Which would increase the likelihood of pesticide resistance?

The likelihood of pesticide resistance is significantly increased when there is continual use of pesticides from the same chemical class. This is because pests can develop resistance to a specific mode of action over time. When a particular chemical is used repeatedly, select individuals within a pest population may survive and reproduce, passing on their resistant traits to future generations. As a result, the effectiveness of that chemical diminishes, leading to a need for higher doses or alternative pesticides to maintain control.

In contrast, rotating between different chemical classes or using biological control as a complementary strategy reduces the pressure on any single mode of action, allowing for better management of pest populations and minimizing the likelihood of resistance development. Similarly, applying pesticides at recommended rates ensures that the chemicals are used effectively without causing undue stress to pest populations, further helping to prevent resistance.