Mesonemoura longiflagellata Xiao & Qian, 2019

Xiao, Qian, Zhao, Jing, Qian, Yu-Han & Du, Yu-Zhou, 2019, Two new species of Mesonemoura (Plecoptera: Nemouridae) from Yunnan Province of China, Zootaxa 4565 (4), pp. 531-538 : 531-533

Mesonemoura longiflagellata Xiao & Qian sp. nov.

Figs. 1–10

Adult habitus. General color dark brown. Head dark brown to black, antennae dark brown, palpi brown. Thorax

dark brown, pronotum trapezoid, wider than long, rugosities scattered. Legs dark brown, femora and tibiae with a yellowish band. Wings light brown, veins dark brown. Abdomen brown, terminal segments dark brown ( Fig. 1 ).

Male terminalia. Terga 1–7 sclerotized of the anterior area. Tergite 8 anteriorly sclerotized. Sterna 1–8 mostly membranous, laterally sometimes speckled. Tergite 9 sclerotized laterally and anteriorly, medially membranous, tiny bristles at the junction of the membranous and sclerotized area ( Figs. 2 , 6 ). Hypoproct of sternite 9 broad basally, abruptly tapering toward the apex, apically blunt; vesicle elliptical and slender, medially membranous ( Fig. 3 ). Tergite 10 strongly sclerotized, medially membranous with sparse tiny bristles laterally of membranous area anteriorly of tergite 10 ( Figs. 2, 5 6, 8 ). Epiproct slender, basally and marginally sclerotized, median portion membranous. Flagellum dark brown, long and broad basally, tapering slightly towards the apex, curved in dorsal view, tip blunt and membranous in dorsal and lateral view ( Figs. 2, 5 , 6, 7 ). Paraproct with 3 lobes: inner lobe sclerotized, apex bifurcate and pointed of the same length; median lobe consists of two parts, inside portion strongly sclerotized with tip with a row of tiny spines, outside portion membranous, shorter than inside portion and with many hairs, connected with outer lobe; outer lobe slender, entirely sclerotized, basal recurved along the cerci, tip blunt. ( Figs. 3 , 9 ). Cerci cylindrical, bearing many hairs, slightly bent inwards ( Figs. 2, 3, 5 , 6 ).

Female terminalia. Pregenital plate on sternite 7 appears as an inverted triangle, posteriorly reaching anterior margin of sternite 8. Sternite 8 with sclerotized subgenital plate, semicircular and deeply indented in the middle. A pair of symmetrical arc-shaped lateral sclerites, a part under the middle of subgenital plate, and the other part stretches out the subgenital plate and reach the posterior margin of sternite 8. Sternite 9 sclerotized posteriorly and medially with indented membranous area. ( Fig. 4 , 10 ).

Material examined. Holotype male, CHINA: Yunnan Province, Shangri-la City, Pudacuo National Park , 27°52’17” N, 99°54’26” E, 3879 m, 11 September 2017, Leg. Qian Xiao, Yu-Han Qian, Jia-Hao Chen . Paratypes: 3 males and 5 females, same data as holotype ( ICSFU) . 3 males and 2 females, CHINA: Yunnan Province, Shangrila City, Baima Snow Mountain Nature Reserve , 28°18’33” N, 99°8’9” E, 3514 m, 18 July 2017, Leg. Yu-Han Qian, Qian Xiao, Ming-Xue Xie, Jia-Hao Chen, Jin-Long Wei .

Etymology. The Latin name “ longiflagellata ” means with a long flagellum, referring to the distinctly long flagellum of the epiproct.

Remarks. The new species is apparently closely related to M. sbordonii Fochetti & Sezzi, 2000 from Yunnan Province of China, M. spiroflagellata ( Wu, 1973) and M. sichuanensis Du & Ji, 2015 from Sichuan Province of China, M. tritaenia Li & Yang, 2007 from Henan Province of China. The male and female of M. longiflagellata can be distinguished from the M. sbordonii by the long flagellum without a forked tip and the pregenital plate of female not reaching sternite 9, and the semicircular subgenital plate with a pair of symmetrical arc-shaped lateral sclerites. Additionally, the male paraproct and the female pregenital plate of the new species differ from M. spiroflagellata and M. tritaenia . Mesonemoura longiflagellata also has a row of tiny spines on the tip of the median lobe of paraproct differing from M. sichuanensis .

Figures

FIGURE 1. Mesonemoura longiflagellata sp. nov. 1. Female and Male habitus, dorsal view.

FIGURES 2–5. Mesonemoura longiflagellata sp. nov. 2. Male terminalia, dorsal view. 3. Male terminalia, ventral view. 4. Female terminalia, ventral view. 5. Male terminalia, lateral view.

FIGURES 6–10. Mesonemoura longiflagellata sp. nov. 6. Male terminalia, dorsal view. 7. Male epiproct, lateral view. 8. Male T10, dorsal view. 9. Male right paraproct, caudal view. 10. Female terminalia, ventral view.