The Yponomeutoid fauna of the Galapagos Islands (Ecuador) comprises two species, Prays galapagosella n. sp. (Plutellidae: Praydiane) and Atteva hysgmiella (Wallengren, 1861) (Yponomeutidae: Attevinae). Atteva monerythra Meyrick, 1926, is synonymized with A. hysgmiella. Atteva hysginiella was reared from Castela galapageia Hooker f. (Simaroubaceae); its genitalia and immature stages are described and illustrated.