Which of the following is considered a last resort method for pest control?

Chemical control is viewed as a last resort method for pest management primarily because of its potential impact on the environment, non-target species, and human health. When pests become resistant to chemical pesticides or when these chemicals disrupt the ecosystem, resulting in negative consequences, they should only be employed after exploring other control methods.

The use of biological control, which leverages natural predators or parasites to manage pest populations, and mechanical control, which involves physical barriers or traps to remove pests, are often implemented first due to their reduced risk to non-target species and less harmful environmental effects. Integrated Pest Management (IPM) embodies a holistic approach, combining various strategies to minimize pest damage while considering economic, environmental, and health factors, typically emphasizing non-chemical methods before resorting to chemicals.

This hierarchy of pest control strategies underscores why chemical control is reserved for situations where other methods have failed and pest populations are threatening crops or ecosystems significantly.