Introduction to Integrated Pest Management (IPM)
for "Urban" Landscapes

Copyright 1994, 1995, 1996 IPM Associates, Inc., all rights reserved

NOTE: The original version of this document is supplemented with graphics which are not included in this file. The graphics will be included in a future version of this document for on-line viewing. However, the complete hard copy version with graphics is available for a nominal shipping and handling charge. If interested, send a request to the IPMPA (see end of document to find out how to contact IPMPA).

Table of Contents

1.0 The Urban Pest Management Complex

Because IPM is conceptually quite simple (IPM is a decision making process to determine if, where, when, and how pest control practices should be applied) it would appear to be an easy task to provide IPM training to field personnel and let them go to work.

And, in the short term, modification of direct pest control practices (such as reducing pesticide use through spot spraying strategies and replacing undesirable chemicals with more environmentally friendly materials) can provide valuable benefits in reducing the use of pesticides.

However, these types of approaches only address existing pest problems; they do not alleviate long-term pest control requirements and the need for treatments, particularly those that involve routine pesticide use. This point underscores the importance of developing management strategies that address the causes of pest problems.

Indeed, when carefully examined, it is evident that indirect factors (particularly site design and construction practices, and lack of adequate cultural maintenance practices) are a great influence on the occurrence of many of the most common pest control and vegetation management problems found in urban environments.

While some of these problems were created prior to the availability of modern pesticides, many public facilities and landscapes in cities were developed after the advent of these chemicals and with the assumption that they would be a principal component of the maintenance program for the site. As a result, many of the pest problems and much of the need for pesticide use in urban landscapes have been "built-in".

These impacts were of course unintentional and resulted from the design and maintenance standards of the time, including general acceptance of widespread chemical pesticide use.

Changing these circumstances requires: 1.) development of appropriate designs for future facilities and landscapes, and, 2.) where cost-effective, retrofitting of existing facilities/features to reduce dependency on pesticides. It also requires prioritizing (in the budget process as well as the maintenance process) the use of cultural maintenance practices for the purpose of optimizing the health and vigor of desirable vegetation, since this facilitates resistance to attacks by pests and reduces the need for control treatments, particularly the use of pesticides.

These requirements involve several layers of operational, administrative, social, and political responsibility. Many links between people and activities must be identified and effectively coordinated to achieve program success.

In addition, the implementation of an urban IPM program is further complicated by the variety of biological and physical features and site conditions that are found and must be maintained in the intensively developed urban environment (i.e., the diverse biophysical environment of the urban pest management system: e.g., golf courses, sports fields, horticultural displays, streets and roads, tennis courts, areas of interlocking pavers, shrub beds, parking lots, wetlands, lakes, median strips, rose gardens, aesthetic lawns, rights-of-ways, natural areas, street trees, running tracks, playgrounds, bikepaths, trails, greenhouses, nurseries, walkways, drainages ditches). Compounding this biophysical diversity is the need to establish and provide various levels of maintenance to address the aesthetic and functional service of each site and/or feature.

Figure 1 is a simple view of the layers of biological, physical, administrative, social, and political layers that surround pest management problems in urban settings.

2.0 What Is IPM?

Implementation of an urban IPM program is enhanced by an understanding of the philosophy, components, and process of the integrated pest management system.

2.1 Definition of IPM

IPM is a pest management system designed to provide long-term management of pests, not temporary eradication of them.

This is reflected in the numerous definitions that have been developed for IPM, including the one prepared by the U.S. Environmental Protection Agency for its publication, IPM for Turfgrass and Ornamentals:

IPM is the coordinated use of pest and environmental information with available pest control methods to prevent unacceptable levels of pest damage by the most economical means with the least possible hazard to people, property, and the environment.

The goal of IPM is to manage pests and the environment so as to balance costs, benefits, public health, and environmental quality. IPM systems use all available technical information on the pest and its interactions with the environment. Because IPM programs apply a holistic approach to pest management decision-making, they take advantage of all appropriate pest management options, including, but not limited to pesticides. Thus IPM is:

- A system using multiple methods.
- A decision-making process.
- A risk reduction system.
- Information intensive.
- Cost-effective.
- Site specific.

The following definition of IPM was developed as part of a Pesticide Management Program, B.C. Environment stakeholder process working toward provincial guidelines for facilitating comprehensive implementation of IPM throughout British Columbia, Canada:

Integrated Pest Management, or IPM, is an ecological approach to suppressing pest populations in which all available necessary techniques are consolidated in a unified program, so that pests are kept at acceptable levels in effective, economical and environmentally safe ways. Because pest problems are often symptomatic of ecological imbalances, the goal is to attempt to plan and manage ecosystems to prevent organisms from becoming pests. [Emphasis added.]

2.2 Evolution of Urban IPM

IPM was developed in the early part of this century in response to the need for cost-effective control of the boll weevil, which was damaging cotton crops in the southeastern United States. At that time, pesticides were not yet well developed. To control this pest, it became clear to entomologists that a detailed understanding of the insect and its relationship to its environment, particularly factors that affected the growth and spread of weevil populations, was necessary so these factors could be manipulated to minimize the occurrence and level of weevil damage.

