Integrated Pest Management
Integrated Pest Management
Conventional pest control and its problems
Integrated pest management (IPM) is a system that incorporates many methods of dealing with pest problems. IPM systems may include pest-resistant crop varieties; modification of habitat to make it less suitable for the pest; pest-specific predators, parasites, herbivores, or diseases; and pesticides when necessary. However, because IMP systems do not rely exclusively on the use of pesticides, they are a key element of any strategy to reduce the overall use of these chemicals, and thereby avoid the toxicological and ecological damages they cause.
Conventional pest control and its problems
Pests can be defined as any animals, plants, or microorganisms that interfere with some human purpose. For example, insects may be considered pests if they eat crop plants or stored foods, or if they are important vectors in the transmission of diseases of humans or domestic animals. Plants are considered pests, or weeds, if they compete excessively with crop plants in agriculture or forestry, or if they have an unwanted aesthetic, as is the case of weeds in grassy lawns. Microorganisms are regarded as pests if they cause disease in humans, domestic animals, or agricultural plants. In eaqch case, humans may attempt to manage their pest problems with pesticides, that is, chemicals toxic to the pest.
The judicious use of pesticides can be beneficial. For example, agricultural yields can be increased, and stored foods can be protected. Human lives can also be saved by decreasing the frequency of diseases spread by arthropods; malaria, for example, is spread through bites of a few species of mosquitoes. However, there are also some important negative consequences of the use of pesticides to achieve these benefits.
Pesticides are toxic chemicals, and they are rarely poisonous only to the pests against which they may be used. The spectrum of pesticide toxicity is usually quite wide, and includes a diverse range of nonpest (or nontarget) species, in addition to the pest. Most insecticides, for example, are poisonous to a wide range of insect species, to other arthropods such as spiders and crustaceans, and often to fish, amphibians, birds, and mammals, including humans.
Moreover, the operational use of pesticides does not usually achieve a specific exposure of only the pest target—many nonpest species are also exposed through offsite drift or other movements of the sprayed pesticide, both on the actual spray site as well as elsewhere. Nontarget exposures are especially important when pesticides are applied as a broadcast spray over a large treatment area, for example, by an aircraft or tractor-drawn apparatus.
Some important ecological effects are caused by the typically broad spectrum of toxicity of pesticides, and the extensive exposures to nonpest species whenever broadcast sprays are used. For example, the extensive spraying of synthetic insecticides to manage epidemic populations of spruce budworm
(Choristoneura fumiferana ), an important defoliator of coniferforests in northeastern North America, results in huge nontarget kills of diverse arthropod species, and deaths of birds and other vertebrate animals. Similarly, the use of herbicides kills large numbers of plants, in addition to the few species that are sufficiently abundant to be considered weeds.
In addition, some pesticides are toxic to humans, and people may be poisoned as a result of exposures occurring through the normal use of these chemicals. The most intense exposures involve accidents; in rare cases people may be killed by pesticide poisoning. Usually, however, the exposure is much smaller, and the toxic response is milder—often not easily measurable. Generally, people who are employed in the manufacture or use of pesticides are subject to relatively intense exposures to these chemicals. However, all people are exposed to some degree, through the food, water, and air in their environments. In fact, there is now a universal contamination of animals, including humans, with certain types of pesticides, most notably the persistent chlorinated hydrocarbons such as DDT.
Other ecological effects of pesticide use occur as a result of habitat changes. These effects are indirect, and they can negatively influence populations of wildlife even if they are not susceptible to direct toxicity from the pesticide. For example, the use of herbicides in forestry causes large changes in the abundance and species composition of the plant community. These changes are highly influential on the wildlife community, even if the herbicide is not very toxic to animals. Alternative methods of pest management would allow reliance on the extensive pesticide use to be diminished.
Integrated pest management
Compared to reliance on the broadcast pesticide use, integrated pest management is preferable. Through IPM an acceptable degree of pest control can be achieved by using a variety of complementary approaches. These include:
(1) Development and use of varieties of pest- and disease-resistant crop species. If there is genetically based susceptibility to the pest or disease, resistant crop varieties can be developed using standard breeding practices. (2) Attacking the pest biologically by introducing or enhancing the populations of its natural predators, parasites, or diseases. (3) Changing other ecological conditions to make the habitat less suitable for the pest. (4) Undertaking careful monitoring of the abundance of pests, so that specific control strategies can be used efficiently, and only when required. (5) Using pesticides as a last resort, and only when they are a necessary component of an integrated, pest-management system.
