Diamesa dragani Makarchenko et Semenchenko, 2022

Makarchenko, Eugenyi A., Semenchenko, Alexander A. & Palatov, Dmitry M., 2022, Taxonomy of Diamesa steinboecki group (Diptera: Chironomidae: Diamesinae) with description and DNA barcoding of new species. I. Subgroups steinboecki and longipes, Zootaxa 5125 (5), pp. 483-512 : 485-487

Diamesa dragani Makarchenko et Semenchenko , sp. nov.

http://zoobank.org/NomenclaturalActs/ B3C5EFC4-7AE3-4419-B2AF-DD40873B467B

( Figs. 1–8 , 30 , 68 )

Type material. Holotype, adult male, RUSSIA: Republic of Khakassia, Tashtypskyi District, Sayan Mountains , unnamed stream of Bolshoi On River basin, altitude 2063 m above sea level, 4.X.2020, N 51.714667, E 89.884500, leg. S. Dragan. Paratypes: 6 adult males, the same data as holotype .

Derivatio nominis. The species is named in honor of Dr. Dragan Sergey Viktorovich from Katanov Khakas State University (Abakan, Republic of Khakassia, Russia) who collected type material in Sayan Mountains.

Description

Adult male (n = 7, except when otherwise stated). Total length 2.1–2.5 mm. Total length/wing length 0.81–1.20.

Coloration. Dark brown to black. Head, thorax and abdomen dark brown to black. Legs black. Wings grey, with brownish veins.

Head ( Figs. 1–2 ). Eyes hairy, reniform. Temporal setae including 6–7 frontals, 3–6 orbitals, 5–10 verticals and 3–4 postorbitals. Clypeus with 4–6 setae.Antenna with 7 flagellomeres and reduced plume of setae ( Fig. 2 ); number and length of these setae on 1–6 flagellomeres respectively: 1–2 (26–28 μm), 1–2 (18–32 μm), 3 (32–44 μm), 1–2 (24–32 μm), 2 (40–44 μm), 4 (40–48 μm); terminal flagellomere with 2–4 setae, 32–48 μm long in basal part and with 2 subapical setae, 20–24 μm long. Length of 1–7 flagellomeres (μm): 96–100, 40–48, 32–36, 24–28, 24–28, 20–24, 120–128; AR 0.48–0.52. Palpomere length (μm): 28–40, 68–72, 84–92, 64–68, 88–100. Palpomere 3 in distal part with sensilla capitata with diameter 12–15 μm. Head width/palpal length 1.0–1.29. Antennal length/palpal length 1.07–1.09.

Thorax. Antepronotum with 8–11 ventrolateral setae, 44–52 μm long. Dorsocentrals 4–6, 56–72 μm long; prealars 5–6, 48–60 μm long. Scutellum with 18–20 setae. AAII with 4–5 setae, 36 μm long.

Wing ( Fig. 30 ). Length 2.16–2.72 mm, width 0.85–0.88 mm. Costal extension 60–76 µm long. Anal lobe rounded-angular. Squama with 3–7 setae, 32–44 μm long. R and R 1 with 7–12 setae, R 4+5 with 13–15. RM/MCu 1.8–2.0.

Legs. Spur of front tibia 36–40 µm long. Spurs of mid tibia 36–44 µm and 40–44 µm long. Spurs of hind tibia 64–72 µm and 40–44 µm long. Hind tibial comb with 16–20 setae. Length (μm) and proportions of leg segments are as in Table 1 .

