Great picture! You might be interested in learning that those are the cocoons of the pupae of the Braconid wasp. The tiny adult wasp lays her eggs on or just under the skin of the caterpillar, and the larvae develop inside the body where they feed on caterpillar innards. When those larvae are ready to become adults, they pupate outside the body after making those little cocoons. They will soon emerge as a brand new generation of adult wasps.

So...egg, larvae (inside the caterpillar), pupae (outside), and adult. Magic.

Wow, nice pic