Caterpillars eat only vegitation and adults eat nectar. Many food plants used by larvae can only be referred to as weeds. The larva stage of the butterfly is the Caterpillar. After the butterfly emerges, it is then an Adult. The amount of time that it takes for a butterfly to pass through these stages varies with species.
Some butterflies require a cold period when they are in their chrysalis stage.
I have a birdbath they use and also small pile of dark, rich soil with a little mature. Scoop out a hole fill with water. This doesn't last long here though becuase of the heavy seasonal rains we get. These are just a few sites that can help you with more information on Butterfly Gardening and Our Environment. The Butterfly Zone is your top destination on the Internet to purchase butterfly gardening supplies.