Action thresholds refer to the number of pests or level of pest damage before requiring action. This is done to prevent damage from exceeding tolerable levels.
For some pests posing an immediate health hazard, the action threshold will be one (for example, a single yellow jacket in a classroom). For others, such as houseflies in the dumpster area, a higher number may be more tolerable before action is needed.
For some pests, action may be needed before pests or pest damage appears. In those cases, an action threshold may be defined as a set of conditions, e.g., a plant is at a susceptible stage for a disease under the right weather conditions.
Including a written action threshold in an IPM plan presents a clear statement of intentions before a pest event occurs. This guidance can prevent under or over-reactions to pest problems by those called to respond to the situation.
