To avoid the development of resistance in pests, you should use pesticides with differing modes of action.

To avoid the development of resistance in pests, you should use pesticides with differing modes of action.

• A. Use pesticides with the same mode of action
• B. Rotate pesticides with different modes of action
• C. Increase application frequency of the same pesticide
• D. Use pesticides with high volatility

Answer: (B)

Rotating pesticides with different modes of action helps prevent resistance by exposing pests to multiple, distinct biological targets. When a pest population is repeatedly exposed to the same mode of action, individuals that happen to have or acquire resistance survive and reproduce, gradually shifting the population toward resistance. Alternating products that work in different ways means no single resistance trait can protect a large portion of the population, so control remains effective longer. Mode of action is how a pesticide affects the pest—what target it hits in the pest’s biology. If you stick to one mode of action, cross-resistance can also build up to others with a similar target, making future controls harder. By using products with different modes, you slow that process and maintain the pesticides’ effectiveness. Using the same mode of action repeatedly or increasing how often you apply the same pesticide both raise the selection pressure for resistance, making resistance develop faster. High volatility affects drift and environmental fate, not the tendency for pests to become resistant, so it’s not a resistance-management strategy.

Rotating pesticides with different modes of action helps prevent resistance by exposing pests to multiple, distinct biological targets. When a pest population is repeatedly exposed to the same mode of action, individuals that happen to have or acquire resistance survive and reproduce, gradually shifting the population toward resistance. Alternating products that work in different ways means no single resistance trait can protect a large portion of the population, so control remains effective longer.

Mode of action is how a pesticide affects the pest—what target it hits in the pest’s biology. If you stick to one mode of action, cross-resistance can also build up to others with a similar target, making future controls harder. By using products with different modes, you slow that process and maintain the pesticides’ effectiveness.

Using the same mode of action repeatedly or increasing how often you apply the same pesticide both raise the selection pressure for resistance, making resistance develop faster. High volatility affects drift and environmental fate, not the tendency for pests to become resistant, so it’s not a resistance-management strategy.