Integrated Pest Management

IPM Manual for Structural Pests in British Columbia

Chapter 1: What is Integrated Pest Management?

Learning Objectives

When you have completed this lesson, you should be able to:

Define the term 'Integrated Pest Management'.
Describe the advantages of IPM over regularly scheduled pesticide spray programs.
Name four ways structural IPM programs differ from agricultural IPM programs.
List the five main steps in an IPM program.
Describe the importance of identifying pests.
Name and describe six factors that affect the development of a pest population.
Describe why monitoring is necessary in a structural IPM program.
Describe pheromone traps and sticky traps.
Describe the difference between an injury level and an action level in an IPM program.
Give examples of barriers, sanitation and environmental modifications used to prevent pest problems.
Name and describe four types of controls used in structural IPM.
Describe problems arising from the use of pesticides to control pests.
List the items to record in evaluating the success of a pest control program.

Introduction

The intent of this chapter is to clarify and standardize what is meant by IPM with respect to the structural pest control industry. Integrated Pest Management (IPM) is an approach that has been used for decades to manage insects and mites in agricultural crops. Over the last 10-15 years, however, IPM methods have also been successfully applied to manage pests of all kinds including plants, animals and diseases. IPM programs are increasingly used in forestry, landscapes and parks and for structural pests. Many structural pest managers in B.C. are already using at least some components of an IPM program. IPM programs continually improve as new products are developed and as information from research and practical experiences becomes available.

IPM programs follow a decision-making approach to managing pests. IPM starts with pest identification and monitoring and uses a combination of methods to provide acceptable control and prevent pest problems. (For a general definition of IPM, see text box). IPM is more than just a combination of treatments; treatments are only one of the components of an IPM program.

IPM for Structural Pests

For structural pests, the aim of an IPM program is to prevent pest problems through sanitation and maintenance of a site or building. When a pest problem does occur, an IPM program starts with making sure the problem is identified correctly. A regular monitoring program is a key component because it provides the information necessary for making decisions about treatments. This includes deciding whether or not treatment is required, what treatments to use and the best timing for treatment. In the follow-up and evaluation process, the IPM program manager not only checks effectiveness, but also goes on to look for ways to correct and eliminate conditions that contribute to pest problems.

IPM programs have several advantages over old-fashioned pest control programs based on regularly scheduled applications of pesticides. IPM programs:

provide long-term solutions to pest problems,
reduce the amount of pesticide used,
prevent pesticide resistance from developing, and
enable pest managers to control pesticide resistant pests.

In the short term, IPM can be more costly because labour to perform inspections and monitoring may be more expensive than labour to apply pesticides. But in the long term, IPM can be more cost effective as it aims to eliminate the current problem and prevent future problems.

General definition of Integrated Pest Management, developed in 1994 by B.C. Environment in consultation with the public and stakeholders from agriculture and other sectors.
Integrated Pest Management is a decision making process that uses a combination of techniques to suppress pests effectively, economically and in an environmentally sound manner. It includes the following elements:

(a) planning and managing ecosystems to prevent organisms from becoming pests,

(b) identifying potential pest organisms,

(d) using injury thresholds in making treatment decisions,

(e) reducing pest populations to acceptable levels using strategies that may include a combination of biological, physical, cultural, mechanical, behavioral and, when necessary, chemical controls, and

(f) evaluating the effects and efficacy of treatments.

Structural IPM programs differ from IPM programs in other sectors (such as agriculture or landscapes) in four main ways:

Unlike pests outdoors, eradication of some species indoors is desirable and is a realistic goal. This is possible because the pests are within restricted boundaries.
A working knowledge of the structural design and plumbing, electrical and ventilation systems of buildings is essential.
Prevention of pest infestations through careful attention to sanitation and good building maintenance is very effective.
Communication with clients is particularly important for establishing tolerances and for educating clients about the IPM approach. Once a problem is under control, the pest manager must also work with clients to develop practical preventative programs.

