Leuctra puskasi Murányi & Kovács, 2024

Murányi, Dávid & Kovács, Tibor, 2024, Four new species of Leuctra Stephens, 1836 from the Balkans (Plecoptera, Leuctridae), ZooKeys 1218, pp. 49-79 : 49-79

Leuctra puskasi Murányi & Kovács sp. nov.

Figs 1 , 8 , 9 , 12 A, E

Type material.

Holotype male: Bosnia & Herzegovina • Republika Srpska, Kozara Mts, forest brook along the Gornji Podgradci-Kozarac road , 595 m, 45.0414°N, 16.9040°E, 16.iii.2012 (field number: loc. 6), leg. T. Kovács, D. Murányi, G. Puskás ( HNHM: PLP 4185 ) . Paratypes: • same locality and date: 1 ♂ 1 ♀ ( BYU) • 1 ♂ 1 ♀ ( CGV) • 10 ♂ 4 ♀ ( HNHM: PLP 3853 ) • 12 ♂ 5 ♀ ( MM: 2012-10 , PLETYP-36 ) • 1 ♂ 1 ♀ ( SMNS) .

Diagnosis.

Brachypterous in both sexes. Male tergite VII with small membranous portion; tergite VIII with strong posteromedial process that is not erect in side view and bear rounded lobes, membranous area usually shorter than 1 / 2 of segment length, the posterior margin is nearly straight between the posteromedial process and segment sides; tergite IX with short but wide posteromedial sclerite; tergite X posterior margin with deep but narrow notch; sternite IX bears a vesicle shorter than 1 / 2 segment length; specillum longer than paraproct, tip subterminally constricted. Female subgenital plate large and trapezoid, incision between the long lobes widening towards the median bulge but not forming a triangular field, median bulge is narrow in ventral view and distinctly raised in lateral view, lacking distinct setation; spermathecal sclerite ring-shaped, with large converging posterior teeth.

Description.

Medium sized, slender species, females brachypterous (Fig. 9 A ), males strongly brachypterous (Fig. 9 B, C ). Forewing length: holotype 1.4 mm, male paratypes 1.0– 1.4 mm, female paratypes 2.6–3.0 mm; body length: holotype 5.4 mm, male paratypes 4.5–5.8 mm, female paratypes 5.5–6.8 mm. Setation generally short and dense. General colour dark brown to blackish. Head and antennae dark brown, palpi brown. Pronotum brown to dark brown, slightly longer than wide and having rounded corners, rugosities distinct. Legs dark brown, tarsi slightly paler. Wings brownish but hyaline, venation brown.

Male abdomen (Figs 8 A – E , 12 A ): Tergite I sclerotised only anteriorly and in lateral stripes, with two medial spots. Transverse row of four pigmented spots distinct on terga II – VII. Terga II and III with medially divided antecosta, tergite II with triangular membranous area anteriorly. Terga IV – VII with entire antecosta and full sclerotised, tergite VII with weakly sclerotised posterior edge and small membranous portion. Tergite VIII: antecosta interrupted by a wide membranous area, each part ends into a small triangular plate; the membranous area is ~ 1 / 3 segment width, and usually do not reach the 1 / 2 of the segment length but in some specimens it reach down to 2 / 3 above the posteromedial process, posterior margin of the membranous portion wavy; the surrounding sclerotisation of the membranous area lighter than the rest of the segment; posteromedial process not darker than the lateral areas of the segment, not erect in side view and not or only slightly overhangs the segment posterior edge, nearly as wide as the membranous area above, bilobed with rounded lobes slightly pointed laterad, the space between the lobes is concave to nearly straight; posterior margin between the posteromedial process and segment sides nearly straight, not indenting nor distinctly lobed. Tergite IX mostly membranous, antecosta interrupted in the medial 1 / 3 to 1 / 2 of its length; posteromedial sclerite short but wide, sublateral areas darker, the medial portion usually narrower than the lateral portions. Anterior margin of tergite X bilobed anteriorly, posterior margin with deep notch, not wider than 1 / 3 tergite width. Epiproct large, posteriorly rounded, sclerotised only at its sides, stalk short. Cercus simple, covered with long setae. Sterna II – VIII simple, sternite IX bears a vesicle shorter than 1 / 2 segment length, its width more than 1 / 2 its length; posteromedial 1 / 2 of the sternum is delimited by a pale and weakly sclerotised area. Paraproct with moderately wide base, abruptly narrowing after basal 1 / 3, apex gently curved in lateral view and tapering towards a sharp tip. Base of paraproct connected to a subrectangular lateral expansion with an apical, blunt triangular process. Specillum longer than the paraproct, gently curved in lateral view and ending in a subterminally constricted, sharp tip.

Female abdomen (Figs 8 F, G , 12 E ): Terga I – VIII with transverse row of four pigmented spots clearly visible; terga I – IV mostly membranous but with lateral sclerites, terga V – VIII with medial sclerite as well; medial sclerite is a longitudinal stripe on tergite V, gradually widens on the following segments and as wide as 1 / 2 segment width on tergite VIII; terga IX – X fully sclerotised. Sterna I – VII simple, sterna II – VII with one subrectangular median sclerite and two small anterior sclerites that are fused with the median sclerite on sternite VII. Subgenital plate of sternite VIII large and trapezoid, not fused with other sclerites. It has two large and wide lobes, slightly darker brown than the rest of the plate; posterior margin convex, incision between the lobes is a membranous strip, widening towards the median bulge near the centre of the plate but not forming a triangular field; median bulge is narrow in ventral view, distinctly raised, nose shaped to rounded in lateral view, lacking distinct setation. Sternite IX with wide but shallow anterior indentation. Paraproct, cercus and epiproct simple. Spermathecal sclerite ring-shaped, with small anterior teeth and large, converging the posterior teeth.

