I found these caterpillars on the lime plants in my balcony. These are the larva of the Common Mormon (Papilio polytes). The butterfly is very common in gardens and is quite interesting in that the female has a number of different forms. Here are some life cycle shots of the caterpillar.
This is the caterpillar a few days after it hatched. This instar is called the bird dropping instar. The caterpillar rests prominently on the leaves and looks like the dropping of a bird. Even the white streaks are copied.
A week later the caterpillar looks like this. Completely green. This caterpillar could be in its 4th or 5th instar. It will pupate after this and I hope to get some nice images of the chrysalis.
The butterfly if it emerges could look like the mother or it could be patterned in a different form. The reasons for the different patterning has got to do with mimicking another poisonous butterfly so that its own chance of survival goes up.
These caterpillars are quite easy to grow and study as long as you have curry patta or lime plants around. These could be observed in a classroom and the class could learn how to feed and clean the caterpillar and its container. They would learn how to keep accurate and disciplined observations about the different activities of the caterpillar. And finally they can have the joy of watching an adult emerge and take flight.