Nemoura rugosa, Zwick, 2010

Zwick, Peter, 2010, New Species And New Records Of Plecoptera From Korea And The Russian Far East, Illiesia 6 (9), pp. 75-97 : 85-86

Nemoura rugosa sp. n.

(Figs. 20-25)

Material examined. ♂ holotype, 6♂ paratypes: REPUBLIC OF KOREA: Gangwondo , Pyeongchang , Yongpyeong-Myeon , Nodong-li, Nodong valley, Alt. 900m, 5.-16-VI. 2006, 37°42.08’N 128°28.89'E, 3 Malaise traps in forest in shade .

Adult habitus. A normal-looking Nemoura without pattern or other distinctive traits, except the genitalia. The present males are fully pigmented, with black head and pronotum. The slightly infuscate fore wings are 7.2-7.9 mm long.

Male. The paraproct is apically deeply excised, ending in two sclerotized acute tips. The slender cerci are in dorsoventral views almost straight, with a large membraneous apex (Figs. 20, 21). In side view (Fig. 22) the slender distal part stands at an angle to the wide base. The outer apical spine is double, the median one single, a little upcurved. In caudal view of the cercus tip, the sclerotized cap is almost horizontally placed over the pale unsclerotized end of cercus with the inconspicuous terminal wart (Fig. 23).

The epiproct is elongate oval (Fig. 24). Its looped sclerite joins the longitudinal spine-bearing sclerite at a right angle. The wide apical sclerite (Fig. 25) lies almost flat in the frontal plane and does not change appearance when slide-mounted. It has a blunt nose on the outside. The anterior edge bears coarse scales and is rough. On the ventral face of the apical sclerite are 2-3 strong outwardly directed spines. The ventral longitudinal sclerites bear several spines, the first points forward, the other backward, as usual.

Female. Not known.

Diagnosis. The wide flat-lying apical sclerite of epiproct reminds one of N. arctica . However, the sclerite of N. arctica is transverse and along its outer edge armed with some short strong spines (see Lillehammer 1988, fig. 172), the anterior edge is not rough. Other Korean species with bifid paraprocts and two outer cercus teeth differ strikingly in the epiproct.

Etymology. The specific name alludes to the rough (Lat. rugosa) surface of the apical epiproct sclerite.