Demicryptochironomus (Irmakia) retusus, Yan & Saether & Jin & Wang, 2008

Yan, Chuncai, Saether, Ole A., Jin, Zhaohui & Wang, Xinhua, 2008, Three new species of the Harnischia complex from the Sino-Indian Region, with a review of Demicryptochironomus Lenz (Diptera: Chironomidae), Zootaxa 1968, pp. 1-22 : 15-16

Demicryptochironomus (Irmakia) retusus sp. n.

( Figs 28–30)

Type material. Holotype male ( BDN No. 24108), CHINA: Jiangxi Province, Wuyi Mountain Nature Conservation Area , 13.vi. 2004, 900 m a.s.l., light trap, C. Yan . Paratypes ( BDN Nos 24114, 24115): 2 males, same as holotype .

Diagnostic characters. The species closely resembles D. (I.) spatulatus Wang et Zheng in the antennal ratio and the swollen anal point. It can be distinguished by the shoulder-like posterior margin of tergite IX, the superior volsella with 3 setae and small notches distally, and by having the gonostylus bent in distal 1/3.

Etymology. From Latin retusus , notch, referring to the distal notch of the superior volsella.

Male (n = 3, unless otherwise stated). Total length 3.20–3.48, 3.36 mm. Wing length 1.68–1.85, 1.67 mm. Total length/wing length 1.73–2.07, 1.91. Wing length/length of profemur 1.95–2.11, 2.01.

Coloration. Thorax yellowish brown, with vittae, mid preepisternum, median anepisternum and anterior 1/3 of postnotum dark brown. Foreleg with femur yellowish brown, tibia blackish brown, and tarsi dark brown; mid- and hind legs with femur and tibia yellowish brown, tarsi dark brown with ta 5 blackish brown. Abdomen with tergite I–V yellowish green, tergite VI–VIII and hypopygium dark brown.

Head. AR 1.91–2.16, 2.00. Ultimate flagellomere 630–690, 653 µm long. Frontal tubercles conical, 10–15, 12 µm long, 5–6, 5 µm wide at base. Temporal setae 22–23, 22 including 6–8, 7 inner verticals; 6–10, 8 outer verticals; and 6–7, 7 postorbitals. Clypeus with 10–15, 12 setae. Tentorium 113–130, 123 µm long, 35–46, 39 µm wide. Palpomere lengths (in µm): 38–40; 43–45; 155–160; 155–163; 233–245 (2). Palp segment 5/3 1.50–1.53 (2).

Thorax. Antepronotals 3–6, 4; acrostichals 8–10, 9; dorsocentrals 9–11, 10; prealars 4–5, 4. Scutellum with 12–14, 13 setae.

Wing ( Fig. 28). VR 1.12–1.18, 1.16. Brachiolum with 2 setae; R with 15–20, 17 setae; R 1 with 10–13, 12 setae; R 4+5 with 15–17, 16 setae. Squama with 9 (2) setae.

Legs. Foretibia with 3 subapical setae, 110–115, 113; 115–132, 122; and 125–140 (2) µm long. Spurs of midtibia 25–30, 27 and 30–36, 33 µm long; comb with 30–36, 34 teeth, 10–12, 11 µm long. Spurs of hind tibia 25–30, 27 and 35–40, 37 µm long; comb with 48–52, 50 teeth, 10–13, 12 µm long. Mid- and hind legs without sensilla chaetica. Lengths and proportion of legs as in Table 1.

Hypopygium ( Figs 29–30). Tergite IX with shoulder-like posteriolateral corners, each with 3 setae. Laterosternite IX with 3–5, 4 setae. Anal tergite bands Y-shaped, transverse bands not united, median longitudinal band not connected to transverse bands. Anal point originating on triangular posterior margin of anal tergite, with 20–26, 24 setae on triangular region. Anal point 105–117, 110 µm long, constricted medially, rounded apically, with ridge at base bearing 7–10, 8 setae and microtrichia. Superior volsella 105–117, 110 µm long, parallel-sided, 10 µm wide medially, 13–15, 14 µm wide distally; with 3 subapical setae, with 2–3, 2 small posterolateral notches. Phallapodeme 80–83, 81 µm long. Transverse sternapodeme narrow, 15–25, 22 µm long. Gonocoxite swollen, 93–100, 95 µm long, inner margin with 6 strong setae. Gonostylus 190–213, 199 µm long, slightly widened in basal 1/3, straight in basal 1/2, strongly curved in distal 1/3, inner margin with 14–18, 15 setae in two rows. HR 0.47–0.49, 0.48; HV 1.50–1.79, 1.69.

Distribution. The species is known only from the type locality in Jiangxi Province in China.