During the search for natural enemies of Old World climbing fern, Lygodium microphyllum (Cav.) R. Br. (Schizaeaceae), in Australia and southeastern Asia, Cataclysta camptozonale (Hampson) was found to be highly specific to this aggressive vine and was tested as a biological control agent. This musotimine moth species has long been misplaced in a European acentropine genus; therefore, we propose Austromusotima, new genus, to accommodate Austromusotima camptozonale, new combination, as the type species. The syntype series of Oligostima camptozonale is a mixture of specimens of the former species (sensu stricto) and its sibling, Austromusotima metastictalis (Hampson), new combination. A lectotype is designated for A. camptozonale to stabilize the use of the name. The immature stages of A. camptozonale are described and compared with other known musotimine immatures. The immatures of Eugauria albidenta (Hampson) and Cataclysta angulata Moore are illustrated for the first time. Austromusotima is most closely related to Cataclysta seriopunctalis Hampson based on adult morphological characters, but immatures of C. seriopunctalis are unknown, and therefore, this species is not included in Austromusotima. The important, yet incongruent, results between immature and adult characters are discussed in the context of phylogenetic relationships of Austromusotima to other taxa.