Polypedilum (Tripodura) nudiprostatum Zhang, Wang & Saether

Zhang, Ruilei, Song, Chao, Qi, Xin & Wang, Xinhua, 2016, Taxonomic review on the subgenus Tripodura Townes (Diptera: Chironomidae: Polypedilum) from China with eleven new species and a supplementary world checklist, Zootaxa 4136 (1), pp. 1-53 : 26

Polypedilum (Tripodura) nudiprostatum Zhang, Wang & Saether

Polypedilum (Tripodura) nudiprostatum Zhang, Wang & Saether, 2006: 43 .

Material examined. Holotype male (BDN No.01560), CHINA: Guangxi Autonomous Region, Longsheng County, Sanmen Town, 26. V. 1990, light trap, X. Wang. Paratype: 1 male, Fujian Province, Jianning County, the forestry bureau of county town, 26. IX. 2002, Z. Liu, light trap.

Diagnostic characters. The species differs from other species of Tripodura in the shape of the straight superior volsella and the trifid anal point with long bare lateral projection.

Key characters of male imago. Total length 1.89 mm, wing length 1.08–1.24 mm. AR 0.58–0.59. Clypeus with 13–14 setae. Wing with 4 markings, 1 at base of cell r4+5, 1 at base of cell m1+2, 1 in cell m3+4 basal and extending to cell cu1 distal, 1 in the middle of cell an. R with 12–14 setae; R1 with 8–9; R4+5 with 14–15. Squama with 5–6 setae. Dorsocentrals 13–16; acrostichals 11–14; prealars 3–4. Scutellum with 9–10 setae. Terminal scale of front tibia with small spur, fore leg ratio 1.88.

Anal tergite bands not fused basal, with 2–3 median setae. Anal point broad and 63–68 µm long; lateral projection without microtrichiae, strongly sclerited and slightly spatulated at apex. Superior volsella 52–60 µm long, with 2 strong diageotropic inner setae at 1/4 apex and 1 outer sub-apical seta; 11–13 slender setae present at apical 1/4. Inferior volsella 65–72 µm long, with 7 oral setae and an apical seta. HR 0.78–0.91. HV 2.01.

Distribution. The superior volsella of the present species without apical extension is unusual in the genus Polypedilum ; relevant discussions on the variation of superior volsella with the genus Polypedilum consult Bidawid & Fittkau (1995) and Zhang et al. (2006). The lateral projections of the anal point are narrow, parallelsided, strongly sclerotized and without setae, i.e. different from nearly all other known species in the subgenus with trifid anal point.