What does augmentation in biological control involve?

Augmentation in biological control specifically involves releasing large numbers of natural enemies that already exist in the area to help manage pest populations. This strategy enhances the existing population of natural predators or parasitoids, allowing them to exert more control over pest species than would occur naturally. By supplementing the numbers of these beneficial organisms, the effectiveness of natural pest control can be significantly increased, leading to better management of pest outbreaks.

The other options focus on different approaches to biological control. Importing new pest predators addresses the introduction of organisms from different environments, which is distinct from augmentation. Changing the environment to support existing natural enemies involves habitat manipulation or providing resources to enhance their survival and reproduction, which differs from the active release of more individuals. Using chemicals to enhance predator effectiveness suggests a synthetic approach rather than a natural enhancement strategy, which diverges from the principles underlying biological control through augmentation.