Components of an IPM Program

An IPM program involves five main steps. When a client calls with an existing pest problem, the pest manager usually proceeds in the following sequence:

IDENTIFICATION - identify the pest,
MONTORING - monitor the pest population and / or damage,
ACTION DECISIONS - use injury and action levels to decide when to treat,
TREATMENTS - apply treatments, including preventative measures, and
EVALUATION - evaluate the effect of treatments.

Identification

It is essential to identify pest problems correctly to plan effective control programs. This is because the key to effective control is knowing the biology of the pest, including the life cycle, behaviour patterns and habitat preferences. Once a problem species is identified, the pest manager can look up information on its biology (suggested references are listed at the end of each chapter in this manual).

Drawing of flea lifecycle A thorough knowledge of the biology of a target species enables the pest manager to:

do an accurate job of monitoring a population by inspecting or trapping where the pest is most likely to be present,
plan preventative measures that modify the habitat to make it unattractive,
use the most appropriate controls at the right time in the pest life cycle, and
place controls where they will have the most effect.

Pests can be identified by:

comparing specimens with an insect collection,
referring to pictures and pictorial keys,
recognizing characteristics of the damage, excrement or castings (called frass), and
consulting experts for assistance with difficult or unfamiliar species.

It is often easier to identify an insect by comparing it to a real specimen than it is to use reference book pictures. We suggest that pest managers keep their own properly preserved collections of insects to use for quick reference and for training employees. Collections of photographs showing pests, damage and other information are also valuable for future reference.

Ideally, the pest manager collects a specimen of the pest for identification. When this isn't possible, pests may also be identified by the appearance of their damage and/or frass. For example, close examination of sawdust or wood chips found in a building will provide clues to the identity of the pest. Carpenter ants produce very fine chips and frass, while rodents produce large chips that may contain a few dark, oval droppings. The size of rodent droppings will show whether rats or mice are the problem; even the species of rat can be deduced from characteristics of the droppings.

Once a pest is identified, the pest manager can find out about its life cycle and conditions that favour the spread of the pest population. The following six factors affect the rate at which pest populations grow:

Reproductive Potential: The reproductive potential of an animal refers to the maximum number of offspring females can produce. Some species have such a large reproductive potential that they could cover the earth in a few generations if it weren't for their natural enemies. Others are slower at reproducing. Fortunately, there are many natural controls that limit pest population growth.

Temperature and Humidity: A general rule for insects is that the warmer the temperature (up to a certain point), the faster they reproduce. As well, each species has an ideal environment or climate for reproduction. Insects generally seek high humidity, rather than dry conditions. In some cases, the building environment can be adjusted to make conditions less suitable for an insect population.

Availability of Food: Food is an important factor for any pest population. Eliminating food sources through proper storage and sanitation can starve the pests. Even where food sources cannot be eliminated, if they can be reduced, the population growth will be slower.

Availability of Water: Water is often the key component for survival of many pests. Population growth can be stopped by removing all sources of water. This is true for both insects and rodents. Many structural pests rely on leaking pipes or other sources of water, therefore finding and repairing moisture leaks is essential for achieving control.

The more mobile the pest, the more difficult it is to completely remove water sources. For some species, such as Western dampwood termites, preventing contact between the wood of structures and the soil is sufficient to eliminate the conditions it needs to survive. For mobile animals, such as rats, eliminating all possible sources of water may be difficult.

Availability of Habitat: Habitat is where the pest population lives. This includes hiding and resting places, shelter, and nesting sites. Removing favourable habitat makes a site unattractive and less likely to support a high pest population. For example, removing brambles and vegetation close to a house foundation removes harbourage favoured by rats.

Natural Enemies: Natural enemies can be predators (which eat several or many individual pests), parasites (which live inside the pest, eventually killing it), or pathogens (which cause disease in the pest). Some species of natural enemies are reared commercially for release as biological control agents.

Monitoring

Monitoring is an essential component of an IPM program. It provides information about the pest population and the site as well as the conditions that contribute to the pest problem. The pest manager needs this information to make decisions about the best treatment. Monitoring is used to:

detect pest populations at an early stage, when they are easier to control,
find the centre of a pest population and the limits of its spread,
assess the size of pest populations and the damage done,
determine the building layout and note conditions contributing to pest problems, and
evaluate the success of pest control programs.

