Two new species of the Rhyacophila nigrocephala species group, R. voluta sp. nov. and R. linguiformis sp. nov., are described, diagnosed and illustrated. Rhyacophila voluta sp. nov. is similar to R. pentagona Malicky & Sun, 2002 in male genitalia, but can be diagnosed by the inferior appendages of the same length as the complex of preanal appendages and dorsal lobe of segment IX, fused base of the basal segments of inferior appendages, and slightly incised distal margin of apical segment of inferior appendage. Rhyacophila linguiformis sp. nov. is similar to R. rima Sun & Yang, 1995 and R. esorima Mey, 1996 in male genitalia, but can be diagnosed by the progressively narrowed complex of preanal appendages and the dorsal lobe of segment X, the short anal sclerites, and the small gap between the upper and lower lobes of apical segment of inferior appendages. An updated checklist of 23 species recorded from China is presented.
Caddisfly, taxonomy, species group, subgroup.