Nemoura tridenticula Li, Wang & Yang

Li, Weihai, Wang, Guoquan & Yang, Ding, 2012, Two new species of Nemoura (Plecoptera: Nemouridae) from China, Zootaxa 3427, pp. 63-68 : 65-67

Nemoura tridenticula Li, Wang & Yang , sp. nov.

( Figs. 8–14 )

Diagnosis. The dorsal sclerite of the epiproct has a pair of lateral and medial processes, of which the lateral ones are basolaterally enlarged in a triangular sclerite in lateral view, distal portion forming a pincer-shaped structure with many tiny spines, medial processes bearing a bifurcate distal process. The outer lobe of the paraproct is laterally distinctly sclerotized, caudal margin concave, basal portion broad with sclerotized rounded lobe, apex forming a blade-shaped process with two dorsolateral subapical teeth.

Male: Forewing length 5.4 mm, hind wing length 4.4 mm. Head dark, compound eyes and mouthparts dark brown, maxillary palpi brownish, antennae dark brown except scape brownish yellow. Thorax dark brown; pronotum trapezoidal with corners bluntly rounded; legs yellowish brown. Wings grayish brown, veins dark. Abdomen including cerci dark brown; hairs on abdomen mostly pale brown.

Terminalia ( Figs. 8-14 ): Tergum eight with darkly sclerotized anterior strip and mid-anterior indentation. Tergum nine weakly sclerotized, anterior margin incised medially and posterior margin fringed with long hairs. Sternum nine with claviform vesicle, basally constricted and anterolaterally sclerotized; hypoproct broad basally, gradually tapering medially toward small tip. Tergum ten mostly sclerotized, with a pair of sclerotized medial lobes anterior to usual concavity beneath epiproct. Cercus darkly sclerotized, with a less sclerotized ventral area subapically, a spots surrounds the wart-like rudiment of segment 2, apical portion upward curved and forming a sharp terminal spine. Epiproct basally quadrate, apical half expanded laterally forming a pincer-shaped structure; the dorsal sclerite with a pair of lateral and medial processes, of which the lateral ones are basolaterally enlarged in a triangular sclerite in lateral view, the distal portion forming a pincer-shaped structure with many tiny spines, each medial process bearing a bifurcate distal process (upper ones with rows of dorsal microtrichia and lower ones each with two distinct ventral spines) extended from sclerotized basal process; ventral sclerite strongly sclerotized, slightly expanded ventrally, bearing one row of tiny spines. Paraproct divided into two lobes: outer lobe laterally distinctly sclerotized, caudal margin concave, basal portion broad with sclerotized rounded lobe, apex forming a blade-shaped process with two dorsolateral subapical teeth; inner lobe slender and slightly sclerotized, basally hidden by the tip of hypoproct, much shorter than outer lobe.

Female: Unknown.

Type Material. Holotype: male, CHINA: Yunnan, 20 km from Dulong River Road, 2100 m, 28.0993 N, 98.3292 E. Xingyue Liu. Paratype: 1 male, same data as holotype.

Distribution. China (Yunnan).

Etymology. The epithet of the species is derived from the Latin “denticulus” which means small tooth, referring to the apical feature of the outer lobe of paraproct.

Remarks. This species is a member of the cercispinosa Complex sensu Baumann (1975). The elongate outer lobe of the paraproct may distinguish the new species from other known recently described species and old species of the genus from China named by Chu (1928) and Wu (1938, 1940, 1962, 1973). It shares a similar outer paraproct lobe with the recently recognized Indonemoura longiplatta Wu (1949) which may result from convergence ( Li and Yang, 2008b). However, similar paraproct structures are also present in N. clavaloba Sivec and Stark, 2010 and N.

tenuiloba Sivec and Stark, 2010 from Vietnam and N. raptoraloba Sivec and Stark, 2010 from Thailand. However, N. tridenticula has the outer lobe of the paraproct lobe enlarged apically, whereas the three above mentioned species have the outer lobe of the paraprocts acute apically ( Sivec and Stark. 2010).

Figures

FIGURES 8 – 14. Nemoura tridenticula Li & Yang, sp. nov. (male). 8. Terminalia, dorsal view. 9. Terminalia, ventral view. 10. Epiproct, dorsal view. 11. Epiproct, lateral view. 12. Right paraproct and cercus, caudal view. 13. Left cercus, ventrolateral view. 14. Right cercus, dorsolateral view.