Action thresholds are often expressed as?

• A. The value of the plant in the landscape.
• B. The number of pests per unit area.
• C. The number of diseased plants.
• D. The amount of the pesticide needed.

Answer: (B)

Action thresholds specify when to start control based on how many pests are present in a given area. They are expressed as pest density per unit area (for example, pests per leaf, per plant, or per square meter). This density-oriented trigger lets you act before damage becomes economic, using scouting data to decide when intervention is warranted.

The other ideas don’t fit because the threshold is not about how valuable the plant is in the landscape, nor about how many diseased plants there are, nor about how much pesticide to apply—that last item is the application rate, not the trigger.