This effort was successful, but it wasn't until the 1940's and 1950's that entomologists formalized the philosophy and structure of IPM to facilitate its use in modern agriculture due to concerns about the rapidly growing reliance on pesticides. These concerns were generated by the negative impacts of pesticides on non-target organisms, particularly pest predators, but other desirable insects as well (bees, butterflies, etc.), and the resurgence of pest populations following their initial control by the application of pesticides.

As technically sophisticated products were developed, pesticides became agriculture's dominant pest control tool. Seeing the opportunity to emulate this success, chemical companies quickly developed pesticides that could be used in other pest management settings. Within two decades, these chemicals were being applied in enormous volumes to industrial settings, rights-of-ways, forests, and ornamental landscapes. The low application costs and effective results of pesticides promoted this growth and created an atmosphere where non-chemical approaches to pest management were discounted as unnecessary and uneconomical. Research of these important methods languished. (Source: Flint and Van den Bosch, 1981)

With proper care in application that minimized the occurrence of obvious negative health effects and environmental impacts, little concern was generated about potential problems from the use of pesticides. And for many years, little evidence was available to validate concerns that did surface. Even today, in the face of mounting scientific data about the adverse environmental and human health impacts of long-term, low-dose exposure to pesticides, the debate continues.

Nevertheless, small groups of dedicated professionals continued to examine and expand the application opportunities of IPM. As pesticide use in urban settings became ubiquitous and public concern escalated, this work included the development of strategies and methods to implement IPM in these environments.

While not fully developed to the point where entire programs can be borrowed "off-the-shelf" by one community from another, urban IPM systems have demonstrated their cost-effectiveness and reliability in reducing pesticide use. This has prompted numerous communities to expend considerable effort to develop and implement an IPM program for use in managing their public lands.

2.3 IPM Philosophy

IPM in theory and practice is guided by an established set of principles:

IPM is an ecologically sophisticated management process.
IPM programs utilize an ecological approach to pest management that employs extensive knowledge of individual pests and their relationship with their environment. This holistic view of the pest management system is essential in managing the variety of factors that influence the development of pest problems.

By comparison, conventional pesticide-based programs focus on the individual pest and its control with little regard to the ecological relationships of the pest and its environment.

IPM is information intensive.
IPM decisions depend on detailed information about a variety of important factors such as: pest life cycles, site conditions where pests are located, the maintenance history of individual sites or features, previously applied pest control techniques, the presence of predatory agents. An IPM program's database is one of its major assets and requires a collection and processing system so this information can be used effectively for implementing pest management activities, for evaluating the program, and for developing program improvements. For large scale, complex urban environments, a computerized information management system is needed to handle the amount and diversity of information required for an effective IPM program.

Conventional pesticide-based programs emphasize identification of the pest and its optimum control method. Little attention is given to gathering information related to pests or their likely cause. Treatment records are generally maintained and used only to meet regulatory requirements concerning pesticide applications.

IPM employs all available pest control methods.
The integrated use of multiple management options is a key to the cost-effectiveness of IPM. While permissible, pesticide use is minimized through development and application of other pest management methods. In addition, careful evaluation and selection of pesticide materials is done to promote maximum utilization of products that are least toxic to non-target organisms and the environment.

Conventional pesticide-based programs have relied principally on only one method of treatment for effective pest control.

IPM mitigates negative environmental impacts.
IPM minimizes pesticide use and other environmentally disruptive pest control treatments to promote environmental quality, preserve the natural ecosystem, and reduce undesirable effects on non-target organisms.

Conventional pesticide-based programs have emphasized treatment timing and equipment technology to minimize non-target impacts.

IPM requires appropriate standards for pest control.
IPM promotes tolerance of non-damaging pest populations and appropriate thresholds for pest control that reduce unnecessary treatments. This enhances program efficacy and minimizes the application of undesirable treatments (e.g., pesticide use).

Conventional pesticide-based programs emphasize treatment as soon as potential pests are observed or pre-emptive chemical treatments in anticipation of potential pest problems. Tolerance thresholds for the presence of pests or pest damage are very low; frequently thresholds are set at zero tolerance levels (i.e., one is too many and requires direct treatment).

Figure 2 is a simplified view of the relationship between the potential need for pesticide use and tolerance for the presence of pests and their impacts. Implementation of an IPM program that incorporates appropriate maintenance standards and tolerance levels can significantly reduce the potential need for pesticide use. Tolerance of pests will vary by site and feature type.

IPM emphasizes prevention of pest problems.
Effective utilization of IPM design and site modification practices reduces the need for pest control treatments, helping minimize pesticide use requirements and making resources available for other maintenance priorities. In turn, these benefits promote environmental quality and facilitate improvements in the aesthetic quality of the resource system. It also reduces the life-cycle maintenance costs of specific landscape features (i.e., costs of maintenance over the entire service life of a facility or feature: e.g., shrub bed, sports field, fenceline). These savings should be calculated in determining the cost-effectiveness of instituting IPM design and site modification practices.

Conventional pesticide-based management programs only provide short-term control of pest problems. Pest populations continue to develop on previously treated sites or features (and must be treated again) because no action has been taken to prevent their recurrence. Repeated applications of pesticides are a burden on the maintenance of environmental quality. In addition, expenditure of maintenance resources without attempting to prevent the recurrence of pest problems is inefficient. In analyzing the costs and savings involved with pest management, it is essential that all costs be valuated over the life of the feature or facility being maintained.

