We discuss 45 Costa Rican species of Ethmia Hübner, 1819, including 23 previously described: Ethmiadelliella (Fernald), Ethmiabittenella (Busck), Ethmiafestiva Busck, Ethmiascythropa Walsingham, Ethmiaperpulchra Walsingham, Ethmiaterpnota Walsingham, Ethmiaelutella Busck, Ethmiajanzeni Powell, Ethmiaungulatella Busck, Ethmiaexornata (Zeller), Ethmiaphylacis Walsingham, Ethmiamnesicosma Meyrick,...
