Olecryptotendipes exilis sp. n.

Yan, Chun-Cai, Wang, Xin-Hua & Bu, Wen-Jun, 2012, Two new species of Olecryptotendipes Zorina, 2007 from China (Diptera, Chironomidae), ZooKeys 208, pp. 41-49 : 42-44

Olecryptotendipes exilis sp. n. Figs 1-4

Diagnostic characters.

The species is separated by the slender posterolateral projection of the superior volsella and the lobate inferior volsella, the posterolateral weak lobes of the anal tergite, and the parallel-sided anal point.

Description.

Male imago (n=2). Total length 2.70−2.94 mm. Wing length 1.38−1.50 mm. Total length / wing length 1.96. Wing length / length of profemur 1.92−2.08.

Coloration. Thorax and legs dark brown. Abdomen with tergite I–V yellowish brown and tergite VI–VIII and hypopygium dark brown.

Head. AR 1.97−2.02. Ultimate flagellomere 590−600 mm long. Frontal tubercles absent. Temporal 13−15 setae, including 4 inner verticals, 5−6 outer verticals and 4−5 postorbitals. Clypeus with 13 setae. Tentorium 103−110 mm long, 28−30 mm wide. Palpomere lengths (in mm): 36−38, 38−40, 118−120, 140−145, 203−210. Palp segment 5th / 3rd 1.72−1.75.

Thorax. Antepronotals with 6−7 setae, dorsocentrals 8−10, acrostichals 8, prealars 3. Scutellum with 12−13 setae.

Wing (Fig. 1). VR 1.19−120, R with 16−18 setae, R1 with 8−10 setae, R4+5 with 10−11 setae. Brachiolum 2 setae. Squama with 2−3 setae.

Legs. Front tibia with 3 subapical setae, 113−120, 138−144 and 141−150 µm long, spurs of mid tibia 30−35 and 37−46 µm long excluding comb, comb with 32−36 teeth, 10 µm long; spurs of hind tibia 28−30 and 38−47 µm long excluding comb, comb with 42−48 teeth, 10−12 µm long. Ta1 of mid legs with only 1 sensilla chaetica, sensilla chaetica absent in hind legs. Lengths (in µm) and proportions of legs as in Table 1.

Hypopygium (Figs 2−4). Tergite IX with weak lobes bearing 3−4 setae at each side of base of anal point. Laterosternite IX with 3 setae. Anal point 45−50 mm long, 5−6 mm wide, originating from caudal margin of anal tergite, completely parallel-side. Anal tergite bands Y-shaped. Phallapodeme 75−82 mm long. Transverse sternapodeme 56−60 mm long. Superior volsella (Fig. 4) slightly curved, with apical, partially sclerotized beak-like protrusion and slender spur-like posterolateral projection, bearing two long setae beside the beak-like protrusion, and covered with microtrichia in inner parts. Inferior volsella with a moderately blunt caudal projection, covered with microtrichia, and not reaching beyond margin of anal tergite. Gonocoxite 98−104 mm long, with 4 strong inner marginal setae. Gonostylus 168−175 mm long, slightly swollen at base, curved medially, moderately slender to apex, bearing 17−20 setae along inner margin. HR 0.58−0.59; HV 1.61−1.68.

Type material.

Holotype ♂ (BDN No. 1291). CHINA: Hainan Province, Ledong Li Nationality Autonomous County, Jianfengling Nature Conservation area, 18°14'45.96"N, 109°30'42.69"E, 21.iv.1985, X. Wang. Paratype 1♂ (BDN No. 03578), same data as holotype.

Etymology.

From Latin exilis, slender, in reference to the slender posterolateral projections of superior volsella.

Distribution.

The species was collected in a subtropical mountain area in Hainan province in Oriental China.