Swelsta bicurvata Li, W.L. & Li, W.H., 2021

Li, Wenliang, Wang, Yingying, Li, Weihai & Li, Mengyu, 2021, Two new species of Sweltsa (Plecoptera: Chloroperlidae) from China, Zootaxa 5057 (1), pp. 145-150 : 145-146

Swelsta bicurvata Li, W.L. & Li, W.H. , sp. nov.

( Figs. 1a, 1c–1e & 2 )

Adult habitus ( Figs. 1a, 1e ). General body color pale in ethanol. Head with a large, rectangular median dark brown marking covering ocellar area and frons; compound eyes dark, ocelli with dark rings, anterior ocellus paler; antennae pale, distal flagella slightly darker ( Fig. 1a ). Pronotum with dark brown medial portion narrowly surrounded by elongate rugosities, rugosities with a paler background, and wide, pale lateral margins. Wing membrane transparent; legs pale. Abdominal tergum 1 with anterior and lateral margins brown, terga 2–7 with a wide median stripe, stripe generally yellow brown but darker from tergum 5, posteromedial portion of terga 6–7 darker brown. Cerci 6- segmented. Setae of dorsal surfaces and inner margins of segments 1–3 are of subequal length, and longer than the length of each segment; distal setae of segments 4–6 longer than the basal setae of each segment. ( Fig. 1e ).

Male ( Figs. 1c–1e & 2 ). Forewing length 8.1 mm; hindwing length 6.7 mm. Tergum 9: transverse ridge strongly sclerotized and band-shaped in dorsal aspect, the ridge elevated and triangular in lateral aspect ( Fig. 1e ). Epiproct long, parallel-sided for most its length with narrower apex in dorsal aspects; in lateral aspect, epiproct recurved and S-shaped, nearly parallel-sided in outline and slightly widened apically ( Figs. 1c–1d & 2 ).

Female. Unknown.

Type Material. Holotype: male ( CAU), CHINA: Zhejiang Province, Longquan City, Fengyangshan , N 27°53.52’, E 119°9.95’, 1450 m, malaise trap, 2007.VII.3, Yajun Zhu.

Etymology. The specific name refers to the lateral profile shape of the epiproct.

Distribution. China (Zhejiang Province).

Remarks. Sweltsa bicurvata sp. n. is similar to the Tibet Autonomous Region species, Sweltsa tibetensis Li, Pan & Liu, 2017 in sharing the similar shape of the epiproct in dorsal and lateral aspects. However, S. bicurvata can be easily separated from S. tibetensis by the following features: head with a large, rectangular median dark brown marking, terga 2–7 with wide, median stripe. In S. tibetensis , the body color is darker than the new species and covered with short, robust hairs. The pronotum bears a large pigmented area which is much wider than in S. bicurvata , and there is no defined dorsal stripe on the abdomen (figs. 2–3, 5, 9–11 in Li et al. 2017).

Figures

FIGURE 1. Sweltsa spp. a, c–e: Sweltsa bicurvata Li, W.L. & Li, W.H., sp. nov. (male); b, f–h: Sweltsa zhejiangensis Li, W.H. & Wang, sp. nov. (male). a. Head and pronotum, dorsal view. c. Epiproct, dorsal view. d. Epiproct, lateral view. e. Terminalia, dorsal view. b. Head and pronotum, dorsal view. f. Terminalia, dorsal view. g. Epiproct, dorsal view. h. Terminalia, lateral view.

FIGURE 2. Swelsta bicurvata Li, W.L. & Li, W.H., sp. nov. (male). a. Terminalia, dorsal view. b. Terminalia, lateral view. c. Epiproct, dorsal view. d. Epiproct, lateral view. e. Terminalia, ventral view.