EN
The author gives four localities of Eryth- romma viridulum situated in the northern Poland at Polish-Russian borderline, outside the up-to-date-known area of its occurrence. E. viridulum has been in the stage of expansion towards the north in last two decades, likewise in other countries of western and central Europe. The changes of climate and eutrophication of surface waters are crucial factors of this state. Its is clear that next records of this species outside its range are expected. The neighbourhood of the localities given in the paper to Kaliningrad District (NW part of Lake Głębockie - only 2.2 km) points out that this species might occur in its area.