Falsivalva , new genus is described and illustrated. In addition to the previously named type species, “Tinea” prensoria Meyrick, three new species, F. clavata, F. nephophila, and F. paraprensoria, are described. The most conspicuous synapomorphy of Falsivalva is the highly specialized tergum IX (tegumen) of the male, which is greatly enlarged and almost completely divided to resemble the male gonopods (valvae). It is suggested, but not observed, that these paired structures may function either to guide or clasp the female oviscapt during copulation. The genus occurs in both coastal and Andean Nothofagus forests primarily in southern Chile from approximately 35°S in Maule Province south to about 45° in Chiloe Island and east to Neuquén Province, Argentina. The biology is unknown.