Four new riodinid taxa in the tribe Symmachiini are described from wet forest habitats between 300 and 1700 m in the eastern Andes of Peru and Ecuador: Mesene leucogyna leucogyna, Mesene leucogyna notia, Mesene margaretta anartia and Symmachia pena. Discussions on their systematic placement are presented. The following taxonomic changes are proposed: Mesene bigemmis Stichel is removed from synonymy with Mesene nepticula stigmosa Stichel and reinstated as a species (rev. stat.); and Mesene oriens Butler is synonymized with Mesene margaretta (White) (n. syn.).
- Montane forest