Diamesa qiangi Wang et Makarchenko, 2019

Sun, Bingjiao, Lin, Xiaolong, Wang, Xinhua & Makarchenko, Eugenyi A., 2019, New or little-known Diamesinae (Diptera: Chironomidae) from Oriental China, Zootaxa 4571 (4), pp. 544-550 : 544-546

Diamesa qiangi Wang et Makarchenko , sp. nov.

( Figs. 1–8 )

urn:lsid:zoobank.org:act:361DEDE8-B7EE-4BFC-836B-F5A838DADE78

Material. Holotype: adult male (BDN No. sun390), China: Tibet, Xizang Autonomous Region, Linzhi County, Lulang Bayi Town , Zhaxigang Village , N 29 ° 44′53.29″, E 94 ° 44′34.70″, alt. 3400 meter above sea level, 14.VIII.2013, light trap, leg. Qiang Wang. Paratypes: 12 males, same data as holotype .

Derivatio nominis. The species is named in honour of Qiang Wang, who collected type material of a new species.

Adult male (n = 6). Total length 2.90–3.38 mm. Wing length 2.95–3.31 mm. Total length/wing length 0.98– 1.12. Wing length/length of profemur 2.36–2.52.

Coloration. Head, thorax, legs and hypopygium dark brown; antenna brown; palpomeres light brown; abdomen light brown to brown; wing veins yellowish brown.

Head. Eyes hairy, i.e., length of eye microtrichia about 1.5 or more times the height of ommatidial lenses and visible along lateral eye margin when head is viewed from front (after: Hansen & Cook 1976). Temporal setae 15– 23, including about 7–15 inner verticals, 4–7 outer verticals and 3–5 postorbitals. Clypeus with 9–12 setae. Antenna with 13 flagellomeres and well-developed plume; terminal flagellomere 495–560 µm long, with 1 subapical seta 24–36 µm long. AR 0.79–0.92. Tentorium 195–310 µm long, 50–70 µm wide. Stipes 180–220 µm long, 12–20 µm wide. Palpomeres lengths (in µm): 43–50; 85–110; 125–155; 135–168; 160–234. Palpomere 3 in distal part with sensilla capitata (sunken organ) with diameter 12 µm. Palpomeres 1–5 length/head width 0.80– 0.94.

Thorax. Antepronotum with 4–8 lateral setae. Dorsocentrals 14–19, prealars 5–10, scutellars 22–27.

Wing. R with 10–15 setae, R 1 with 7–11 setae; R 4+5 with 8–12 setae. Costa extension 105–125 µm long. RM length/MCu length 3.0. Brachiolum with 2–3 setae. Anal lobe well developed. Squama with 26–35 setae. VR 0.88– 0.93.

Legs. Spur of fore tibia 60–65 µm long; spurs of mid tibia 50–60 µm and 24–59 µm long; of hind tibia 75–85 µm and 45–60 µm long. Hind tibial comb with 12–15 setae. Width at apex of fore tibia 58–70 µm, of mid tibia 60– 65 µm, of hind tibia 75–90 µm. Pseudospurs of ta 3 absent. Lengths and proportions of leg segments as in Table 1.

Hypopygium ( Figs. 1–8 ). Tergite IX with 18–22 setae. Laterosternite IX with 4–9 setae. Anal point developed, tapering to pointed apex, 265–290 µm long, 45–75 µm wide at base; 3–5 µm wide at apex. Phallapodeme 93–130 µm long. Transverse sternapodeme 105–150 µm long. Gonocoxite 375–395 µm long. Inferior volsella finger-like, 108–155 µm long; with a projection at basal 1/3, 12–15 µm long, with 2–4 long setae; distal slender, with 9–15 strong setae, and with 2–3 strong setae at the apex. Basimedial setal cluster with numerous long and hair-like setae, located on the long stalks. Gonostylus strong, curved inwardly, with projection of median field and with short megaseta; gonostylus 225–260 µm long; megaseta 10–12 µm long. HR 1.46–1.69. HV 0.83–0.40.

Pupa and larva unknown.

Diagnostic characters. The new species is closely related to Diamesa insignipes Kieffer , namely adult male has similar finger-like inferior volsella of hypopygium, which with some long setae in outer part in middle ( Figs. 4 , 7 ). It should also be noted that the male of the new species has on the gonocoxite numerous long and hair-like basimedial setal cluster located on the long stalks ( Figs. 2 , 8 ). Such kind of the basimedial setal cluster present only in D. zhiltzovae Makarchenko (Makarchenko 1989: Fig.1 ). The male of D. qiangi sp. nov. is well distinguished from both the above species by the shape of the gonostylus, which curved inwardly, with projection of median field and with short megaseta ( Figs. 1, 3 , 6 ).

Distribution and biology. The species is known only from the type locality in China, Tibet Autonomous Region. The adult males were collected by light trap near the grass, across which there is a stream, stemming from the melting frazil.

Figures

FIGURES 1–5. Adult male of Diamesa qiangi sp. nov. 1, 3, hypopygium in dorsal view; 2, basimedial setal cluster in ventral view; 4, inferior volsella; 5, distal part of gonostylus.

FIGURES 6–10. Adult male of Diamesa qiangi sp. nov. (6–8), Linevitshia prima Makarchenko (9) and Sasayusurika nigatana (Tokunaga) (10). 6, gonostylus; 7, inferior volsella; 8, basimedial setal cluster; 9–10, hypopygium in dorsal view. Scale bars 50 µm.