Nemoura aquila Murányi, 2011

Murányi, Dávid & Park, Sun Jae, 2011, Contribution To The Fall Stonefly (Plecoptera) Fauna Of Korea, Illiesia 7 (6), pp. 70-85 : 76-80

Nemoura aquila Murányi sp. n.

( Fig. 20-29 )

Type material. REPUBLIC OF KOREA: Holotype male: Gangwon Province, Yangyang-gun, Seorak Mts., Hangae-ryeong Pass , 1.5km S of the rest area, brook in deciduous forest, 875m, N38°05.481’ E128°24.267’, 09.09.2010, leg. L á szló Forró, György Makranczy, D á vid Mur á nyi, Sun Jae Park, Jung Do Yoon ( HNHM; epiproct prepared on slide, used for drawings Figs. 20-24 ) . Allotype female: same locality and data ( NIBR; caught in copula with the holotype, used for drawing Fig. 25 ) . Paratype: same locality and data: 1♀ ( HNHM; terminalia prepared on slide, used for drawing Fig. 26 ) .

Diagnosis. Male: Cercus straight and stout with strong apical hook, sclerotization forming an open ring around the prominent vestigial second segment. Paraproct with a pronounced outer tip. Apical sclerites of the epiproct erect, long and slender, tip with four finger-like parts.

Description. Medium sized species, macropterous in both sexes. Body length: ♂ holotype 7.0 mm, ♀ allotype 8.0 mm, paratype 7.5 mm; forewing length: ♂ holotype 6.5 mm, ♀ allotype 8.5 mm, paratype 8.0 mm. Head and basal half of the antenna black, rest of the antenna dark brown, palpi yellowish. Pronotum trapezoidal with rounded corners, dark brown. Legs yellow, distal end of tibiae and tarsal segments darkened. Wings brownish, venation dark brown. Abdomen reddish brown except for terminal segments, which are dark brown.

Male terminalia ( Figs. 20-24 ). Hypoproct rounded, as long as wide, tip short, darker than the rest of the plate. Vesicle more than three times as long as wide. Paraproct: inner margin of the outer lobe slightly convex with a prominence in the distal third, outer margin curved. Apical part of the lobe with a small but pronounced offset outer tip. Inner paraproct lobe yellowish. Cercus straight, stout and strongly sclerotized, being membranous only at the apex around the vestigial segment, and on the inner side. Base slightly wider than the rest of the cerci. Vestigial second segment prominent, placed on the ventral part of the head of cerci, sclerotization forming an open ring around it. Apical hook strong, curved ventrolaterally; the inner tooth forming the ring around the vestigial second segment is downcurved in caudal view. Tergite IX bearing four strong spines dorsomedially, and a medial light area. Tergite X medially bearing two small, diverging ridges under the tip of the epiproct. Epiproct stout, subtrapezoidal. Ventral sclerite narrow, with parallel ridges bearing 12 spines ventrally. Arms of the ventral sclerite forming a wide and strong, heart-shaped ring. Apical sclerites long, relatively slender and erect (directed forward when flattened on slide), their tip slightly bent inward, and hardly separated into four fingerlike parts. Sclerotized parts of the lateral arms dark, long and narrow.

Female terminalia ( Figs. 25-26 ). Pregenital plate small, its width is half the width of sternite VII, overhanging the whole length of sternite VIII. Posterior edge rounded, most of the plate dark brown but lateral edges light. Sternite VIII with brown patches laterally. Vaginal complex with membranous receptaculum seminis bearing two small, elongate lateral sclerites, and with slightly sclerotized edges of the narrowing central section. Cerci, epiproct and paraprocts normal, dark brown. Larva. unknown.

Affinities. The species cannot be placed into an existing species group. It appears closely related to N. ussuriensis Zhiltzova 1997 (in Teslenko & Zhiltzova 1997), N. espera Ham & Lee 1999 and N. tripotini Zwick 2010 . The male differs from these species by the erect and relatively slender apical sclerites of the epiproct, ending in finger-like parts that bear no spines, by the pronounced outer tip of the paraprocts, and by the more strongly sclerotized head of cerci, with the inner tooth forming a ring around the vestigial segment. The ventral sclerite of the epiproct also distinguishes N. aquila from N. ussuriensis and N. espera , being narrow and armed with numerous spines in the new species. The female cannot be distinguished with certainty from the other Far East Nemoura .

Geographical distribution and ecology ( Figs. 27-29 ). The species was found at a single locality in the Seorak Mts. in September. All three specimens were fully pigmented, and the holotype male was found in copula with the allotype female. The type locality is a small (width 0.5-1 m) forest brook with cold water and gravel substrate mixed with a few sandy patches. The section where the specimens were caught has moderately fast flow, while most of the brook has fast flow in a steep bed. Specimens were found associated with adults of A. steinmanni , N. geei Wu 1929 and adults and larva of D. asiatica Zwick 2010 ( Table 1 ).

Etymology. The name aquila (meaning eagle in Latin) refers to the shape of the cerci that look like eagle heads. This method of naming is frequently used in the genus (e.g. N. avicularis Morton , N. sciurus Aubert and N. anas Mur á nyi). Used as a noun, gender feminine.

Figures

Figs. 20-26. Terminalia of the adult of Nemoura aquila Murányi. 20: male terminalia, dorsal view; 21: male terminalia, ventral view; 22: male terminalia, lateral view; 23: male epiproct, left side dorsal, right side ventral view; 24: head of male cerci, ventrocaudal and caudal views; 25: female terminalia, ventral view; 26: vaginal complex (scale a 0.5 mm (for Figs. 20-22, 25), scales b-d 0.1 mm).

Figs. 27-29. Type locality of Nemoura aquila Murányi and the distribution of the Korean endemics included in this paper. 27: type locality: Seorak Mts., Hangae-ryeong Pass; 28: substrate of the type locality brook; 29: known occurrences of Protonemura villosa Ham & Lee 1999 (■), Despaxia asiatica Zwick 2010 and N. aquila Murányi (○), and D. asiatica (●) (dark grey areas are above 500 m).