Potamophylax idliri Ibrahimi, Bilalli & Kučinić, 2022

Potamophylax idliri Ibrahimi, Bilalli & Kučinić sp. nov.

( Figs 3 View FIGURE 3 , 4 View FIGURE 4 , 5 View FIGURE 5 ).

Type material. Holotype (male): Serbia, Kruševac Municipality, Jastrebac Mountain, Majorova Česma spring, 43.39818°N, 21.39549°E, 988 m asl, 21.x.2016, leg. Halil Ibrahimi and Astrit Bilalli. GoogleMaps Paratypes (1 male): same locality data as holotype, 16.x.2020, leg. Halil Ibrahimi, Agim Gashi, Linda Grapci-Kotori. (1 male): Serbia, Kruševac Municipality, Jastrebac Mountain , stream nearby Majorova Česma spring, 43.40276°N, 21.40018 °E, 891 m asl, 21.x.2016, leg. Halil Ibrahimi and Astrit Bilalli. GoogleMaps

The holotype and paratypes are deposited at the Department of Biology , Faculty of Mathematics and Natural Sciences, University of Prishtina “Hasan Prishtina,” Prishtinë, Kosovo, collection “Halil Ibrahimi-Jastrebac Collection” .

Distribution. Serbia, Jastrebac Mountains.

Diagnosis. Males of the new species are most similar to those of Potamophylax coronavirus and P. juliani . The male of the new species differs from those of all known species of the Potamophylax winneguthi Species Group by its uniquely shaped parameres, which are short, narrow, slightly sinuate in lateral view ( Figs 4E View FIGURE 4 , 5A View FIGURE 5 ), each with its apex slightly wider than the base, supporting a bunch of apical spines of different sizes. The P. idliri sp. nov. male further differs from that of its most similar congeners mainly in exhibiting a combination of the following characters: (1) elongate subrectangular superior appendages in lateral view; (2) acuminate, rounded apices of intermediate appendages; (3) short inferior appendages in lateral view, turned upwards, each with a longer ventral edge and with dorsal and ventral margins of the upper portion not set parallel but diverging from each other; (4) tergum VIII with a narrow spinate area, roughly rectangular in dorsal view, slightly wider at the base. Males of P. coronavirus , similar to P. idliri sp. nov., have elongate subrectangular superior appendages in lateral view and rounded apices of intermediate appendages, but a totally different shape of the inferior appendages and parameres. In P. coronavirus (1) inferior appendages are irregular, considerably longer, bulging dorsally at the area between them and segment IX in lateral view, each with a high and broad upper protruding portion and with a narrower distance between the dorsal and ventral corners of the upper portion, which are set parallel to each other and directed mesad in lateral view; (2) parameres are short and stout, each with a wider base and narrower apex and with very thick spines originating on the distal third, reaching only slightly beyond the apex. The P. juliani male has (1) small ovoid superior appendages; (2) long, slender intermediate appendages each with a sharply acuminate apex; (3) inferior appendages each with a short protruding upper portion as high as half of the entire appendage’s height and with a wide distance between the dorsal and ventral corners, set parallel to each other and directed mesad; (4) tergum VIII has a spinate area in dorsal view that is narrow at the apex and considerably wider at the base; and (5) the short stout parameres each have a wider base, with 15–20 thick spines of medium length originating mostly from the tip.

The new species has some resemblance with P. winneguthi , as well. However, the male of P. winneguthi differs from all the above-mentioned three species mostly by its (1) small, laterally rounded superior appendages; (2) long inferior appendages, parallel-edged and dorsally truncated in a rectangular manner, each longer on its ventral edge, directed dorsad; and (3) short and stout, parallel-edged parameres each with 5–7 very long spines originating from the distal half. The other species of this group, P. haidukorum is characterized by its long, filamentous, sinuate parameres without apical spines.

In addition to the above-mentioned diagnosis, the new species differs from its most similar congeners in several other minor characters, such as the following: (1) the apicomesal excision of the aedeagus tip in P. idliri sp. nov. is narrower than in P. coronavirus ; (2) the aedeagus tips in ventral view in the new species are shorter than in P. juliani ; (3) the paramere sacks in P. idliri sp. nov. are smaller than in P. coronavirus and P. juliani ; (4) the parameres of the new species in ventral view are narrower than in P. coronavirus and P. juliani ; (5) the parameres of the new species in lateral view are narrow at the base and wider at their distal third, contrary to the parameres of P. winneguthi which are wider at the base and narrower at distal third; and (6) the terminalia (segment IX, appendages and aedeagus and parameres) are smaller versus segment VIII and the rest of the body in the new species as compared to those of P. coronavirus , P. juliani , and P. winneguthi .

Description. General appearance ( Fig. 3 View FIGURE 3 ). Head and appendages brown, prothorax, sclerites of meso- and metathorax, coxae, and femora dark brown to black; tibiae and tarsi brown. Wings brown with dark setae. Male maxillary palps each 3-segmented. Length of each forewing 14–15 mm. Spur formula 1-3-4. Antennae dark brown.

