What is an action threshold in turfgrass IPM?

• A. The pest density at which action must be taken to prevent the pest from reaching the economic injury level.
• B. The maximum pest density observed in a season.
• C. The level of cosmetic damage allowed before action.
• D. The time to apply pesticides after pests are detected.

Answer: (A)

Action threshold in turfgrass IPM is the pest density or level of pest activity at which you should begin control measures to prevent economic damage. It’s the proactive decision point used to stop pests before they reach a level where costs exceed benefits.

This threshold sits with the economic injury level, which is the point where pest damage equals the cost of control. In practice, the action threshold is set lower than the EIL to allow time for scouting, decision-making, and treatment, reducing the risk of economic loss. Thresholds are often specific to the pest, turf type, value of the turf, and available control options.

It’s not just the maximum pest density observed in a season, nor the level of cosmetic damage you’re willing to tolerate, nor simply the time to apply pesticides after pests are detected. Those are not proactive decision points tied to preventing economic injury.