA, Gansu, Tianshui, Maiji Mountain, 1,396 m, collected by sweep net in grassland, 2012.VII.16, leg. Zehui Kang. Paratypes: two males, same data as holotype; four males, Beijing, Miyunxian, Caojialucun, 561 m, collected by sweep net in grassland, 2013.V.23, leg. Xunkun Li.

Distribution.

Palaearctic: China (Gansu, Beijing).

Remarks.

The new species is similar to R. mediocre (Becker, 1922), but the two species can be separated by several features. In R. tianshuiense , the squama with black hairs, the surstylus is basally thick, apically sharp, has one protuberance and the cercus is bifoliate (Fig. 9). In R. mediocre , the squama with yellow hairs, the surstylus is short and thick, the cercus is not bifoliate ( Yang et al. 2011: 1258, fig. 806).

Etymology.

The specific name refers to the type locality, Tianshui.