Nemoura taihangshana, Wang, Hongliang, Li, Weihai & Yang, Ding, 2013

Wang, Hongliang, Li, Weihai & Yang, Ding, 2013, Species of the family Nemouridae (Plecoptera) from Taihang Mountains of Northern China, with description of Nemoura taihangshana sp. n., Zootaxa 3637 (5), pp. 561-568 : 562-566

Nemoura taihangshana sp. nov.

( Figs. 1–17 )

Adult habitus. Head brown with occiput brownish, compound eyes dark, antennae and mouthparts brown, maxillary palpi yellowish brown. Thorax mostly brown, pronotum brownish, nearly rectangular, surface with brown lateral and irregular median rugosities, corners obtuse ( Fig. 11 ); legs brown. Wings subhyaline, veins dark brown. Abdomen brown; hairs on abdomen mostly pale.

Male: Forewing length 5.0–5.4mm, hind wing length 4.2–4.5 mm. Terminalia ( Figs. 1–10 , 12–16 ): Tergum 8 constricted medially, mostly sclerotized, posterior margin membranous medially. Tergum 9 with broad anterior indentation, medially membranous next to sclerotized anterior margin, with 2–4 pairs of paramedial spines along posterior margin ( Figs. 1 , 12 ). Tergum 10 sclerotized, a narrow longitudinal concavity present anterior to base of epiproct, many spinules located along anterior margins of the concavity. Cercus mostly sclerotized ( Figs. 9 , 14 ), with a mesoventral swelling ( Figs. 3–4 ) and a large down-curved apical cercal spine, the spine forming a large hook in dorsal view ( Fig. 1 ). Epiproct ( Figs. 5–8 ) short, nearly rectangular basally and with a triangular tip; dorsal sclerite with a pair of darkly sclerotized, medial sclerites extended toward apex along lateral margins, ending in a large and a smaller apical spines ( Figs. 8 , 16 ); ventral sclerite strongly sclerotized, fringed with a row of tiny spines (ca. 26–30) medially ( Fig. 16 ); lateral knob ( Fig. 10 ) large, covered with spinules. Vesicle on sternum 9 claviform slightly constricted subapically; hypoproct broad and rounded basally, gradually narrowing medially toward triangular apex ( Fig. 2 ). Paraproct ( Figs. 4 , 15 ) outer lobe sclerotized and basally subquadrate, apex bearing a tubular process and neighboring large hook; inner lobe typical, slightly shorter than outer lobe.

Female ( Fig. 17 ): Pregenital plate on sternum 7 with slightly sclerotized, large quadrate expansion, overlapping anterior margin of sternum 9. Posterolateral corners of the plate slightly humped. Cercus membranous.

Type Material. Holotype: male, CHINA: Henan Province, Huixian County, Mt. Wanxianshan of Taihangshan mountain range, 1000 m, 35°72.80’ N, 113°62.55’ E, 30. III. 2012, coll. X.P. Li. Paratypes: 12 males, 3 females, the same locality and data as holotype.

Distribution. China (Henan).

Etymology. The species is named after the Taihang Mountains.

Diagnosis. Nemoura taihangshana is easily recognized by a large down-curved apical cercal spine which forms a large apical hook in dorsal view. Its epiproct is nearly rectangular and has a triangular tip; dorsal sclerite has a pair of darkly sclerotized, medial sclerites extended toward apex along lateral margins, ending in a large and a smaller apical spines. Paraproct ( Figs. 4 , 16 ) outer lobe bears a tubular process and neighboring large hook apically.

A large hook on the tip of paraproct outer lobe is similar to those found in N. stellata Li and Yang, 2008a from Sichuan, N. mesospina Li and Yang, 2008a from Tibet, and the recently described species, N. baiyunshana Li, Wang & Yang, 2012 from Henan and N. bidentata Wang and Du, 2008 from Xinjiang. However, the hook of N. stellata appears spoon-shaped with a beak-like apex, and the cercal apex of N. mesospina is swollen and spherical.

The structure of the epiproct allies N. taihangshana to a group of species including N. ovocercia Kawai, 1960 as indicated by Shimizu (1997). Nemoura baiyunshana and N. bidentata both have an epiproct similar to that of N. taihangshana , but details of the cercal apex easily distinguishes the new species. The cerci of N. baiyunshana have an out curved subapical spine and a tiny proximal apical spine ( Figs. 2 , 6 & 7 in Li et al. 2012) and N. bidentata has a large sclerotized spine curving outward at apex ( Figs. 1 & 2 in Wang and Du. 2008), whereas N. taihangshana has a large down-curved apical cercal spine ( Fig. 9 ).

Figures

FIGURES 1 – 4. Nemoura taihangshana sp. nov. (male). 1. Terminalia, dorsal view. 2. Terminalia, ventral view. 3. Terminalia, lateral view. 4. Paraproct with cercus, caudal view.

FIGURES 5 – 10. Nemoura taihangshana sp. nov. (male) 5. Epiproct, dorsal view. 6. Epiproct, lateral view. 7. Apical half of epiproct, lateral view. 8. Apex of epiproct, lateral view. 9. Left cercus, top view. 10. Lateral knob, lateral view.

FIGURES 11 – 16. Nemoura taihangshana sp. nov. (male). 11. Pronotum, dorsal view. 12. Terminalia, dorsal view. 13. Epiproct, lateral view. 14. Left and right cerci, slightly oblique caudal view (same view). 15. Paraproct, slightly oblique caudal view. (Note that fully relaxed specimens may have a different appearance from those that have been prepared for SEM, especially for the cerci in dorsal view which is oriented differently from Fig. 1)

FIGURES 16 – 17. Nemoura taihangshana sp. nov. 16. Male epiproct, dorsal (left) and ventral views. 17. Female terminalia, ventral view.