Affinities.

Both sexes are morphologically the closest to L. dalmoni (compare with Fig. 12 C, D ). Males can be distinguished on the basis of the following characters: posteromedial process of tergite VIII stronger, its lobes are not teeth-like, and preceded by a more shallow membranous area than of those of L. dalmoni ; the posterior margin of tergite VIII is nearly straight between the posteromedial process and segment sides, while it is clearly indented in a rounded membranous field in L. dalmoni ; the posterior indentation of tergite X is a deep notch that is not wider than 1 / 3 tergite width, while that is usually wider than 1 / 2 tergite width in L. dalmoni ; the ventral vesicle of sternite IX is shorter than 1 / 2 segment length, while that is clearly longer than 1 / 2 segment length in L. dalmoni . Females are nearly identical (compare with Fig. 12 G, H ), but variability might be high; however, in the available females, the incision between the lobes of the subgenital plate widens towards the median bulge, while it is only a narrow strip in L. dalmoni , and the median bulge is more robust in lateral view. The males of the new species can be easily distinguished from the other regional early spring species of the prima species complex: L. pseudosignifera is characterised by a pair of rounded sclerotised expansions, located between the posteromedial process and segment sides of tergite VIII (Fig. 12 K ); the posteromedial process of tergite VIII is erect in lateral view in case of L. prima . Furthermore, this species has a divided posteromedial sclerite on tergite IX (Fig. 12 I ); L. visitor has a crossband on the membranous area of tergite VIII, the membranous area is deeper, and the posteromedial process has stronger, angular teeth; additionally, the posterior notch of tergite X is a wide V-shape (Fig. 12 B ). The females are also easily distinguishable: L. pseudosignifera is characterised by a triangular membranous field at the end of the incision between the lobes of the subgenital plate (Fig. 12 L ); the median bulge of the subgenital plate is much wider in L. prima , and the lobes of the subgenital plate are shorter (Fig. 12 J ); L. visitor has a wide median bulge of the subgenital plate, and the plate has distinctive, erect setation in lateral view (Fig. 10 F ). In addition, all the other species are macropterous.

Distribution and ecology.

The species was collected at a single forest brook in the Kozara Mts of northwestern Bosnia & Herzegovina (Fig. 1 ). The Kozara is of low elevation, a northern foothill of the Dinarids, rather separated from the higher ranges and also stands far from the Slavonian mountains, separated by the plain of the Sava River. The habitat is a slowly running small brook in mixed forest dominated by fir and beech, which probably often runs dry in summer (Fig. 9 D ). It has a stony substrate mixed with mud and plenty of dead wood and fallen leaves (Fig. 9 E ). This habitat type is very different from those of the closely related L. dalmoni , and probably unsuitable even for the more eurytopic L. prima . No other member of the Leuctra prima species complex was found in the Kozara, despite the fact that some other habitats seemed suitable at least for L. prima . The type specimens were the only adult stoneflies found there (in partial snow cover), but last instar larvae of Leuctra nigra , Nemoura sciurus Aubert, 1949 , and a Nemoura marginata group member were found in the brook. We visited the locality twice more, once in May (24. v. 2012, leg. T. Kovács, G. Puskás) and once in November (7. xi. 2012, leg. T. Kovács, G. Magos). In May, adults of Leuctra nigra , single females of a N. marginata group member and of Siphonoperla torrentium ( Pictet, 1841) were collected. In November, no stoneflies but only autumnal Trichoptera were collected ( Oláh and Kovács 2012 a; Oláh et al. 2012): Chaetopteryx gonospina , C. papukensis .

Etymology.

We dedicate this species to our friend and orthopterologist colleague, Gellért Puskás, with whom we made several collecting expeditions in the Balkans, and who regularly provides us stoneflies from his travels. Used as a noun, gender masculine.

Figures

Figure 1. Collection sites of the four new Leuctra species.

Figure 8. Terminalia of Leuctra puskasi sp. nov. A male terminalia, dorsal view B same, lateral view C same, ventral view D variation of male tergite 8, dorsal view E male paraprocts and specillae, caudal view F female terminalia, ventral view G same, lateral view. Setation omitted with the exception of subgenital plate on G. Scale bar: 1 mm.

Figure 9. Habitus and habitat of Leuctra puskasi sp. nov. A female habitus B, C male habitus D type locality: forest brook in the Kozara Mts. E substrate of the type locality. Photographs A – C by Gellért Puskás.

Figure 10. Terminalia of Leuctra visitor sp. nov. A male terminalia, dorsal view B same, lateral view C same, ventral view D male paraprocts and specillae, caudal view E female terminalia, ventral view F same, lateral view. Setation omitted with the exception of subgenital plate on F. Scale bar: 1 mm.

Figure 12. Terminalia of five Balkan members of the Leuctra prima group A – D, I, K male terminalia, dorsal view E – H, J, L female terminalia, ventral view A, E L. puskasi sp. nov., Kozara Mts, Bosnia & Herzegovina B, F L. visitor sp. nov., Visitor Mts, Montenegro C, G L. dalmoni Vinçon & Murányi, 2007, Visitor Mts, Montenegro D, H L. dalmoni, Golija Mts, Serbia I – J L. prima Kempny, 1899, Börzsöny Mts, Hungary K – L L. pseudosignifera Aubert, 1954, Poljana Mts, Slovakia. Scale bars: 1 mm (D for A – D, I, K; E for E – H, J, L).