What is the term for a substance used to prevent, destroy, or control pests?

The term for a substance used to prevent, destroy, or control pests is "pesticide." This broad category encompasses various types of substances designed to manage pest populations, which can include insects, weeds, fungi, and other organisms that may cause harm to crops, plants, or human health. Pesticides are formulated to target specific pests while minimizing risks to non-target organisms and the environment.

While herbicides and insect repellents are specific types of pesticides (herbicides target weeds, and insect repellents deter insects), the term "pesticide" covers all potential pest control agents, which is why it is the correct choice in this context. Fertilizers, on the other hand, are used to enhance the growth of plants rather than control pests, making them unrelated to the core question.