Potamophylaxkosovaensis sp. nov. (Trichoptera, Limnephilidae), a new species of the Potamophylaxwinneguthi species cluster from the Ibër River Basin in Kosovo.

BACKGROUND: The Potamophylaxwinneguthi species cluster comprises species with limited distribution, currently documented from Kosovo, Serbia, Bosnia and Herzegovina and Bulgaria.

NEW INFORMATION: In this paper, we describe a new species, Potamophylaxkosovaensis sp. nov., discovered in two tributaries of the Ibër River Basin, within the Kopaonik Mountains of the Republic of Kosovo. Morphologically, males of this species closely resemble those of P.idliri Ibrahimi, Bilalli & Kučinić, 2022 from Serbia's Jastrebac Mountain and P.humoinsapiens Ibrahimi & Bilalli, 2023 from the Sharr Mountains in the Republic of Kosovo. However, the new species can be distinguished by its smaller aedeagus, thicker and differently-shaped parameres, as well as distinctive patterns and elongated spines on the parameres. Notably, this species is restricted to spring areas, indicating sensitivity to water pollution and habitat degradation. Additionally, we provide a list of caddisfly species found in sympatry with the new species. Potamophylaxkosovaensis sp. nov. is the third known species within the Potamophylaxwinneguthi species cluster, identified in the Republic of Kosovo.