Certified Crop Advisor Practice Exam

Natural enemies of pests can help to do what with pest populations?

1. Increase

2. Stabilize

3. Decrease

4. Eliminate

The correct answer is: Decrease

Natural enemies of pests, such as predators, parasitoids, and pathogens, play a significant role in biological pest control. They help decrease pest populations by directly attacking and feeding on them, thus reducing their numbers. This dynamic is crucial in agricultural ecosystems, where maintaining pest populations at manageable levels is essential for crop health and yield. When natural enemies are present in an ecosystem, they can disrupt the growth and reproduction of pest populations, limiting their ability to thrive. For example, ladybugs consume aphids, and parasitic wasps lay their eggs inside pest insects, resulting in the eventual death of the host. This natural regulation can lead to a decline in pest populations without the need for synthetic pesticides. While natural enemies can help stabilize pest populations by providing a balance, their primary impact is often a reduction in numbers. Complete elimination of pest populations is typically not sustainable or desirable, as some pests can play roles in the ecosystem as well. Therefore, the focus is on decreasing their populations to levels that are less damaging to crops.