What is Integrated Pest Management?

Integrated pest management (IPM) is an approach that uses a combination of pest management techniques in an organized program to suppress pest populations in effective, economical and environmentally sound ways.

IPM programs are being used to help make pest management more environmentally sustainable in many areas of our lives. The concept of IPM was first applied in agricultural systems. It is not new. In fact, some Canadian apple growers have been using IPM for over 20 years and many greenhouse vegetable growers have been using IPM in their crops since the early 1980s. Over the last decade, the concept of IPM has been increasingly applied to pests of all kinds, including weeds, insects and wildlife. IPM programs are now used in agriculture, forestry, gardens and landscapes, and for household and structural pests.

IPM is a process for planning and managing sites to prevent pest problems and for making decisions about when and how to intervene when pest problems occur. In an IPM program, pest managers use regular inspections, called monitoring, to collect the information needed to decide whether or not action must be taken. A key idea in IPM is that it is necessary to take action against pests only when their numbers warrant it, not as a routine measure. In most cases it is only necessary to suppress pest populations to non-damaging levels, not to eliminate them. If treatment is warranted, pest managers choose the most appropriate combination of control measures for the site.

IPM is highly adaptable, taking into account goals and preferences established for the particular situation, such as the purpose of the landscape and the level of damage that can be accepted. Experience has shown that IPM programs can be more effective and cost-efficient than other approaches to managing pests.

Prevention is the Key

Although treating pests is usually the focus of initial IPM programs, a well developed program emphasizes making changes in the management of the plants and design of the site to prevent pest problems from occurring. This includes protecting and attracting native beneficial species, such as insects and birds that keep pest populations in check. At times, this might even mean changing human activities as well.

Components of an IPM Program

When pests appear, the first step in an IPM program is correct identification of the problem. This is essential because most of the treatments must be tailored to a particular species. Once the species is known, information about the pest’s biology can be used to identify the weak points in its life cycle when suppressive measures will have the greatest effect.

The next step is monitoring pest populations and environmental conditions. This is crucial to a successful IPM program because it provides the information needed to make decisions about the timing of treatments and whether or not they are necessary. Most monitoring programs are based on a regular inspection for pests or signs of their presence. Some monitoring programs also look for natural enemies of pests, such as lady bird beetles, which can contribute to suppressing pest populations. Pest managers use a variety of methods, such as visual inspections, counts of insects caught in traps or sweep nets, or counts of weeds in turf, to estimate pest populations. Often, just by instituting a monitoring program pest managers find that they use fewer sprays.

The third component of an IPM program is determining the unacceptable amount of damage, or injury level, for a particular pest. While one aphid on a tree or a single weed in a lawn is not a problem, at some point, a population of pests may reach an intolerable level. The injury level depends on what part of a plant is affected and to what extent, the purpose of the plant in the landscape, the cost of the treatments and the cost of negative side effects, such as the loss of beneficial insects that might be controlling other pests.

Because plantings are often grown to provide pleasant surroundings, aesthetics can be important in setting an injury level. In an IPM program, the landscape manager takes into account the level of a pest population the users of the site can tolerate. The tolerance of site users for pests depends in part on personal taste and attitudes. For example, while some homeowners perceive clover as lowering the quality of their lawns, others value it’s drought resistance and contribution to soil fertility. Similarly, dandelions in a roadside ditch provide food for bees, but in fine turf they are considered a weed.

The fourth component of an IPM program is the action or treatment level. This is the time at which a particular treatment should be applied to deter pest populations from rising above the injury level. When using a biological control agent, the best timing of a treatment is often when the pest population is still low. This is because predators must be released early enough to give them time to reproduce and build up an effective population. For example, a parasitic wasp that attacks moth eggs must be released when the eggs are present, while a microbial spray that infects caterpillars is only effective when they are present. For chemical insecticides, the most cost effective timing is often just before insects reach the injury level because such sprays have an immediate effect.

The fifth component is the treatment. One or several treatment methods may be coordinated into a management program for a target pest or for the entire complex of pests. Examples are:

• biological controls, such as predatory and parasitic insects, beneficial nematodes and microbial controls;
• physical and mechanical controls, such as barriers, screens, traps and mulches; also flame, infra-red and hot water weeders;
• cultural controls (or preventative methods), such as resistant varieties, crop rotation, pruning methods, plant nutrition and sanitation measures;
• chemical controls, including synthetic and naturally derived pesticides, insect growth regulators and other products.

Where pesticides are used, they should be chosen for compatibility with IPM practices. For example, narrow spectrum products could be used in spot applications to avoid harming beneficial species or sensitive vegetation.

The sixth component is evaluation of the pest management program. Follow-up monitoring or inspections may be necessary to find out how successful an IPM program has been. It is essential to maintain and review records to determine what worked, where improvements should be made, and to determine costs and benefits.

A final word…

IPM programs depend on the participation and support of many people. Pest control technicians and other authorized persons who carry out monitoring, maintenance and treatment activities will make the program work when they understand the principles of IPM, what their roles are, and how they can contribute to the program’s success. Communicating with customers and clients is essential to understanding what they want the programme to achieve and so that the pest manager can develop a program that meets their goals and expectations.