Amnihayesomyia vittata, Hongqu & Niitsuma, 2020

Hongqu, Tang & Niitsuma, Hiromi, 2020, Review of the genus Amnihayesomyia Niitsuma (Diptera: Chironomidae: Tanypodinae), with descriptions of three new species from China, Zootaxa 4743 (3), pp. 411-418 : 413-415

Amnihayesomyia vittata sp. n

( Fig. 1 )

Type material. Holotype male, CHINA: Tibet Autonomous Region, Nyingchi Prefecture, Medog Country, Yarlung Tsangpo Grand Canyon , Zhamog-Medog Road , between mileposts 62K and 80K, alt. 2345 m, 5.viii.2015, HQ Tang . Paratypes: 2 males and 2 females, as holotype except alt. 2682 m, 8.viii.2015; 1 male, Yunnan Province, Honghe Prefecture, Pingbian County, Daweishan National Nature Reserve , alt. 2110 m, 6.vi.2017 , HQ Tang.

Etymology. From the Latin vittatus, vittate, referring to the banded wing.

Description. Male (n=4). Total length 2.8–3.6, 3.2 mm.

Coloration. Head with palp dark brown. Body mostly pale brown. Thorax dark brown on prescutellar area, anepisternum II, preepisternum, scutellum and postnotum. Scutal vittae yellowish, partially darkened on anterior margin and middle of median vitta, and outer margin of lateral vitta. Abdomen pale brown; T I, II, IV and V each with apical transverse dark band; T III, VI–IX entirely dark brown; T III–V each with anteromedial group of dark setae. Wing ( Fig. 1A ) with two dark bands sub-basally and sub-apically, cross-vein RM dark brown. Legs pale yellow with markings by dark setae; each apical half of femur, tibia and ta 2, and entire length of ta 3 or ta 3–5 dark brown.

Head. Temporals 12–16, 14, uniserial.AR 0.83–1.1, 0.96 (3). Clypeus rounded with 16–30, 21 setae. Lengths of palpomeres 1–5 (μm): 44–57, 50; 59–75, 66; 93–133, 113; 135–205, 161; 197–310, 246 (3); Pm 4 / Pm 3 1.1–1.6, 1.4; Pm 5 / Pm 4 1.5, 1.5 (3). Pm 2 ( Fig. 1B ) apically with one stout spine 39–50, 46 μm long, and 4–5 robust setae 62–80, 72 μm long, 1.7–1.9, 1.8 times as long as palpomere width. Eyes projected dorsally, forming parallel-sided, narrow bridge with 3 ommatidia at narrowest point.

Thorax. Aps 2–8, 5. ScuT absent. Ac 26–48, 36 (3), biserial, diverging posteriorly; Dc 20–24, 22 (3), mostly uniserial, irregularly biserial posteriorly; H 7–8, 8 (3); Pa 10–16, 12, uniserial, partly biserial; Su 1; As II 0–6, 2; Pes 2–12, 6. Scutellum with apical row of 9–11, 10 large setae and anterior group of about 50–110 small setae.

Wing. Length 1.8–2.4, 2.1 mm. VR 0.83–0.87, 0.85. Squama with 20–26, 23 setae.

Legs. Ti I spur 47–65, 55 μm long, with 7–8, 7 lateral teeth. Ti II spurs 49–60, 56 and 44–54, 50 μm long, with 6–10, 9 (3) and 6–9, 8 (3) lateral teeth, respectively; inner spur 1.0–1.2, 1.1 times as long as outer spur. Ti III spurs 62–85, 71 and 49–60, 53 μm long, with 5–10, 8 (3) and 4–9, 6 (3) lateral teeth, respectively; inner spur 1.3–1.4, 1.3 times as long as outer spur. Ti III comb consisting of 5–6, 6 bristles. Lengths and proportions of legs as in Table 1 .

Hypopygium ( Fig. 1C ). T IX with 12–19, 15 posterior setae. Gonocoxite 130–160, 148 μm long, 1.7–2.2, 2.0 times as long as broad at middle. Gonostylus stout, relatively short, 81–103, 95 μm long.

Female (n=2). Total length 2.0– 2.5 mm.

Coloration. Similar to male. Wing bands broader than those of male. Seminal capsules brown on oral 2/3 or more.

Head. Temporals 10–13. Antenna with terminal flagellomere almost as long as preceding 3 flagellomeres together; AR 0.23–0.27. Clypeus with 24–36 setae. Lengths of palpomeres 1–5 (μm): 60 (1), 75 (1), 135 (1), 185 (1), 270 (1); Pm 4 / Pm 3 1.4 (1), Pm 5 / Pm 4 1.5 (1). Pm 2 apically with one stout spine 39–50 μm long, and 5 robust setae 39–70 μm long, 1.1–1.2 times as long as palpomere width.

Thorax. Aps 0–2. ScuT absent. Ac 21–42, Dc 11–30, H 5–6, Su 1, Pa 8–17, As II 0–4, Pes 5–10. Scutellum with 8–14 large apical setae and about 30–100 small anterior setae.

Wing. Length 1.7–2.2 mm. VR 0.89–0.93. Squama with 10–20 setae.

Legs. Ti I spur 44–45 μm long, with 5–6 lateral teeth. Ti II spurs 47–50 and 44–45 μm long, with 6–7 and 5 lateral teeth, respectively; inner spur 1.1 times as long as outer spur. Ti III spurs 65 (1) and 50 (1) μm long, each with 6 (1) lateral teeth; inner spur 1.3 (1) times as long as outer spur. Ti III comb with 5–6 bristles. Lengths and proportions of legs as in Table 1 .

Genitalia ( Fig. 1D ). Sternite VIII with about 20–30 setae on each side. Notum 98–115 μm long. Segment X with 4–5 lateral setae. Labium with apical microtrichia. Seminal capsules oval, 60–64 μm long, 1.1–1.3 times as long as broad.

Pupa and larva. Unknown.

Remarks. The male resembles that of Amnihayesomyia ikawensis in the banded wing, but differs in the pale wing apex, the second palpomere with robust apical setae, and the bicolored femur and tibia in the foreleg. The male of A. ikawensis possesses a dark apex in the wing, no robust seta in the second palpomere, and entirely yellow femur and tibia in the foreleg ( Niitsuma 2007).

Figures

FIGURE 1. Amnihayesomyia vittata sp. n., male (A–C) and female (D). A, Wing; B, palpomere 2; C, hypopygium, dorsal view; D, genitalia, ventral view.