A new synonym species with description of a new species of Rhopalopsole from China (Plecoptera: Leuctridae)

Abstract Recently, we reviewed the specimens belonging to Rhopalopsole we have collected and compared them with the holotype and paratypes of Rhopalopsole vespertilio Chen & Du, 2017. We found that R. vespertilio should be synonymized with R. xui Yang, Li & Zhu, 2004. Additionally, a new species of the genus Rhopalopsole, R. nanlinga sp. nov. from Guangdong Province of southwestern China, is described and illustrated. The new species is compared to the Rhopalopsole vietnamica west group.


Material and methods
The specimens were collected by hand picking and preserved in 75% ethanol. Morphological details were examined with a Leica MZAPO microscope. Color illustrations were taken with a KEYENCE VHX-5000. All specimens used in this study are deposited in the Insect Collection of Yangzhou University (ICYZU), Jiangsu Province, China. The morphological terminology follows that of Sivec et al. (2008).

Diagnosis
Male (Figures 1 and 2). The three elements of central plates of tergum 10 are broadly fused, plates covered with macrotrichia (Figure 1(c)). Subanal lobes typical of the group. Cerci without a spine. Other characteristics were shown in Figure 1, and described in Yang et al. (2004). Figure 3). Subgenital plate produced into a rounded sclerotized plate medially with a semicircular notch (Figure 3(b)). Yang et al. (2004) did not describe the female of R. xui, and we firstly describe the female of R. xui, we found that R. xui and R. vespertilio share exactly the same subgenital plate (Figure 3; Fig. 11 in Chen & Du 2017). We checked the holotype and paratypes of R. vespertilio from  (Figure 1(c)), additionally, R. vespertilio and R. xui share the same characteristics of tergum 9, lateral projections, epiproct, subanal lobes (Figures 1 and 2). We therefore define R. vespertilio as a synonym of R. xui.
Male (Figures 4 and 5). Tergum 9 mostly sclerotized, somewhat less so on median area with an upturned curved ridge on hind margin, behind which is a small field of cuticular knobs. Sternum 9 basally with flabelliform vesicle bearing dense hairs, apically with a triangular subgenital plate. Tergum 10 bearing a large central plate covered with macrotrichia and lateral bars strongly sclerotized. Transverse plates thin with apically strongly sclerotized. Lateral projections parallel-sided, ending in a small and sharp point. Epiproct thick at base, hook-like, not tapering appreciably along its course, ending in a round point covered with short macrotrichia. Subanal lobes of medium size, flat and plate-like, expanding posteriorly, with ventral furrows, ending in a point. Cercus hairy and upcurved, with a small spine (Figures 4 and 5).

Female. Unknown.
Nymph. Unknown.   This new species is named after the collection place.

Remarks
R. nanlinga is a member of the R. vietnamica west group as proposed by Sivec et al. (2008), with tergum 9 that shows an upturned curved ridge on hind margin, tergum 10 possesses a central plate with lateral bars strongly sclerotized, epiproct simple and thick, subanal lobes and cerci typical of this group (Figure 4). Males of this group are also generally characterized by lateral projections of tergum 10 typically ending in a forked process . The new species share the typical subanal lobes, cerci, epiproct, the tergum 9 possesses some kind of ornamentation the central plate of tergum 10 with lateral bars strongly sclerotized of R. vietnamica west group, however, the lateral projections of tergum 10 of the new species are unique into this group, ending in a small and sharp point, but not ending in a forked process (Figures 4 and 5).