Diagnosis. This and the next species are a similar size and dark brown colour with paler fasciation. The forewing postmedial in serrata Prout has a more definite dark component on the basal side, and the pale submarginal is much more clearly defined. The labial palps of male undulata have apical hair scales that are paler and more rufous than in serrata. Worn specimens may need to be separated by dissection, however. The valves in the male genitalia of serrata are more rectangular over the basal two-thirds, and the aedeagus vesica has a zone with massive cornuti that is absent from undulata.
Geographical range. Java, Peninsular Malaysia, Sumatra, Borneo.
Habitat preference. Three specimens were taken in lower montane forest at 1000m on G. Mulu.
