Rhopalopsole trichotoma Yang & Du, 2021

Yang, Yu-Ben, Du, Yu-Zhou & Zhu, Bin-Qing, 2021, Two new species of Rhopalopsole (Plecoptera: Leuctridae) from Wuyi Mountains of China, Zootaxa 5071 (1), pp. 143-150 : 146-148

Rhopalopsole trichotoma Yang & Du , sp. nov.

Figs. 5–8 .

Adult habitus. Body length 6.8–7.2 mm, forewing length 6.7–7.1 mm, hindwing length 4.8–5.1 mm (N=3). Head brown, wider than pronotum; ocelli pale brown; antennae and palpi light brown ( Fig. 5A ). Pronotum brown. Legs light brown. Wings hyaline and veins light brown.

Male terminalia. ( Figs. 5B , 6–7 ) Tergum 9 mostly sclerotized but weakly on median area, with a small oval sclerotized process on hind margin. Sternum 9 basally with flabelliform vesicle bearing dense hairs, apically with a rounded triangular subgenital plate. Tergum 10 is bearing a large central plate covered with sensilla basiconica patch in two oval, lightly sclerotized posteromedial areas. Transverse plates roughly triangular with inner section strongly sclerotized. Lateral projections of tergum 10 thin, its long and sinuous process is pointing medially and dorsally. The processes meet each other above the posteromedial portion of the segment. Epiproct thick at base, hook-like, not tapering appreciably along its course, ending in a shallow trilobed process as seen in dorsal view. Subanal lobes of medium size, with weak ventral furrows. Cercus hairy and upcurved, lacks spine.

Female. Unknown.

Type materials. Holotype: ♂, China: Fujian Province, Wuyi Mountains , 303m, 27°39′33″N, 117°57′50″E ( Fig. 8 ), 2021-III-19, leg. Yang Yu-Ben and Zhu Bin-Qing. Paratypes: 2 ♂♂, same data as holotype .

Etymology. The species name refers to the trilobed process at the end of the epiproct.

Diagnosis and remarks. Rhopalopsole trichotoma is a member of the R. dentata group as proposed by Sivec et al. (2008). The new species is most similar to Rhopalopsole wulingensis Sivec & Shimizu, 2008 . The males share the similar shape of subanal lobes, lateral projections and epiproct, but can be distinguished as follows. In R. trichotoma , the edge of tergum 9 is smooth. Tergum 10 is bearing a large central plate with sensilla basiconica patches in two oval areas. However, in R. wulingensis , there is a short bottle-shaped sclerotized plate on hind margin of tergum 9, it bears an upturned arched rib, barely projecting beyond the posterior margin of tergum 9, and there is no obvious oval area on tergum 10.

The new species is also similar to Rhopalopsole duyuzhoui Sivec & Harper, 2008 . They share the similar epiproct and lateral projections.After we checked the holotype and paratypes of R. duyuzhoui , we found that the two species can be distinguished on the basis of a different tergum 10. In R. duyuzhoui , the middle of the central plate is covered with a band of scale-like cuticular ornamentations. However, in R. trichotoma , the central plate is covered with a pair of oval sensilla basiconica patches. We think paired, oval patches of sensilla basiconica are unique to this new species.

Figures

FIGURE 5. Rhopalopsole trichotoma, sp. nov. A. Male head and pronotum, dorsal view; B. Tergum 10, dorsal view.

FIGURE 6. Rhopalopsole trichotoma, sp. nov. A. Male terminalia, dorsal view; B. Male terminalia, lateral view; C. Male terminalia, ventral view.

FIGURE 7. Rhopalopsole trichotoma, sp. nov. A. Male terminalia, dorsal view; B. Male terminalia, ventral view; C. Lateral processes of tergum 10; D. Epiproct, lateral view.

FIGURE 8. Type locality stream of Rhopalopsole trichotoma in Wuyi Mountains, Fujian Province, China.