In IPM, what is the role of monitoring pests and thresholds?

• A. Do not monitor
• B. Monitor pests and apply controls only when thresholds reached
• C. Always apply pesticides regardless
• D. Monitor pests and treat immediately

Answer: (B)

In IPM, decisions about control are driven by what you’re finding in the field, not on a calendar. You scout or monitor to know how many pests are present and whether their level is likely to cause economic damage. An action threshold is the point at which pest populations (or damage they’re causing) suggest that not taking action will likely result in unacceptable harm to the crop. When monitoring shows pest levels are below that threshold, you avoid applying pesticides. If they reach or exceed the threshold, you choose an appropriate control, aiming for the least disruptive method and the most targeted option. This approach helps save money, protects beneficial organisms, reduces pesticide resistance, and minimizes environmental impact.

Choosing to monitor and apply controls only when thresholds are reached is preferable to spraying without regard to pest levels, or to spraying all the time. Treating immediately without reference to thresholds can lead to unnecessary applications, higher costs, and more risk to non-target organisms.