IPM promotes the use of methods that provide long-term pest control.
Like IPM practices that prevent pest problems, those methods which provide long-term pest control benefits also enhance program efficacy, promote environmental quality by reducing the need for undesirable treatments such as pesticide use, and enhance the aesthetic quality of resource system components.

Conventional pesticide-based management programs provide only short-term pest control and, in the long-term, potentially involve negative impacts on program efficacy and environmental quality. The "pesticide-treadmill" is a well-documented phenomenon.

2.4 IPM System Components

All IPM systems are composed of the same basic components. The details and application of these components will vary with the setting, focus, and other factors that drive a particular IPM program.

Effective development and implementation of these components are the principal requirements in getting an urban IPM program on-line in a manner that will provide the benefits of IPM while achieving the organization's goals and objectives for pest management.

The recognized components which are used to build and operate an IPM program include:

  1. A structured decision making process,
  2. Detailed, interdisciplinary knowledge and information,
  3. Comprehensive management, communication, and operational systems,
  4. Appropriate thresholds for maintenance and control activities,
  5. A monitoring system,
  6. IPM strategies and prescriptions, and
  7. Program evaluation and modification.

    (After Flint and Van den Bosch, 1981, 1983; and BIRC 1988)

These components are used to build and operate the IPM program which is illustrated in the simple diagram in Figure 3.

The IPM Process
IPM involves a structured decision-making process that embodies the philosophy and the components of the IPM system. The many aspects involved in each step in the IPM process are discussed below. Application of this process will lead practitioners through the basic steps required for implementation of IPM.

  1. Documentation of Pest Control Problems
    (Identification of the nature, location, scale, and intensity of pest problems.)

  2. Establishment of Decision Levels
    (Establishment of injury and action thresholds; see "Appropriate Standards".)

  3. Review of Options for Treatment
    (Research and development of treatment strategies, methods, tools, etc.)

  4. Determination of Operational Requirements
    (Application procedures for tools, equipment, materials, methods; timing and frequency of treatments.)

  5. Development of Management Plans
    (Development of general and site specific short and long-term treatment strategies and prescriptions; documentation of management decisions.)

  6. Communication/Notification of Management Plans
    (Within the organization, with policy makers and the public, with pertinent regulatory agencies.)

  7. Implementation of Management Plans
    (Timely and effective delivery of strategies and prescriptions.)

  8. Monitoring/Recording of Control Actions and Impacts
    (On-going documentation of program implementation and its results.)

  9. Analysis and Evaluation of Monitoring Data
    (Critical review of monitoring information.)

  10. Program Modification
    (Program improvement based on evaluation of IPM system components, decision processes, and monitoring data.)

    (IPM Associates, 1993; After Greg Prull, 1984)

A great deal of interdisciplinary knowledge is necessary for developing and implementing an effective IPM program for complex urban environments. Generally, this information can be classified into four areas of need:

Pests and Ecosystems
IPM managers must understand pests and their requirements and relationships with their physical environment (soil, air, water, temperature, etc.), and their interactions with other living organisms with which they are associated (e.g., other pests, predators, plants, etc.).

Integrated Pest Management
This includes not only a thorough understanding of basic IPM system philosophy, principles, and components, but also the information found in a wide variety of other disciplines that can bear directly on the implementation of an IPM program. In complex urban environments this may include technical information about landscape design, building, and construction; entomology; plant pathology; horticulture; sports fields (design, requirements for maintenance and play, etc.); road construction and maintenance; soils; irrigation systems; weed ecology; geotextiles; landscape maintenance equipment and tools; chemicals (pesticides, fertilizers, toxicology); meteorology; cost analysis; aquatic vegetation; computer systems; arboriculture; native plants; turf management; forestry; etc. The list is extensive and limited only by the specific circumstances of the management program.

IPM Strategies and Practices
Pest management practices must be integrated together into a holistic, total management program (see Fig. 11) that includes short and long-term approaches for successfully managing the pest. A "little of this" and "some of that" approach to designing IPM prescriptions is not genuine integrated pest management. IPM prescriptions are carefully organized pest management methods, derived from IPM knowledge using data from monitoring activities and evaluations of related pest control treatments, with decisions for action based on defined thresholds of unacceptable damage that the pest is likely to cause.

Operational, Administrative, Social, and Political Systems
IPM programs are designed and applied within a set of layers that affect its implementation. These layers include: the pests, the "pest/resource complex" (diverse ecosystems and physical features), maintenance operations, administrative policies and budgets, politicians and the general public, and governmental policies and regulations (see Figure 1). IPM managers must identify and coordinate the needs of the IPM program within the context of this complex of relationships, requirements, and constraints.

A Management System
The management system is the mechanism for administering and implementing the IPM program. It provides the mechanisms and capacity to get the work done.

Key elements of this system include administrative guidelines, communication procedures, and implementation tools:

Uniform Approach
Development of a "common vision" is essential for effective and efficient implementation of IPM. It provides a basis for approaching pest management requirements as a team, with members of the team working together to fashion feasible and effective answers to the complex problems they face. Ideally, operational as well as administrative staff are included in the preparation of the written IPM management plan. This gives a sense of program ownership to the operations staff, enhancing staff morale and their pride in the maintenance program. It also provides the administrative staff with an in-depth understanding of the field requirements and impacts of implementing the IPM program. Maintenance standards, IPM prescriptions, and a Maintenance Management Information System are three key areas of an IPM program that provide excellent opportunities for administrative staff and field personnel to work together to develop a unified approach to vegetation and pest management.

