Sweltsa tibetensis, Li & Pan & Liu, 2017

Li, Weihai, Pan, Zhaohui & Liu, Ruijun, 2017, Description of Sweltsa tibetensis sp. n. (Plecoptera: Chloroperlidae) from Tibet Autonomous Region of China, Zootaxa 4365 (3), pp. 378-384 : 379-383

Sweltsa tibetensis sp. nov.

( Figs. 1–15 )

Male habitus ( Figs. 1–15 ). General color greenish, becoming pale in ethanol. Head with a large hexagonal median dark area, occiput with a distinct transverse, posterior stripe extending to posterior corners of compound eyes and rugose surface. Pronotum mostly dark brown to black, with yellow paralateral area. Compound eyes black, ocelli pale with dark rings. Antennae brown, basal segments paler, palpi yellowish brown. Meso- and metathoracic nota with typical U-marks. Wing membrane transparent, legs brownish. Abdominal tergum 1 with quadrate median stripe, terga 2-8 with trapezoidal median stripe, anterior margins of the stripes darker; stripe of tergum 8 only covering anterior third of the segment. Terga 2-8 each with a pair of distinct dark median spots.

Forewing length 8.4 mm, hindwing length 7.5 mm. Lateral hair brush typical, present at abdominal segments 7–9 ( Figs. 7–8 ). Tergum 9 sclerotized except the membranous median third posterior to sclerotized anteromedial transverse ridge, the ridge appearing as a pair of small erect triangular sclerites encompassing the scalloped posterior edge ( Figs. 5, 7 ). Sternum 9 with broad trapezoidal subgenital plate, posterior margin truncate. Sternum 10 mostly membranous, laterally sclerotized, posterior margin truncate ( Fig. 6 ). Tergum 10 with darkly sclerotized transverse bands, the medial portion between the bands greatly enlarged in a shield–like basal anchor, the anchor much longer than wide and with typical membranous groove and paragential plates between hemiterga ( Figs. 5 , 9, 10 ), basal bar concave ventrally and abruptly up-curved medially, thus L-shaped in lateral aspect ( Fig. 10 ). Epiproct tip slender and recurved, parallel-sided for most of its length, with sharp apex in dorsal view; in lateral aspect the apex moderately enlarged and evenly up curved ( Figs. 9–11 ); dorsal surface of epiproct mostly covered with rugose striations, the apex with a smooth lateral cap at the slightly expanded distal portion ( Figs. 9–11 ). Aedeagus triangular in lateral aspect and “starfish-like” in caudal view. The dorsal lobe and dorsolateral lobes triangular and the ventrolateral lobes rounded ( Figs. 12, 14 ). Posterior portion of aedeagus with a pair of nippleshaped lobes, each with several long hairs ( Figs. 13, 15 ).

Female and larva. Unknown.

Type Material. Holotype male ( HIST), CHINA: Tibet Autonomous Region, Nyingchi City, Nyingchi County, Sejilashan ( Sejila Mountains ), Sejilashan National Natural Reserve , unnamed stream at Zhongshan Station , 29°36.60'N, 94°36.19'E, 4200 m, 2014. VII.10, coll. Zhao Hui Pan.

Etymology. The species name refers to the Tibet Autonomous Region, China.

Distribution. Presently only known from the Sejilashan National Nature Reserve, Nyingchi (Linzhi) of the southeastern Tibet Autonomous Region, China.

Diagnosis and Remarks. The epiproct of the new species is most similar to S. longistyla ( Wu, 1938) , a species known from Gansu ( Wu 1938), Henan, Hebei, Shaanxi, and Ningxia provinces ( Li et al. 2014) of China. However, the apex of the epiproct of this species only slightly tapers in lateral view as compared to the more enlarged apex of the new species (compare fig. 25, Li et al. 2014 and Fig. 10 ). Sweltsa tibetensis appears also to be similar to the northwestern Indian species, S. assam Zwick, 1971 in sharing a similar head pattern, possessing a similar transverse ridge on tergum 9 and the general shape of the epiproct. However, S. tibetensis may be easily separated from S. assam by the enlarged epiproct apex being evenly up curved toward apex and by the dark brown pronotum with paler lateral stripes. The epiproct of S. assam bears a subapical indentation in lateral aspect forming a parallelsided apex, and the pronotum is only darkly pigmented medially and along the margins (figs. a & d in Zwick 1971).

Figures

FIGURES 1–2. Sweltsa tibetensis sp. nov. (male):1. Head and thorax, dorsal view. 2. Abdomen, dorsal view.

FIGURES 3–8. Sweltsa tibetensis sp. nov. (male): 3. Head and pronotum, dorsal view. 4. Head, dorsal view. 5. Terminalia, dorsal view.6. Terminalia, ventral view.7. Terminalia,lateral view.8. Hair brush of abdominal segment 7, lateral view.

FIGURES 9–11. Sweltsa tibetensis sp. nov. (male): 9. Epiproct, dorsal view. 10. Epiproct, lateral view. 11. Epiproct, dorsolateralview.

FIGURES 12–15. Sweltsa tibetensis sp. nov. (male aedeagus): 12. Aedeagus, lateral view. 13. Hairy lobes, caudal view. 14. Aedeagus, caudal view. 15. Aedeagus, oblique lateral view.