Heleodromia pullata (Melander)

(Fig. 2)

Sciodromia pullata Melander, 1902: 345. Type locality (by lectotype designation): Las Vegas Range, New Mexico, USA. Other references: Sinclair et al., 2011: 642 (lectotype designation, redescription); Shamshev, 2016: 17 (checklist).

Material examined. RUSSIA. Chukotka AO (Wrangel Island): Somnitelnaya Bay, on stony river shore, 23.vii.1971, KBG (1 ♂, ZIN); upper flow of river Khischniki, 7 km SE Sovetskaya Mtn, 200 m, dryad tundra near river, 11.vii.1972, KBG (3 ♂, 1 ♀, ZIN); middle flow of river Mamontovaya, 71°10′N 179°45′W, BT 2, YPT, 2–4.vii.2015, OAK (2 ♂, 2 ♀, ZIN); same locality, 71°10′N 179°45′W, BT 3, Sw, 1.vii.2015, OAK (1 ♀, ZIN); upper flow of river Neizvestnaya, 71°13′N 179°19′W, BT 2 В, 8–29.vii.2015, OAK (1 ♂, 1 ♀, ZIN); same locality, 71°13′N 179°19′W, BT 13, YPT, 6–15.vii.2015, OAK (1 ♂, ZIN).

Recognition. Small greyish delicate flies (body length 3–3.5 mm) with very slender legs almost lacking distinct setae, eyes dichoptic in both sexes, separated by broad V-shaped flattened frons; legs black to reddish brown, “knees” often somewhat paler (Fig. 2). Male terminalia large, reniform; tergite 8 simple, lacking dorsomedial elongation or process (Sinclair et al. 2011: 644, fig. 11B); epandrial lobe slender, digitiform; surstylus slightly shorter than epandrial lobe, with apical third slender and digitiform; phallus with apex membranous and broad.

Distribution. Holarctic; in North America, H. pullata is widely distributed in northern Canada and Alaska, occurring on tundra and in boreal forests, with isolated populations in the Rocky Mountains of Arizona, Colorado and New Mexico (Sinclair et al. 2011); in Eurasia, it is known from Taymyr Peninsula and Magadanskaya Province of Russia. Among the Russian Arctic islands, H. pullata is recorded only from Wrangel Island.

Habitat. This species was collected on Wrangel Island mainly in river beds, where it was found in biotopes with different moisture levels (also on stones).

Family EMPIDIDAE