Cosmoplatidius Gounelle, 1911 and its species are redescribed. The following synonymies are established: C. mandibularis Gounelle, 1911 = C. simulans (Bates, 1870) comb. nov.; C. ochraceus Linsley, 1961 = C. sellatus (White, 1853). New species described: C. abare sp. nov. from Peru, Bolívia, Brazil (Amazonas, Pará, Mato Grosso). A key to species is provided.
Cerambycinae; Neotropical; Pteroplatini; revision