Nemoura asceta, Murányi, Dávid, 2007

Murányi, Dávid, 2007, New and little – known stoneflies (Plecoptera) from Albania and the neighbouring countries, Zootaxa 1533, pp. 1-40 : 13-17

Nemoura asceta sp. n. ( Figs 29 –42)

Type material: Holotype male: ALBANIA, Shkodër County, Prokletije Mountains, karst spring and its outlet along the road from Terthorë Pass to Okol, N 42°23.168’ E 19°44.876’, 1622 m, 29.05.2005, leg. KB, ZB, DM, DP ( HNHM: PLP1932). Allotype female: ALBANIA, Shkodër County, Prokletije Mountains, side torrent of Sheu River below Rioli, N 42°12.267’ E 19°34.079’, 270 m, 16.04.2006, leg. ZE, ZF, AH, DM ( HNHM: PLP2275). Paratypes: same locality and date like holotype: 1♂, 3 larvae, 1 exuviae ( HNHM: PLP1933, male epiproct prepared on slide, exuviae partly prepared for SEM), 1♂ ( CPZ); same locality and date like allotype: 2Ψ ( HNHM: PLP2251), 1Ψ, 1 larva ( CPZ), 1♂ 1Ψ (CGV).

Diagnosis: Male: Apical sclerite of the epiproct spike–like, the ring of the ventral sclerite bears two lobes ending in lateral horns; the lateral arms are relatively large. Cerci strongly curved, their apex bears a sharp dorsal and a rounded ventral hooks. Larva: body slender, setation scarce. Posterior row of setae on tergal segments erect, uniformly long.

Description: Small species, macropterous in both sexes. Body length: ♂ holotype 5.5 mm, paratypes 5.5– 6.0 mm, Ψ allotype 6.5 mm, other paratypes 6.0–7.0 mm; forewing length: ♂ holotype 7.0 mm, paratypes 7.0– 7.5 mm, Ψ allotype 7.5 mm, paratypes 7.0– 8.5 mm. Head brown, postclypeus, sides of occiput and frons around scapes black. Scapes yellowish brown, rest of the antenna black, palpi yellowish. Pronotum brown, subtrapezoidal, anterior edges angled. Femora yellow, tibia obscured, tarsal segments dark brown. Wings clear, venation dark brown. Abdomen uniformly off white except for terminal segments, which are dark brown.

Male terminalia: Hypoproct as long as wide, vesicle about twice as long as wide. Paraproct outer lobe triangular with its inner margin nearly straight and outer margin slightly undulate ( Figs 29–31 ). Cerci membranous medially, sclerotized on its outer side including most of the apex. Cerci strongly curved, its apex curled outwards; base slightly bulbous. Membranous part around the vestigial segment placed close to the outer margin of the apex ( Fig 34 ). The apex bears two hooks, the dorsal one sharp and the ventral one rounded. Tergite X with a light strip medially. Epiproct widest in its apical half; its ventral sclerite with parallel ridges bearing 10–11 spines ventrally. Arms of the ventral sclerite dorsally forming a wide, strong ring, which extends into straight, spike–like apical sclerites. Length of the apical sclerites is one third of the arms length. Besides these apical sclerites, the apical part of the ring bears two distinct lobes ending in lateral horns. Sclerotized parts of the lateral arms distinct, relatively large ( Figs 32–33 ).

Female terminalia: Pregenital plate covering most of length and over half the width of sternite VII, overhanging most of length of sternite VIII. Posterior edge of plate rectilinear, sides sinuous. Most of the plate brown, with dark brown patches posterolaterally. Sternite VIII laterally brown ( Figs 35 ). Vaginal complex with simple receptaculum seminis ( Fig 36 ). Cerci and paraprocts typical for the genus.

Mature Larva: Slender, body length 5.5–6.0 mm. General colour pale brown. Pilosity sparse but distinct. Scales present only in the dorsal midline of the femora. Legs slender, tibiae as long as femora; hind femora three times as long as wide. Head stout, with cloudy, indistinct pattern. Pronotum subtrapezoidal, corners rounded, narrowing towards the posterior margin; its length two thirds of its maximum width. Wing pads of length typical for the genus, abdomen slender, cerci with more than 15 segments. Beyond the basal segments, cercal segments become slightly clubbed apically, segments 13–15 are more than five times as long as wide.

