Togoperla thinhi, a new stonefly from central Vietnam (Plecoptera: Perlidae)

A new and rare perlid stonefly, Togoperla thinhi n. sp., is described from male and female adults and egg specimens from tropical central Vietnam. The male adult of T. thinhi n. sp. can be distinguished from other congeners by the distinct head markings, bilobed processes on the posterior margin of the abdominal tergum V, and S-shaped aedeagus. The female adult has a long and tongue-shaped subgenital plate on the abdominal sternum VIII, which extends to the posterior margin of the abdominal sternum IX. A male key to the Vietnamese species of Togoperla is provided. The finding of this new species provides evidence of an extension of the geographical distribution of Togoperla to tropical mainland Southeast Asia.