Nemoura longistyla Zhao, Rehman & Du, 2023

Zhao, Meng-Yuan, Rehman, Abdur & Du, Yu-Zhou, 2023, New species of Illiesonemoura and Nemoura (Plecoptera: Nemouridae) from Yunnan Province of southern China, Zootaxa 5249 (4), pp. 477-484 : 480-483

Nemoura longistyla Zhao, Rehman & Du , sp. nov.

Type material: Holotype, 1♁, China, Yunnan Province, Yunlong County, Daoren Mountain , 2265m, N 28.7813 E 99.2575, 2009-VI-3, leg. Qian Yu-Han ( ICYZU) . Paratype, 1♀, the same data as the holotype ( ICYZU) .

Adult habitus: Head and antennae brown, pronotum dark brown, rectangular in shape, angle blunt rounded ( Figs. 5A–5B ). Wings hyaline, veins brown. Legs are slightly brown, and the joints of legs are brownish.

Male: Forewing length 7.1 mm, hind wing length 6.0 mm. Tergum 9 sclerotized, anterior margin darkly sclerotized, concaved at median of anterior margin. Tergum 10 typically sclerotized, with a membranous area below the epiproct, bearing small spines laterally ( Figs. 6A, 6C ). Hypoproct broad basally, with finger-like tip; vesicle long and broad, half-length of hypoproct, length 2 × width. Paraprocts are divided into 2 lobes; inner lobe slightly sclerotized, slender; outer lobe sclerotized, the outer edge is darkly sclerotized, broad basally, narrower to apex, forming a darkly sclerotized pointed tip ( Figs. 6B , 7B ). Epiproct oval-shape, with pair of sclerotized stripes medially, forming long oval shape projection extending forward, projection slightly shorter than epiproct, forming sclerotized annulus medially, with pair of small projections on the lateral side in the middle, bearing 3 small teeth on the tip of each small projection ( Figs. 6A , 7A ); ventral sclerite sclerotized, forming pair of ridges, broad basally, with small spines ventrally ( Fig. 6C ). Cerci sclerotized ventrally, membranous dorsally, with a rounded tip ( Figs. 6A–6B, 6D , 7A–7C ).

Female: Females share a similar pattern and coloration to males ( Figs. 8A–8B ). Forewing length 7.5 mm, hind wing length 6.2 mm. Sternum 7 with a sclerotized pregenital plate, darker bilaterally and overlapping nearly half of sternum 8. Sternum 8 forms two vaginal lobes at each lateral side ( Fig. 9A ). Sternum 9 with a distinct mid-anterior projection, extending to almost half of sternum 8 ( Figs. 9A–9B ). Paraprocts and cerci are brownish ( Fig. 9A ).

Etymology: The Latin “ longistyla ” meaning long protrusions, refers to epiproct forming long protrusions on the median of the apex.

Remarks: The new species belongs to Nemoura ovocercia species group. The male of N. longistyla sp. nov. appears most similar to N. geei Wu, 1938 . The epiproct of both species have a pair of projections, but in N. geei , the projections are long, half-length of the median long projection (see fig. 41–42 in Shimizu, 1997), while the membranous projection in N. longistyla sp. nov. is much shorter. Additionally, the tip of the cerci in N. geei forms a hook, while the new species has a rounded tip ( Fig. 6A ). The new species is also close to other N. ovocercia group species, including like N. quadrituberata Shimizu, 1997 , N. longilobata Shimizu, 1997 , and N. babai Kawai, 1966 . Tergum 10 of N. quadrituberata forms two pairs of protuberances and expanded upward to a knob-like projection (see figs. 43–44 in Shimizu, 1997), while new species have no projection. The epiproct of N. longilobata and N. babai are membranous and lacking lateral projections (see fig. 34 in Shimizu, 1997) while the new species epiproct is oval in shape and lateral projection in the epiproct have well-developed three teeth on the tip of projection ( Figs. 6–7 ). The cerci of new species are also different from both species, which easily differ the new species.

Figures

FIGURE 5. Nemoura longistyla Zhao, Rehman & Du, sp. nov. Male, A: head and pronotum, dorsal view; B: head and cervical region, ventral view.

FIGURE 6. Nemoura longistyla Zhao, Rehman & Du sp. nov. Male terminalia, A: dorsal view; B: ventral view; C: lateral view; D: epiproct, dorsal view. T9: tergum 9, T10: Tergum 10, ep: epiproct, opl: outer paraproct lobe, ipl: inner paraproct lobe, ce: cerci, ve: vesicle.

FIGURE 7. Nemoura longistyla Zhao, Rehman & Du sp. nov. Male, A: terminalia, dorsal view; B: terminalia, ventral view; C: terminalia, lateral view.

FIGURE 8. Nemoura longistyla Zhao, Rehman & Du, sp. nov. Female, A: head and pronotum, dorsal view; B: head and cervical region, ventral view.

FIGURE 9. Nemoura longistyla Zhao, Rehman & Du, sp. nov. Female abdomen, A: terminalia, ventral view; B: pregenital plate and vaginal lobes, ventral view.