Diamesa tsutsuii Tokunaga
Creators: name: Makarchenko, Eugenyi A.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Chironomidae
Diamesa
Diamesa tsutsuii

description: Diamesa tsutsuii Tokunaga
(Figs. 1–4, 7–17)
Diamesa tsutsuii Tokunaga, 1936: 546; 1964: 22; Makarchenko 1977: 113, 1985: 82; 2006: 261, 477, 614; Linevich & Makarchenko 1989: 32; Ashe & O’Connor 2009: 287; Makarchenko & Makarchenko 2017: 130.
Diamesa coquilletti Sublette, 1966: 584; Hansen & Cook 1976: 78. Syn. nov.
Diamesa matuimpedita Sasa, 1989: 149–150.
Material examined. Japan: 1 adult male (holotype), Nagano Prefecture, Hosono, from snow, alt. 600 m above sea level, 17.III.1935, leg. K. Tsutsui. Russia: 15 adult males, 5 pupae, 11 larvae, Primorye Territory, Khasansk District, Kedrovaya Pad Nature Reserve, Kedrovaya River, 15–17.II.1975, leg. E. Makarchenko; 1 adult male, Ternei District, Sikhote-Alin Nature Reserve, Spornyi Stream (Serebrianka River basin), leg. O. Zorina; 12 adult males, 6 pupae, 14 larvae, Jewish Autonomous Region, Obluchie District, Bidzhan River, (Amur River basin), from snow, N 48º38’409’’, E 131º37’217’’, 27.III.2013, leg. E. Makarchenko; 5 adult males, Khabarovsk Territory, Nanaisky District, Anyuisky National Park, Pihtsa River (tributary of Gassi Lake), Amur River basin, 25. V 2019, leg. N. Yavorskaya; 2 adult males, Magadan Region, Olskyi District, Ola River, 29.IV.2014, leg. E. Khamenkova, 2 adult males, the same data except 3. V.2019, leg. E. Khamenkova; 3 adult males, 3 pupae, Sakhalin Island, Yuzhno-Sakhalinsk City, Bereznjaki River, 17.IV.2015, leg. E. Zhivogliadova.
Adult male (n = 7, except when otherwise stated).
Total length 4.3–6.2 mm. Wing length 3.2–4.0 mm. Total length/wing length 1.33–1.35.
Coloration. Head, thorax, legs, and abdomen dark brown; scutellum brown, palp light brown, antennae brown to dark brown; wings greyish, with brownish veins.
Head. Eyes hairy, reniform. Temporal setae including 7–8 preoculars, 8–11 verticals and 3–4 postorbitals. Clypeus with 11–14 setae. Antenna with 8 flagellomeres and reduced plume of setae (Fig. 1); number and length of these setae on 1–7 flagellomeres respectively (n=2): 2–3 (36–40 μm), 1 (40–42 μm), 3–4 (56–60 μm), 3–4 (48–56 μm), 3–4 (48–56 μm), 2–3 (80–82 μm), 2–3 (80–82 μm); terminal flagellomere with 3–4 setae, 72–80 μm long in basal part and with 1 subapical setae, 20–22 μm long. Length of 1–8 flagellomeres (μm) (n=4): 76–84, 52–56, 60–64, 48–56, 52–56, 42–44, 38–44, 156– 164; AR 0.40–0.50. Palpomere length (μm): 46–48, 55–100, 134–140, 143–152, 212–220. Palpomere 3 in distal part with sensilla capitata with diameter 20 μm. Head width/palpal length 1.05–1.06. Antennal length/palpal length 0.80–0.84.
Thorax. Antepronotum with 9–11 ventrolateral setae. Dorsocentrals 10–13, prealars 6–10. Scutellum with 20–42 setae.
Wing. Length 3.2–4.0 mm, width 1.0– 1.2 mm. Anal lobe rounded-angular. Squama with 26–31 setae, 80–136 μm long. R and R 1 with 32–35 setae, R 4+5 with 13–18. Costal extension 70–82 µm long. RM /MCu 2.0–2.5.
Legs. Spur of front tibia 44–56 µm long. Spurs of mid tibia 44–56 µm and 56–60 µm long. Spurs of hind tibia 67–100 µm and 64–68 µm long. Hind tibial comb with 16–18 setae. Length (μm) and proportions of leg segments are as in Table 1. continued
Hypopygium (Figs. 2–4). Tergite IX with 12–24 setae and anal point, 124–164 µm long, ca 40 µm wide, which slender apically, broadening basally, usually does not go beyond top of proctiger or only slightly goes (Figs. 2–3). Laterosternite IX with 10–11 setae. Transverse sternopodeme trapezoidal, without antero-lateral projections, 204–280 µm long, 44–52 µm wide. Gonocoxite 400–508 µm long; inferior volsella ca 260 µm long, basal half widened, narrow distal, with setae along inner margin, which are longest in basal part. Gonostylus 280–360 µm long, curved, widened and rounded in basal third, narrow in distal two-thirds, with megaseta 32–36 µm long. HR 1.40–1.43.
Pupa (n=5). Total length 5.7–6.0 mm. Coloration dark brown. Exuviae yellow.
