Neoperla nigromarginata Li, Weihai & S. Q. Zhang 2014

Neoperla nigromarginata is a species of stonefly native to the Henan province of China. The forewing measures 11.8 millimeters in males, and 13.4–14.0 millimeters in females. The head is pale yellow to brown with black markings. Legs and antennae are brown. The species name refers to the dark-colored margins of the pronotum. The species is similar in many aspects to Neoperla flagellate and N. tuberculata, but can be distinguished by the size of the aedeagus. The Aedeagal sac and tube are approximately the same length, with the sac being membranous and covered in numerous small spines. A pair of flagella are discernable at the sac's apex.

Distance between ocelli slightly wider than diameter of the ocellus. Head pale yellow to brownish with black areas, slightly wider than pronotum, with a black rectangular area covering ocelli, a large black anterior spot and two small lateral spots present on frons (Fig. 1a); compound eyes black, antennae dark brown except several basal segments which are brown; maxillary palpi dark brown. Pronotum with black median areas of rugosities and lateral margins around the kidney shaped pale disc area (Fig. 1a); wings subhyaline, veins dark brown; legs dark brown with femora and inner part of tibia brownish to brown (Fig. 1e). Cerci dark brown, basal segments brown. Male. Forewing length 11.8 mm. Tergum 7 with an anteromedian pair of sclerotized, upraised, nipple-shaped processes and a distal subquadrate process on posterior margin, covered with small sensilla basiconica (Fig. 1b). Tergum 8 with a recurved tongue shaped process, fringed with small spines at its distal margin (Figs 1b). Tergum 9 without patches of sensilla basiconica. Hemitergal processes of tergum 10 with a swollen wide base medially curved with sharp tip (Fig. 1b). Aedeagal tube nearly straight, with basoventral and dorsal sclerites. Aedeagal sac membranous but basal half heavily sclerotized ventrally (Figs 1d, 2b). Sac about as long as tube and curved ventrally forming a right angle to tube, dorsal surface with 2-3 irregular rows of numerous small spines (Fig. 2a); lateral surface of sac with a large patch of numerous small spines at subapcial region (Fig. 2b); a pair of flagella present more evident in uneverted sac apex in dorsal view (Fig. 2a). Forewing length 13.4–14.0 mm. General color pattern similar to male. Sternum 7 slightly sclerotized except the posterior margin slightly produced forming sclerotized subgenital fig. Subgenital fig a small dark brown tab with slightly emarginate tip (Fig. 1f). Sternum 8 moderately sclerotized medially, posterior margin slightly produced in a narrow wide lobe.

China (Henan Province).