Potanthus serina has an orange-yellow upperwings with black spots on the 6 hind wings, three separate apical spots in spaces 4 and 5. The underside has an orange tinge with patches in spaces 5 and 6 forwards. There is black hair on the back of the head, the antennae are yellow with black stripes, and the legs are yellow.
Larva: larvae of Potanthus serina are cylindrical, yellowish green in color with a body covered with slightly short dorso-lateral setae on the 1st instar. The head capsule is black, the next instar has a whitish color on both sides like the letter Y.
Pupa: Potanthus serina pupae are brownish yellow in color, stomach and chest are rather long, pupae are about 20-22 mm long.