Cephalothorax. Frontal apotome with 2 setae 168–180 μm long. Thorax granulated in anterodorsal part and smooth in middle and posteriodorsal parts. Antepronotum with 2 median and 2 lateral antepronotals; dorsocentrals 2. Thoracic horn pale, filiform, peaked, 280–359 μm long and 12–16 μm wide (Fig. 7). Precorneal setae lengths (μm): Pc 1 – 75–102, Pc 2 – 211–237, Pc 3 – 105–177. Basal part of antennal case with tubercle (Fig. 8)
Abdomen. Tergite I and sternite I without shagreen of spinules. Anterior 2/3 of tergites II–VIII with shagreen of spinules. The lateral margins of the segments are slightly serrated, with brown sharp corners protruding anally-laterally. Tergite I and sternites I–II without posterior transverse row of large thorn-like spines. Number of these spines on tergites II–VIII accordingly – 9–12: 8–9: 6–11: 5–9: 6–11: 6–11: 5–7 (Figs. 11–12). Number of thorn-like spines on sternites III–VIII accordingly – 10–20: 9–13: 7–10: 11–13: 8–15: 19–18. Size of spines on tergites and sternites subequal or spines of sternites slightly narrower (Fig. 9–10). Segment I with 2 pairs of lateral setae 48–88 μm long. Segments II–VIII with 4 pairs of lateral setae; length of L 1 –L 3 92–148 μm, length of L 4 28–68 μm. Anal lobe with 3 needle-shaped anal macrosetae 240–284 μm long, subapically recurved. Male genital sac rounded extending beyond anal lobe (Fig. 12).
Fourth instar larva (n = 5). Coloration brown. Total length 6.4–10.1 mm. Head capsule brownish-yellow, with diffuse brown spots and brown or dark brown triangular spot at epistomal suture; postoccipital margin wide and black (Fig. 15). Two eye spots do not touch and there is light spot around them. Antenna yellowish brown; a large ring organ is located at base of basal segment, a small one is in middle; blade reaches base of the 4 th segment, accessory blade reaches base of 3 rd segment; style of 2 nd segment flat, reaching base of 4 th segment (Fig.13). AR 1.8. Premandible with 6 yellow inner teeth (Fig. 14). Mandible dark brown, apical tooth long and thin, other teeth acutely triangular; seta subdentalis flat and short; seta interna with 20–22 simple pinnate branches (Fig. 17). Mentum with 1 median tooth and 10 pairs of lateral teeth; median and first pair of lateral teeth are distinguished by lighter color (Fig. 16). Maxillar palp with 8 short setae in distal part. Procercus in the form of an incompletely sclerotized ring, with 4 long and light yellow anal setae.
Remarks. Adult male of D. tsutsuii is closely related to European species of cinerella group (D. cinerella Meigen, D. hamaticornis Kieffer, D. hyperborea Holmgren, D. kasymovi Kownacki et Kownacka and D. tonsa (Haliday) and can be included in this group of species.
The synonymy of D. tsutsuii and D. coquilletti is supported by Dr. D. Hansen, who studied the type material of D. coquilletti from Bering Island (Hansen & Cook 1976). Here is what he wrote in his letter about it. “Comparing description of Tokunaga (1936) and illustrations with those in my Diamesa revision, it appears to me that D. coquilletti Sublette could certainly be a synonym of Tokunaga’s D. tsutsuii. What would be of interest to you would be those two slides of the male collected on Bering Island by Stejneger in 1897. When I received this lone male from the USNM, the male genitalia had already been slide-mounted (by Coquillett? by Sublette?), but the rest of the specimen was still on a pin. I slide-mounted this pinned portion of the male specimen. Both these slides were returned to the USNM in the mid-1970s. Coquillett (1899: 342) designated the species as type 4047 in the USNM’s system. Sublette (1966) illustrated the male genitalia, as did I. I also illustrated the male antenna: Fig. 41 in my Diamesa revision. This looks so very close to your illustration of the antenna of D. tsutusii: Fig. 13 in your 1985 Podonomidae, Diamesinae, and Prodiamesinae revision. The only specimens of D. coquilletti that I know of are the lone male and lone female collected by Stejneger and used by Coquillett in his description of Eutanypus borealis. Simply stated, that’s all the material there is and only the single male is, in fact, worth dealing with. That lone male specimen was what I used in the description of the species in my 1976 revision. I feel that you could very safely regard D. coquilletti as a junior synonym of D. tsutsuii ”.
Biology. Apparently a bivoltine species. In Southern Primorye, the “flying” of adults occurs from the first half of December to the first half of March (maximum at the end of February) as well as in June. On Sakhalin Island adults were collected in the first half of March, on the Kunashir and Iturup Islands (Kurile Islands) from the first half of March to the end of April, in the Amur River basin in March as well as in late July, the first half of August and in November, in the Magadan Region in May and the first half of August. Adult males and females caught in winter and spring were usually found on the snow near the gullies, on the lower surface of the ice and on dry stones in the watercourse (Fig. 18). The water temperature at that time was 0.1–2ºC. Copulation of chironomids, both in winter-spring time and in summer, takes place on the ground. Larvae and pupae live in foothill and mountain rivers on stones.
In Japan, D. tsutsuii lives in mountainous areas, at an altitude of about 600 m above sea level. Imago males were collected in the second half of March in the snow. It is also reported that adult females were caught in August (Tokunaga 1936, 1964).
Distribution. East Palaearctic species. The western border of the range is the basin of Baikal Lake. Identification by the larva and the record for Armenia of D. tsutsuii (Kachvoryan et al. 2007; Petrova et al. 2011) doubtful in my opinion.
description: Published as part of Makarchenko, Eugenyi A., 2023, Correction of mistakes. I. New synonyms of two species Diamesa Meigen (Diptera: Chironomidae, Diamesinae) from the Russian Far East, with redescription of D. tsutsuii Tokunaga and D. nivoriunda (Fitch), pp. 144-150 in Zootaxa 5297 (1) on pages 144-148, DOI: 10.11646/zootaxa.5297.1.10, http://zenodo.org/record/7989281