Male genitalia ( Figs 4 View FIGURE 4 , 5 View FIGURE 5 ). Tergite VIII dark brown, in dorsal view roughly rectangular, with apical portion slightly narrower, setation concentrated on proximal sclerotized portion of segment VIII, spinate area located on semimembranous distal portion of segment VIII roughly rectangular in shape with slightly wider proximal portion in dorsal view, covered by small black spines, more abundant apically ( Figures 4B View FIGURE 4 , 5B View FIGURE 5 ). Segment IX with short and narrow dorsal and ventral portions, laterally broad, convex anteriorly. Superior appendages in lateral view long, subrectangular, with rounded tips, covered with fine setae of medium length ( Fig. 4A View FIGURE 4 ). Intermediate appendages, sickle-shaped with acuminate rounded apex, turned upwards ( Fig. 4A View FIGURE 4 ). Inferior appendages short, turned upwards, each with longer ventral edge ( Figs 4A, 4C View FIGURE 4 , 5A View FIGURE 5 ). Phallic apparatus consisting of aedeagus of medium length and pair of parameres ( Figs 4D View FIGURE 4 , 5C View FIGURE 5 ). Aedeagus bulbous in ventral view, wide at tip, with bifid apex, apicomesal excision medium-U-shaped; parameres short, slender, slightly sinuate in lateral view ( Fig. 4E View FIGURE 4 ), each with apex slightly wider than base, bearing bunch of apical spines of different lengths.

Female, larva, pupa. Unknown.

Etymology. Species epithet ‘idliri’, coined from “i dëlirë” (meaning “pure, chaste or clean” in Albanian), refers to the clean and almost untouched freshwater ecosystems in and around the type locality in the Jastrebac Mountains. The species epithet is also dedicated and refers to the first author’s son, Idlir, who is a frequent assistant in collecting caddisflies throughout the Balkans. The species epithet is not a Latin or latinized word and therefore is to be treated as indeclinable and not needing to agree in gender with the generic name with which it is combined.

Ecology and distribution. Potamophylax idliri sp. nov. was found at two localities in the Jastrebac Mountains within a 1 km perimeter, although several other streams of lower altitudes were sampled. Both sampling sites are located inside a densely forested area. The substrate of streams close to the sampling sites was dominated by mesoto macrolithal substrate, surrounded by a dense riparian vegetation. The species was captured only by ultraviolet light traps. The species was collected during October, implying it has an autumn flying period. At the first site it was found at the spring source (eucrenon), while at the second site, much lower (hypocrenon).

The new species was found in sympatry with the following species: Rhyacophila brevifurcata Kumanski 1985 , R. obtusa Klapálek 1894 , Philopotamus montanus ( Donovan 1813) , Wormaldia cf. subterranea / hellenica , Potamophylax pallidus Klapálek 1899 , P. depilis Szczesny 1994 (in Moretti et al. 1994), Micropterna sequax McLachlan 1875 , Chaetopteroides kosovarorum Ibrahimi & Oláh 2013 (in Oláh et al. 2013a), Chaetopteryx bosniaca Marinković 1955 , Chaetopteryx gonospina Marinkovic-Gospodnetic 1966 , Stenophylax mitis McLachlan 1875 , S. meridiorientalis Malicky 1980 , Limnephilus lunatus Curtis 1834 , and Halesus digitatus (von Paula Schrank 1781) .

Phylogenetic reconstruction. Mitochondrial COI sequences (CROTR356-21 and CROTR357-21) obtained from two males of Potamophylax idliri sp. nov. were identical and form one unique haplotype. Two implemented criteria of phylogenetic reconstruction (ML and BI) yielded congruent topologies and highly similar support values. The new species Potamophylax idliri sp. nov. appeared as a separate lineage, sister to Potamophylax sp. Sharr, which together with P. juliani Kumanski 1999 , Potamophylax sp. Rila, Potamophylax sp. Bajgorë, P. coronavirus , P. winneguthi , P. tagas , P. hajlos , and P. qafshtamaensis represented a monophyletic clade, well supported by bootstrap values and Bayesian posterior probabilities ( Fig. 7 View FIGURE 7 ). Relationships within the P. winneguthi Species Group were unresolved and showing different supported values with respect to the applied method.

The obtained values of uncorrected sequence divergence (p- distances) between P. idliri sp. nov. and other species of the P. winneguthi Species Group support the morphologically recognized species and are shown in Table 2. Intraspecific uncorrected p -distances are 0.3% in P. juliani and 2% in P. rotundipennis ( Brauer 1857) . A significantly high value was recorded for specimens of P. pallidus ( Klapálek 1899) (9.5%). Interspecific uncorrected p -distances for P. idliri sp. nov. ranged from 4.2% to 15.3%, specifically, 4.2% to Potamophylax sp. Sharr, 4.4% to P. juliani , 4.7% to Potamophylax sp. Rila, 5.3% to Potamophylax sp. Bajgorë, from 5.8% to 6.1% to P. coronavirus , 8.6% to P. winneguthi , 8.8% to P. hajlos , 9.7% to P. qafshtamaensis , 11% to P. tagas , 13.1% to P. rotundipennis , 14.6% to P. luctuosus (Piller & Mitterpacher 1783) , 14.9% to P. seprus Oláh, Lodovici & Valle 2011 , from 13.2% to 14.9% to P. pallidus , and 15.3% to P. nigricornis ( Pictet 1834) . The obtained values also support the species status of Potamophylax qafshtamaensis , described based only on morphological differences, with the interspecific uncorrected p -distance to its most close species ranging from 4.4% ( Potamophylax hajlos ) to 7.3% ( Potamophylax tagas ).