Monitoring consists of regular inspections, done systematically, to get an estimate of the size, extent and location of pest populations. It is essential to keep detailed, written records. Some companies now keep complete computerised records, which are entered onto a portable computer by the service technician at the site. Especially for large buildings, records should include maps of building layouts, with positions of traps or other monitoring devices. Traps may be numbered or coded to simplify record keeping.

Visual Inspections

Thorough visual inspections are the most common monitoring method for structural pests. This should include an inspection of the building to determine how it is built and the type and layout of its heating, plumbing and electrical systems. This is important because pests use these systems as pathways into and through buildings.

Every area in a structure should be inspected, including under counters, in cupboard and storage areas, garbage collection areas and potted plants. It is particularly important to inspect hard-to-reach sites, kitchen and bathroom areas, and entry points around pipes, duct work and utility lines. A good inspection is hard work!

The amount of time spent inspecting will vary according to the type of building and pest. According to a recent article in a trade journal, about 80 to 90% of the service time in an IPM program will likely be spent on inspections as opposed to applying pest control materials (Pest Control Technology, Nov., 1995; vol 23(11):34-38, 46, 110).

Useful tools for visual inspections include:

a small, powerful flashlight
good kneepads
magnifying lens (10-15 X magnification)
a sturdy hand mirror
collecting vials or plastic bags (for samples examined later under a microscope
note pad and pencil

Monitoring Traps

Pest managers use various kinds of traps to monitor insect and rodent populations in a structure. Examples are pheromone traps, sticky traps and baited traps (the latter are discussed under controls, pg.8). These are valuable tools for pinpointing an infestation and estimating the size of a population.

Pheromone Traps: Pheromone traps contain synthetic pheromones that mimic the pheromones produced by insects (see box). They are used to attract specific insect pests to determine if they are present.

The pheromone is usually contained on a rubber or plastic lure that is hung inside a cardboard trap, such as the delta trap shown. The inside surface of the trap is coated with sticky glue, which catches the insects that enter. To inspect the trap, the pest manager opens it and counts the captured insects.

The pheromone trap is a very effective monitoring tool because it is so specific. Usually a different pheromone is needed for each species of insect being monitored. In some cases where the pheromones of closely related species are similar, the synthetic pheromone may attract more than one species. For example, the commercially available Indian meal moth pheromone attracts almond moths, Mediterranean flour moths, raisin moths, tobacco moths, and Indian meal moths.

Many insects communicate with members of their own species through chemical compounds called pheromones. For example:

sex pheromones are emitted by females to attract males
aggregation pheromones are emitted to attract others
alarm pheromones are emitted to warn others

Sticky Traps: Sticky traps are used to monitor crawling insects, such as cockroaches and silverfish. (They can also be used as a control measure). Sticky traps for insects are made of heavy paper or cardboard coated with a non-repellent, sticky glue. Insects that crawl over the trap are held fast by the glue. In dusty sites, these traps may need to be replaced weekly to maintain effectiveness.

Glue boards are larger versions of sticky traps. They are made of cardboard or plastic, coated with an extremely strong, sticky glue. They are used for monitoring and control of rats and mice.

To prevent dust from coating sticky traps, they can be placed inside open ended tubes that allow pests access.

Action Decisions

In IPM programs, deciding when to take action and apply treatments is based on the information from a monitoring program. Treatments are not made according to a predetermined schedule. They are made only when and where monitoring has shown they are needed. Determining when treatments are needed involves two concepts. In most descriptions of IPM programs, these are called:

injury level (or injury threshold)
action level (or treatment threshold)

The injury level is the unacceptable level of injury or damage from a particular pest population. What injury level is unacceptable depends on the pest and where it is. In structural pest control the concept of "injury" includes:

economic damage to goods and structures
medical or health hazards posed by pests
nuisance or aesthetic tolerability

Tolerance for a structural pest may seem like a contradiction, but in practice, there can be wide differences from site to site in the level of control that is required or that is practical. Some pests, such as silverfish and flies, are primarily nuisance pests and the tolerance level strongly depends on the client's preferences. Carpenter ants and rats, however, cause structural damage so none are tolerated inside a building. For others, such as birds or cornfield ants, it is usually only when they reach extremely high numbers that they become intolerable. Even for the same pest, how many can be tolerated can vary with the location. For example, the tolerance for flies in a hospital will be much lower than in an apartment building.

