Diamesa japonica Tokunaga, 1936

Makarchenko Usgs, Eugenyi A., 2021, Confirmation of a species status of Diamesa leoniella Hansen, 1976, stat. resurr (Diptera, Chironomidae) from North America, Zootaxa 4985 (3), pp. 439-442 : 440-442

Diamesa japonica Tokunaga, 1936

( Figs. 3–4 )

Diamesa japonica Tokunaga, 1936: 542 ; Makarchenko 1981: 110, 1985: 76, 2006: 260; Ashe & O’Connor 2009: 278.

Diamesa kurobemijikaia Sasa et Okazava, 1992: 60 ; Ashe & O’Connor 2009: 278.

Material examined. 2 adult males, Russia: Kurile Islands , Kunashir Island , Sernovodsk Village, Tiurino River, 24.IV.1978, leg. E. Makarchenko ; 23 adult males, the same data except 26.IV.1978, leg. E. Makarchenko.

Adult male (n = 12). Total length 3.1–4.0 mm. Wing length 2.76–3.17 mm. Total length/wing length 0.90–1.38.

Colouration. Head, thorax, legs and hypopygium dark brown; antenna and palpomeres brown; abdomen light brown to dark brown; wing greyish, veins brownish.

Head. Eyes hairy. Temporal setae including 12–15 verticals, 6–12 preoculars, 4–5 postorbitals. Clypeus with 6–8 setae. Antenna with 8 flagellomeres and reduced plume of setae; number and length of these setae on 1–7 flagellomeres respectively: 2–3 (28–40 μm), 1–2 (28–36 μm), 1–2 (26–40 μm), 0, 0, 0, 0; terminal flagellomere in basal part with 5–6 setae, 60–80 μm long and with 2 subapical setae, 40–52 μm long. Flagellomeres 1–8 length (μm): 71–88, 34–38, 25–34, 25–30, 25–34, 25–34, 34–38, 193–218; AR 0.68–0.81. Antennal length/palp length 1.05–1.11. Palpomeres lengths (in μm): 36–40; 55–63; 88–105; 76–105; 105–147. Palpomere 3 in distal part with sensilla capitata with diameter 20–24 μm. Palpomeres 1–5 length/head width 0.80–0.84.

Thorax. Antepronotum with 7–12 ventrolateral setae. Dorsocentrals 6–10, prealars 5, scutellars 11–24.

Wing. R and R 1 with 15–25 setae; R 4+5 with 8–12 setae. Costa extension ca 48 μm long. RM length/MCu length 2.0–3.6. Anal lobe well developed, rounded. Squama with 18–25 setae 28–52 μm long. VR 0.96–1.0.

Legs. Spur of fore tibia 34–46 μm long; spurs of mid tibia 46–55 μm long; of hind tibia 50–71 μm and 34–50 μm long. Hind tibial comb with 16 – 20 setae. Lengths and proportions of leg segments as in Table 2 .

Hypopygium ( Figs. 3–4 ). Tergite IX with 10–11 setae (from one side), 20–28 μm long and wedge-shaped anal point 63–136 μm long, covered in basal 2/3 with numerous microtrichia forward and laterally directed. Laterosternite IX with 9–10 short setae. Transverse sternapodeme triangular ca 128 μm long. Gonocoxite 350–476 μm long. Inferior volsella absent. Superior volsella in form of angular tubercle. Gonostylus slightly curved, 220–236 μm long, with numerous, proximally directed strong setae, 44–52 μm long; megaseta 6–8 μm long. HR 1.92–2.23.

Distribution. East Palaearctic island species. Known from Japan and Russian Far East (Kunashir Island, Kurile Islands ( Ashe & O’Connor 2009).

Figures

FIGURES 1–4. Males of Diamesa leoniella Hansen (1–2) and D. japonica Tokunaga (3–4). 1, 4, central part of hypopygium without tergite IX; 2–3, hypopygium in dorsal view.

Tables

TABLE 2. Lengths (in µm) and proportions of leg segments of Diamesa japonica Tokunaga, male (n=12)

	fe	ti	ta 1	ta 2	ta 3	ta 4	ta 5
P1	1496–1768	1513–1716	918–1105	425–527	255–306	102–136	136–153
P2	1496–1768	1292–1479	476–544	238–289	170–204	85–119	119–153
P3	1615–1872	1530–1768	850–1054	442–527	221–255	102–119	136–153

Continued.