Introduced from the New World, H. aenescens is rapidly spreading in Europe. This paper reports new records of H. aenescens from Eastern Europe. Among these records, the one from the Far North of European Russia is the most remarkable. Also new data of seasonal activity and mating behavior of H. aenescens is given. A peak of H. aenescens imago activity in southern Turkey takes place during very early spring. Mating behavior of H. aenescens differs from that of other members of the Hydrotaea genus.