The action level is when a particular treatment should be applied to keep the pest numbers from reaching the injury level.

Drawing of fly For some treatments, the action level may be reached when the pest populations has reached unacceptable numbers. For other types of controls, such as biological controls, the treatment might be applied at a particular time in the pest's life cycle, rather than at a particular population level. Some treatments are better suited to dealing with high pest populations, therefore the action level might be relatively high. Other treatments are more effective (or more cost-effective) when used while pest numbers are low, which may be long before the population reaches damaging or intolerable levels. Applying chemicals only when the appropriate action level is reached is economical and eliminates unnecessary pesticide use.

Establishing injury and action levels is a relatively new area for structural pests, therefore, specific information is lacking for many situations. Many structural pests are nuisance pests, and for these, in particular, it is important for the pest manager to work with the client to:

establish the injury level by finding out what level of pest population would be intolerable,
establish action levels that keep the pest populations to acceptable numbers, below injury level.

Treatments

In structural IPM programs, treatments generally fall into two main categories: preventive measures and control measures.

Prevention includes barriers, sanitation and environmental modifications;
Controls include physical, mechanical, biological and chemical controls.

Ideally, an IPM program should begin by looking at ways to prevent pest problems from occurring. In practice, however, pest management programs usually begin with a service request to deal with an existing pest problem. Once controls have been used to deal with the problem in the short-term, the pest manager should work with the client to develop a pest management program based on preventive measures to avoid future problems.

Prevention

The aim of a structural IPM program should be prevention. This includes barriers (to keep pests out), sanitation (cleaning up), and environmental modifications (such as eliminating sources of food and water). In many cases structural pest problems can be eliminated with these methods alone. These methods also make other controls more effective and help prevent the recurrence of problems.

Barriers

Drawing of wirebarrier Examples of barriers are:

placing screening over air intakes, ventilation grills and drains to prevent insects and rodents from entering,
sealing cracks and crevices in a structure, and
using screening, wire spikes or electrified wires to prevent birds from roosting and perching.

Sanitation

Common sanitation steps include:

removing nesting and hiding sites for pests in and around structures
cleaning up spilled food in storage cupboards
ensuring garbage containers are tightly closed and pest-proof
steam cleaning to remove layers of grease in a restaurant kitchen

Environmental Modifications

Environmental modifications may be an effective control for some species.

Examples include:

eliminating water and food sources
altering humidity and temperature conditions

Pest managers usually make recommendations to clients on sanitation, repairs and installation of screens and other barriers. To ensure an IPM program is successful, however, pest managers may want to provide these services to ensure that they are done properly.

Controls

Ideally, controls become necessary where preventative measures do not solve a pest problem. Often, however, a control program must be undertaken before a client can move to a prevention program. Controls used in the structural pest control industry include four main types:

physical
mechanical
biological
chemical controls

These may be used separately or in combination to give the required level of control.

In choosing controls, select methods that are:

least hazardous to human health,
least toxic to non-target organisms,
least damaging to the environment,
most likely to produce a permanent solution, and
most cost effective over time.

Physical Controls

Physical controls include barriers (discussed above under Prevention), sticky traps and glue boards (discussed above under Monitoring) as well various kinds of baited traps. The use of extreme temperatures to kill pests could be considered a physical control.

Baited Traps: These contain substances, usually food, that attract pests to traps. Common baited traps include snap traps for rodents, wasp traps and fruit fly traps. Some sticky traps and glue boards are also baited with food or other attractants.

Some toxic bait stations for ants are commonly called ant traps, although they do not actually trap the ants.

Extreme Temperatures: Insects become stressed and most start to die as temperatures rise over 40°C. Research has shown that termites and powderpost beetles can be killed in a structure if exposed to temperatures over 50°C for as little as half an hour. At this time it is only practical for special cases, however, the use of heat to eliminate insect infestations in structures is currently under development in the U.S.

