From Science Online

Definition and History

Integrated Pest Management (also called Integrated Pest Control) is an ecological approach to suppressing pest populations in a unified program, so pests are kept at acceptable levels in effective, economical and environmentally safe ways. the goal is to attempt to plan and manage ecosystems to prevent organisms from becoming pests. Uses a system of controlling pests by combining biological, mechanical, cultural, physical and chemical control methods in a way the minimizes economic, health and environmental risks.

IPM Elements (TEAM Leafy Spurge)

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. 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.

Pest Damaged Crop (UGA Entomology Department)

Steps of Integrated Pest Control

Step 1: Monitor and Identify Pests

Not all insects, weeds, and other living organisms require control. Many organisms are innocuous, and some are even beneficial. IPM programs work to monitor for pests and identify them accurately, so that appropriate control decisions can be made in conjunction with action thresholds. This monitoring and identification removes the possibility that pesticides will be used when they are not really needed or that the wrong kind of pesticide will be used.

Step 2: Set Action Thresholds

Before taking any pest control action, IPM first sets an action threshold, a point at which pest populations or environmental conditions indicate that pest control action must be taken. Sighting a single pest does not always mean control is needed. The level at which pests will either become an economic threat is critical to guide future pest control decisions.

IPM Process (Agricultural Department of ND State University)

Step 3: Prevention

As a first line of pest control, IPM programs work to manage the crop, lawn, or indoor space to prevent pests from becoming a threat. In an agricultural crop, this may mean using cultural methods, such as rotating between different crops, selecting pest-resistant varieties, and planting pest-free rootstock. These control methods can be very effective and cost-efficient and present little to no risk to people or the environment

Step 4: Control

Once monitoring, identification, and action thresholds indicate that pest control is required, and preventive methods are no longer effective or available, IPM programs then evaluate the proper control method both for effectiveness and risk. Effective, less risky pest controls are chosen first, including highly targeted chemicals, such as pheromones to disrupt pest mating, or mechanical control, such as trapping or weeding. If further monitoring, identifications and action thresholds indicate that less risky controls are not working, then additional pest control methods would be employed, such as targeted spraying of pesticides. Broadcast spraying of non-specific pesticides is a last resort.

Control Classifications

Cultural controls: Modifying the activities of the occupants, grounds keepers, and custodians.

Physical Controls: Modifying a habitat, using mechanical traps to capture pests, or using barriers or other materials to exclude pests from an area.

Biological Controls: The use of living organisms to control other living organisms. Most pests have natural enemies that control or suppress them effectively in some situations.

Chemical Controls: The use of pesticides in a proper manner and in accordance with the label.

Methods and Applications

A. Beneficial Insects

Most people start using Beneficial Insects because of safety concerns and then after they realize they are easier to use, give better long term results, and are priced competitively. When people stop using toxic chemicals, natural predators such as ladybugs and green lacewing start to make a comeback and butterflies and birds become more plentiful. Prior to the introduction of toxic insecticides in the 1940's, the use of Beneficial Insects for pest control was standard practice. Both the California citrus crop and the Hawaiian sugar field were saved with the use of Beneficial Insects. Every pest has a natural enemy, the key to successful pest control is to identify the pest and their natural enemies, releasing the Beneficial Insect early when pest levels are low and let nature take its course. Beneficial Insects attack and destroy only target insects; they will not bother people, plants or pets.

Examples of Beneficial Insects and Their Targets

Beneficial Insects ...................... Target Pests

• Lady Bugs...............................• Aphids, Whitefly, Fruitworms, Mites

• Praying Mantis........................• General Predator

• Whitefly Parasite...................• Whitefly

• Beneficial Nematodes..............• Fleas, Grubs, Cranefly, Root Weevil

• Green Lacewing........................• Aphids, Whitefly, Leafminer, Mites

• Trichogramma...........................• Moths, Borers, Webworm, Fruitworms

• Fly Parasites..........................• House Flies, Horse Flies

• Mason Bee................................• Crop and fruit tree pollination

Example Beneficial Insect Species (Ohio State University Extension, Integrated Pest Management Program)