Physical Inventory
An inventory of the resource complex and its physical features is critical for identifying key management requirements and pest problems (e.g., pests and features that require routine applications of pesticides or those that involve extensive labor and materials requirements). Information in the inventory is used to develop both short and long-term plans to address these needs. Without the inventory, plans for reducing pesticide use and maintenance requirements cannot be accomplished efficiently and economically. As a result, the IPM program is limited to reactive pest management practices, much like conventional pesticide-based programs. Implementation is then much less cost-effective than is potentially achievable through appropriate planning, budgeting, and scheduling.

Good communication and the careful timing of activities are also essential for effective and efficient IPM program implementation. Of particular need is the requirement to identify and coordinate maintenance and development activities related to specific "windows of opportunity" that occur during these processes. For example, mowing is an activity that can be deferred for a week or more without significant impact on many areas of turf. Likewise, spreading of fertilizer can often be delayed without negative impacts. However, the application of biological agents or pheromone traps to control specific pests or the installation of a mowing strip along the walls of a new building are very affected by timing. Missing the opportunity to complete IPM strategies or practices within specific timeframes will reduce program efficacy, delay benefits from their implementation, and perhaps lead to an incorrect assumption that the IPM program itself is ineffective. Where this involves the implementation of IPM design principles, the long-term effects on the IPM program can be profound.

Staff Training
Because IPM is an ecologically sophisticated process that requires professional expertise in vegetation and pest management, it demands trained field personnel that are knowledgeable about:

  1. Ecological interactions and relationships among vegetation and pests;
  2. Potential tools and materials that can be used to effectively manage vegetation and pests by manipulating environmental conditions; and
  3. Correct timing for implementing specific management practices relative to vegetation and pest biology.

Due to the complex nature of urban biophysical environments and the dynamic status of knowledge about IPM methods and tools for vegetation and pest management, it is important that field personnel receive regular IPM training. Educational and career opportunities in IPM will enhance crew professionalism, their knowledge of current vegetation and pest management practices, and their stewardship of managed landscapes.

Tools and Materials
IPM practitioners must also be equipped with a wide range of tools and materials in sufficient quantity and at specific times of the year to implement management practices in a manner that optimizes their cost-effectiveness (i.e., windows of opportunity for managing vegetation and pests are often narrow and occur only once per year; therefore, timing of practices is critical for their success and efficiency and must be facilitated by access to the proper tools and materials at precisely the time that action is most appropriate).

To this end, it is important to analyze the costs of IPM training, tools, and materials in a long-term manner (i.e., life-cycle costing). While skimping on these program components in the short run may appear economical, in the long run they actually add significantly to the costs of vegetation and pest management.

Appropriate Maintenance Standards
Standards identify the priority and level of maintenance that specific sites, facilities, or features receive. In turn, these factors determine the type of and extent to which pest management activities are implemented in these areas. Most resource complexes include a range of maintenance priorities and standards that reflect the type of resources involved and their importance to the community.

IPM programs promote the establishment of appropriate maintenance standards to reduce the need for pest management treatments wherever possible. Unnecessary treatments are not cost-effective; and some, pesticide use for example, have the potential to also pose unnecessary risks to human and environmental health.

Appropriate maintenance standards are determined through two processes - objective and subjective:

  1. Objective data about known pest problems (e.g., the type of damage created, the rate at which damage occurs, the targeted areas where problems exist, available control methods) are used to determine potential or actual levels of damage and intervention points necessary to control or prevent damage.
  2. Subjective opinions of experts and the community are used to develop aesthetic guidelines for determining acceptable pest and damage levels.

Information from both of these processes (the hard data and the aesthetic values) are interrelated and can be developed concurrently.

The successful development of IPM program standards depends upon the participation and coordination of all stakeholders.

Figures 4, 5, and 6 illustrate the practical application and relationship of maintenance standards and treatment thresholds in an IPM program. Each diagram indicates:

  1. Changes in a pest population over time.
    Pest populations are naturally dynamic and rise and fall without management intervention. However, when their growth results in unacceptable impacts they must be controlled.

  2. Injury and Action Levels.
    The upper line represents the Maintenance Standard for a specific feature (e.g., shrub bed, road, lawn, sports field) - in classic IPM terms, this level of pest development is called the Injury Level. Undesirable pest impacts (e.g., aesthetic, physical, economic) beyond this point are not acceptable. The lower line represents a pest population level which triggers the onset of proactive measures to control the population before it can cause damage that exceeds the Injury Level (i.e., the Maintenance Standard). In classic IPM terms, this level of pest population development is called the Action Level.

  3. Treatment Applications
    Reductions in the level of the pest population occur at points where an IPM treatment is applied. In Figure 4, after treatment the pest population falls below the Action Level and remains there. In Figure 5, the pest population recovers quickly from the first IPM treatment and exceeds the action threshold again, initiating a second treatment. Following this control, the pest population declines and remains below the Action Level. In Figure 6, the pest population remains at low levels, well below the action threshold; therefore no control treatments are required.

