The precise type-locality of the infrequently encountered Western Australian species Nascio chydaea Olliff, 1886 is redefined from 28˚44ʹS, 116˚24ʹE to 34˚11ʹS, 118˚19ʹE, and thus George Masters is identified as the original collector and January–February 1869 as the date of collection of its lectotype and paralectotype. The first larval and adult hostplant records, Eucalyptus wandoo and an unidentified Asteraceae species respectively, as well as three further distributional records from south-west Western Australia, are provided for N . chydaea and discussed. A colour photograph of its dorsal habitus is also provided, as well as a distribution map for this species. Relationships, general zoogeography and biology of all Nascio species are briefly discussed.