Olecryptotendipes arienus Yan & Wang, 2017

Yan, Chuncai, Liu, Ting, Zhao, Guangjun, Shi, Yafeng & Wang, Xinhua, 2017, A new species of Olecryptotendipes Zorina from China (Diptera, Chironomidae), Zootaxa 4299 (2), pp. 291-296 : 292-293

Olecryptotendipes arienus Yan & Wang sp. n.

( Figs. 1–6 )

Diagnostic characters. The new species can be separated from other ones in the genus by having banana-like superior volsella, with median black brown spots of thorax; anal tergite bands Y-shaped, transversals and median longitudinal band not fused, and inferior volsella with a moderately developed caudal projection.

Description. Male imago (n=2, unless otherwise stated). Total length 3.53–4.10 mm. Wing length 1.42–2.05 mm. Total length / wing length 2.00–2.49. Wing length / length of profemur 2.00–2.44.

Coloration. Thorax yellowish brown, with slightly dark brown spots ( Fig. 2 ), Legs and abdomen yellowish brown.

Head. AR 1.13–1.64. Ultimate flagellomere 450–540 µm long. Temporal 16–19 setae, including 2–5 inner verticals, 8 outer verticals and 6 postorbitals. Clypeus with 12–16 setae. Tentorium 110–115 µm long, 23–25 µm wide. Palpomere lengths (in µm): 30–33, 35–50, 118–130, 125–138, 175–203. Palp segment 5th / 3rd: 1.48–1.56.

Thorax. ( Fig. 2 ) Antepronotals with 2–7 setae, dorsocentrals 8–10, acrostichals 7–8, prealars 3–4. Scutellum with 12–18 setae.

Wing ( Fig.1 ) VR 1.20–1.28, R with 8–14 setae, R1 with 0–1 seta, R4+5 with 2 setae at apex. Brachiolum 2 setae. Squama with 2–4 setae.

Legs. Front tibia with 3 subapical setae, 105–118, 138–145 and 150 µm long, spurs of middle tibia 30–34 and 33–37 µm long, comb with 30–32 teeth, 10–12 µm long; spurs of hind tibia 35 and 37–38 µm long, comb with 44– 46 teeth, 10–13 µm long. Sensilla chaetica of mid and hind legs absent. Lengths (in µm) and proportions of legs as in Table 1.

Hypopygium ( Figs. 3–6 ). Tergite IX with slightly shoulder-like margin, bearing 16–24 setae at base of anal point. Laterosternite IX with 3–4 setae. Anal point originating from caudal margin of anal tergite, concaved median, rounded apically, 67–70 µm long, 20 (1) µm wide at middle. Anal tergite bands Y-shaped, transversals and median longitudinal band non-fusion. Phallapodeme 75–90 µm long. Transverse sternapodeme 58–73 µm long. Superior volsella banana-like as in Fig. 3 , bearing two long subapical setae and a triangular posterolateral projection in distal 1/3. Inferior volsella with comparatively narrow base and caudal projection, covered with microtrichia. Gonocoxite 80–100 µm long, with 4–5 strong inner marginal setae. Gonostylus 165–205 µm long, strongly joined with gonocoxite, parallel-sided, curved inwards, bearing 8–9 long setae along the basal inner margin, and 10–16 short setae along the distal inner margin. HR 0.46–0.49; HV 1.49–2.02.

Type material. Holotype: ♂ (BDN No. 11599). CHINA: Sichuan Province, Yajiang County, Sandaoqiao Town, 2460 m a.s.l., 9. vi. 1996, light trap, X. Wang. Paratype: 1♂ (BDN No. 09000), Guizhou Province, Wangmo County , 11. viii. 1995, light trap, W. Bu.

Etymology. From Latin ariena, banana, in reference to the banana-like superior volsella.

Distribution. Oriental China (Sichuan and Guizhou Provinces)

Remarks. The species well fit in the genus Olecryptotendipes by Zorina (2007) by having shoulder-like of margin tergite IX, Y-shaped anal tergite bands and special superior volsella. The main difference of morphological characters among the genus are list in table 2 and 3.

Female, pupa and larva are unknown.

Figures

FIGURES 1 – 6. Adult male of Olecryptotendipes arienus Yan & Wang sp. n. 1 – wing; 2 – thorax; 3 – superior volsella; 4 – hypopygium (dorsal view); 5 – photo of hypopygium; 6 – hypopygium (ventral view).