Diamesa maisaraensis 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 : 490-492

Diamesa maisaraensis Makarchenko et Semenchenko , sp. nov.

http://zoobank.org/NomenclaturalActs/ C386C93E-5502-4D9E-B02C-EB88357BA021

( Figs. 15–21 , 32 , 71 )

Type material. Holotype, adult male, TAJIKISTAN: Gorno-Badakhshan Autonomous Region, Shugnanskiy District, Pamir Mountains , Maisara River near Maisara Pass , altitude 4168 m above sea level, 1.VII.2016, N 37.483017, E 72.639133, leg. D. Palatov. Paratypes: 4 adult males, the same data as holotype .

Derivatio nominis. The species is named as maisaraensis after the type locality in Maisara River near the pass of the same name in the Pamir Mountains.

Description

Adult male (n = 6, except when otherwise stated). Total length 2.7–3.2 mm. Total length/wing length 0.85–1.07.

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

Head ( Fig. 15 ). Eyes hairy, reniform. Temporal setae including 3–8 frontals, 6–8 orbitals, 7–17 verticals and 8–9 postorbitals. Clypeus with 4–7 setae. Antenna with 8 flagellomeres and reduced plume of setae; number and length of these setae on 1–7 flagellomeres respectively: 4–6 (24–28 μm), 1–2 (40 μm), 1–2 (32–40 μm), 1–2 (32–36 μm), 1–2 (24–32 μm), 2–3 (48–60 μm), 2 (48–60 μm); terminal flagellomere with 2–4 setae, 40–60 μm long in basal part and with 2 subapical setae, 16–20 μm long. Length of 1–8 flagellomeres (μm): 108–120, 42–52, 32–44, 28–36, 24–40, 24–34,24–36,124–142; AR 0.39–0.42. Palpomere length (μm): 40–88, 72–116, 116–132, 72–92, 120–140. Palpomere 3 in distal part with sensilla capitata with diameter 18–20 μm. Head width/palpal length 0.93–1.27. Antennal length/palpal length 0.89–1.08.

Thorax ( Fig. 16 ).Antepronotum with 8–14 ventrolateral setae, 100–102 μm long. Dorsocentrals 6–8, 84–100 μm long; prealars 6–10, 77–100 μm long. Scutellum with 39–50 setae. AAII with 5–10 setae, 40–88 μm long ( Fig. 16 ).

Wing ( Fig. 32 ). Length 3.0– 3.16 mm, width 1.04–1.12 mm. Costal extension 36–60 µm long. Anal lobe rounded. Squama with 3–8 setae, 28–60 μm long. R and R 1 with 16–17 setae, R 4+5 with 10–19. RM/MCu 2.0.

Legs. Spur of front tibia 48–56 µm long. Spurs of mid tibia 48–60 µm and 52–64 µm long. Spurs of hind tibia 84–96 µm and 52–60 µm long. Hind tibial comb with 14–19 setae. Length (μm) and proportions of leg segments are as in Table 3.

Hypopygium ( Figs. 17–21 ). Tergite IX with 10–19 setae, 20–44 µm long and with narrow (6–6 µm), pale, and naked anal point, 100–120 µm long which in lateral view apically curved upwards and sometimes forked ( Figs. 19–20 ); posterior edge of tergite IX almost straight, anal-lateral angles are rounded and slightly projecting ( Fig.18 ); anal tergal bands X-type; median tergal band 28–32 µm long. Laterosternite IX with 10–16 setae, 32–40 µm long. Transverse sternopodeme (TSA) triangular, 144–168 µm high, 180–200 µm wide at the base; TSA height/TSA width 0.73–0.89. Aedeagal lobe as in Fig. 21 ; phallapodeme sclerotized, 216–276 µm long. Gonocoxite 558–574 µm long, in middle part of dorso-internal position with small flattened transverse lobe, 104–112 µm long and 24–32 µm wide, directed backwards and with large longitudinal lobe in middle, anterior outer margin of which is rounded and slightly projecting ( Fig. 17 ). Gonostylus 224–236 µm long, curved, megaseta in form of wide terminal spine 8–12 μm long, next to it there is tooth and two setae of 8–12 µm long ( Fig. 6 ). HR 2.40–2.50.

Pupa and larva unknown.

Diagnosis The male of D. maisaraensis sp. nov. is closely related in the subgroup to the D. dragani sp. nov. and D. marinskiyi sp. nov. which have anal tergal bands X-type, but more similar to the latter because both have antenna with 8 flagellomeres, while antenna of D. dragani sp. nov. with 7 flagellomeres.Among other characteristic features of the male D. maisaraensis sp. nov. the following can be noted: AR 0.39–0.42, dorsocentrals 6–8, scutellars 39–50, femur of front leg length 1880–1960 µm, median tergal band length 28–32 µm, anal point length 100–120 µm. The male of D. marinskiyi sp. nov. has AR 0.32–0.39, dorsocentrals 8–10, scutellars 44–46, femur of front leg length 1624–1476 µm, median tergal band length 20–24 µm, anal point length 104–116 µm.

Ecology. Adult males were collected from stones and boulders near mountain river, located at an altitude of 4168 m, at a flow rate of 0.9–1.0 m/s, with water temperatures ca 7–8°C.

Distribution. Known only from the type locality—Maisara River of Pamir Mountains (Gorno-Badakhshan Autonomous Region, Tajikistan) ( Fig. 71 ).

Figures

FIGURES 15–21. Diamesa maisaraensis sp. nov., males. 15, head; 16, part of thorax in lateral view; 17, gonocoxite and gonostylus; 18, tergite IX; 19–20, anal point in lateral view; 21, phallapodeme and aedeagal lobe.AAII—anterior anepisternum II, Pa—prealars.

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).

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.