  4. Allowable Level of Damage (ALD)
    The ALD is similar to the Action Level but represents a measure of damage rather than the size of the pest population. It can be used in place of the Action Level when pest populations are difficult to monitor or with pests for which it is difficult to correlate the size of the pest population with the amount of damage that is occurring. The ALD can be difficult to establish due to its subjective nature. As with maintenance standards, stakeholder participation is essential in setting allowable levels of damage.

  5. Monitoring
    Monitoring involves routine observations of the resource complex to determine current conditions and the need for pest management treatments. While pest populations and their damage are the primary concern of monitoring, it is important to review all factors that influence the need for pest management to establish action plans for appropriate maintenance activities. In Figures 4, 5, and 6, monitoring is a background operation that is assessing pest population levels so necessary control treatments can be applied when the Action Level or ALD is exceeded.

The establishment of appropriate standards is one of the most difficult aspects of implementing urban IPM for two principle reasons: 1.) it involves aesthetic values which are subjective in nature and variable according to individual views, and 2.) it requires coordinating the roles and responsibilities of many of the groups and individuals in the urban pest management complex (see Figure 1). The principal issue involved in this area of program development is who decides what level of quality and service is appropriate in the maintenance of public lands? Factors involved in this process include:

The preventive maintenance approach embodied in IPM facilitates reductions in pest management requirements. This improves program efficacy and permits resources to be applied to further investments in preventive maintenance or to deferred maintenance requirements. Both lead to improved resource quality without additional cost. A major requirement of this approach is labor and material cost data concerning the level of maintenance and amount of pesticide use necessary for specific sites and features. Of critical importance is the identification of "key pests" that are associated with high maintenance costs and routine pesticide use.

Figure 7 is a simple diagram that illustrates the favorable impact of IPM on maintenance costs and site quality. Pesticide-based landscape management programs involve a range of costs and standards (represented by line A). Implementation of IPM is often viewed as potentially negative, reducing landscape standards without reducing, or perhaps even increasing, maintenance costs (B). However, through pro-active use of a full range of mitigative measures, IPM can actually be used to improve landscape quality without increasing maintenance costs (C) (See also discussion of Figure 12).

Establishment of appropriate and effective maintenance standards may be accomplished through an advisory committee that is composed of administrative and operational staff and personnel as well as concerned citizens. This approach has worked well for many organizations that have successfully developed IPM programs.

Such a group may be temporary or more long-term and provide a review and recommendation function for other important aspects of the IPM program, including for example: management goals and objectives (in general or for specific sites or features); controversial practices (e.g., pesticide use, tree removal); and design or development practices for new or rebuilt facilities.

A Monitoring System
Monitoring is a critical element of IPM programs. It involves regular inspections of areas and features where pest problems might occur to provide information for determining if, when, where, and how pest management practices should be implemented. Once treatments have been applied (cultural as well as control practices), monitoring is done to record the results of those treatments.

Over time, as monitoring results accumulate, patterns in the occurrence of pests and the results of applied pest management practices become evident. This information can then be used to evaluate and then improve the pest management program. Figure 8 is a simple diagram illustrating the use of monitoring in an IPM program.

A monitoring system should be developed using an organized approach that will identify priorities for pest management, provide information for developing short and long-term pest management strategies, indicate the optimum timing to implement pest management practices, and reveal factors that influence and must be coordinated to effectively resolve pest management problems - including those that may not be obvious (e.g., design), or necessarily in the control of the pest management program (level of use of sports fields).

Of primary importance is the need to identify key pests - generally considered to be those that: create unacceptable safety hazards, cause the most economic or aesthetic damage, require the most labor and material resources, cannot be adequately controlled by the current management program, involve the largest amount or routine application of pesticides, generate chronic complaints by the public. Key pests can be identified using staff experience and records of past management practices. This process and the baseline information collected by monitoring will highlight data gaps in knowledge that is needed to develop effective IPM strategies and practices for key pests, and it will indicate what labor and material information is necessary to facilitate evaluation of the cost-effectiveness of applied management practices.

A monitoring system should be designed to collect only the amount and type of information that is necessary and useful for the IPM program. Gathering unnecessary information is not cost-effective or practical for managing pest problems or for the collecting, recording, and handling of monitoring data. Depending on the resource being monitored (e.g., sports field, pavement, shrub bed, tree), monitoring may only need to involve information about the location, type, and extent of a pest population and its impacts (for example, weeds in pavement cracks). On the other hand, extensive information may be valuable to obtain - for example, monitoring of weevil problems on rhododendrons might include information about adult pest population levels, the extent of notching on leaves, condition of the plants involved, amount and types of debris or groundcover under the plants, the extent to which lower branches touch the ground, depth of mulch, soil moisture and temperature, the effects of pest control treatments (such as sticky traps on the stems), and the occurrence of natural predators and opportunities to enhance their presence. As the "memory" of the pest management system becomes well developed through the accumulation of historical information about pest problems, site conditions, and applied management practices, the monitoring program can be refined and focused.

