The taxon Naarda ineffectalis (Walker, 1859) has had an eventful taxonomic history; in certain periods it was even synonymised with the type species of the genus. Treated recently as a species distinct from Naarda bisignata Walker, 1866, i.e. the type species, its female form has been hitherto unknown. In this paper the female of the species is described and the known range of it is extended by new data from Cambodia, Thailand, Japan, Korea and Sumatra. The species rank of Naarda notata (Hampson, 1891) is formally reinstated (stat. rev.). An identification key to the Naarda species of Korea and main islands of Japan is also given. With 21 figures.