Nemoura cf. securigera Klapálek, 1907

Li, Weihai, Murányi, Dávid, Pan, Jingjun & Yang, Ding, 2013, New and little known species of Nemouridae (Plecoptera) from Inner Mongolia of China, Zootaxa 3746 (3), pp. 473-480 : 475-478

Nemoura cf. securigera Klapálek, 1907

( Figs. 3–4 )

Nemoura securigera Klapálek, 1907 . Filchner Exped. Zool.-Bot. Ergebn., 10: 63. Type locality: Shaanxi (Tsing Ling), China; Wu 1938. Plecopt. Sin., 185.

Material examined: 2 males (HIST), CHINA: Inner Mongolia, Bayehot, Helanshan Mountain, Shuimogou Gully, 38.5465° N, 105.6576° E, 2011. VIII.9, Weihai Li.

Male terminalia ( Figs. 3-4 ): Hypoproct oval, with a small triangular apex ( Fig. 4 a). Vesicle slightly widened toward tip. Paraproct ( Fig. 4 a): inner lobe slender, as long as outer lobe, outer lobe basally a sloping quadrate lobe, apex triangular. Cercus ( Figs. 3 b & f; 4a & c) long and only slightly curved, strongly sclerotized. Cercal hook large, placed dorsally about midlength of cercus, dorsal edge nearly straight from the hook to the rounded apex; vestigial second segment indistinct, in a membranous rounded apical marking. Tergite IX without prominent spines, slightly sclerotized. Tergite X medially with two diverging ridges under the tip of the epiproct, and bearing distinct, dark coloured pleural projections ( Fig. 4 b & c). These are wing-like with acute posterior tip, bent over the ridges and pointing to the epiproct. Epiproct ( Figs. 3 c & d; 4 b & c) small, contrastive black and white coloured ( Fig. 4 c), subapically dilated and with an apical projection as long as one fourth of the epiproct’s total length. The apical projection is fusing the apical part of spiny prongs and the apico-mesal projection (rostrum). The spiny prongs form the subapical dilatation with a few, small teeth on its medial edge, then projecting as narrow bars on each sides of the rostrum, ending in a small, globular head armed with tiny teeth.

Remarks. Nemoura securigera is known only from the holotype; however, the type is not available (Zwick 1982). Our specimens seem to be conspecific on the basis of characteristic pleural projections of tergite X and the shape of cerci. We report these two specimens as N. cf. securigera because of the large geographical distance between the type locality, Qinling Mountains, Shaanxi, China and Inner Mongolia.

On the basis of the form of the cerci and epiproct, this species should be placed in the N. ovocercia group (sensu Shimizu 1997). It differs from other members of the group by rather elongated spiny prongs, projecting together with the apico-mesal projection of epiproct. In addition, large pleural projections of tergite ten are also distinctive, these are usually lacking or vestigial in case of other members of the group, or spike-like in case of N. dentata Shimizu, 1997 and N. dentifera Shimizu, 1997 ; however, pleural projections also can be found in certain species of other groups (e.g. N. schmidi Aubert, 1967 ).

Figures

FIGURE 3. Nemoura cf. securigera Klapálek, 1907 (male). a. Terminalia, dorsal view. b. Terminalia, lateral view. c. Epiproct, dorsal view. d. Apical part of epiproct, dosral view. e. Pleural projection of tergite X, dorsolateral view. f. Cercus, dorsolateral view. Scale 50 µm.

FIGURE 4. color pattern of Nemoura cf. securigera Klapálek, 1907. a. Male terminalia, ventral view. b. Male terminalia, lateral view. c. Male terminalia, dorsal view.