Potamophylax rilaensis Ibrahimi, Oláh & Kovács, 2025

Ibrahimi, Halil, Oláh, Janos & Kovács, Tibor, 2025, Potamophylax rilaensis sp. nov. (Trichoptera: Limnephilidae), a new species of the Potamophylax winneguthi Species Cluster from Bulgaria, Zootaxa 5642 (3), pp. 260-270 : 262-266

Potamophylax rilaensis Ibrahimi, Oláh & Kovács sp. nov.

( Figs 2A, 2B, 2C, 2D ).

Type material. Holotype (male): „Bulgaria: Rila Mts, Ezero Vira—Tiha Rila, Rilska Reka, 42°08’20.5”, 23°27’52.3”, 1935 m, 07.10.2011, leg. Á. Ecsedi, T. Kovács, G. Puskás (1 male, OPC)” Oláh (2011): sub nomen Potamophylax juliani Kumanski, 1999 . (The type locality is illustrated in Fig. 1 ). Bulgaria, Rila National Park , Rila Mountains, Manastirska River , 42.139028°N, 23.46452°E, 1935 m asl, 07.x.2011, leg. Á. Ecsedi, T. Kovács and G. Puskás .

Paratypes (1 male): Bulgaria, Rila National Park , Rila Mountain , Kirilova Polyana Meadow , Manastirska Reka River , 42.152710°N, 23.39809°E, 1462 m asl, 11.11.2023, leg. Halil Ibrahimi. The two different river names mean the same watercourse, the upper section of the Rilska Reka is called Manastirska Reka .

Distribution. Bulgaria, Rila Mountains.

Diagnosis. Males of the new species are most similar to those of P. juliani Kumanski 1999 and P. kosovaensis but differ mainly in exhibiting a combination of the following characters: (1) short inferior appendages with outwardly directed tips in lateral view, each with a slightly longer ventral edge and with dorsal and ventral margins of the upper portion slightly diverging from each other; (2) strongly concave ventral margin of each inferior appendage in lateral view; (3) medium-long stout parameres, wider basally, bearing a bunch of short spines in lateral view; (4) apically deeply incised inferior appendages in lateral view; (5) elongate subrectangular superior appendages in lateral view. Potamophylax juliani males have: (1) short inferior appendages with outwardly directed tips in lateral view, each with equally long ventral and dorsal edge and with dorsal and ventral margins of the upper portion set parallel to each other; (2) ventral margin of each inferior appendage mesally curved at an angle in lateral view; (3) short slender parameres, wider basally, bearing a bunch of spines of medium length in lateral view; (4) apically shallowly incised inferior appendages in lateral view; (5) ovoid superior appendages in lateral view. Potamophylax kosovaensis males exhibit: (1) short inferior appendages with upward directed tips in lateral view, each with a longer ventral edge and with dorsal and ventral margins of the upper portion diverging from each other; (2) strongly concave ventral margin of inferior appendages in lateral view; (3) elongated parameres, equally broad along the entire length in lateral view, bearing a bunch of thick and long spines distributed apicodorsally in a regular manner, distinctly separated from each other; (4) apically deeply incised inferior appendages in lateral view; (5) elongate subrectangular superior appendages in lateral view.

In addition to this, Potamophylax rilaensis sp. nov. differs from P. juliani and P. kosovaensis by its apically more produced and more curved parameres, diverging from each other, in ventral view. The aedeagus of P. rilaensis sp. nov. is smaller apically and with thin apical lobes compared to its two most close congeners. Parameres of P. rilaensis sp. nov. are also more produced basally as compared to P. juliani in ventral view.

Description. General appearance. Head and appendages brown, prothorax, sclerites of meso- and metathorax, coxae, and femora dark brown to castanean; tibiae and tarsi brown. Wings brown with dark setae. Male maxillary palps each 3-segmented. Length of each forewing 14.5–14.9 mm. Spur formula 1-3-4. Antennae dark brown.

Male genitalia ( Fig. 2 ). Tergite VIII subquadrangular, setose; in lateral view, truncate posteroventrally; in dorsal view, narrower posteriorly, slightly incised anteriorly, sclerotized proximal portion dark brown, semimembranous distal portion light brown, posterodorsal spinate area long, covered with small black spines, more abundant distally ( Figs 2A, 2B ). Segment IX elongate-oval; in lateral view, dorsal and ventral portions acuminate, lateral sides broad, anteriorly convex, posteriorly almost fused with inferior appendages. Superior appendages elongate subrectangular, with rounded tips, covered with fine setae of medium length, in lateral and dorsal views ( Fig. 2A , sa). Intermediate appendages sickle-shaped; in lateral view with pointed tips, turned upwards; in dorsal view almost straight, apically diverging ( Fig. 2B , ia). Inferior appendages typical for P. winneguthi Species Complex, setose; in lateral view each with slightly longer ventral edge, turned outwardly; in dorsal view turned mesad, deeply incised apically ( Figs 2A, 2B , ima). Phallic apparatus consisting of long aedeagus and a pair of parameres ( Figs 2C, 2D, a, p ). Aedeagus wider at tip in ventral view, with bifid apex, apicomesal excision wide-U-shaped ( Fig 2D, a ). Parameres short, stout, with short apical spines ( Fig 2D, p ); in lateral view basally wider, ( Fig 2C, p ); in ventral view equally broad along the entire height.

Female, larva, pupa. Unknown.

Etymology. The species epithet is derived from the Latinized adjectival form “rilaensis ,” signifying its association with Rila Mountain where it was found.

Ecology and distribution. Potamophylax rilaensis sp. nov. was found at two localities along the Manastirska Reka River with more than 5 km distance in between, implying that the species is distributed from the eucrenal segment down to the hypocrenon of this river. Both sites where the species was found were located inside a relatively densely forested area. The substrate of the streams close to the sampling sites was dominated by meso to macrolithal. The species was captured during October and November, implying it has an autumnal flying period. Another Trichoptera , Psilopteryx schmidi , was also collected at the type locality ( Oláh & Kovács 2012a).

Figures

FIGURE 1. Type locality of Potamophylax rilaensis sp. nov.: Manastirska Reka River, Rila Mountain, Bulgaria.

FIGURE 2. Male genitalia of Potamophylax rilaensis sp. nov. 2A, left lateral; 2B, dorsal; 2C, aedeagus and parameres, left lateral; 2D, aedeagus and parameres, ventral. a—aedeagus; adt—apicodorsal tip; avt—apicoventral tip; ia—inferior appendages; ima—intermediate appendages; IX—segment IX; p—parameres; s—spines; sa—superior appendages; t VIII—tergite VIII. Scale bars = 0.5 mm.