Amnihayesomyia tibetica, 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 : 415

Amnihayesomyia tibetica sp. n.

( Fig. 2 )

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. 2682 m, 7.viii.2015, HQ Tang . Paratypes: 3 males and 1 female, as holotype.

Etymology. From the Latin tibeticus, Tibetan, referring to the type locality.

Description. Male (n=4). Total length 3.1–4.0, 3.7 mm.

Coloration. Body predominantly yellowish brown. Thorax dark brown on scutal vittae and postnotum. Abdomen yellow; T III–VI each with anterior transverse dark band interrupted narrowly at middle, VII–VIII entirely dark brown. Wing without markings, RM pale. Legs mostly pale yellow, with apical half of femur, entire length of tibia and ta 4–5 dark brown.

Head. Temporals 13–16, 15. AR 0.94–1.1, 1.0. Clypeus with 15–22, 18 setae. Lengths of palpomeres 1–5 (μm): 60–74, 64; 100–111, 105; 150–180, 160; 165–190, 176; 250–275 (2); Pm 4 / Pm 3 1.1–1.2, 1.1, Pm 5 / Pm 4 1.4 (2). Pm 2 ( Fig. 2A ) without robust setae. Eye bridge distinctly concave in ventral border, with 4 ommatidia at narrowest point.

Thorax. Aps 4–5, 5. ScuT absent. Ac 30–34, 32; Dc 13–16, 15; H 5–6, 6; Pa 10–14, 12; Su 1; As II 0; Pes 3 (2). Scutellum with 10–12, 11 large apical and 6–7, 6 small anterior setae.

Wing. Length 2.6–3.0, 2.8 mm. VR 0.87–0.92 (2). Squama with 24–29, 26 setae.

Legs. Ti I spur 50–57, 54 μm long, with 5–10, 7 lateral teeth. Ti II spurs 60–64, 61 and 49–55, 52 μm long, with 6–11, 8 and 6–8, 7 lateral teeth, respectively; inner spur / outer spur 1.1–1.3, 1.2. Ti III spurs 75–79, 77 and 49–54, 51 μm long, with 6–8, 7 and 5–8, 6 lateral teeth, respectively; inner spur / outer spur 1.4–1.6, 1.5. Ti III comb with 6–9, 8 bristles. Lengths and proportions of legs as in Table 2.

Hypopygium ( Fig. 2B ). T IX with 11–16, 14 posterior setae. Gonocoxite 180–200, 190 μm long, and almost twice as long as broad at middle. Gonostylus 123–125, 124 μm long.

Female (n=1). Total length 3.5 mm.

Coloration. Similar to male. Seminal capsules brown.

Head. Temporals 15. Antenna with terminal flagellomere longer than preceding 2 flagellomeres together; AR 0.23. Clypeus with 32 setae. Lengths of palpomeres 1–5 (μm): 65, 110, 150, 165, 275; Pm 4 / Pm 3 1.1, Pm 5 / Pm 4 1.7.

Thorax. Aps 4. ScuT absent. Ac 46, Dc 24, H 12, Su 1, Pa 10, As II 0, Pes 3. Scutellum with 13 large apical setae and 6 small anterior setae.

Wing. Length 3.0 mm. VR 0.91. Squama with 22 setae.

Legs. Ti I spur 55 μm long, with 7 lateral teeth. Ti II spurs 65 and 50 μm long, with 7 and 6 lateral teeth, re- spectively; inner spur 1.3 times as long as outer spur. Ti III spurs 60 and 50μm long, with 6 and 4 lateral teeth, respectively; inner spur 1.2 times as long as outer spur. Ti III comb with 7 bristles. Lengths and proportions of legs as in Table 2.

Genitalia ( Fig. 2C ). Sternite VIII with about 30 setae on each side. Notum 160 μm long. Segment X with 3 lateral setae. Labium with apical microtrichia. Seminal capsules 60 μm long, 1.1 times as long as broad.

Pupa and larva. Unknown.

Remarks. The male resembles that of Amnihayesomyia dartofi in the plain wing, the second palpomere without robust setae, and the eye bridge distinctly concaved in the ventral border. However, both the males are distinct in the leg coloration. In the former, the femora are dark brown on the apical half and the tibiae are entirely dark brown, while in the latter, the femora are entirely pale yellow, and the tibiae are brown on the apex ( Murray 1976).

Figures

FIGURE 2. Amnihayesomyia tibetica sp. n., male (A–B) and female (C). A, Palpomere 2; B, hypopygium, dorsal view; C, genitalia, ventral view.