Theory of IPM

Integrated Pest Management (IPM) is a decision-making process that uses all available pest management strategies to prevent economically damaging pest outbreaks while reducing risks to human health and the environment. IPM is a continuum along which there are many levels of adoption. It can range from simple monitoring to properly timed pesticide use all the way to "biointensive" IPM in which there is total elimination of synthetic pesticides such as in organic farming. {48}

GOALS OF IPM {48}

IPM in schools protects human health by: 

• Suppressing pests that may carry diseases 

• Reducing pest damage

• Reducing environmental pollution 

• Reducing human exposure to pesticides 

In an IPM program, treatments are not made without first monitoring the situation and evaluating whether a pest is likely to be a problem. In schools, there are three injury levels used to determine when to implement pest management strategies: 

• Economic Injury Levels determine the level of damage to a structure or plant. Once damage has reached a level that is severe enough to cause economic loss, control should be implemented. An example would be a termite infestation that requires replacement of some structure.

• Aesthetic Injury Levels, on the other hand, are the levels at which a pest becomes a nuisance for whatever reason. Perhaps this is the level at which an aphid population drops enough honeydew onto a picnic table beneath a shade tree to disturb the people using the table. Aesthetic injury levels are subjective, that is, what is tolerated by one person may not be tolerated by another. 

• Medical Injury Levels are used whenever a pest can cause illness to humans either directly or indirectly. Rodent-transmitted diseases would be one example. 

COMPONENTS OF AN IPM PROGRAM {48}

All IPM programs, regardless of the situation, share the same components. 

• Monitoring the pest population and other relevant factors

• Accurate identification of the pest

• Determining injury levels and thresholds that trigger treatments

• Timing treatments to the best advantage

• Spot-treating for the pest

• Selecting the least-disruptive tactics

• Evaluating the effectiveness of treatments to fine-tune future actions

• Educating all people involved with the pest problem 

Each of these components will be discussed throughout this manual when discussing pest management in each of the various situations. 

IPM IS A DECISION-MAKING PROCESS {48}

IPM requires continuous assessment of a situation. There are four key questions that must be answered before implementing any management strategy.

• Is treatment necessary? The mere presence of a pest doesn’t necessarily warrant treatment. Sometimes a fairly large population of pests can be tolerated while other times the presence of a single pest is intolerable. In addition, the determination of treatment will vary among individuals. 

• Where should the treatment take place? Pest managers must look at the whole system to determine the best place to solve the problem. Apply treatments where the actions will have the greatest effect. In order to do this you must completely understand the biology and behavior of the pest at hand. 

• When should action be taken? Timing is very important. There are optimum times in both insect and disease life cycles when they are most susceptible to control. Again, it is very important to understand the biology and behavior of your pest. 

• Which strategies should be used? IPM uses a multi-tactic approach. Because biological systems are complex, management strategies must also integrate several strategies. Rarely will a single tactic solve the problem for long. Implementing an IPM program means taking a "whole system" or ecosystem approach to solve a pest problem. You must think of both the living and non-living components when determining which approach to take. Each component has an impact on every other component. This manual will help you look at the specific pest problems you are likely to encounter using a system approach. It will also help you develop an integrated management plan to deal with the problem. 

There are four control strategies that can be used in developing an IPM program. 

• Cultural control uses fertilization, irrigation, site selection, plant selection and/or sanitation to prevent pest problems in the first place 

• Physical control is another preventative strategy. It includes screens or other barriers, temperature and humidity modification, traps, physical repellents, and hand removal of weeds. 

• Biological control uses beneficial organisms (insects, bacteria, etc.) to control pests. IPM programs seek to conserve naturally occurring beneficial insects by providing them with food and shelter and not using broad-spectrum insecticides that will inadvertently kill the beneficial insects. 

• Chemical control is used only after all other suitable control strategies are not fully effective or practical. Always use chemicals in an environmentally responsible manner and in accordance with the label.