Holding goods at temperatures below freezing is also effective for killing insects. This is most useful for stored products pests. It is applied on a larger scale in regions with cold winters, where grain storage facilities are allowed to freeze. It is also useful on a household scale to clean up infestations in stored products.

Mechanical Controls

Mechanical controls are machines or devices that control pests. They include equipment such as vacuums, ultraviolet light traps and ultrasonic repellers.

Vacuums: A vacuum cleaner is an important tool for structural pest control. Vacuuming is an effective way to remove pests such as domestic beetles and carpenter ants in buildings. It is also becoming popular for reducing high populations of cockroaches. A handheld vacuum modified to collect insects is particularly useful during monitoring inspections. Larger vacuums are used in control of pests such as house dust mites and fleas and have been adapted for removing underground wasp nests.

Several backpack models of vacuums are now sold for use in the structural pest control industry. The best vacuum cleaners for pest control purposes are those with very fine dust filters or water filters. For use in cockroach control work, it is recommended that the vacuums be fitted with a High Efficiency Particulate Air (HEPA) filter to prevent fine particles from being blown back into the room. This is because dust from cockroaches contains a protein that can cause severe allergic reactions in some people when it gets into the air.

Ultraviolet Light Traps: These light traps consist of one or two ultraviolet lights surrounded by an electrically energized grid. Any insect that flies towards the light is electrocuted when it reaches the bars of the grid. Electrocutor traps are used indoor to control flies in offices, warehouses, small barns, etc. They are not effective in controlling flies outdoors, where they also destroy beneficial insects.

One difficulty with electrocutor traps is that when insects are killed, they may "explode". Falling body parts land beyond the catch tray below the trap. This is unacceptable in many environments (e.g., food preparation areas).

Ultraviolet light traps that use sticky boards to capture insects have recently been introduced to the market as an alternative to electrocutor traps. Captured insects and insect parts do not fall off these traps unless the sticky board dries out or becomes covered with insects.

Repellent Sound Devices: Some ultrasonic devices have been registered in Canada for rodent control. They repel rodents by generating a sound that annoys them, but at a frequency that isn't heard by humans. These devices are best used in combination with a sanitation program to remove food sources. Rodents become accustomed to the sound and learn to ignore it, particularly where it is associated with the presence of food.

Ultrasonic devices have been shown to be ineffective for controlling insects, therefore are not registered in Canada and cannot be legally sold for this purpose.

Biological Controls

Biological control is the use of natural enemies to control pests. The natural enemy of the target pest is released into the pest's local environment. For structural pests, natural enemies are usually not expected to become established or provide control indefinitely. They are usually released repeatedly until control is achieved. This is especially true if the natural control is a pathogen (called a microbial control).

Drawing of biological control There are few biological controls for structural pests, although more are becoming available. A biological control for flea larvae is now available in Canada. These are insect parasitic nematodes (e.g., Vector®) that are applied as a spray to control fleas outdoors.

A successful example of releasing a natural enemy into structures to limit pest populations is the use of tiny parasitic wasps in California to control cockroaches.

Pest managers should watch the market for new biological control products to be introduced. For example, the Bio-PathTM Cockroach Control Chamber is now registered in the U.S. The chamber contains a fungus that infects cockroaches when they enter the chamber to feed. The infected cockroach spreads the fungus to other cockroaches it contacts.

Chemical Controls

Pesticides are one of the variety of methods and tools that may be used for pest control. In IPM programs the goal is to minimize the use of pesticides. The more toxic products are used as a last resort when careful assessment of the problems indicates their use is required. This assessment is based on information from a monitoring program.

ONLY pesticides with a Canadian Pest Control Products (PCP) Act registration number on the label may be used for pest control. Pesticide products may only be used for the pests, and in the locations, specifically listed on the label.

When pesticides are necessary, the pest manager must choose the most appropriate formulations and methods of application. Several approaches reduce the use of pesticides and limit exposure of occupants, pesticide applicators and non-target species to pesticides.

