Which of the following practices helps prevent pest resistance to pesticides?

Rotating different classes of pesticides is a crucial strategy in preventing pest resistance. This practice disrupts the selection pressure on pest populations that can lead to resistance. When pests are continually exposed to the same class of pesticides, they can develop resistance mechanisms over time, rendering the pesticide less effective. By alternating between different classes, each with distinct modes of action, the potential for pests to adapt and develop resistance is significantly reduced. This approach not only maintains the efficacy of pesticides but also contributes to more sustainable pest management practices.

In contrast, continuously using the same pesticide would create an environment where pests can easily adapt, leading to increased resistance. Applying pesticides at high concentrations may initially seem beneficial for efficacy, but it could also hasten resistance if repeated without rotation. Lastly, avoiding monitoring pest populations prevents farmers and pesticide applicators from understanding which pests are present and how they are evolving, making it difficult to implement effective resistance management strategies. Thus, rotating different classes of pesticides is the most effective measure to mitigate the risk of resistance.