The objective of an integrated pest management program is to manage pests and the environment in a manner that balances the benefits of selected control measures against their costs, the public health and welfare, and the impact on environmental quality. Three steps are involved in its implementation.
Determining the Action Threshold In commercial horticulture, profitable control is the goal of pest control. Some level of plant injury and/ or some presence of the pest must be accepted. The point at which the injury to the host plants or the number of pests present is unacceptable is termed the action threshold.
The action threshold signals the need for control measures to be applied, but the same signal does not apply to every situation. In greenhouse or nursery production, the threshold signal would sound when the economic profitability of a crop is threatened. In a landscape or golf course, there may be no danger of plant loss, but the appearance of key plants is marred, resulting in an outcry against the declining esthetics. In such cases the action threshold is reached when the appearance of the landscape falls below a level acceptable to viewers. Obviously, there is room for subjective variation when esthetics are the measure.
Measuring for Pest Presence The site and host plants must be checked regularly and methodically for the presence of pests. The monitor or scout must fully understand what pests are of concern, their life cycles, their appearance at different stages of the life cycle, and their time of greatest potential threat to the host plants. Monitors must also be able to recognize desirable or harmless insects and other agents. Monitoring requires immediate recognition of when the action threshold is near.
Selecting and Initiating the Proper Control Method For profitable control in an IPM program, there are numerous options, commonly used in combinations.
• use resistant varieties of host plants
• eliminate infected plants and/or alternate hosts
• cultural manipulation of the production site and environment
• biological controls
• chemical controls