Parasitoids, like parasites, depend on other organisms for part of their life cycle, during which they feed on the host.
The adult parasitoid is free-living though. Parasitoid larvae may live inside the host (endoparasitoids) or on the host (ectoparasitoid).
Unlike parasites, parasitoids kill or at least sterilize the host in the end. The distinction between parasites and parasitoids is not
alwyas easy to make. Likewise, the distinction betweem a parasitoid and a predator is not always clear cut.
The difference between ectoparasitoids and predators is mostly one of the time it takes to devour the prey. If a larva
eats from a single prey during its entire larval development, it seems more useful to consider it an ectoparasitoid than a predator.
But if a larva devours more than one host, with an increasing number of prey the feeding strategy more and more resembles predation.