Integrated 
Pest 
Management 

Decision Making Tools for Farmers --
Coping with Pest Variability 

What Is Integrated Pest Management 

Integrated Pest Management (IPM) goes beyond calendar-based spraying of pesticides. It is a decision making process whereby growers select from a variety of tactics to keep pests below an economically damaging level, while minimizing environmental impact. Pesticides remain an important method of control, but IPM integrates other tactics where compatible including biological control, cultural practices, and the use of selective and environmentally friendly tactics which are called "biorational". This integration of tactics can be used to manage all categories of pests including insects, mites, weeds, diseases, nematodes and vertebrate animals. 

The essential ingredients of IPM are field monitoring or scouting, pest identification, and identifying and encouraging a pest's natural enemies. Growers use information gathered from scouting to select and schedule appropriate control tactics. In most field situations, this means observing and sampling at several sites and recording the data. This field record usually includes a map showing site location and sampling results. The grower now has a record of pest and natural enemy conditions at a particular point in time, a snapshot, which can be compared to previous and subsequent data. This forms the basis for pest management decisions. 

"Careful observation of diseases, insect pests, and predators is what IPM is all about. Regular monitoring allows for more efficient use of pesticides. Less trips are made through the orchard and with improved timing of application, pesticide expense is lowered. Fewer sprays also helps preserve natural enemies. IPM means having a working knowledge of the biology within your orchard." 

Tom Thornton, Cloud Mountain Farm
Apples
Everson, WA

Why Talk About IPM Now? 

It is no secret that fewer pesticides are available every year. One reason for this is that it has become expensive to research, develop, license, and market new pesticides, particularly for minor crops that represent a limited market. By using IPM, the pesticides we still have will be used less frequently, which gives pests fewer opportunities to develop resistance. This extends the effective life span of currently available pesticides. 

IPM makes good economic sense. Growers who reduce pesticide use through improved timing and elimination of unnecessary sprays save money. IPM also helps to reduce risk because with regular scouting you know what's happening in your fields. 

The 1993 Statewide IPM Report, which summarizes the activities and achievements of the Cooperative Extension IPM Program, estimates that over $667 million in reduced pesticide expenditures was attributable to implementation of IPM systems. Below is a table which includes some examples of economic benefits of IPM from this report. 

The Basic Elements of an IPM Program 

• Understand the biology of the crop or resource. 

IPM Monitoring Tools 

Most field monitoring for insect and mite pests involves directly counting pests and assessing damage. For example, in berry crops, spider mites are sampled by collecting sets of 10 leaflets from each of four or five sites within a field. Since mites are small, use a hand lens to count them accurately. The pest manager also looks for mite eggs and natural enemies such as predatory mites or the small Stethorus beetle. Counts are recorded at each site, and mites and mite predators are reported as number per leaflet.

Some insects, for example the adult black vine weevil, are impossible to count this way. Once disturbed, they quickly drop to the ground. These pests are counted using a drop sheet or beating tray, which is placed under the canopy. Shake the canopy to dislodge insects, which drop onto the tray and are counted. The sheet or tray must be a specified size. Sweep nets are also used to dislodge and count insects from plant foliage.

The most common sampling design is the random sample. Usually a minimum of four sites, chosen somewhat at random, are checked in each field. Results are recorded for each site along with a map showing the field and site location. This record provides the basis for decision making and can be referred to in later visits. Below is an example of a simple format used to record pest densities and observations in raspberries.

(Adapted courtesy of
The Good Fruit Grower)

Pheromone traps are 
another method of monitoring insects 

A variety of traps also are used to monitor insects. The most common is thepheromone trap which relies on a specific chemical attractant to lure individuals of the same species. Traps are used to monitor leafrollers in raspberry and codling moth in tree fruit in western Washington. Periodic counts of trapped insects determine whether a population is large enough to warrant control and helps growers time pesticide sprays to achieve maximum control. 

Weather stations help monitor environmental factors such as temperature, humidity, rainfall, and leaf wetness, factors that influence disease development. This information can be entered into a disease prediction model and is used to schedule fungicide applications. Such systems have aided managers in controlling late blight in potato and apple scab in tree fruit in the Pacific Northwest. 

The chart below illustrates the variation in spider mite populations in three different fields of Meeker raspberries during the 1995 season (Source: Braeside Consulting Inc.). 

"IPM helps reduce my pesticide expense by better tracking of pest populations. Many farmers aren't familiar with pest identification and are inclined to take preventative chemical measures that may not be necessary." 

John Clark, Clark's Berry Farm
Raspberries and Strawberries
Lynden, WA 

Deciding When to Control 

Decision-making in IPM is usually based on a combination of pest and beneficial population estimates, pest life cycle stage, crop stage and susceptibility, availability of and labeling restrictions on pesticides, personal field experience, and specific field history. Regular monitoring is the key ingredient in decision-making, because it provides information on: 

• Pest and beneficial population density and trends 

"The biggest benefit of IPM is that it allows me to time my sprays, which means better control and dollar savings. Regular scouting shows me there is variation between fields, and if the numbers aren't there, I don't spray. The challenge to further development of IPM is in finding alternative pest control methods that are cost effective and get the job done." 

Frank DeVries, Berry Acres
Raspberries
Lynden, WA 

IPM Control Options  IPM programs use four basic methods to achieve effective control in the least disruptive manner possible. These methods are: 

• Cultural Practices 

"IPM means considering all of my options for pest control. It may be a release of natural enemies for mite control, the use of a cover crop for weed suppression, or a conventional pesticide. It makes my day when we can use something that's safer for workers and the environment, and leaves no residue on the fruit." 

Brian Cieslar, Tri-Fruit
Raspberries, Strawberries, and Blueberries
Lynden, WA 

Summary 

IPM employs all appropriate control strategies to reduce pest populations below economically damaging levels while minimizing negative impacts on the environment. Most growers who have tried IPM, like it and are continuing to use an IPM approach. Benefits typically include dollar savings to the grower, an extension of the effective use period of pesticides, and protection of resources such as ground water from pesticide contamination. Regular monitoring is the key component of IPM and is the basis for improved decision-making regarding timing and selection of appropriate control strategies. The use of IPM will expand as more research into alternative methods is completed and as more people realize that it is a sensible, cost-effective approach to pest control. 

"Integrated pest management includes monitoring, identification, and recommending the best solution for grower profitability. Our field men monitor for insect pests before recommending a spray. That's their job; identification of the problem, and then choosing a pesticide that will do the job with the least effect on the environment. Our field men provide a solution that will maximize grower's returns." 

Rich Stipe, Whatcom Farmer's Co-op
Agricultural Product Dealer
Lynden, WA 

Further reading on IPM available from WSU Cooperative Extension 

• Extension Bulletin 1786 "Integrated Pest Management: Effective Options for Farmers" - 1995 

• "Orchard Pest Management, A Resource Book for the Pacific Northwest" published by Good Fruit Grower - 1993 

Geoff Menzies, M.P.M.
Washington State University, Cooperative Extension Nooksack IPM Project Manager, Whatcom County 

Craig B. MacConnell, M.S., Agent and Chair 
Washington State University, Cooperative Extension
Whatcom County   

Funded in part by:
Washington State Department of Ecology
United States Environmental Protection Agency
through Section 319 of the Clean Water Act
April 1996