Abiskomyia levanidovi Makarchenko et Makarchenko, sp. nov.

Abiskomyia levanidovi Makarchenko et Makarchenko, sp. nov.

(Figs. 27, 28–38)

Material. Holotype: adult male, Russian Far East, the Chukotka Autonomous Okrug, Anadyrskyi District, Gytgylveirgytgyn Lake (upper stream of Velikaya River basin), 22.VII. 1980, leg. E. Makarchenko. Paratypes: 1 adult male, same data as holotype; 2 mature pupae, same data as holotype except 23–24.VII. 1980; 1 pupal exuvia, Magadan Region, Olskyi District, Chelomdzha River (Taui River basin), 14.VII. 2001, leg. S. Kocharina; 2 larvae, Magadan Region, Olskyi District, Ola River, in 0.5–1 km lower of Mayakan River, 25.V. 2013, leg. E. Khamenkova; 2 males, extracted from mature pupa, 2 pupal exuviae, Kamchatka Peninsula, Ust’-Kamchatsky district, Ushkovskoye Lake (Kamchatka River basin), about 20 km from Kozyrevsk Village, 18.VIII. 2006, leg. T. Butorina; 2 pupal exuviae, Amur Region, Zeya Nature Reserve, Bol. Garmakan River (Zeya Reservoir basin), 25.VI. 2013, leg. E. Makarchenko.

Adult male (n=3)

Total length 3.0– 3.1 mm. Wing length 2.44 mm. Total length/wing length 1.2–1.3. Colouration brown to dark brown.

Head. Temporal setae 8–12, including outer verticals and postorbitals, inner verticals absent. Clypeus massive, with 17–20 setae. Antenna with 13 flagellomeres and well developed plume; AR 0.94–1.0. Palp with 5 palpomeres. Palpomere length (in µm): 28, 48–60, 100–104, 76–80, 124–128.

Thorax. Antepronotum and scutellum yellowish; scutum with 3 dark brown stripes (vittae) on yellow surface; postscutum, mesanepisternum II and preepisternum dark brown. Antepronotum with 3–6 lateral setae. Acrostichals 19–23, beginning close to antepronotum and ending in lightly coloured oval area; dorsocentrals 11–13; prealars 3–4; scutellum with 10–15 setae in 1 row (Fig. 28).

Wing. R with 6–11 setae, R1 without setae, R4+5 with 2–3 setae subapically. Costa extension absent. Anal lobe rectangular-rounded. Squama with 7–15 setae.

Legs. Spur of fore tibia 48–60 µm. Spurs of mid tibia about 44–48 µm and 48–56 µm long, of hind tibia 60 µm and 68–76 µm long. Hind tibial comb with 11–12 setae. Length and proportions of leg segments as in Table 2.

Hypopygium (Figs. 29). Tergite IX with 18–21 long setae and narrow, subparallel-sided and bare anal point. Laterosternite IX with 6–8 setae on each side. Transverse sternapodeme 80–84 µm long, without oral projections. Gonocoxite 220–240 µm long; inferior volsella as in Fig. 29. Gonostylus 116–120 µm long, widest in basal twothirds, gradually narrowing towards apex, apical part slightly curved inwards, covered with few long setae in outer part, without crista dorsalis, megaseta absent.

Pupa (n=4). Total length 4.5 mm.

Cephalothorax. Cephalic tubercles 16–20 µm long and 16–28 µm wide, with simple setae 192–240 µm long; frontal apotome and cephalic tubercles covered with small spines. Thoracic horn yellow or yellowish, 348–364 µm (males) or 300–336 µm (females) long, tapering to pointed apex, apical part slightly curved, rarely covered with small spinules in males (Fig. 32); thoracic horn of females almost naked, with only a few spinules in distal part.

Precorneal setae: Pc1 with 4–6 branches, at distance of 200–244 µm from the thoracic horn; Pc2 with 3–6 branches, at distance of 76–116 µm from the thoracic horn, Pc3 with 2–4 branches, at distance of 60–72 µm from the thoracic horn. Median two antepronotals usually with 2–5 branches (males and females) but sometimes simple (females) with one lateral antepronotal seta hair-like. Dorsocentrals: Dc1 with 2–5 branches, Dc2 simple, Dc3 with 2–4 branches, Dc4 with 2–3 branches; distance between Dc1 and Dc2 48 µm; between Dc2 and Dc3 68 µm; between Dc3 and Dc4 128 µm.

