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).

Figures

FIGURE 4. Tyloperla sinensis Yang & Yang, 1993 (male). a. Head and pronotum, dorsal view. b. Terminalia after being cleared, dorsal view. c. Terminalia after being cleared, lateral view. d. Aedeagus, lateral view.

FIGURE 5. Tyloperla sinensis Yang & Yang, 1993 (male). a. Aedeagus, dorsal view. b. Aedeagus, ventral view.