Two new species of the genus Drusus (Trichoptera, Limnephilidae, Drusinae) from the Western Balkans are described. Additionally, observations on the biodiversity and threats to the region’s endemic aquatic fauna are discussed. Drusus
krpachi
sp. n. is a micro-endemic of the Korab Mountains, Macedonia, and Drusus
malickyi
sp. n. is a micro-endemic of the Prokletije Mountains, Albania. Both new species are most similar to Drusus
macedonicus but differ from the latter in the shape of segment IX, the shape of the tips of the intermediate appendages in lateral view, the shape of the inferior appendages, and the form and shape of the parameres. In addition, males of the European species of filtering carnivore Drusinae are diagnosed and illustrated, including Cryptothrix
nebulicola McLachlan, Drusus
chrysotus Rambur, Drusus
discolor Rambur, Drusus
macedonicus Schmid, Drusus
meridionalis Kumanski, Drusus
muelleri McLachlan, Drusus
romanicus Murgoci and Botosaneanu, and Drusus
siveci Malicky. These additions to the Western Balkan fauna demonstrate the significance of this region for European biodiversity and further highlight the importance of faunistic studies in Europe.