Ponowne stwierdzenie Onychogomphus forcipatus (Linnaeus, 1758) w izolowanej wyspie areału na Pojezierzu Gnieźnieńskim (Polska środkowozachodnia)

On July 8, 2010 and 9 VII 2011 in Przybrodzin by Lake Powidzkie (UTM: XU91; 52°25’45” N, 17°55’47” E) a male and a female of Onychogomphus forcipatus were recoded respectively. More than 30 years ago on nearby Lake Niedzięgiel and Białe, situated at the same UTM square UTM (XU91), the presence of the species was found. All of the discussed lakes are located at the distance more than 100–130 km towards the west, north-west and north of the nearest known sites of the species (Bernard i in. 2009). Probably the sites from the Gnieźnieńskie Lakeland are disjunctive area of the occurrence of the species, however, the existence of other sites joining them with more densely inhabited area of lake districts can not be excluded. Duration of the distribution island in the Gnieźnieńskie Lakeland confirms the maintenance of the suitable habitat base, especially lakes with good water quality.