Polypedilum (Polypedilum) depile, Zhang, Ruilei & Wang, Xinhua, 2008

Zhang, Ruilei & Wang, Xinhua, 2008, Three new species of Polypedilum s. str. Kieffer from China, with L-shaped superior volsella (Diptera: Chironomidae), Zootaxa 1702, pp. 61-68 : 63-65

Polypedilum (Polypedilum) depile sp. nov.

( Fig. 2 )

Type material: Holotype male, CHINA: Henan Province, Songxian County, Baiyun Mountain, Forest Farm, 15.vii.1996, sweep net, J. Li (BDN. No. 10232). Paratypes: 7 males, data as in holotype. Etymology: From Latin depilis, without hair, referring to the lack of setae on squama. Diagnostic characters: The cuneiform wing with bare squama is unique within the genus. Male (n = 6)

Total length 2.05–2.25, 2.12 mm. Wing length 1.40–1.65, 1.52 mm. Total length / wing length 1.36–1.45, 1.40. Wing length / length of profemur 2.25–2.41, 2.34.

Coloration. Head brown with yellow palpomeres. Thorax brown with darker vittae, postnotum and preepisternum, halteres dark brown. Femora brown, paler in distal 1/2–1/4; foretibia brown, mid and hind tibiae yellow. Abdominal segment I and hypopygium brown, other segments yellow.

Head. Frontal tubercles absent. AR 1.11–1.27, 1.18; ultimate flagellomere 400–470, 445 µm long. Temporal setae 8–10, 9, including 2–3, 3 inner verticals, 3–4, 4 outer verticals, and 2–4, 3 postorbitals. Clypeus with 10–13, 11 setae. Tentorium 90–105, 99 µm long; 15–23, 17 µm wide. Palpomere lengths (in µm): 20–38, 28; 23–35, 30; 65–83, 74; 73–83, 77; 113–145, 129.

Wing ( Fig. 2 A) cuneiform, with bare squama. VR 1.21–1.27, 1.24. R with 5–11, 8 setae; R1 with 0–3, 2; R4+5 with 1–4, 2 setae.

Thorax. Dorsocentrals 9–10, 10; acrostichals 5–9, 7; prealars 4. Scutellum with 6–7, 7 setae.

Legs. Scale of foretibia 23–30, 27 µm long, triangular, with rounded apex ( Fig. 2 B). Spur of midtibia 43– 50, 45 µm long, including 20–25, 22 µm long comb; un-spurred comb 18–25, 21 µm long. Spur of hind tibia 45–55, 51 µm long, including 28–35, 31 µm long comb; un-spurred comb 20–25, 23 µm long. Width at apex of foretibia 40–45, 43 µm; of midtibia 38–45, 42 µm; of hind tibia 43–53, 49 µm. Lengths (in µm) and proportions of legs as in Table 2 .

Hypopygium ( Fig. 2 C–E). Anal tergite bands distinct, not fused basally. Tergite IX with 5–8, 7 median setae. Laterosternite with 2–3, 2 setae. Anal point 43–53, 48 µm long, slender, with basal half tapering and apical half parallel-sided. Phallapodeme 80–90, 95 µm long; transverse sternapodeme 40–45, 43 µm long. Gonocoxite 125–135, 129 µm long. Superior volsella ( Fig. 2 C) strongly bent medially, with 1 strong lateral seta medially and 3 weaker subapical seta. Inferior volsella 115–135, 125 µm long, slender, apically weakly swollen, with 1 strong apical seta projecting caudad, and 8–10 orally directed setae some of which are split apically. Gonostylus 140–150, 146 µm long; with 5–6 setae along inner margin and 1 apical seta. HR 0.85– 0.90, 0.89; HV 1.43–1.50, 1.45.

Distribution. The species was collected in a mountain area in Henan Province, Palaearctic China.

Remarks. The squama of Polypedilum (P.) depile is bare, which is not in accordance with the diagnosis of the genus Polypedilum given by Cranston et al. (1989). The diagnosis should thus be emended to "squama with relatively few long setae, sometimes bare".

Figures

FIGURE 2. Polypedilum (Polypedilum) depile sp. nov., male imago. A. Wing. B. Fore tibial scale. C. Superior volsella. D. Hypopygium, dorsal view. E. Hypopygium, ventral view.

Tables

TABLE 2. Lengths (in µm) and proportions of legs of Polypedilum (Polypedilum) depile sp. nov., male (n = 6, except when otherwise stated).

	fe	ti	ta1	ta2	ta3	ta4	ta5 LR
p1	580–690, 650	365–400, 385	630–700 (2)	355–380 (2)	280–285 (2)	175–180 (2)	100–105 (2) 1.73–1.82 (2)
p2	600–710, 660	410–540, 483	300–370, 334	125–140, 130	105–125, 111	55–75, 63	48–58, 53 0.68–0.73, 0.70
p3	670–810, 752	530–640, 590	425–510, 464	200–240, 218	175–215, 194	110–125, 118	75–80, 77 0.73–0.83, 0.79