Nemoura jixiangwangi Yang & Li, 2022

Yan, Yanhua, Ma, Cunxin, Yang, Ding & Li, Weihai, 2022, Species of Nemoura (Plecoptera: Nemouridae) from Qinghai, China, Zootaxa 5168 (4), pp. 485-493 : 486

Nemoura jixiangwangi Yang & Li , sp. nov.

( Figs. 1–3 )

Adult habitus. Head brown to dark brown; antennae, mouthparts and palpi lighter than head; compound eyes black. Pronotum brown to dark brown, rectangular, anterior corners obtuse and posterior ones nearly right-angled. Legs generally brownish but femora darker; wing membranes pale to brownish with darker veins. Abdominal segments brown with paler hairs.

Male ( Figs. 1–2 ). Forewing length 6.0 mm (n=3), hindwing length 5.0 mm. Tergum 9 sclerotized, anterior margin with a wide, shallow medial incision, posterior margin without spines or long hairs. Sternum 9 ( Figs. 1b , 2b ) with oval-shaped vesicle, length ca. 1.3X maximum width, lacks clothing hairs; hypoproct basally broad and rectangular, gradually tapering towards short, triangular apex. Tergum 10 ( Figs. 1a , 2a ) darkly sclerotized except the narrow, longitudinal, medial concavity beneath epiproct; anterolateral part of the concavity bears many tiny black spines. Cercus long and distinctly sclerotized except for inner portion and center of apex, generally parallelsided posterior to wider base and before enlarged apex, erect in lateral view. Apex with a strong ventrolateral hook pointing caudally, and a rounded intralateral bulb; vestigial second segment located on distal extreme of cercal head, surrounded by an open membranous ring ( Figs. 1a–e , 2a–c ). Epiproct ( Figs. 1a, c, f , 2a, d–e ): subrectangular, with widened apical half and abruptly narrowed, triangular apex; nearly 2X longer than maximum width. Ventral sclerite heavily sclerotized, forming large lateral knobs at basolateral corners, with 7–8 ventral spines on the narrow parallel ridges; the ridges are distinctly diverging towards the apical sclerites. Arms of ventral sclerite forming an incomplete, relatively short and thin ring in dorsal view. Apical sclerites large, extend along apicolateral margin of the epiproct and joined with apical lobes of the ring, bearing 2–4 stout lateral spines. Heavily sclerotized lateral arms slender and short, extend along lower surface of elevated medial hump ( Fig. 2c–d ). Paraproct ( Fig. 2b ): outer lobe short and subquadrate, outer margin strongly sclerotized, apex narrower and slightly bilobed but the recessed edge is obscure in one paratype; inner lobe short and well sclerotized, narrow at base and then slightly swollen towards obtusely triangular apex.

Female ( Fig. 3 ). Forewing length 6.9 mm (n=1), hindwing length 5.9 mm. Pregenital plate trapezoidal, its apical width is one third the width and over half the length of sternum 8. Posterior margin nearly truncate, the overhanging part dark brown. A pair of lateral brown markings present on sternum 8 ( Figs. 3a–b ), but poorly delimited after being cleared. Sternum 9 moderately sclerotized, anterior edge nearly straight. Vaginal complex ( Figs. 3c–d ) with membranous spermatheca bearing two wrinkled lateral pockets; medially depressed and posteriorly divergent with two slender bifurcations.

Type material. Holotype male ( HIST): China: Qinghai Province, Haibei Tibetan Autonomous Prefecture, Menyuan County, Xianmi Township , Deqian Village , 3001 m, 37.2180º N, 102.2098º E, 2.VII.2021, leg. Weihai Li. Paratypes: 1 male ( HIST): same village and date as holotype, 3110 m, 37.2180º N, 102.2098º E, leg. Wei Zeng ; 2 males and 1 female ( HIST): Qinghai Province, Haibei Tibetan Autonomous Prefecture, Qilian County, Yeniugou Township , Dayu Village , 3308 m, 38.4096º N, 99.5498º E, 11.VII.2021, leg. Weihai Li, Haoming Zang, Cong Li.

Etymology. The epithet refers to Mr. Jixiang Wang, who guided us to these far and hardly accessible villages.

Distribution and ecology ( Figs. 4a–b ). China (Qinghai Province). The types are known only from two sites of the Qilian Mountain National Park. They were collected in headwater of two small creeks with stony substrate over 3000 m above sea level, and one male paratype was caught by sweeping the alpine meadows near a creek in Deqian Village.

Remarks. On the basis of the epiproct’s large apical sclerite and lobed ring, and the strong apical hook of the cerci, the new species seems to be related to the Nemoura brevipennis group sensu Murányi (2007). This group is the most diverse in the Caucasus and Anatolia, and the epiproct of N. jixiangwangi is most similar to N. taurica Zhiltzova 1967 , known from Greece, Crimea and Turkey. N. jixiangwangi can be separated from that species by larger lateral arm of the epiproct and more robust cercus. The male of N. jixiangwangi is also reminiscent of the Central Asian N. alaica Zhiltzova, 1976 , especially in the shape of paraproct and cercus, but differs in the epiproct and the apex of the cercus. Some Far East species like N. aquila Murányi, 2011 (in: Murányi & Park 2011), N. rugosa Zwick, 2010 , N. sirotskii Teslenko, 2018 (in: Teslenko & Boumans 2018) and N. tripotini Zwick, 2010 are superficially similar to the new species, but all differ with much narrow apical sclerite and ring lobe complex of the epiproct. There is no known Chinese species that can be closely related. The trapezoidal female pregenital plate of N. jixiangwangi is similar to that of the females of the brevipennis group, but its characters do not allow distinction at the specific level.

Figures

FIGURE 1. Nemoura jixiangwangi sp. nov. (male, a–e: paratype; f: holotype). A. Cleared terminalia, dorsal view. B. Cleared terminalia, ventral view. C. Cleared terminalia, showing cerci and epiproct in dorsocaudal view. D. Cerci and paraproct before NaOH treatment, ventrocaudal view. E. Cleared terminalia, showing oblique lateral view of cerci and epiproct. F. Cleared epiproct, ventral view.

FIGURE 2. Nemoura jixiangwangi sp. nov. (holotype male). A. Terminalia, dorsal, view. B. Terminalia, ventral view. C. Terminalia, lateral view. D. Cleared epiproct, dorsal view. E. Cleared epiproct, ventral view.

FIGURE 3. Nemoura jixiangwangi sp. nov. (female paratype). A. Terminalia, ventral view. B. Cleared pregential plate, ventral view. C. Cleared vagina, dorsal view. D. Cleared vagina, lateral view.

FIGURE 4. Nemoura habitats in Qinghai, China. A. Habitat of Nemoura jixiangwangi sp. nov. and Nemoura securigera Klapálek, 1907: Deqian Village. B. Habitat of Nemoura jixiangwangi sp. nov.: Dayu Village. C. Habitat of Nemoura geei Wu, 1929 and Nemoura papilla Okamoto, 1922: Sigou. D. Habitat of Nemoura papilla Okamoto, 1922: Huzhu County, Weibei Highway. E–F. Habitat of Nemoura securigera Klapálek, 1907: Qihankaigou (Qihankai valley), main river and sidestream.