The Western Balkans are an important hotspot of caddisfly diversity in Europe, with several microscale endemics, many of which were discovered during the recent years. The genus Potamophylax Wallengren, 1891 likely originated and diversified in Europe, with the Balkan Peninsula being one of the most important diversity hotspots.
In this paper, we describe the new species Potamophylax coronavirus sp. n. from Bjeshkët e Nemuna National Park in the Republic of Kosovo. The new species belongs to the Potamophylax winneguthi species group and is morphologically most similar to Potamophylax juliani Kumanski, 1999, currently known only from Bulgaria and Potamophylax winneguthi Klapalek, 1902, known from Bosnia and Herzegovina and Serbia. The male of the new species differs from its most similar congeners mainly in exhibiting: (1) elongated subrectangular superior appendages in lateral view; (2) hardly acuminate, almost rounded apex of intermediate appendages; (3) differently shaped, irregular and higher inferior appendages; (4) narrow spinate area, roughly rectangular in dorsal view, slightly wider at the base and (5) different paramere shape and/or spine pattern. The new species also differs by its considerably smaller size and association with open, high altitude eucrenal zones.
The uncorrected interspecific pairwise distance between P. coronavirus and other species of the P. winneguthi species group is on par with those amongst other recognised species in the group, as well as with the yet ambiguously identified taxa from the Sharr, Rila and Bajgorë Mountains.
The new species is most probably a microendemic of Bjeshkët e Nemuna, thus highlighting further this area as an important hotspot of caddisfly biodiversity in Europe.