Which condition would increase the likelihood of pesticide resistance?

The likelihood of pesticide resistance increases when there is continual use of pesticides from the same chemical class because this practice exposes pest populations repeatedly to the same mode of action. When a specific pesticide is used frequently, any pests that have any level of resistance to that chemical can survive and reproduce, leading to a population more resistant to that pesticide over time. This selective pressure results in a higher frequency of resistant individuals, diminishing the effectiveness of that chemical class.

In contrast, alternating different pesticides (which may belong to varying classes) can disrupt the lifecycle of pests and mitigate the development of resistance by exposing them to multiple modes of action. Similarly, integrating cultural practices or employing biological controls introduces alternative methods for pest management that can reduce dependency on chemical pesticides, further limiting the risks of resistance development.