FIGURES 28–38. Abiskomyia levanidovi sp. nov., male (28–29), pupa (30–32) and larva of fourth instar (33–38). 28, scutum and scutellum in dorsal view; 29, hypopygium in dorsal view; 30–31, project of anal lobe; 32, thoracic horn and precorneal seta; 33, seta submenti; 34, antenna; 35, distal part of mandible; 36, distal part of premandible; 37, S1 and labral lamella; 38, mentum. Scale bars: Figs. 28–32—50 µm; Figs 33–38—20 µm.

Abdomen. Tergite I without shagreen. Tergite II with spot of shagreen along posterior edge, occupying about 40 percent of tergite width. Spot of shagreen on tergites III–V with larger spinules than on tergite I, occupying 63–65 percent of tergite width and located in a relatively large brown spots at base. Tergites IV–VI with anteromedian oval group of brown spines. Sternites III–VII with weak PSA of 8–12 spinules, sometimes absent. Segment I without lateral setae, only with one pore. Segments II–VII with 3 pairs of lateral setae and one pore. Segment VIII without lateral setae. Anal lobe 352–400 µm long and 384–480 µm wide (females); with chitinized projection 80–104 µm long, bearing 4–8 lateral teeth and 3–4 teeth on apex (females) (Figs. 30–31). Male genital sac extending 80–96 µm beyond anal lobe, reaching apex of anal lobe projection.

Forth instar larva (n=3). Total length 4.7 mm.

Head. Head capsule brown, postoccipital margin black. S I of labrum large and palmate, with 16–20 branches (Fig. 37), S II strong, S III weak and hair-like, S IV short. Labral lamella rounded (Fig. 37). Pecten epipharyngis consisted of 3 narrow pointed scales. Premandible with two apical teeth and with two shorter and wide inner teeth (Fig. 36); brush developed and consisted of simple long spines. Antenna with 5 segments, placed on pedestal 22.6–31.7 µm long; length of antennal segments 1–5 (in µm): 99–110, 20–23, 25–27, 5.0–7.0, 5–7; three ring organs on proximal 1/4 of basal segment, distal ring organ with seta 53.4–63.5 µm long, proximal ring organ with setae 16.7 µm long; lauterborn organs large, one on apex of second segment and one on apex of third segment; longest branch of blade 58.5 µm, ending about middle part of segment 4, second branch of blade 13.4–16.7 µm long; style absent (Fig. 34); AR 1.68–1.80. Mandible with 4 teeth, apical tooth lighter and slightly longer or equal to combined width of 3 inner teeth; seta subdentalis 20 µm long, slightly curved, tapering to pointed apex (Fig. 35); seta interna with 4 plumose branches. Pecten galearis weakly developed and visible only on magnification higher than x100. Mentum with 4 median yellow teeth and 5 pairs of lateral teeth; first pair of lateral teeth yellow and smallest, located at base of median teeth of mentum; central pair of median teeth slightly narrower than other median teeth, but the same length; ventromental plate broad, subtriangular; covered with small spines; setae submenti branched (Figs. 27, 33, 38). Anal tubules short and roundish at apex. Each posterior parapod with 28–33 hooks in circle. Procercus dark, sclerotized, 16 µm long and 20 µm wide, bearing 7–9 apical anal setae of diverse length and thickness; strongest seta 544 µm long, weakest seta 72 µm long. Thoracic segments I–III with 21–24 branched setae, abdominal segment I in basal part with 2 lateral branched setae and 1 simple seta; segments II–VI with one bifurcate seta in basal half and with tuft of setae in apical part, segment VII with bifurcate seta in basal half and simple seta in apical part.

Diagnostic characters. See the keys.

Etymology. The species is named in honour of founder of freshwater hydrobiology school in the Russian Far East and our mentor Professor V.Ya. Levanidov.

Ecology. Pupae and larvae live in submountain or mountain rivers and in oligotrophic lakes.