Isoperla qinlinga Chen, 2019

Chen, Zhi-Teng, Song, Liang-Dong & Feng, Wen-Tao, 2019, A new species of Isoperla (Plecoptera: Perlodidae) from the Qinling Mountains of northwestern China and notes on the Chinese species of the genus, Zootaxa 4651 (2), pp. 379-391 : 387-390

publication ID	https://doi.org/ 10.11646/zootaxa.4651.2.11
publication LSID	lsid:zoobank.org:pub:459C44D9-55A5-4FD3-8245-8C08E2DC2631
persistent identifier	https://treatment.plazi.org/id/03B187CB-7022-FFD5-CB89-FF05FC2632A8
treatment provided by	Plazi
scientific name	Isoperla qinlinga Chen
status	sp. nov.

Treatment

Isoperla qinlinga Chen View in CoL , sp. nov.

Figs. 2–8 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 .

Adult habitus ( Figs. 2 View FIGURE 2 , 6 View FIGURE 6 , 7B View FIGURE 7 ). Body generally reddish to dark brown. Head mostly covered by a brown stigma, anterior and posterolateral areas pale; tentorial callosities and M-line distinct. Triocellate, anterior ocellus slightly smaller than posterior ones; compound eyes small rounded. Antennae slender, generally dark brown, basal segments pale, subequal in length to the body. Maxillary palps slender, four-segmented with a strongly reduced apical segment; labial palps shorter, three-segmented with a strongly reduced apical segment. Pronotum sub-rectangular with angled corners, anterior margin arched; most part of pronotum rugose and dark brown, lateral margins pale. Meso- and metanota reddish-yellow with dark sclerites; meso- and metabasisterna with pale lateral stripes. Macropterous; wings pale yellow, veins brown. Legs generally yellow, apex of femur and base of tibia dark; two tibial spurs present. Abdominal segments generally yellow to pale brown. Cerci slender, length subequal to the abdomen, generally yellow but the three apical segments dark brown.

Male ( Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 ). Body length ca. 11.0 mm; forewings length ca. 12.0 mm, hindwings length ca. 9.0 mm. In the forewing, seven crossveins present between C and Sc; two extra crossveins present beyond Sc; RP with three branches; CuA with five branches; AA1 simple, AA2forked. In the hind wing, six crossveins present between C and Sc; two extra crossveins present beyond Sc; RP with three branches; anal area large and folded with eight anal branches.

Abdominal terga 1–9 with paired, brown median spots. Tergum 10 unmodified, posterior margin subtriangular. Paraprocts slender, hook-shaped and upcurved, apices red and pointed. Vesicle less developed, reduced into a subtriangular patch of short hairs, slighlt exceeding posterior margin of sternum 8. Sternum 9 broadly produced, expanded backwards with a subtriangular apex, inserting into base of the extruded aedeagus. Everted aedeagus oval in shape, spinulose, venral aspect with a Y-shaped lobe, the lobe with thickened arms and stem, the stem extended into dorsum of sternum 9; lateral areas of the Y-shaped lobe covered with unconspicuous scales, posterior of the lobe with a subtriangular patch of scales; dorsal aspect of the aedeagus with a large, rugose, apple-shaped lobe, which is covered with very unconspicuous scales.

Female ( Fig. 6 View FIGURE 6 ). Body length ca. 14.0 mm; forewings length ca. 14.0 mm, hindwings length ca. 12.0 mm. General color pattern similar to males; tibiae dark brown; posteromedial margin of each tergum with obscure brown marks; posterior margin of each sternum dark brown. Tergum 10 similar to males. Subgenital plate broad, slightly produced with rounded posterior margin. Paraprocts strongly sclerotized and long triangular.

Ova Unknown.

Type material. Holotype male, China: Shaanxi Province, Xi’an City, Qinling Mountains, Taiping National Forest Park , on handrail near a fast-flowing stream ( Fig. 7A View FIGURE 7 ), 900–1100 m, 33°59′18″N, 108°59′52″E, 28 April 2019, leg. Zhi-Teng Chen & Liang-Dong Song (ICJUST) GoogleMaps . Paratype: 12 males and 9 females, same locality and data as holotype GoogleMaps ; 1 male and 1 female, China: Shaanxi Province, Xi’an City, Qinling Mountains, Cuihuashan National Geopark , a fast-flowing stream ( Fig. 8 View FIGURE 8 ), 1000–1200 m, 33°58′45″N, 108°59′45″E, 29 April 2019, leg. Zhi-Teng Chen (ICJUST) GoogleMaps .

Etymology. The species is named for its type locality in the Qinling Mountains.

Remarks. When compared to the above species, the reduced male vesicle of the new species only resembles the recently described I. oncocauda . However, I. qinlinga can be distinguished from I. oncocauda by the generally reddish abdomen when alive, the absence of posteromedial process on tergum 10, the modified dorsal and ventral aedeagal lobes, and the less developed subgenital plate in female (see figs. 5–16 in Huo & Du 2018). Another Chinese species with a reduced male vesicle is I. neimongolica , whose vesicle is obsolescent. However, the mostly pale head, pale pronotum and dorsally dark femora and tibiae of I. neimongolica (original description in Chinese, Yang & Yang 1996) can be separated from the color pattern of I. qinlinga ( Fig. 2 View FIGURE 2 ). When compared with other known Isoperla females from China, the slightly developed rounded subgenital plate of I. qinlinga is only similar to that of I. eximia (see fig. 220 in Teslenko & Zhiltzova 2009), but the two species can be easily distinguished by the vesicle and aedeagus in males. When compared with the East Palaearctic congeners ( Inada 1996, Zwick & Surenkhorloo 2005, Teslenko & Zhiltzova 2009, Judson & Nelson 2012, Teslenko & Khamenkova 2017), the combination of the following characters is also diagnostic for I. qinlinga : head and pronotum mostly dark without banded patterns; vesicle reduced into a triangular hair patch; aedeagus membranous, lacking sclerites.

In the nine plausible Chinese species of Isoperla including the new species in this study, eight species have relatively detailed male descriptions ( Table 1 View TABLE 1 ). However, in almost all older Isoperla species from China, the color patterns of the head and pronotum, the everted aedeagus and eggs have not been described and illustrated adequately as those from the Nearctic and north Palearctic regions ( Zwick & Surenkhorloo 2005, Teslenko & Zhiltzova 2009, Murányi 2011, Judson & Nelson 2012, Szczytko & Kondratieff 2015), which should be supplemented in future works. Finally, according to the recorded localities of known Isoperla species from China, this genus is expected to have a wide distribution in northern two-thirds of mainland China ( Fig. 9 View FIGURE 9 ).