During the early phases of an IPM program, when pest management histories are being developed, monitoring may need to be intensive. As the program matures, the level of monitoring can usually be reduced since a great deal of information about the biophysical nature of the resource system will be on record. Still, there may always be program needs that require intensive monitoring. Examples include: wherever important pest problems are potentially very dynamic (such as in a greenhouse operation); wherever maintenance of high quality site conditions are essential (as in ornamental displays which receive intimite daily public viewing); or where there is minimal allowance for a response time to applied pest management treatments (this occurs when pest populations increase very rapidly and a slight delay in rewsponse can result in a significant amount of damage, such as turf disease levels on golf course greens). Ultimately however, a monitoring program should be as simple as possible. Figure 9 is a simple diagram illustrating the potential range of monitoring intensity that can be applied in an IPM program. For complex urban environments, IPM monitoring programs should utilize careful observations, written records, and quantitative descriptions, with the timing of monitoring practices varying from carefully scheduled, perhaps even frequent, site visits (A), to inspections that are completed during the course of implementing other routine maintenance activities, such as mowing or weeding (B). Most urban pest management programs operate on the left hand side of the illustration, in what is known as a reactive, or crisis management mode. It is much more desirable to operate at the right end of the scale with an information base that allows a pro-active, or preventive approach to management.

To develop a clear and easily implemented monitoring system, it is helpful to break down the information required into discrete categories. In such a process, important categories to consider would include:

Figure 10 illustrates the potential simplicity of a routine monitoring form once baseline data on site conditions and past management practices have been compiled. All information on the form can be recorded in brief terms or codes and easily entered in a computerized database.

IPM Strategies and Prescriptions
Strategies and prescriptions are the "bottom-line" of any pest management program - they provide the required product: adequate pest management. While conventional pest control programs have generally relied upon a single tool (pesticides) to achieve this objective, IPM programs utilize an array of tools that are integrated in strategies and prescriptions designed not only to control pests, but to manage them, focusing largely on options to prevent or mitigate the occurrence of pest problems.

Strategies are a combination of short and long-term approaches to managing a pest problem - for example, using direct manual or mechanical methods to control tall grass and weeds under a picnic table on a turf area, while planning and budgeting for the installation of concrete underlayment to eliminate the need for vegetation management for that particular situation.

Prescriptions are the implementation plans for one or more practices that are applied to pest management problems. A prescription for turfgrass management might include a strong cultural program consisting of mowing at an appropriate height and frequency, fertilizing, irrigating, aerating, overseeding, and topdressing. It might also include plans for rest periods to allow the turf to recover from heavy use or other factors that create stress.

This prescription would encourage a vigorous, healthy turf that would dominate the site, retarding the development of weeds. If weeds did develop, the prescription might call for no action, use of manual methods, and/or spot spraying with an herbicide. The decision to use any one or combination of these three methods would depend on the established purpose and use profile of the turf area (whether ornamental, sports, or picnicking), its size, and the tolerance level for weeds.

Figure 11 is a simple diagram that illustrates the major pest management strategies that are available for urban IPM programs. Prescriptions for specific pest problems may include one or more strategies and a variety of tactics within each strategy.

A key requirement of IPM is that the selection of strategies and prescriptions be selected using specific criteria which ensure these methods address the goals and objectives of IPM. Selected strategies and prescriptions should:

  1. Promote natural controls.
  2. Protect human health.
  3. Minimize negative impacts to non-target organism.
  4. Enhance the general environment.
  5. Be most likely to produce long-term, beneficial results.
  6. Be easily and efficiently implemented.
  7. Be cost-effective in the short and long-term.

Together, the interrelated methods in Figure 11 and the selection criteria outlined above suggest that the optimum pest management program would be able to focus primarily on strategies A.1.a., b., and c. (problem prevention through indirect control methods by: incorporating low-chemical and low-maintenance design principles in initial facility development plans; planning for a comprehensive cultural maintenance program; and educating the public, policy makers, and staff to promote an understanding of IPM and in developing appropriate maintenance standards) to maximize prevention of potential problems while utilizing strategy B.1. (treatment of existing problems through direct control methods) to manage problems that do arise.

However, for most urban communities, immediate implementation of a program that focuses on prevention is not practical since they already have extensively developed landscapes with significant pest management requirements. Under these conditions it is necessary to develop a long-term management plan that will reduce existing problems while moving the program toward a prevention focus.

This goal can be accomplished by maximizing opportunities to integrate strategy B.2.a., b., and c. (treatment of existing problems through indirect control methods by: implementing site modifications to prevent recurrence or mitigate impacts of key pest problems; instituting comprehensive cultural managemnt programs for sites with pest problems; and educating the public, policy makers, and IPM practitioners by promoting a better understanding of IPM and developing appropriate maintenance standards) into the pest management program.

A successful approach to implementing an urban IPM program would then involve the application of three principle pest management strategies:

  1. Direct, short-term strategies to manage existing pest problems.
  2. Indirect, long-term strategies to reduce the occurrence, extent, or intensity of existing pest problems.
  3. Indirect, long-term strategies to minimize development of new pest problems.
In developing and implementing such a program, the initial proportion of use of each of these strategies and the specific prescriptions they employ will vary with the biophysical and political conditions of the pest management system. As long-term strategies reduce on-going pest management requirements, these proportions will change. Eventually, program component number 2 will be minimal as existing design conditions that contribute to recurring key pest problems are modified. The length of time required to achieve this level of site control will depend on the financial resources applied to program implementation. The level of benefits available from effective application of prevention strategies suggests that maximizing site modifications is desirable.

