Predators are organisms that kill and feed on their prey outright.
They are generally larger than their prey and must consume numerous prey in order to complete development. Parasites, on the other hand, are usually smaller and often weaker than their prey. Individual parasites utilize only one or a few insects for food. Predators and parasites account for much of the reduction of pest insect populations in nature. However, in agricultural and sometimes garden situations, their effects are often not dramatic enough to satisfy a farmer or homeowner.