Results of a pilot caddisfly study from two Pannonian rivers in Slovakia with special remark on rare Leptocerus interruptus (Fabricius, 1775)

During the hydrobiological survey of lowland stretches of two rivers in Pannonia in southern Slovakia – the Hron and the Ipeľ – we investigated the distribution of caddisfly species. In the field, both adult and larval stages were collected at three sites in the Hron and eight sites in the Ipeľ, with two sites located in neighbouring standing waters. We discovered an apparently stable population of a critically endangered species, Leptocerus interruptus, at several sites along the Ipeľ and at its mouth into the Danube River. A total of one male, three females and nine larvae of the species were recorded. The presence of the species was also confirmed in the Hron River. In addition to this discovery, we also recorded 44 caddisfly species from the study area. Other species of faunistic interest were Adicella syriaca, Limnephilus fuscicornis and Agapetus delicatulus.