Protonemura bispina Vinçon, Ravizza & Reding sp. n.

(Figs. 13–22)

Morphological diagnosis. A medium-sized Protonemura species. Body length of males 5–7 mm, females 7–9 mm. Males and females macropterous. General color light reddish-brown; head dark; antennae and legs light-colored. Forewings smoky brown. Cervical gills short, without pre-apical constriction (cf. Figs. 9, 32). Sclerotized base of the median lobe of the paraprocts of adult males small and nearly square; sclerotized stem short and thick (Figs. 16–18). Tip of epiproct with two small spines (Fig. 13, arrow).

Type material. Holotype male: ITALY: Carnic Alps: S.E. Auronzo di Cadore,> Passo di Rezzo, below Sella Ciampigotto, spring and brook, 1750 m, 46.487N, 12.589E, 22.06.2018, leg. G. Vinçon (deposited in the MZL, catalogue number: GBIFCH00660505).

Paratypes: same locality (Fig. 40) and date, 3♂, 3♀, leg. G. Vinçon (deposited in the MZL, catalogue number: GBIFCH00660506) .

Additional material. ITALY: Carnic Alps. S.W. Feltre, Séren del Grappa, 650–750 m, 45.923N, 11.811E, 8.06.2008, 1♂, 1♀, leg. G. Vinçon (VIN); S.E. Ampezzo,> Préone, Casali Cjampon, W. slope of Verzegnis Mount, big spring, 750–800 m, 46.355N, 12.875E, 11.10.2008, 3♀; 14.05.2010, 1♂, 1♀, leg. G. Vinçon (VIN), 22.06.2018, 3♂, 2♀, leg. G. Vinçon (RED); S.E. Auronzo di Cadore,> Passo di Rezzo, below Sella Ciampigotto, spring and brook, 1750 m, 46.487N, 12.589E, 22.06.2018, 2♂, leg. G. Vinçon (RED); 21.09.1980, 1♂, 1♀, leg. C. Ravizza (MZL, catalogue number: GBIFCH00967670); Moggio Udinese, Loc Saps, torrent Aupa, 800 m, 46.495N, 13.22E, 15.06.1994, 2♂, 1♀, leg. C. Ravizza (VIN); 2♂, 2♀, leg. C. Ravizza (MZL, catalogue number: GBIFCH00967665); Studena Alta, rio Bianco, 830m, 46.508N, 13.27E, 15.06.1994, 1♂, leg. C. Ravizza (VIN); 2♂, 1♀, leg. C. Ravizza (MZL, catalogue number: GBIFCH00967669); 02.12.1979, 1♀, leg. C. Ravizza (MZL, catalogue number: GBIFCH00967668); NE Belluno, Passo Mauria, eastern slope, brook and spring, 1100 m, 46.446N, 12.539E, 14.05.2010, 1♂, leg. G. Vinçon (VIN); Belluno, before Levego, Sagrogna, artificial brook, 400 m, 46.154N, 12.266E, 24.04.1999, 3♂, 3♀, leg. G. Vinçon (VIN); W. Belluno, N.E. Feltre, Canzoi Valley, above the dam, spring and brook, 800 m, 46.143N, 11.951E, 5.04.2009, 1♂, leg. G. Vinçon (VIN).

ITALY: Julian Alps. N.E. Cividale del Friuli, Cepletischis, near the Slovenia border, spring above the village, 600 m, 46.179N, 13.568E, 15.05.2010, 4♂, 2♀, leg. G. Vinçon (VIN); E. Cividale del Friuli, below Stregna, below Zamir, 200 m, 46.122N, 13.55E, 21.04.2008, 1♂, leg. G. Vinçon (VIN); Resia, Valle dell’Uccea, torrent, 700 m, 46.306N, 13.378E, 14.07.1974, 3♂, leg. C. Ravizza (MZL, catalogue number: GBIFCH00967676).

SLOVENIA: Julian Alps. Goriska region, tributary to Limarica river, Vršič Pass, 1400 m, 46.414N, 13.744E, 23.06.2018, 5♂, 4♀, leg. G. Vinçon (RED); Vršič Pass, S. slope, Limarica trib., Soca trib., 1400–1550 m, 46.431N, 13.743E, 23.06.2018, 4♂, 2♀, leg. G. Vinçon (VIN); Vršič Pass, S. slope, 1300 m, 46.411N, 13.749E, 15.05.2010, 2♂, 1♀, leg. G. Vinçon (VIN); N. Bovec, Passo del Predil, Slovenian slope of the Pass, 1100 m, 46.419N, 13.586E, 15.05.2010, 1♂, 1♀, leg. G. Vinçon (VIN) .

