Tyloperla sinensis Yang & Yang, 1993

Mo, Raorao, Wang, Guoquan & Li, Weihai, 2020, A new species of Tyloperla (Plecoptera: Perlidae) from Guangxi, China, with a redescription of the male of T. sinensis Yang & Yang, 1993, Zootaxa 4763 (1), pp. 109-116 : 113

Tyloperla sinensis Yang & Yang, 1993

( Figs. 4–5)

Tyloperla sinensis Yang & Yang, 1993: 61 ; Du, Sivec & He, 1999: 62.

Redescription. Male habitus ( Figs. 4a). General color brown. Triocellate, anterior ocellus smaller. Head slightly wider than pronotum, pale brown, with a dark brown triangular ocellar patch extending to anterior ocellus and a brown triangular stigma; compound eyes dark; antennae brown. Pronotum pale brown, rectangular with brown rugosities, anterior corners pointed but posterior corners obtuse; wings membrane brownish, veins brown; legs mostly pale brown, knees and tarsi dark brown; cerci brown.

Terminalia ( Figs. 4 b–4c). Posterior margin of tergum 7 with a small patch of sensilla basiconica. Tergum 8 with a large raised well sclerotized lobe posteromedially covered with a small field of sensilla basiconica. Membranous portion of tergum 9 with a mesal patch of sensilla basiconica set on a higher sclerotized triangular mound. Hemitergal processes of tergum 10 acute, finger-like and strongly curved inward; process in lateral aspect subtrapezoidal; basal callus rounded.

Aedeagus ( Figs. 4d, 5). Hook-like, mostly membranous, with a blunt tip; basal sclerite well developed; tube with a pair of small dorsomedial spiny lobes ( Figs. 4d, 5a). Aedeagal sac strongly curved ventrad, covered with mixed armatures of stout spines and spinules but interrupted by a long membranous band on ventral surface; apical ⅓ offset by a distinct groove.

Female. Unknown.

Material examined. Holotype, male ( CAU), China: Guangxi Zhuang Autonomous Region, Laibin City , Jinxiu County, Mt. Dayaoshan , 1982.VI.3, Chikun Yang.

Distribution. China (Guangxi).

Remarks. The aedeagus of T. sinensis was not described in the original description. The general color of the holotype is faded because of long-term preservation in ethanol. Tyloperla sinensis is most similar to T. courtneyi Stark & Sivec, 2005 from Thailand, sharing a similar aedeagus and hemitergal processes of tergum 10. However, T. sinensis can be easily separated from T. courtneyi by the ocellar patch and the triangular stigma, tergum 8 and 9 with a well sclerotized lobe or mound. In T. courtneyi , the ocellar patch is subrectangular, stigma is indistinct, tergum 8 and 9 lack distinct lobes. The aedeagus of T. courtneyi is abruptly constricted subapically with a semicircular notch, whereas subapically, the aedeagus of T. sinensis lacks a constriction. Additionally, both species can be distinguished by the details of the aedeagal armature, especially of ventral surface of aedeagus, naked in T. sinensis and spinous in T. courtneyi (compare Figs. 4d, 5 with fig. 4 in Stark & Sivec 2005).