The Cecidosidae (including Ridiaschinidae) is a small family (18 species) of primarily gall-forming moths restricted to the southern Hemisphere. Four genera (Cecidoses - 1 sp., Dicranoses (= Ridiaschinia) - 2 sp., Eucecidoses - 1 sp., and Oliera - 1 sp.) have been described from southern South America, one genus (Scyrothis (= Lipopseustis, Ptisanora, Sapheneustis) - 12 sp.) from South Africa, and the monotypic genus Xanadoses from New Zealand. Except for two gall-producing species of Prodoxidae (*Lampronia fuscatella* and possibly *Prodoxus y-inversus*), the Cecidosidae are the only Incurvarioidea with this habit. Together with the Prodoxinae, Cecidosidae are the only incurvarioids to have adapted to arid and semiarid environments.