A medium-sized, orange butterfly with a white-spotted black border all around both sets of wings, broad at the apex of the forewings and thin elsewhere (Pic 1). The undersurface of the wings is much paler with larger, bead-like white spots along the black border (Pic 2). The thorax is black with white markings and the abdomen is yellow. The greenish caterpillar is thick and smooth with a few sets of long, curling spines and is heavily marked with thin, black and reddish bands.
Behaviour
These are active butterflies with strong flight and are common in Chennai - in fact, they are among the commonest of Indian butterflies. They rest with the wings closed above the back or opened flat. When the wings are held flat and drooping back, the black spots on the hind wings may get hidden by the overlapping forewings. The adults visit various flowers, but females lay their eggs mainly on the leaves of milkweed plants (family Asclepiadaceae), like the giant milkweed, which is also favoured by the Common Crow butterfly (see April bulletin) and also by the Painted Grasshopper.
The caterpillars devour the leaves of these poisonous milk-exuding plants and injest the poison therein which makes them, as adult butterflies, unpalatable to predators. Some other non-toxic butterflies like the Daniad Eggfly (female), mimic this butterfly to gain protection from its distasteful reputation. Plain Tigers are found over India, in the plains and upto 1800 mts. in the hills.
