Diagnosis. This is the smallest species of its genus in Borneo and has an unmistakable forewing pattern in dull brown, with the basal zone very much darker, almost black, up to a sharply convex boundary that runs from the centre of the dorsum to the costa at one quarter.
Taxonomic note. Lödl (1998a, 1999b) transferred the species from Catada Walker to Acidon. The male genitalia have a rather catocaline ‘ball and claw’ apex to the uncus; the valves are very narrow, with the subbasal process to the saccular zone being slender, acute.
Geographical range. Indian Subregion, Taiwan, Borneo.
Habitat preference. Two specimens have been taken in recent surveys: in alluvial forest at 170m near G. Mulu; in lowland forest at 100m on G. Santubong near Kuching.
