Tyloperla bimaculata Li & Kong, 2020

Zeng, Liang-Liang, Huo, Qing-Bo & Du, Yu-Zhou, 2025, A new species of Tyloperla (Plecoptera: Perlidae) from China, with a supplementary description of T. bimaculata Li & Kong, 2020, Zootaxa 5661 (4), pp. 567-572 : 569-571

Tyloperla bimaculata Li & Kong, 2020

Tyloperla bimaculata Li & Kong, 2020: 290 .

Supplementary description. Head yellow-brown, with only a single dark brown ocellar patch and a light brown patch anterior to the M-line ( Fig. 3A ). The posterior margin of tergum 7 lacks a small patch of sensilla basiconica. Tergum 8 possesses a bird-shaped sclerotized area medially containing a transverse brown ridge posteriorly; sensilla basiconica patch present in middle of tergum ( Fig. 3B ). The hemitergal processes of tergum 10 are acute, finger-like and strongly curved inward, with rounded basal callus on the inner side of their base ( Fig. 3B ).

The spines on the dorsal side of the endophallus are interrupted into two patches with a wide medial area ( Fig. 4A ). On the ventral side of the endophallus, there are a pair of large projections covered with large spines ( Fig. 4B ). The apex of the endophallus is covered with large spines that curve toward the ventral side, forming a conical projection directed anteriorly ( Fig. 4C ).

Material examined. 1 male ( ICYZU), China: Chongqing, Wuxi County, Yintiaoling National Nature Reserve, Linkouzi , 1285 m, 2022.VI.21, leg Luyu Wang, Zhisheng Zhang .

Distribution. China (Chongqing, Guizhou)

Remarks. This species was originally described from Guizhou Province by Li & Kong (2020). The original description stated that the head is mostly pale, with a pair of small dark brown patches forward of the posterior ocelli, with each patch subequal in size to one posterior ocellus. Tergum 8 has an upraised brown sclerite area (see fig. 1 in Li & Kong, 2020). In our specimens, however, the head is yellow-brown, bearing only a single dark brown ocellar patch, along with a light brown patch anterior to the M-line ( Fig. 3A ). Tergum 8 also possesses an upraised brown sclerite area, although it is distinctly narrower than originally described ( Fig. 3B ). Our observations reveal variations in both the position of dark spot on the head and the thickness of the transverse brown ridge compared to the original description. These morphological differences likely represent intraspecific variation.

Figures

FIGURE 3. Tyloperla bimaculata, male. A: head and pronotum, dorsal view. B: abdominal terminalia, dorsal view.

FIGURE 4. Tyloperla bimaculata, male, everted penis. A: dorsal view. B: ventral view. C: lateral view.