Biological control can be defined as the deliberate use of natural enemies – predators, parasites, pathogens, and competitors to suppress and maintain populations of a target pest speicies (insects, mites, weeds, plant pathogens, and other pest organisms).
Biological control is particularly desirable because the tactic is environmentally safe, energy self-sufficient, cost-effective, sustainable, and can be readily incorporated into integrated pest management programs.
Excerpt from “Biological Control Overview, USDA”