Cordulegaster bidentata Selys, 1843 in fragmented landscape of the Wielickie Foothills: reassesement of the northern limit of species range in the Western Carpathians

In 2018–2019, the occurrence of Cordulegaster bidentata Selys, 1843 in the Wielickie Foothills, located between the Beskidy mountain ranges (in the south) and the Vistula river valley (in the north) was investigated. It was examined whether C. bidentata inhabits fragmented landscape, with forest patches of various sizes. Larvae of this dragonfly were searched in the forest streams, the bottom of which was visually scanned using binoculars. The presence of 49 larvae was confirmed on 17 stream sections out of 53 (32%). They were recorded in almost the entire geographical extent of the study area, from the southernmost to the northernmost forest patches. The neighboring occupied streams were separated by a maximum of 3.7 km, and breeding sites were found in forest patches of an area of 75–1280 ha. It was confirmed that C. bidentata occurs up to the orographic edge of the Western Carpathians. Its range is continuous between the northern edge of the Beskidy Mountains and the Vistula valley. New data shift the northern range limit of C. bidentata in the Western Carpathians by nearly 20 km. The field method used proved to be efficient in assessing the distribution of larvae in large areas, with relatively little field effort. Its wider use would allow a more complete recognition of distribution of C. bidentata in the Carpathian Foothills.