Assessing stream dwelling caddisfly assemblages (Insecta: Trichoptera) collected by light traps in Hungary

In the present study the conservation status of light trap-collected stream dwelling caddisfly assemblages was evaluated on the basis of original data and also from the literature representing different regions in Hungary. Altogether the catches of eight complete seasons were compared. Species richness, diversity and endangerment indices as well as a newly introduced rarity index (RI) expressing the average rarity of the collected species in Hungary were calculated to evaluate the conservation status of the streams in the Bakony, Borzsony and Bukk Mountains and in the Zala Hills. The results highlight the importance of streams in maintaining endangered species of caddisfly in Hungary and bring to attention the fact that species richness or diversity are not necessarily the best indicators of conservation status of caddisfly assemblages. Indicators, for instance RI, which take into consideration the general rarity of the species seem to reflect more sharply conservation status and thus are more appropriate for the assessment of caddisfly assemblages.