Practice question

Parasitoids develop in or on a single host and normally require that host's death to complete their life cycle. Many parasitoid wasps lay eggs in caterpillars or other arthropods; larvae consume host tissues progressively, often delaying lethal damage until development is nearly complete. Typical parasites exploit a host for resources but generally gain from keeping it alive long enough for repeated feeding or transmission, so host death is not an obligatory endpoint. Parasitoids may be internal or external, and they certainly harm rather than coexist harmlessly with hosts. Their combination of intimate association and eventual lethality places them between conventional parasites and predators in consumer-resource classifications. This reasoning connects organismal behavior with broader ecological consequences. A mechanism that changes encounter rates, resource use, or reproductive success can scale up to alter population trajectories and the structure of species interactions. The alternatives can be separated by asking what changes for each participant and which process causes that change. That approach is more reliable than treating familiar examples as fixed labels, because many interactions shift with environmental context.