A cocoon is a covering which an insect larva forms around itself and in which it passes the pupa stage [source: Merriam Webster]. There are four stages in a butterfly's life cycle. First, the female butterfly lays eggs on plants. Then the caterpillar emerges from the egg [source: AMNH]. During this stage the caterpillar grows by eating plants and other vegetation. When the caterpillar is fully grown it becomes a pupa. It's at this stage that it will hide among leaves and spin a cocoon around itself. It will remain in this stage until it breaks out of the cocoon as a butterfly. The final stage is when it becomes a full-grown adult butterfly, and then the process begins all over again [source: ANS]. Here's how to care for butterfly cocoons at home.
- Place a small plant in a pot or vase in a large, wide-mouthed jar.
- Lean several branches against the wall of the jar. This will provide a place for the caterpillar to attach itself and spin its cocoon.
- Place a paper towel along one side of the jar. When the adult butterfly emerges it will use the paper towel to spread its wings and let them dry.
- Place some moist paper towels on the bottom of the jar to keep the moisture level in the jar elevated.
- Place some caterpillars in the jar. Note what type of plant you found the caterpillars on.
- Cover the jar with a cloth and secure the cloth with a rubber band.
- Place fresh leaves in the jar daily. Since caterpillars eat a lot, you'll have to supply a few fresh leaves each day.
- Clean the jar out whenever you notice it getting dirty. This is important to prevent mold from growing. Replace the caterpillar and all the accessories after cleaning the jar [source: University of Arizona].
- Spray some water in the jar from time to time, after the butterfly pupates. Other than this, the cocoon won't need any other care [source: butterfly school]. //]]]]> ]]>