Which of the following is not an integrated pest management (IPM) strategy?

The choice of applying pesticides at the first sign of a problem does not align with the principles of Integrated Pest Management (IPM). IPM emphasizes a holistic approach to pest control that focuses on prevention and management rather than immediate chemical intervention. The foundation of IPM involves monitoring pest populations, understanding their life cycles, and using a combination of various strategies to keep pest levels below economic thresholds.

In contrast, the other options represent key components of IPM. Excluding pests from environments is a preventive measure aimed at stopping pests from entering an area, while selecting pest-resistant plants reduces the likelihood of pest infestations. Furthermore, employing cost-effective actions at the right time is essential in IPM, as it ensures that resources are used efficiently and effectively to manage pest populations without over-relying on pesticides. This integrated approach minimizes the risks associated with pesticide use, including resistance development and environmental impact.