When we talk about parasitism, we often use the term host to denote the organism that is supplying the nourishment to the parasite or parasitoid. A parasitoid is an organism whose size is relatively close to that of their host; that lives about the same length of time as their host, and that usually kills the host. Contrast that with a parasite such as a tick that is much smaller than its host, has a shorter life cycle than its host, and does not kill its host.

General characteristics of natural enemies feeding on other insect species are as follows:

Predatory Insects:

1. Consume more than one prey to complete development
2. Relatively large size compared to prey
3. Predaceous as both immature and adults
4. Immature stages are active
5. Prey are consumed immediately—except for predatory wasps that store prey for immatures

Parasitoids (parasitic insects):

1. Require only one host to complete development
2. Smaller or similar size as host
3. The female lays her eggs on or in host. The larvae hatch from the egg and feed. Only immature stages are parasitic.
4. Most commonly found in Hymenoptera (wasps) and Diptera (flies)
5. Host-specific (attacking one or several related host species)