Compterosmittia duodecima, Lin, Xiaolong, Yao, Yuanyuan, Liu, Wenbin & Wang, Xinhua, 2013

Lin, Xiaolong, Yao, Yuanyuan, Liu, Wenbin & Wang, Xinhua, 2013, A review of the genus Compterosmittia Saether, 1981 (Diptera: Chironomidae) from China, Zootaxa 3669 (2), pp. 129-138 : 130-132

Compterosmittia duodecima sp. n.

( Figs 1–6 )

Type material. Holotype male (BDN No. I4 B6), China: Zhejiang Province, Quzhou City, Kaihua County, Gutian Mountain, 29°14’35’’N, 118°06’41’’E, 18.iv.2011, X. Lin, sweep net. Paratypes: 2 males, Zhejiang Province, Taizhou City, Xianju County, Shenxianju Scenic Area, 28°42’14’’N, 120°36’25’’E, 14.iv.2011, X. Lin, sweep net.

Diagnostic characters. The adult male of the new species can be distinguished from known species of the genus by the following combination of characters: antenna with 12 flagellomeres; low AR (0.35–0.39); wing membrane with several setae in apical part of r4+5; anal point triangular, acute.

Etymology. The specific name, derived from Latin duodecim (twelve), refers to the antenna with 12 flagellomeres.

Description. Adult male (n = 3)

Total length 1.80–1.96 mm. Wing length 1.10–1.18 mm. Total length/wing length 1.63–1.74. Wing length/ length of profemur 2.27–2.61.

Coloration. Head, thorax, legs and abdomen light brown.

Head. AR 0.35–0.39. Antenna ( Fig. 1 ) with 12 flagellomeres, ultimate flagellomere 135–155 μm long. Temporal setae 5–7, including 2–4 inner verticals; 2 outer verticals and 1 postorbital. Clypeus with 13–17 setae. Tentorium, stipes and cibarial pump as in Fig. 2 . Tentorium 100–125 μm long, 15–25 μm wide. Stipes 90–100 μm long, 5 μm wide. Palpomere lengths (in μm): 13–20; 23–28; 50–60; 50–58; 73–90. Length ratio of palpomeres 5/3 1.46–1.50.

Wing ( Fig. 3 ). Anal lobe reduced. VR 1.46–1.68. Costal extension 115–140 μm long. Brachiolum with 1 seta. R with 9–11 setae; R1 with 3–5 setae; R4+5 with 0–1 seta. Wing membrane with 3–11 setae in cell r4+5. Remaining veins and cells bare. Cu1 strongly sinuous. Squama bare.

Thorax ( Fig. 4 ). Antepronotum without seta. Dorsocentrals 12–16; acrostichals 7–9; prealars 3–4; supraalar 0– 1. Scutellum with 4 setae.

Legs. Spur of fore tibia 25–33 μm long; spurs of mid tibia 15–20 μm and 15–20 μm long; spurs of hind tibia 35–40 μm and 15–18 μm long. Hind tibial comb with 6–13 spines, 20–43 μm long. Width of fore tibia at apex 29– 40 Μm, of mid tibia 23–35 Μm, of hind tibia 35–45 Μm. Lengths (in μm) and proportions of legs as in Table 1 .

Hypopygium ( Figs 5–6 ). Anal point triangular, acute, 33–40 μm long, 30–45 μm wide at base; with 6–8 strong lateral setae, free of microtrichia excepting base. Laterosernite IX with 3 setae. Phallapodeme 52–60 μm long. Transverse sternapodeme arcuate with developed oral projection, 60–65 μm long. Gonocoxite 135–150 μm long. Inferior volsella thumb-shaped, with rounded projection orally. Gonostylus 65 μm long. Megaseta dentate, 10 μm long. Virga weak, 39–41 μm long. HR 2.08–2.31. HV 2.77–3.01.

Remarks. The new species resembles C. oyabelurida (Sasa, Kawai et Ueno, 1988) in having the low AR (0.40), but it can be separated from the latter species on the basis of following characters: (1) the antenna of C. duodecima with 12 flagellomeres, whereas the antenna with 13 flagellomeres in the latter species; (2) the cell r4+5 of C. duodecima with 3–11 setae, whereas the cell r4+5 without seta in the latter species; (3) the anal point of C. duodecima with pointed apex, but rounded in the latter species.

Female and immatures unknown.

Figures

FIGURES 1 – 6. Compterosmittia duodecima sp. n., male. 1 — antenna; 2 — cibarial pump, tentorium and stipes; 3 — wing; 4 — thorax; 5 — hypopygium, dorsal view; 6 — hypopygium, ventral view.

Tables

TABLE 1. Lengths (in μm) and proportions of legs of Compterosmittia duodecima sp. n. (n = 3).

fe	ti	ta1	ta2	ta3	ta4
P1 450–485	500–520	350–375	178–185	118–125	70–75
P2 460–490	470–500	250–270	110–115	75–90	50–55
P3 490–520	530–580	330–350	120–165	120–145	60–75
ta5	LR	BV	SV	BR
P1 60–70	0.70–0.72	3.02–3.03	2.68–2.75	1.57–1.75
P2 50–58	0.53–0.54	3.83–4.24	3.67–3.73	1.85–3.00
P3 55–60	0.59–0.66	3.29–4.28	2.91–3.18	1.56–2.22