Neoperla circuloloba Zeng, Huo & Du 2025, sp. nov.

Neoperla circuloloba Zeng, Huo & Du, sp. nov. Figures 1–2 Male. General color brown (Fig. 1). The head is mostly yellowish-brown, featuring a brown marking that covers the ocellar triangle. This marking extends forward to the pale M-line, transitioning to brown, with a narrow triangular marking located just ahead of the M-line. The pronotum is trapezoidal, with the posterior part slightly narrower than the anterior part. Antennae and palpi yellow brown; legs pale to yellowish brown, femorotibial joint dark brown. Wings subhyaline, veins brown. Forewing length 15 mm, hindwing length 14 mm, body length 17 mm. Tergum 1–6 unmodified. Tergum 7 features a sclerotized area in its mid-posterior part, behind which is a pair of cleft lobes adorned with abundant sensilla basiconica at their tips. Tergum 8 possesses a tongue-shaped, upcurved process, featuring numerous sensilla basiconica along its distal margin. The hemitergal processes of tergum 10 are sclerotized and exhibit a finger-like shape. The penis tube is long and tubular with a high degree of sclerotization, exhibiting a slight curvature (Fig. 2). At the ventral end of the penis tube, there is a process that is bifurcated, forming a "C" shape, with the ends of the bifurcation close to each other. The endophallus is relatively short and has tiny spines on its surface. Female, egg, larva. Unknown. Etymology. The name refers to the shape formed by the branching on the ventral side of the penis tube. Type material. 1 male (ICYZU), China: Guizhou Province, Libo County, Maolan National Nature Reserve, Dongtang Village, 25.24594°N, 107.955993°E, 730 m, 2008.Ⅹ.5, leg Xingmin Wang. Distribution. China (Guizhou). Diagnosis and remarks: The new species appears to be closely related to N. furcostyla Li & Qin, 2013 (see figs. 1–2 in Li et al., 2013) from Guangxi Province, as it shares similar terminalia and penis structures. However, it can be distinguished from N. furcostyla by the male’s ventral end of the penis tube, which exhibits a "C" shaped bifurcation.