The relationship between the catalpa hornworm, a caterpillar, and Cotesia congregata, a wasp, is an example of parasitism in the deciduous forest. The wasp lays its eggs inside the caterpillar, and the larvae feed off of, and kill, the caterpillar.
Cotesia congregata is a member of the genus Cotesia. All members of the Cotesia genus are parasitoid wasps. Parasitoids are animals that spend part of their life cycle developing inside another organism, ultimately killing the host organism. Some Cotesia not only inject their eggs into the host, they inject a virus that halts the development of the caterpillar. The halted development means that the caterpillar never goes through metamorphosis, allowing the wasp larvae to develop fully inside the caterpillar.