Determination of the specific strategies and prescriptions to utilize in an IPM program depends on a comprehensive inventory of all the sites and their physical features in the pest management system, an estimate of the pest management problems associated with these features, and established maintenance standards (e.g, injury and action levels) for all features. This information indicates the types of pest management work that must be done, how much of each there is to do, annual labor and material requirements to complete the work, and what level of site quality is expected/will be provided.

This information is also essential for developing an accurate estimate of the costs of implementing IPM. An appropriate timeframe must be included in such an analysis since the costs of long-term IPM strategies are only fairly evaluated by utilizing life-cycle costing concepts (i.e., determining a unit cost by including the life of the facility in estimating the length of benefit of applied practices).

Likewise, to evaluate the cost of implementing IPM through comparisons with other pest management programs (e.g., a pesticide based program, a program that bans the use of any chemicals, or a program that permits limited use of pesticides in particular settings for specific purposes), the costs for each alternative must be available and based on identical criteria (i.e., the same pest management needs, workloads, standards for maintenance quality, timeframes, etc.).

Of particular interest to many is the extent to which pesticides would be utilized in the implementation of an IPM program. This analysis requires information similar to that needed for cost evaluations: a list of features requiring pesticide use; type, extent, and intensity of pest problems per feature; expected level of control for each pest; types of chemicals that would be utilized; and methods of application that would be employed. Very important too would be the anticipated level of use of prevention strategies to mitigate the need for pesticides (e.g., new and retrofit design installations, cultural maintenance practices, and establishment of appropriate maintenance standards).

Consideration must also be given to the IPM principle of selection criteria for choosing applied strategies and prescriptions (i.e, any choice involving pesticides must emphasize the selection of materials with the least potential for negative impacts to non-target organisms and the environment in general). Of course, there are a range of factors that influence this selection process, and in some cases the choices are not necessarily clear-cut. However, genuine application of the IPM approach involves consideration of human health and safety as well as environmental quality.

The benefits of pesticide use reductions and favorable changes in product selection by applying IPM principles in an urban landscape management program are illustrated in Figure 12. This table indicates the change in pesticide use (an average decrease of 78% in conventional pesticides) when an IPM program was implemented on a 1,000 acre conservation/ornamental landscape, of which 350 acres are intensively managed as horticultural display gardens and conservatories that attract more than 700,000 people each year (Longwood Gardens in Pennsylvania).

Noteworthy in this example is that one of the requirements in shifting to an IPM approach was that no reduction in the horticultural excellence of the displays was acceptable. The stated goal was decreased use of conventional pesticides while maintaining or improving the quality of the garden displays. To accomplish this, Longwood Gardens discovered it was necessary to find a person trained in the principles of IPM and familiar with the practices of pest control. This manager provided hands-on review of pest problems, developed pest management plans, coordinated implementation, and ensured follow-up of all pest control procedures.

Prior to the IPM program, pest control treatments consisted of cover-sprays applied on a calendar basis supplemented by general plant inspections to determine when additional spraying was necessary (i.e., a conventional pesticide-based, calendar driven, cover-spray operation).

Donald Buma, Horticulturalist at Longwood Gardens, reported that following implementation of IPM, conventional pesticide use decreased in favor of more environmentally sound materials, quality of the landscape improved due to more timely and specific pest control treatments, pest management needs decreased due to an increase in natural predators, and that the costs of initiating the IPM program were recovered by the improvement in landscape quality.

Similar results from the implementation of IPM can be expected in most landscape management programs.

Program Evaluation
Evaluation of individual program activities, system components, and the overall pest management program are an integral part of an IPM system.

These evaluations are used to analyze the effectiveness, costs, and benefits of the program and its components to highlight opportunities to adjust the program to better serve its intended implementation goals and objectives.

Timeframes of program evaluations vary from short-term (e.g., effectiveness of a specific direct pest control treatment) to long-term (e.g., analysis of program institutionalization). Likewise, the scope of evaluations varies from review of site specific pest management practices, to examination of program components that involve the entire pest management system (e.g., the record-keeping system), to analysis of the program as a whole.

In addition, the process of evaluation involves education and communication: education and communication help people understand the complexities of implementing urban IPM; this understanding provides an informed basis for fair and effective evaluation of the IPM program.

Too often, the focus of evaluation rests on pesticide use. While this is frequently an important public issue and also a critical factor in an IPM program, it can overshadow and seriously detract from the development and evaluation of other key components of the program. As a result, education and communication are important not only in facilitating program implementation but also in developing program support throughout the political and social layers in which the pest management system must operate (see Figure 1). In providing leadership for the development and implementation of a complex urban IPM program, organizations should select a coordinator that is skilled not only in IPM and the diversity of urban pest management requirements but also an individual that is also good at educating and communicating with people.

Figure 3, the urban IPM system, indicates the major levels of program evaluation that are necessary in implementing IPM:

Evaluation of an IPM program should include at least the:

Key aspects of these evaluation requirements include:

In developing an IPM program so that it will facilitate evaluation of the pest management system and its components, it is useful to outline objectives or criteria by which the success of implementation can be measured. These milestones can be developed initially as part of a strategy for implementing the IPM program and include short, intermediate, and long-range goals and objectives. In preparing such a strategy, it is important to use timelines that accurately reflect the requirements and constraints of implementing each component and the program as a whole. Setting unrealistic expectations for "success" may jeopardize a fair evaluation of the program.