How to Attract Beneficial Insects

1. Plant flowers The key to attracting beneficial insects is to plant a variety of flowers. Pollen and nectar from flowers (especially wildflowers) attract beneficial insects and encourage them to lay their eggs nearby. 2. Supply water Beneficial insects need water to survive. A small water garden or a shallow dish filled with pebbles and water will attract and support beneficial insects during drought 3. Provide shelter Beneficial insects require nearby vegetation (e.g., woods, weeds, mulch) for protection during the warm months and shelter during the winter. Garden pathways and borders offer shelter to soil-dwelling beneficials. 4. Provide food To attract beneficial insects, provide a pollen/nectar food source by spraying your garden and/or borders with a solution of sugar and water. 5. Eliminate pesticides Since beneficial insects will only stay on your property if they have enough harmful insects to feed upon, traditional pesticides should not be used. Pesticide sprays kill both beneficial insects and their food source, often causing an eventual resurgence of the pests. Less toxic pesticides such as insecticidal soap or horticultural oil can be used to knock down harmful insects, thus allowing beneficial insects that survive to continue feeding.

B. Insect Sterilization

The sterile insect technique, SIT, is an area wide strategy for the control of pest insects based on the irradiation and continuous release of a large number of sterile males in the infested area. Sterilization with chemosterilant is no longer practiced because of environmental concerns. When sterile males mate with wild fertile females, the eggs produced and/ or the subsequent progeny do not develop due to the dominant lethal mutation induced in the parents' reproductive cells. E.F. Knipling was the first to develop SIT for the control of wild insect populations forty years ago. Since then, many successful programs were implemented in different parts of the world and have had a significant impact on agriculture and human health. The main advantages of Sterilizing Insect Treatment is that it is species specific, environment friendly and can be used in area wide management as a tool for prevention, suppression or eradication. To apply SIT certain conditions should be fulfilled: Good quality mass reared and irradiated insects should be well distributed in the field in order to be able to find the females, compete with wild fertile males and transfer sperm.

Application of the Sterile Insect Technique (SIT). Following an accidental introduction of a foreign insect pest or an increase in numbers of an endemic insect pest, as determined through monitoring programs, sterilized male flies are mass released across the target area by airplanes. The sexually sterile males, which outnumber the wild-type males, mate with wild-type females resulting in infertile mating events. This results in a decrease of the pest levels and, if continued over several generations, the potential eradication of the pest from the target area. (Wimmer, 2005)

A new method is suggested for controlling species of insect pests in which the female is heterogametic. This method, involving the use of balanced lethals on the Z chromosome, causes the death of females in the embryonic stage. The method has already been tested in practical sericulture for the production of entirely male progeny of the silkworm. The method requires the construction of two strains of the pest, one carrying two balanced non-allelic but closely located lethals on the Z chromosome, and another with two other pairs of lethals of the same type. In the hybrid progeny from the crosses between the two strains, 100% of the female embryos would die, thus making it possible to release only males without any laborious procedure for sex discrimination. In the progeny from the crosses between the released males and females from the natural population, again 100% of females would die, but the males would survive and when they mated — 62.5% of the female progeny would die. This rate would decline to 34.4 and 16.6% in the sons and grandsons respectively. The repeated release of hybrid males would lead to a progressive increase, with each successive generation, in the percentage of female mortality in the natural population until its total extinction.

C. Odor Management

Odor is the way many insects locate food and sites to lay eggs. If you control odor from decomposing organic matter you can decrease flies attracted to scent from fermenting manure and alcohols from fermenting sugars. Consider animal health and comfort in areas with strong odors. Odor can be a sign that a biological process has gone wrong and can benefit from some managerial attention. Change conditions to stop decomposition. Shift decomposition process, such as with acid, inoculants, or composting, away from anaerobic microbes that live without oxygen and produce bad odors to aerobic microbes that need oxygen and give off pleasant odors. Use of chemical insect pheromone substitutes to lure aroused insects towards the scent has become more prevelant, as the pests may then be captured, treated for sterilization, or may simply attempt to mate with whatever the source of the smell is instead of successfully mating with another insect and increasing the population. See image: (Pheromone Trap Using Organic Pesticide) (Plettner, 2002)

D. Pesticides

Though commercial advertising of insecticides and “weed killers” has de-villainized the now common practice of spraying broad chemical toxins in our backyards and even inside our homes, science teaches personal and environmental risks associated with the use of toxic chemical insecticides.

