What are examples of biological control methods?

Biological control methods focus on the use of natural processes or organisms to manage pest populations, enhancing ecological balance. The correct answer highlights methods that utilize plant chemicals known as secondary metabolites, which can be toxic to certain pests, and the use of parasitic insects that can diminish pest populations by feeding on or laying eggs within them. Additionally, it points to the use of competitive organisms that can occupy the same ecological niche as pests, reducing their access to food sources and thereby controlling their populations.

These methods emphasize a natural approach to pest management that relies on the intrinsic relationships found in ecosystems. By employing such strategies, we can reduce chemical inputs and foster a healthier environment, making biological control a vital component of Integrated Pest Management (IPM).

The other choices point towards various control methods that either do not align with the principles of biological control or incorporate non-biological elements. For instance, habitat destruction and chemical sprays can harm beneficial organisms and disrupt ecological balance, thus not qualifying as biological methods.