FIGURES 37–42. Larva of Nemoura asceta sp. n. —37: marginal setae of pronotum; 38: bristles and spikes of the femora; 39: fore tarsus; 40: bristles on tergite V; 41: cercus, basal segments; 42: cercus, 15th segment —scale 0.1 mm Pilosity: Head with dense, stout bristles and a few thin hairs. Antennal segments with short pilosity. Pronotum with stout bristles and thin hairs. Margin of the pronotum with bristles of variable length, some short ones are club–shaped, the longest ones are acute and reach one tenth of the pronotum’s width (Fig 37). The bristles on the anterior corners of mesonotum and metanotum are not longer than the marginal bristles of pronotum. The setae placed in lines on wing pads are acute and short. Legs with scarce but distinct pilosity. All femora bear short, acute bristles, thin hairs and long, stout bristles. Long bristles occur on the apical half of femora, but not in a regular arrangement; the longest ones reach half the femur width on all legs. Bald median line is conspicuous on the dorsal surface of all femora, covered with large, rounded scales. Apical row of short bristles present on all femora (Figs 38). Tarsi stout, covered with thin hairs, apical spike of tibiae short (Fig 39). Tergal segments with scarce, short bristles; distal row of bristles more or less uniform, erect, the bristles are slightly curved and about as long as the segment’s length (Fig 40). Distal margin covered with tiny triangular spikes around the row of bristles. Cercal segments with a very few, inconspicuous hairs besides the apical whorl of bristles (Figs 41–42). The apical whorl is a set of 17–20 bristles mixed with short hairs. Longest bristles reach the fourth of the segment’s length on segments 13–15.

Affinities: This is a member of the brevipennis group. Regarding both the epiproct and cerci, it is closely related to N. taurica Zhiltzova , N. aetolica Zwick and N. brevipennis Martynov , but it differs from them in the hooks of the cercal apex (dorsally sharp, ventrally rounded), and in the relatively large lateral arms of the epiproct. The epiproct also resembles that of N. uncinata Despax , but the cerci are rather different both in the curvature and the cercal hooks. The female cannot be distinguished with certainty from others in the group. The larva is similar to the larvae of the marginata group, but it differs with slender body, scarcer setation and erect, uniformly long marginal row of setae on tergal segments. The larvae of the brevipennis group members are not known except this species.

Ecology and distribution: The species was only found at two small karst torrents in the Prokletije Mountains. One of them is an outlet of a karst spring above 1600 m ( Fig 106 ), the other one is a temporary side torrent in the deep valley of the Sheu River at 270 m. We found the animals after the melting of snow, at the elevation 1600 m at the end of May and at 270 m at the end of April. The insect is apparently rare as we found only a few specimens at both localities, and, despite efforts in similar habitat in the region, no other populations were found.

Etymology: The name asceta means ascetic in Latin. The species is dedicated to Zoltán Barina, Herbarium Carpato–Pannonicum, Department of Botany, HNHM, who hurt his leg at the type locality on the first day of our tour to the Prokletije Mountains, and followed out this rather ascetic tour with a notable wound on his shin. The name also refers to the unfriendly habitat of the species. Used as a noun, gender masculine.

Figures

FIGURES 29 – 34. Male of Nemoura asceta sp. n. – 29: terminalia, ventral view; 30: terminalia, dorsal view; 31: terminalia, lateral view; 32: epiproct, apical view; 33: epiproct, left side dorsal, right side ventral view; 34: pilosity of cercus, ventro – caudal view – scale 0.5 mm, Figs 32 – 34 not to scale.

FIGURES 35 – 36. Female of Nemoura asceta sp. n. – 35: female terminalia, ventral view; 36: vaginal complex – scale 0.5 mm, Fig 38 not to scale

FIGURES 106 – 109. Locus typicus habitat photos — 106: Terthorë Pass – Nemoura asceta sp. n.; 107: Valbonë spring – Leuctra malcor sp. n., Nemoura vinconi sp. n.; 108: Valbonë River – Leuctra mortoni feheri ssp. n.; 109: Shtamë Pass – Nemoura anas sp. n.