3.0 Role of Pesticides in Urban IPM

IPM does not exclude the use of pesticides. At the same time, IPM is not a system designed to justify the use of pesticides. Both views are common misrepresentations of IPM.

In fact, IPM does permit integrated utilization of pesticides. But at the same time, it actively seeks to minimize these applications through the use of three primary strategies:

In an urban IPM program, pesticide use may be necessary for several reasons, including:

These uses of pesticides will not necessarily involve the application of conventional pest control chemicals. It is a fundamental principle of IPM that such products will be replaced to the maximum feasible extent with materials that are least-toxic to the environment in general and to human health and safety. In combination with consistent efforts to design-out pest problems, the use of least-toxic products can substantially reduce the use of conventional pesticides.

In addition to the experience of Longwood Gardens in Pennsylvania, this concept has been clearly and successfully demonstrated by the Davey Tree Expert Company, one of the largest commercial landscape management companies in North America. Once a cover-spray operation using conventional pesticides, in 1988 Davey Tree converted to an IPM-based management system it labeled "Plant Health Care". As a result, the company reduced overall pesticide use by 80%, and remaining uses substantially involve least-toxic products (e.g., insecticidal soaps, horticultural oil), many of which they have developed or refined at their national headquarters. Further reductions in pesticide use are anticipated. In addition, profits for the company have gone up every year since the adoption of its IPM program (i.e., in a business where the quality of the product - their clients' ornamental landscapes - is the key factor influencing customer satisfaction and continued business, the IPM program was more successful than their previous pesticide-based operation). With IPM/Plant Health Care, Davey Tree found they were producing better landscape quality with much less pesticide use, providing more customer satisfaction, and improving their profit margin. (Source: Dr. Roger Funk, Davey Tree Expert Company, 1991)

A major discovery that supported the company's move to IPM was the result of a comprehensive survey of their client's properties. In this survey, Davey Tree found that at any one time, only 10% of their client's landscapes had pest problems. With this information, they realized that 90% of their cover spray operations were wasted applications of pesticides. With additional follow-through work, the company learned that most of the problems with the quality of their client's landscapes were related to cultural problems (poor soil, poor drainage, inappropriate plant material, etc.). In turn, these conditions were often the factors that induced the pest problems they did find (i.e., the pest problems they found were frequently on unhealthy, unthrifty plants - not a surprising discovery since it is well documented that pests are attracted to plants under stress).

These examples of implementing IPM on high quality, ornamental landscapes suggest that the use of conventional pesticides can be effectively minimized (see Figure 7) without a decrease in site quality and that IPM is as, or more, cost-effective than pesticide-based maintenance programs.

However, in many urban communities, the issue of any pesticide use can be more of a concern as landscape quality and cost-effectiveness. When implementing IPM in these circumstances it is important to provide assurance that environmental quality and human health will not be compromised by applications of chemicals. Education about IPM and communication with the public are essential in this process. Of particular value is the development of documentation that clearly defines the intention in implementing IPM, especially with regard to pesticide use.

For many organizations, a clearly written policy is the first step in developing this documentation. Included should be: the purpose of the policy (to implement IPM); the guiding principles of the policy (ecosystem approach, minimum pesticide use, maintenance of environmental quality and human health, etc.); a clear definition of IPM; components of the IPM program(s) that will be implemented (monitoring system, IPM prescriptions, record-keeping system, etc.); and, special roles and responsibilities required for implementing the policy.

With respect to pesticide use in particular, it is especially important to indicate in the policy that:

The second step in providing documentation for the IPM program is maintenance of records and recording of decisions as required by the policy. This includes documentation regarding:

An IPM program that is well-developed, implemented, and documented will minimize the need for and use of pesticides, maintain or improve the quality of managed lands, utilize fiscal resources efficiently, and promote political, administrative, and public approval and support.

4.0 Stages of Program Implementation

The transition to an IPM program depends on the size of the project and the barriers involved. Communities and organizations with diverse biophysical environments and layers of operational, administrative, social, and political roles and responsibilities may require several years of coordinated efforts to fully institutionalize an IPM program.

The commonly recognized time periods for urban IPM implementation include:


The early developmental stage of the IPM program. During this phase, information must be collected from two primary components of the system - the biophysical component and the social/political component:

Information from the start-up phase is used for initial IPM program development (e.g., documentation, injury levels, monitoring system, options for pest management) and implementation of field trials of potentially useful IPM strategies and prescriptions.


The growth stage of the urban IPM implementation process involves widening the application of proven IPM strategies and prescriptions, and reviewing, evaluating, and refining the pest management system components developed in the start-up phase (e.g., documentation, decision-making processes, record-keeping and monitoring systems, cost analysis of pest management practices, education and training programs, and research of pest management options).


In the mature stage of implementing urban IPM, the focus of work involves fine tuning the developed components of the program and continuing research on options for pest management. All aspects of the pest management system are in a routine mode of operation.

Key activities for each of these stages of implementation include:

These activities may be viewed as measurements of the development of the IPM program and used as milestones in evaluating progress toward its institutionalization.

Last Modified: Friday, August 04, 1995 - 1:24:35 PM

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