One previously named and two new species of the tineid genus Erechthias Meyrick are described and illustrated from the small, remote, mid-Atlantic Ascension Island. With these additions the Lepidoptera fauna of Ascension now totals 38 known species. Little is known regarding the biology of the two new species of Erechthias, and none of the species has been reared from larvae from Ascension. Erechthias minuscula (Walsingham) is a widespread, largely pantropical species first described from the West Indies. Larvae of E. minuscula are known to be scavengers on a wide variety of dead plant material. Erechthias ascensionae, new species, is one of two species of Erechthias now known to be endemic to the island. The other endemic species, Erechthias grayi, new species, is further remarkable inwing reduction occurring in both sexes. It is one of the few species of Lepidoptera known where this extreme of brachyptery involving both sexes has evolved. The larvae of E. grayi are believed to be lichenivorous, and larval cases suspected to represent this species are illustrated.