These are:

choose 'preferred pesticides' where possible (see below),
choose formulations that minimize the amount of active ingredient required,
choose application methods that limit the amount of pesticide used, and
notify all those who could be exposed to pesticides of the date and time of treatments, and give recommendations to prevent exposure of occupants.

Preferred Pesticides

Preferred pesticides in this manual are generally least toxic to humans, have the lowest impact on non-target organisms and are most specific to the target species. Some are new compounds, such as insect growth hormones or extracts from micro-organisms. Others, such as boric acid or diatomaceous earth have been around for years, although they are now available in new formulations. Types of preferred pesticides are described in more detail in Chapter 2.

Other Pesticides

Conventional pesticides, such as organo-phosphorus and carbamate pesticides registered for structural pest control uses may be necessary in certain situations, especially as a short-term measure. These should always be used in a way to limit risks of exposure. For example, toxic baits would be preferable to using sprays, while crack and crevice treatments would be preferable to baseboard sprays. The characteristics of these pesticides and precautions for their use are described in chapters 12 and 13.

Problems with Pesticide Use

Drawing of bait gun Much of the interest in promoting IPM has come as a result of problems arising from the use of pesticides alone to control pests. Pesticide use can result in:

development of pests resistant to pesticides,
exposure of human, pets and other non-target organisms to pesticides, and
environmental contamination with pesticides.

In comparison to other types of controls used in IPM programs, pesticide use:

provides short-term control, but rarely a long lasting solution to pest problems,
requires considerable effort and cost for the service company to provide adequate safety and application equipment and storage facilities,
requires careful planning and use of application techniques that protect people and the environment, and
incurs inconvenience and cost to clients who may have to vacate a building or take other precautions.

Pesticide Resistant Pests

The development of pesticide resistant pests is a major problem in agriculture and, to a lesser extent, a problem in other sectors. It has been a driving force behind the development of IPM programs.

Resistance occurs when a pest population is repeatedly treated with the same pesticide. A few individuals in the population survive the spray because they have genetic characteristics that give them resistance. When they breed, they produce offspring that are also likely to be resistant to the pesticide. As each spray kills the susceptible individuals, the resistant individuals continue to reproduce. Eventually, the entire population of pests is made up of individuals with resistance to the pesticide.

In structural pests, resistance to pesticides has been found in cockroaches, flies and rodents. In some areas of British Columbia, for example, house mice have been found to be resistant to the rodenticide, warfarin.

The best way to prevent the development of pesticide resistance is to use non-pesticidal methods to control pest populations whenever possible. This helps ensure that when pesticides must be used, they will still be effective.

Pesticide Risks to Humans and Non-target Organisms

Drawing of child and dog Most common pesticides are broad-spectrum poisons. If used improperly, they can kill or cause other effects in non target organisms. In addition to humans, non target organisms include pets, plants and wildlife, such as birds, native rodents and fish. They are most at risk from broadcast applications of long-lasting, residual pesticides.

Many pest management professionals, their clients and members of the public are concerned about the possible effects of pesticide exposure on their health. Some people are sensitive to certain pesticides or the carriers in the formulated products. They may experience adverse reactions from exposure to very low levels of a pesticide. Also, some people are concerned about developing an illness in the future as a result of exposure to pesticides. These concerns can often be addressed by minimizing the use of pesticides wherever possible.

When a decision is made to use pesticides, all possible precautions must be taken to prevent the exposure of humans and non target organisms to the pesticide applied. The pest manager should choose application methods and equipment that limit the distribution of the pesticide (see guidelines and precautions in Chapter 12).

Evaluation

Evaluation is an essential part of every IPM program. Evaluation helps the pest manager:

decide what worked and what didn't,
identify possible improvements, and
assess the long-term costs of the program.

To be able to evaluate an IPM program, the pest manager needs accurate records of treatments and their outcomes. Notes should be kept of:

discussions with the client,
monitoring records of pest numbers and locations before treatment,
treatment specifics, including date and time, and
monitoring records of pest levels after treatment.

Accurate records of labour and other costs should also be kept so that the pest manager can set a fair price for IPM services.

Conclusion