What does cross resistance mean in pest populations?

Cross resistance refers to a situation where a pest population that has developed resistance to one pesticide also shows resistance to another pesticide that has a similar chemical structure or mode of action. This means that the pest has essentially adapted to effectively survive exposure to related chemicals, making control measures less effective.

When pests develop cross resistance, it creates significant challenges in pest management because traditional methods of control become less effective. This phenomenon emphasizes the importance of rotating different classes of chemicals and using integrated pest management strategies to combat resistance.

In this context, the other options don’t accurately describe cross resistance. Resistance to a single pesticide refers to the development of resilience to just one chemical, while resistance to unrelated pesticides would imply a different mechanism of adaptation. Lastly, absence of resistance indicates that pests can be effectively managed using pesticides, which contradicts the very notion of resistance.