MORPHOLOGY
External characteristics
Male
Forewing length (mm): 42 - 60 (Jonko, 2021). Wingspan (mm): 50 - 60 (Agriculture, Fisheries and Conservation Department, 2022) .
Forewings: The forewing has triangular black subapical spot from the costa to the outer margin (Yata and Morishita, 1979). Hindwings The hindwing upper side has black coloured dots on the termen. The hindwing underside has a black distal stipe (Yata and Morishita, 1979).
Female
Forewing length (mm): 42 - 60 (Jonko, 2021).
Subspecies and variation
Two subspecies are described. There is seasonal variation; the spring form is smaller than the summer form and the black scales are vestigial. Ssp. malayica is smaller than the nominate species and has undeveloped black markings (Yata and Morishita, 1979).