Sasayusurika nigatana (Tokunaga)

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 : 547-549

Sasayusurika nigatana (Tokunaga)

( Fig. 10 )

Diamesa (Psilodiamesa) nigatana Tokunaga, 1936: 537 .

Sasayusurika aenigmata Makarchenko, 1993: 119 –121; Willassen 2007: 316.

Sasayusurika nigatana (Tokunaga) ; Makarchenko & Endo 2009: 67 –70.

Material: 1 adult male (BDN No. K 5B6), China, Zhejiang Province, Taizhou City, Huading Mountain , N 29 ° 15′08.3″, E 121 ° 05′26.1″, alt. 1000 meters above sea level, 12.IV.2011, sweep net, leg. Xiaolong Lin.

Adult male (n = 1). Total length 6.12 mm. Wing length 4.20 mm. Total length/wing length 1.45. Coloration dark brown, wing greyish.

Head. Eyes nude to very weakly pubescent, moderately extending dorsomedially. Temporal setae 26–29, consisting verticals and postorbitals. Clypeus with 22 setae. Antenna with 13 flagellomeres and well-developed plume; terminal flagellomere with 1 subapical seta 28 µm long. AR 2.52–2.60. Palpomeres lengths (in µm): 64; 124; 224; 320; 312. Palpomere 3 in distal part with sensilla capitata (sunken organ) with diameter 24 µm. Palpomeres 1–5 length/head width 1.16.

Thorax. Antepronotum with 9 lateral setae. Acrostichals 12 (36–40 µm), dorsocentrals 21, prealars 10–11, supraalars 1, scutellars ca 50.

Wing. Wing width 0.96 mm. R and R 1 with 35–37 setae; R 4+5 with 4–6 setae. Costa extension 24 µm long. RM length/MCu length 4.5. Anal lobe well developed. Squama with 19 setae. VR 0.90–0.93.

Legs. Spur of fore tibia 128 µm long; spurs of mid tibia 112 µm and 100 µm long; of hind tibia 136 µm and 104 µm long. Hind tibial comb with 21 setae. Tip of claws serrate, with about 6 teeth. Lengths and proportions of leg segments as in Table 3.

fe ti ta 1 ta 2 ta 3 ta 4 ta 5 LR BV SV BR

P 1 1680 2040 1360 720 520 260 200 0.67 2.99 2.74 4.7

P 2 1960 1960 1040 520 360 240 200 0.53 3.76 3.77 2.1

P 3 2360 2600 1720 820 480 260 200 0.66 2.98 2.88 3.3

Hypopygium ( Fig. 10 ). Tergite IX with 28 setae. Laterosternite IX with 6–7 setae. Transverse sternapodeme 148 µm long and 24 µm wide, with fairly straight anterior margin and anterpronotal projections. Aedeagal lobe apparently large and rounded. Gonocoxite 404 µm long. Inferior volsella absent. Gonostylus long, 244 µm long, with short megaseta ca 9 µm long. HR 1.45.

Pupa and larva are absent in our material but they are described before by Makarchenko & Endo (2009).

Remarks. From the males of Japan and India, a specimen of S. nigatana from Oriental China is distinguished by the presence of setae on the clypeus. The presence of setae on the clypeus is in conflict with the diagnosis of the genus Sasayusurika Makarchenko , according to which the representatives of the genus are characterized by their lack. Apparently, diagnosis of the genus in the future should be expanded after studying additional material.

Distribution. For the first time recorded for the Oriental Region, it was previously known only from Palaearctic—Japan and Indian Himalaya ( Makarchenko 1993; Willassen 2007; Ashe & Connor 2009; Makarchenko & Endo 2009).

Figures

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.