The species in the genus Potanthus, are not easy to identify in the field. The easiest way to identify a P. trachala is to observed the upperside forewing, where the spots in spaces 4 and 5, are out of line with the spots below.
The species is quite common in Singapore and not rare in Peninsula Malaysia, and can be found at all usual elevations, in both primary and secondary forest. Range from India to China and Sundaland.
Male valva of P. trachala (Note; uncus tapering to a blunt triangular point)
Overview of the male valva of Potanthus sp. from "The Butterflies of the Malay Peninsula"