Description of Protonemura bispina sp. n. Males (Figs. 13–18). Tergites 8 and 7 with several rows of strong spines on each side, medially interrupted (Fig. 15); tergite 6 without spines. Hypoproct nearly square, terminated by a finger-shaped expansion (Fig. 16). Ventral vesicle ovoid-shaped (Fig. 16). Inner lobe of paraprocts hidden by hypoproct. In ventral and lateral view, sclerotized base of median lobe of the paraprocts small and nearly square; membranous field reduced, not extending over the length of the cercus (Figs. 16–18), often with a dark thorn. Sclerotized stem arising from the inner upper edge of the sclerotized median lobe short and thick, not extending over the membranous field, and with apical spines (Figs. 16–18). The sclerite of the outer lobe is trifurcated (Fig. 18), with a narrow basal branch turning around the cercus (= OLS1, Fig. 18), a second, thin and curled branch, located between the cercus and the membranous field of the median lobe (= OLS2, Fig. 18), and a third, thin sclerite, sometimes invisible because hidden by the cercus (cf. Fig. 8), that arises from the second branch (= OLS3, Fig. 18). Epiproct with a strong median widening (Figs. 13, 14). Tip of the epiproct very large and bent upwards, with a deep and narrow U-shaped notch between the tip and the upper median part of the epiproct (Figs. 13, 14). Tip of epiproct with two light-colored small protruding spines pointing forward (Figs. 13 (arrow), 14). Tip of epiproct with a dark tulip-shaped sclerite, in dorsal view (Fig. 15). Ventral sclerite of the epiproct with a median bulge bearing a row of short spines pointing backward (Figs. 13, 14).

Females (Figs. 20–22). Pregenital plate of sternite 7 brightened, large and wide, with rounded margin slightly extending over sternite 8 (Figs. 20, 22). Subgenital plate with a narrow ribbon-shaped sclerotized band, slightly constricted in its middle and terminated by an acuminated edge on both sides (Figs. 20, 22). Vaginal lobes of the subgenital plate reniform, partly covering sternite 9, and extending almost to the edge of sternite 8 (Figs. 20, 22). Vaginal lobes medially separated by a deep V-shaped notch (Fig. 20). In lateral view, pregenital and genital plates prominent (Fig. 21). Paraprocts large and rounded at apex, acuminated laterally (Fig. 22).

Larvae: unknown.

Morphological affinities. Males. Adult males of Protonemura bispina sp. n. differ from those of P. auberti by the tip of the epiproct, which is much wider in P. bispina sp. n. (Figs. 13, 14) than in P. auberti (Figs. 1, 2). Moreover, the gap between the median part of the epiproct and its tip is very narrow and U-shaped in Protonemura bispina sp. n. (Figs. 13, 14), whereas this gap is much wider in P. auberti (Figs. 1, 2). Two clearly visible spines are protruding forward at the tip of the epiproct of Protonemura bispina sp. n. (Figs. 13, 14) while in P. auberti there is only a small, transparent, globulous extension, flanked by two short and thick dark thorns on each side which are visible only by transparency through the cuticle (Figs. 1, 2). In ventral and lateral views, the paraprocts median lobe and the sclerotized stem form a piriform structure in Protonemura auberti (Figs. 5–7), whereas both meet at a nearly right angle in P. bispina sp. n. (Figs. 16–18).

Females. In female adults, the subgenital plate of Protonemura bispina sp. n. bears a narrow ribbon-shaped sclerotized band, slightly constricted in its middle and terminated by an acuminated edge on both sides (Figs. 20, 22), whereas this band is much wider in P. auberti (Figs. 10, 12). Vaginal lobes of Protonemura auberti are voluminous and bulbiform (Figs. 10, 12), whereas they are smaller and reniform in P. bispina sp. n. (Figs. 20, 22).

Distribution area and biogeographical notes. This steno-endemic species inhabits the Carnic and Julian Alps (Figs. 39, 40). It is strongly crenophilic, mainly occurring in brooklets and springs in a wide altitudinal range (200– 1750 m a.s.l.). The flight period is mainly in spring (IV–VI) but exceptionally extends into late autumn (X–XII) at lower altitudes (<850 m).

Derivatio nominis of Protonemura bispina sp. n. This species is named after the two spines located at the tip of the epiproct in adult males (Figs. 13, 14). The epithet is to be treated as a Latin adjective, feminine in gender combined with Protonemura .