Which practice best helps reduce resistance development in pests?

• A. Rotating pesticides with different modes of action.
• B. Using the same MOA repeatedly.
• C. Applying pesticides more frequently in the same season.
• D. Skipping applications.

Answer: (A)

Pest resistance develops when pests are repeatedly exposed to pesticides that kill them in the same way, so switching to products with different modes of action slows that selection process. Rotating MOAs reduces the chance that survivors from one treatment will carry forward resistance traits into the next round, because the next pesticide attacks a different biological target. It also helps avoid cross-resistance, where a pest that tolerates one mode of action is already tolerant to a related one. In contrast, using the same mode of action repeatedly continually selects for resistant individuals, applying pesticides more often increases this pressure, and skipping applications reduces control without reliably delaying resistance.