Why rotate modes of action in pesticides?

• A. To reduce application costs.
• B. To prevent pests from developing resistance.
• C. To diversify crop colors.
• D. To avoid using any protective equipment.

Answer: (B)

Rotating modes of action helps delay resistance by not consistently exposing pests to the same pesticide target. When a single mode of action is used repeatedly, pests with natural or newly developed changes that reduce sensitivity survive and reproduce, gradually making that pesticide less effective. Switching to products with different modes of action changes the selective pressure on the pest population, making it harder for resistance traits to spread and thus extending the useful life of each pesticide. This approach is a key part of resistance management within integrated pest management, and it pairs well with monitoring and non-chemical controls. The other options don’t address resistance: rotation isn’t primarily about lowering costs, it doesn’t relate to crop color, and protective equipment requirements are determined by safety guidelines, not rotation strategy.