Mesonemoura aberransterga Du & Zhou

Du, Yu-Zhou, Wang, Zhi-Jie & Zhou, Pei, 2007, Two new species of the genus Mesonemoura and redescription of M. spiroglagellate (Plecoptera: Nemouridae) from China, Zootaxa 1495, pp. 47-52 : 47-49

Mesonemoura aberransterga Du & Zhou , sp. nov.

( Fig. 1–8 )

Adult habitus. Head and pronotum dark brown and equal in width to pronotum; wings subhyaline, brown, veins dark brown. Cervical gills single, short and oval, each one is located outside of lateral cervical sclerite.

4 6 7 8 Male. Forewing length 6.8–8.3 mm, hindwing length 5.6–6.8 mm. Tergum 9 sclerotized and bizarre in shape, middle of posterior and anterior margin extending acutely toward tergum 8, even inserting past posterior margin of tergum 8. Tergum 10 sclerotized, forming a large concave area anterior to base of epiproct, bearing a few hairs anteriomedially; margin of the tergum also extending acutely into tergum 9, reaching to its posterior margin. Cercus longer than wide. Hypoproct broad at base, tapering to a narrow apex, covering part of inner lobes of paraprocts. Paraprocts divided into 3 lobes; inner lobe triangular, slightly sclerotized, and branched at apex; median lobe partially sclerotized, forming a long sclerotized bar without spines, membranous portions broad at base; outer lobe mostly sclerotized, without spines or hairs. Epiproct short and thin; dorsal sclerite narrow; lateral arms darkly sclerotized; ventral sclerite darkly sclerotized, becoming narrower toward apex, bearing a few stout denticles, the apex extended distally, forming a flagelliform sclerotized structure reaching to posterior margin of tergum 8, length of the projection is about two times the length of the epiproct.

Female. Forewing length 8.5–9.0 mm, hindwing length 7.5–8.0 mm. Sternum 8 produced posteriorly, forming two long and flat lobes extending across half of sternum 9, produced area lightly sclerotized; sternum 9 produced posteriorly into lightly sclerotized dome bearing a few hairs on it.

Type material. Holotype male, from Daocheng county to Xiangcheng county (the 149th highway maintenance squad where is 50 km north away from Xiangcheng county), Sichuan province, 4060 m, 12 June 1996, Leg. Du Yu-Zhou. Paratypes 4 m and 4 f, same data as the holotype.

Etymology. The name refers to the bizarre shape of terga 9 & 10, the Latin aberrans meaning to go astray or wander.

Remarks. This new species is similar to Mesonemoura spiroflagellata (Wu) in the shape of epiproct, but distinctly differ in the bizarre shape of terga 9 & 10.

Figures

FIGURES 1 – 8. Mesonemoura aberransterga, sp. nov. 1. Male terminalia, dorsal; 2. Male terminalia, ventral; 3. Male terminalia, lateral; 4. Male paraproct (left); 5. Male epiproct, dorsal; 6. Male epiproct, ventral; 7. Male epiproct, lateral; 8. Female terminalia, ventral.