1. Opazon apertum (Kieffer, 1908)

Figs 1, 5, 9, 17.

Rhynchopsilus apertus Kieffer, 1908 .

Opazon opertum Chemyreva, 2019: 37 (erratum).

MATERIAL EXAMINED: Lithuania. 1 ♀, 3 ♂♂ (ZIN): vicinity of Vilnius, 17. VI.1971, V. Tobias leg. Estonia. 2 ♂♂ (TUZ): Paluküla 58.2571°N 26.9326°E, YPT, 15. VI.2017, V. Soon leg. ; 2 ♂♂ (ZIN): Võru. Russia. ♂: Leningradskaya Area, Ladoga Lake Station, 13. VI.1983, S. Belokobylskij leg. ; 5 ♀♀, 109 ♂♂ (ZIN, ZMUM): Moscow Area, Moscow City, Krylatskoe, Rublevskiy forest, 1–30. VI.2004, V. Kolyada leg.

VARIATIONS. Radial cell well developed (close or open at apex) to strongly reduced to transparent point.

DISTRIBUTION. England, Germany, Italy, Poland, Czech Republic, Austria, * Lithuania, * Estonia, Russia (*European part, Ural).