What method uses natural enemies to manage pest populations?

The method that uses natural enemies to manage pest populations is biological control. This approach involves the introduction or encouragement of natural predators, parasites, or pathogens of the pest species to suppress their populations. For instance, lady beetles are often released into gardens to feed on aphids, thereby reducing their numbers without the need for synthetic pesticides. Biological control is particularly effective in sustainable agriculture because it aims to use existing natural processes to manage pests, reducing reliance on chemical interventions and minimizing environmental impact.

In contrast, mechanical control involves physical methods such as traps or barriers to remove or prevent pests, cultural control refers to practices that alter the farming environment or crop management to make conditions less favorable for pests, and chemical control relies on synthetic pesticides to kill or repel pests. These methods do not engage the natural enemy relationships present in ecosystems, which is the defining characteristic of biological control.