Abstract
Contrary to a common conception, employment of biological control of weeds is fundamentally the same as the employment of biological control of insect pests. The goal in each case is not eradication but the reduction of pest populations to non-injurious levels. The ecological relationships which apply in the regulation of any organism by natural enemies in the undisturbed natural scene also apply when we attempt to introduce a natural enemy not already present. While it is true that our work has an economic or applied objective, the pursuit of objectives in biological control in general takes us deeply into fundamental considerations – fundamentals which constitute the broad science of ecology.