Boletina pyasina Maximova et Subbotina 2020, sp.n.

Boletina pyasina Maximova et Subbotina, sp.n.

Figs 14–24.

MATERIAL. Holotype. ♂. Russia, Krasnoyarsk region, River Pyasina, 90 km N of Norilsk, 70.15°N, 88.28°E, 46 m above sea level, 13.08.2015, M. Shcherbakov leg. (UTR).

Paratypes. 2 ♂♂, same data as holotype (UTR); 2 ♂♂, same data as holotype (ZISP).

Other material. 12 ♂♂, same data as holotype (UTR); 2 ♂♂, Russia, Krasnoyarsk region, River Pyasina, 93 km N of Norilsk, 70.18°N, 88.18°E, 12.08.2015, M. Shcherbakov leg. (UTR).

Male (n=5).

Head dark brown. Mouthparts dark brown, palpi brownish. Clypeus brown. Antenna light brown. Sixth flagellomere about twice as long as wide.

Thorax. Mesonotum dark brown, thinly dusted with subshining longitudinal stripes along acrostichal and lateral to dorsocentral rows of setae. Pleurae brown. Laterotergite bare.

Wing length 3.39–3.45 (mean value 3.42) mm. Wings hyaline. Veins yellow, except C and R brownish. Costa extending beyond tip of R 5 up to the middle of the distance between R 5 and M 1 . Sc bare, ending in costa opposite to the base of R s . Sc-r located slightly beyond the middle of Sc. The stem of M fork 1.1–1.2 times as long as r-m. Base of posterior ( M 4 -CuA ) fork slightly beyond the base of r-m. R 1 and R 5 with macrotrichia all over dorsal surface. R-m bare. M 1 and M 2 bare at the basal 1/3. M 4 and CuA 1 with macrotrichia in the apical 1/2 to 2/3. Halteres yellow.

Legs yellow. Coxa darkened basally. Trochanters brown. Fore tibia with 1 pd and 1–2 pv. Mid tibia with 3 ad, 2–3 pd, 3 v, 3–5 av and 4 pv. Hind tibia with 3 v, 7–10 ad, 2 av, 3–4 d and 1– 3 p. Ratio of tibia to first tarsomere for fore, mid and hind legs: 1.46–1.58 (1.53); 1.41–1.49 (1.48); 1.82–1.93 (1.88). Fore tibia with 1 pv spur, mid and hind tibia each with two spurs (av spur about 0.6 times as long as pv spur). Tarsal claws slightly thickened.

Abdomen brownish, with pale hairs.

Terminalia brown. Gonocoxites divided by deep median cleft, sternal submedian appendages relatively long, apically rounded (Fig. 14, 19). Gonostylus bears 3 short black spines and 2–3 longer seta apically, and with the well-developed horn-like ventral process (Fig. 16, 23–24). Tergite 9 ovate, cerci rounded, covered with irregularly arranged 13–18 spines (Fig. 15, 20). Parameres relatively narrow, slightly bent near the apex and then pointed (Fig. 17–18, 21–22).

Female unknown.

DIAGNOSIS.A small dark Boletina with transparent wings and yellow legs. B. pyasina is most similar to B. silvatica Dziedzicki, 1885, which also has gonostylus with the ventral horn-like process. These species can be easily distinguished by sternal submedian appendages of gonocoxites, which are relatively wide and rounded apically in B. pyasina, and pointed in B. sylvatica. Other related species B. triangularis Polevoi, 1995, B. subtriangularis Polevoi et Hedmark, 2004 have a shorter ventral process on the gonostylus and short triangular sternal submedian appendages of gonocoxites. Boletina nuortti Salmela, 2016 is also somewhat similar, but lacking ventral process on the gonostylus and has distinctly shorter parameres as compared to all above-mentioned species.

ETYMOLOGY. The species name is derived from the River Pyasina in the Krasnoyarsk Region of Russia.

ECOLOGY. The habitats in the type locality are sedge-dwarf tundra communities. The species has been collected with Malaise traps and sweep net.

DISTRIBUTION. N Palaearctic: Russia (N Siberia).