Preventative or pre-emptive tactics are the first line of defense against potential pests. However, other management options, such as chemical treatment, may be used when crop injury or loss is determined to be significant and other methods have not been sufficient to suppress pest injury below acceptable levels.

Control of pests is rarely, if ever, 100%. Rather than expecting 100% control of pests, the aim in an IPM program is to achieve a control level that results in a clear benefit. For a commercial tomato grower this would be measured by the economic benefit that results from the use of control tactics (e.g. The estimated economic loss from pest injury to the crop would have been greater than the cost of implementing controls.). For a homeowner pondering whether controls should be taken against a pest on a landscape ornamental, the benefit is more difficult to measure.

In order to foster an IPM approach, certain steps and questions should be addressed. The more information that the grower has about the pest, the host plant, and the environment, the better equipped s/he will be to develop a successful IPM strategy. Here are steps and some examples of the types of questions that should be asked:

• Identify the pest.
  • Don t make assumptions about what the problem is. Take time to definitively identify the problem or pest, particularly before applying a chemical control. This may require input from an expert (i.e. extension agent, diagnostic lab, crop consultant).
  • The extra time required to correctly diagnose the problem will be well worth it accurate diagnosis is essential to implementing an IPM program.
• Is a control action warranted?
  • Is the health or value of the plant/crop threatened or is the problem a minor cosmetic problem?
  • Have populations of the pests or incidence of the pest reached a level where a control action will be of benefit (e.g. economically)?
  • Are environmental conditions favorable for development of the pest or are the environmental conditions likely to inhibit development of a pest problem?
• Learn about the lifecycle and biology of the pest and the host plant to identify control strategies to reduce or avoid pest populations and to identify the best timing of control tactics if they become necessary.
  • When is the pest most affected by control tactics?
  • How does the pest reproduce and move? Does it have alternate hosts (e.g. weeds adjacent to the planting, etc.)?
  • What environmental conditions favor development of the pest or what environmental conditions deter development of the pest?
  • Is the plant at a vulnerable stage in its lifecycle where a control action will be worthwhile or is the plant at a developmental stage that will not be affected in any significant manner by the pest?
• Identify prevention and avoidance tactics and implement them into an overall IPM strategy (i.e. before there is a pest problem) to avoid occurrence of a pest problem or to limit injury from pests.
  • Use pest-resistant plants, rouge out alternate hosts, keep plants healthy and stress-free (i.e. less prone to pest attack), practice crop rotation, etc.
  • If a pest does become a problem despite preventative tactics, identify management tactics to keep the problem at an acceptable level.

• See the PAMS Approach to Practicing IPM and The IPM Tactical Toolbox for more.

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Virginia Cooperative Extension - Virginia Agriculture & Experiment Station