Pesticide Transportation through the Water Cycle

Many of the pests we are trying to kill are developing a tolerance to chemicals from overuse of the perceived panaceas to pest woes, making them harder to control, while the Beneficial Insects nature provides to control pests and balance the ecosystem are being killed off by the higher concentrations they consume from ingesting infected prey.

Risks of Pesticide Use

Actual Risk

Actual risk is an estimable value, consisting of the potential danger of a situation multiplied by the likelihood of its occurrence, and is represented by the equation R = P*C(1) where R= risk (a measure of how often something will happen and how bad it will be), P= probability of undesirable event 1, and C= adverse consequences of event 1.

Perceived Risk

Control: Consumers have no control over the pesticide content in food

Catastrophic Potential & Dread: Pesticides are feared because of their possible harmful delayed effects such as cancer

Familiarity: Pesticides are a familiar product to almost everyone. They are used in homes, personal gardens, on skin and clothes to control everyday pests before organic food became a choice in grocery stores, everyone was at equal risk of being exposed to pesticides in their food. Now, however, the rich have the option to buy the expensive organic products and the poor do not

Chain of DDT Biomagnification (Meyer, 2006)

Effects on Children & Future Generations

Clarity of Benefits: Benefits of pesticides to control mosquito and tick borne illness such as malaria and lyme disease are commonly thought to outweigh the risks of pesticide use Benefits of greater crop yields and economic savings by use of pesticides do not sway public opinion in favor of pesticide use

Media Attention

Trust in Organizations or Institutions: The public lacks confidence in experts about the risks of pesticides because they know that the experts advocated use of DDT without full knowledge of its potential hazards

Voluntariness of Exposure: People can not decide to stop eating so there is little voluntary exposure. People can and do, however, choose whether or not to use pesticides on themselves or in their homes and gardens.

Biochemical Pesticides

Biochemical pesticides are naturally occurring substances that control pests by non-toxic mechanisms. Conventional pesticides, by contrast, are generally synthetic materials that directly kill or inactivate the pest. Biochemical pesticides include substances, such as insect sex pheromones, which interfere with mating, as well as various scented plant extracts that attract insect pests to traps. Because it is sometimes difficult to determine whether a substance meets the criteria for classification as a biochemical pesticide, EPA has established a special committee to make such decisions.

See image: (Pesticide is Broadly Projected over Field)

Advantages: Biopesticides are usually inherently less toxic than conventional pesticides. Biopesticides generally affect only the target pest and closely related organisms, in contrast to broad spectrum, conventional pesticides that may affect organisms as different as birds, insects, and mammals. Biopesticides often are effective in very small quantities and often decompose quickly, thereby resulting in lower exposures and largely avoiding the pollution problems caused by conventional pesticides. When used as a component of Integrated Pest Management (IPM) programs, biopesticides can greatly decrease the use of conventional pesticides, while crop yields remain high.

Microbial Pesticides

Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Microbial pesticides can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pest. For example, there are fungi that control certain weeds, and other fungi that kill specific insects. The most widely used microbial pesticides are subspecies and strains of Bacillus thuringiensis, or B.T. Each strain of this bacterium produces a different mix of proteins, and specifically kills one or a few related species of insect larvae. While some Bt's control moth larvae found on plants, other Bt's are specific for larvae of flies and mosquitoes. The target insect species are determined by whether the particular Bt produces a protein that can bind to a larval gut receptor, thereby causing the insect larvae to starve.

Popularity of IPM

With these steps, IPM is best described as a continuum. Many, if not most, agricultural growers identify their pests before spraying. A smaller subset of growers use less risky pesticides such as pheromones. All of these growers are on the IPM continuum. The goal is to move growers further along the continuum to using all appropriate IPM techniques.

(Dent, 1995) (Feder, 2005) (Alavanja, 2004) (McFadyen, 1998) (Kopel, 1992) (US Environmental Protection Agency) (Kogan, 1/1998)

--Anonymous 20:09, 26 March 2007 (EDT)

References