MORPHOLOGY
External characteristics
Male
Forewing length (mm): 15 - 23.5 (Yata, 1991).
Forewings: The forewing upper side has a black margin (D'Abrera, 1982; Yata and Morishita, 1979), this black border is smoothly rounded and angled towards the tornus (D'Abrera, 1982). The forewing underside has a single cell spot. The upper side wing surface has a lemon yellow ground-colour (Yata and Morishita, 1979).
Female
Forewing length (mm): 15 - 22 (Yata, 1991).
Subspecies and variation
Seven (D'Abrera, 1982) to eight (Yata and Morishita, 1979) subspecies are described. There is geographical variation, especially the females can vary in ground-colour from area to area. Subspecies from Peninsula, Formosa and others vary also seasonally; the dry season form has narrower black borders on the upper side wing surface, sometimes this border is on the hindwing reduced to a series of spots. The black border on the hindwing is narrower in ssp. evansi. The male from ssp. borneensis is indistinctly spottend on the underside wing surface and the female of this subspecies has a milky white ground-colour. The male of ssp. prabha has rather angulate termen on the hindwing and the female of this subspecies has a yellowish green ground-colour, tinged with milky white colouration, and the basal area black dusted. The submarginal series of spots becomes in ssp. nishiyamai extinct on the hindwing underside. The black border on the hindwing upper side is narrower in ssp. udana, the female of this subspecies is yellowish green, tinged with milky white. The spots on the underside wing surface are well developed in ssp. kashiwaii and the male has also a tornal black spot on the forewing (Yata and Morishita, 1979).