Nanna obscuripes (Becker, 1915)

Figs 140–145.

obscuripes Becker, 1915: 64 (Acerocnema) . Type-locality: “Tundra des Fl. Kara” [Valley of the River Nyarma-Yaga [Nyarmayakha], 80 m (about 68°36′N, 65°57′E, see Sorokina & Pont, 2014)] (Russia: Tumen' Oblast).

indotatum Engelmark, 1999: 163 (Nanna) . Type-locality: Ayon Island (69.7833N 168.5666E), Chukotka (Russia).

Remarks. Reported by Becker (1915: 64, 65) from Tumen' Oblast and by Engelmark (1999: 163, 164) from Chukotka.

Material examined. Chukotka: Kolyuchin Island (67.4647N 174.6178W) (1 ♂, 3 ♀♀, ZISP); Krasnoyarsk Kray: River Nizhnyaya Agapa about 40 km lower of springhead (~ 70.0972N 86.6883E), 12–14.VII.1973, V. Zherikhin and I. Sukacheva (2 ♂♂, ZMUM).

Diagnostic description. Body-length about 4 mm. Head. Frons black, only lower quarter always yellow, grey dusted. 3 orbital setae present. Antenna black. Postpedicel with acutely angled upper apical corner, approximately 2–2.5 times as long as wide. Thorax black, extensively grey dusted. Proepisternum with hairs in central part. Katepisternum with 2–3 strong (anterior katepisternal may be absent) pale setae. Legs. All coxae blackish; femora black, but narrowly yellow apically; tibiae yellow, usually mid and hind tibiae darkened on apical half; tarsi darkened. Fore femur without anteroventral setae (Fig. 140). Hind tibia without apical posteroventral seta. Wing clear. Abdomen black, greyish dusted. Male sternite 4 rectangular, slightly longer than wide (Fig. 144). Male sternite 5 with black lobes, as in Fig. 141. Epandrium, cerci and surstyli as in Figs 142, 143.

Female unknown.

Distribution. Russia (Fig. 145): Chukotka, Krasnoyarsk Kray, Tyumen' Oblast.