Nacoleia octasema, the Banana Scab Moth, is a moth in the Crambidae family. It was described by Meyrick in 1886. It is found on Vanuatu and in Indonesia, New Guinea, the Solomon Islands, New Caledonia, Fiji, Tonga, Samoa and Australia, where it has been recorded from Queensland. The wingspan is about 30 mm. Adults are pale straw colour with a double discal spot, as well as a row of small black dots along the margin of both the fore- and hindwings.