Ethmia nigroapicella, commonly known as the kou leafworm, is a moth of the Depressariidae family. It is found in Madagascar, the Seychelles, India, Assam, Burma, Samoa, the Philippines, Hawaii, Taiwan, Japan and Australia. The wingspan is 24–28 mm. The forewings are overlaid with fifteen black dots on a grey background and a row of seven marginal dots. The hindwings are orange-yellow, but the apical patch is dark brown and covers one-seventh of the hindwing. The larvae feed on Ehretia species (including Ehretia dicksoni var. japonica, Ehretia laevis and Ehretia buxifolia) and Cordia subcordata.