Largusoperla Chen, Wang & Du 2018

Key to males of species of LargUSoperla

1. Paraprocts asymmetrical, weakly sclerotized, subtriangular with sharp apex; left paraproct widened at mid-length, right parap- roct constricted at mid-length................................................................ L. difformitatem

-. Paraprocts symmetrical................................................................................. 2

2. Paraproct finger-shaped, thick, with banded coloration.......................................... L. dewalti sp. nov.

-. Paraproct sub-triangular, without banded coloration.......................................................... 3

3. Paraproct subapically constricted to a needle-like large spine.............................................. L. acus

-. Paraproct without needle-like apical spine.................................................................. 4

4. Paraproct weakly sclerotized, almost flat, laterally thickened and upcurved................................... L. flata

-. Paraproct strongly sclerotized, more or less upcurved......................................................... 5

5. Paraproct with concave inner margin, convex outer margin and obtuse apex........................... L. borisi sp. nov.

-. Paraproct with convex inner margin, concave outer margin and sharp apex.................................. L. arcus