Hypopygium ( Figs. 3–8 ). Tergite IX with 8–14 setae, 16–24 µm long and with narrow (4–6 µm), pale, and naked anal point, 120–126 µm long which in lateral view apically curved upwards ( Fig. 7 ); posterior edge of tergite IX almost straight, anal-lateral angles are rounded and slightly projecting ( Fig. 3 ); anal tergal bands X-type; median tergal band 16–20 µm long. Laterosternite IX with 7–12 setae, 20–24 µm long. Transverse sternopodeme (TSA) triangular, peaked ( Figs. 4, 8 ), 120–128 µm high, 156–176 µm wide at the base; TSA height/TSA width 0.70–0.77. Aedeagal lobe as in Fig. 8 , weakly chitinized, apically with small digitiform process; phallapodeme sclerotized, 210–232 µm long. Gonocoxite 400–443 µm long, in middle part of dorso-internal position with small flattened transverse lobe, 98–100 µm long and 28–32 µm wide, directed backwards, and with large longitudinal lobe in middle, anterior outer margin of which is rounded or rounded-angular and slightly projecting ( Fig. 5 ); Gonostylus 197–236 µm long, slightly curved, megaseta in form of wide terminal spine 8–12 μm long, next to it there is tooth and two setae of 12–16 length µm long ( Fig. 6 ). HR 2.01–2.25.

Pupa and larva unknown.

Diagnosis. The male of D. dragani sp. nov. is most closely related in the subgroup to the D. maisaraensis sp. nov. and D. marinskiyi sp. nov., which have anal tergal bands X-type, but the new species is a little shorter than others (2.1–2.5 mm), antenna with 7 flagellomeres, AR 0.48–0.52, dorsocentrals 4–6, scutellars 18–20, femur of front leg 1394–1689 µm long, median tergal band 16–20 µm long, anal point 230–126 µm long. The males of D. maisaraensis sp. nov. and D. marinskiyi sp. nov. have the following characteristics respectively: total length 2.7–3.2 mm and 2.5–2.7 mm, antenna with 8 flagellomeres, AR 0.39–0.42 and 0.32–0.39, dorsocentrals 6–8 and 8–10, scutellars 39–50 and 44–46, femur of front leg length 1880–1960 µm and 1624–1476 µm, median tergal band length 28–32 µm and 20–24 µm, anal point length 100–120 µm and 104–116 µm.

Ecology. Adult males were collected from stones and boulders in mountain stream, located at an altitude of 2063 m, at a flow rate of 0.6 m /s, with water temperatures 0.4°C, pH 7.92, general mineralization 0.02 g /l, electrical conductivity 0.03 mS (pers. comm. by S.V. Dragan).

Distribution. Known only from the type locality in Sayan Mountains ( Fig. 68 ).

Figures

FIGURES 1–8. Diamesa dragani sp. nov., male. 1, head; 2, antenna; 3, tergite IX; 4, hypopygium in dorsal view; 5, gonocoxite and gonostylus; 6, apex of gonostylus; 7, anal point in lateral view; 8, transverse sternapodeme, phallapodeme and aedeagal lobe. ATB—anterolateral anal tergal bands, MTB—median anal tergal band, PTB—posterolateral anal tergal band.

FIGURES 30–36. Wings of Diamesa dragani sp. nov. (30), D. kownackii sp. nov. (31), D. maisaraensis sp. nov. (32), D. marinskiyi sp. nov. (33) and D. steinboecki Goetghebuer from Swiss Alps (34), French Alps (35) and Pamir Mountains (36).

FIGURES 68–74. Type localities of Diamesa dragani sp. nov. (68), D. kownackii sp. nov. (69–70), D. maisaraensis sp. nov. (71), D. marinskiyi sp. nov. (72), D. steinboecki Goetghebuer (73) and D. sakartvella Kownacki et Kownacka (74). 68, unnamed stream of Bolshoi On River basin, alt. 2063 m a. sea l., Sayan Mountains (photo by S.V. Dragan); 69, unnamed stream of Somnitelnaya River basin, Wrangel Island (photo by E.A. Makarchenko); 70, Somnitelnaya River, upper stream, alt. 205–210 m a. sea l., Wrangel Island (photo by O.A. Khruleva); 71, Maisara River near Maisara Pass, alt. 4168 m a. sea l., Pamir Mountains (photo by D.M. Palatov); 72, Zienzan River, Tien Shan Mountains, alt. 1923 m a. sea l., Xinjiang Uygur Autonomous Region, China (photo by D.M. Palatov); 73, Balm stream, Massif of Aiguilles–Rouges, French Alps (photo by Pierre Clévenot); 74, Skazdon River near the Tsey (Tseyskoe gorge), alt. 1943 m a. sea l., North Caucasus (photo by D.M. Palatov).