Revision of the genus Philopotamus Stephens (Trichoptera, Philopotamidae): Lumping and splitting

Philopotamus is a common and abundant European caddisfly genus, but it is hard to identify them. Applying fine phenomics, and combining the principles and procedures of lumping and splitting together, here we revised its taxonomy. Based on gross character states of lumpers, narrow or wide dorsal profile of segment X; presence or absence of basomesal dent on coxopodite; curvature of the dorsal branch of harpago; hooked or pointed terminal of the ventral sclerite of the phallic organ and number of primary endothecal spines we have established three species groups: Philopotamus montanus including P. achemenus and P. montanus species complexes, P. variegatus and P. ludificatus. Based on fine character states of the dorsal profile of segment X, terminalia of ventral sclerite, endothecal spine structure we have delineated the species inside each species group. We have described eleven new species: Philopotamus azerorum Oláh sp. nov., P. graecus Oláh sp. nov., P. albanicus Oláh sp. nov., P. marignanicus Oláh sp. nov., P. adjaricus Oláh & Vinçon sp. nov., P. bulgaricus Oláh sp. nov., P. emiliacus Oláh & Vinçon sp. nov., P. epirus Oláh & Ibrahimi sp. nov., P. gionicus Oláh sp. nov., P. ibericus Oláh sp. nov., P. tavigan Oláh sp. nov. and re-diagnosed eleven known species: P. achemenus Schmid, 1959, P. caurelensis González & Terra, 1979 stat. nov., P. montanus (Donovan, 1813), P. perversus McLachlan, 1884 stat. restit., P. siculus Hagen, 1860, P. amphilectus McLachlan, 1884 stat. restit., P. liguricus Malicky, 1984, P. tenuis Martynov, 1913, P. variegatus (Scopoli, 1763), P. corsicanus Mosely, 1938, P. ludificatus McLachlan, 1878. We have raised the subspecies status of P. montanus caurelensis González & Terra, 1979, to species rank as P. caurelensis González & Terra, 1979, stat. nov. We reinstated the species status of P. perversus McLachlan, 1884 stat. restit. and P. amphilectus McLachlan, 1884 stat. restit. In addition to the new species, we have redrawn the eleven known species too using the same principles and procedures as before, creating a perfectly comparable genital atlas in diagrammatic style. Unfortunately eight species of Sipahiler and one species of Giudicelli & Dakki were not available for this study.