If a system of integrated management can be successfully designed and implemented to deal with a pest problem, reliance on pesticides can be greatly reduced, although their use is not necessarily eliminated. For example, a system of integrated pest management has been developed to control boll weevils (Anthonomus grandis ) in Texas cottonfields. The widespread use of this system has allowed large reductions in the use of insecticides for this purpose. About 19 million pounds(8.8 million kg) of insecticides were used against boll weevil in 1964, but only 2.4 million pounds (1.1 million kg) in 1976 after an IPM system became widely used.
Biological control of pests
A very beneficial aspect of IPM is that its control methods are highly specific to the pest, whenever this is biologically or ecologically possible. This allows non-target damages to be avoided or greatly reduced.
Often, the most useful pest-specific control methods involve some sort of biological-control agent, such as a disease, predator, or herbivore that specifically attacks the pest species. Biological agents have been most successful against invasive pests introduced from another continent that are thriving in the absence of their natural control agents.
In the late-nineteenth century, for example, the cottony-cushion scale insect (Icyera purchasi ) was accidentally introduced from Australia to the United States, where it became a serious threat to the developing California citrus industry. In one of the first triumphs of biological control, this pest was successfully managed by introducing an Australian lady beetle (Vedalia cardinalis ) and parasitic fly (Cryptochetum iceryae ).
Because it is toxic to cattle, the klamath weed (Hypericum perforatum ) became a serious problem in pastures in southwestern North America after it was introduced from Europe. However, this weed was controlled by the introducing two European beetles that eat its foliage. A similar success is the control of European ragwort (Senecio jacobea ) in pastures in western North America through the introduction of three of its insect herbivores.
The common vampire bat (Desmodus rotundus ) from subtropical parts of the Americas bites cattle and other animals to obtain a blood meal, which may weaken the victims or cause them to develop diseases. This serious livestockpest can now be controlled by capturing individual bats, treating them with petroleum jelly that contains a pesticide, and then setting the animals free to return to their communal roosts in caves, where the poison is transferred to other bats during social grooming. This treatment is specific, and other bat species are not affected.
Another serious pest of cattle is the screw-worms (Callitroga ominivorax ), whose larvae feed on open wounds and can prevent them from healing. This pest has been controlled in some areas by releasing large numbers of male flies that have been sterilized by exposure to gamma radiation. Because females of this species will only mate once, any copulation with a sterile male prevents them from reproducing. The sterile-male technique works by overwhelming wild populations with infertile males, resulting in few successful matings, and a decline of the pest to an economically acceptable abundance.
The future of pest management
Clearly, it is highly desirable to use IPM systems, especially in comparison with broadcast sprays of conventional, synthetic pesticides. This is particularly true of those relatively few pests for which effective biological controls have been discovered, because these methods have few nontarget effects. IPMs are the key to reducing reliance on pesticides in agriculture, forestry, horticulture, and public health.
It is unfortunate that in spite of ongoing research into their development, effective integrated systems have not yet been discovered for most pest management problems. Because it is important to manage pests, their control must therefore continue to rely heavily on synthetic pesticides. Regrettably, the toxicological and ecological
KEY TERMS
Agroecosystem —An agricultural ecosystem, comprised of crop species, noncrop plants and animals, and their environment.
Drift —Movement of sprayed pesticide by wind beyond the intended place of treatment.
Nontarget effects —Effects on organisms other than the intended pest target of pesticide spraying.
damages associated with a heavy reliance on pesticides will continue until a broader range of integrated tools is available to pest managers.
Resources
BOOKS
Briggs, S.A. Basic Guide to Pesticides. Their Characteristics and Hazards. Washington, DC: Taylor & Francis, 1992.
Freedman, B. Environmental Ecology. 2nd ed. San Diego: Academic Press, 1994.
OTHER
National Sustainable Agriculture Information Service. “Biointensive Integrated Pest Management: Fundamentals of Sustainable Agriculture” <http://attra.ncat.org/attra-pub/ipm.html> (accessed November 29, 2006).
U.S. Environmental Protection Agency—Pesticides: Topical & Chemical Fact Sheets “Integrated Pest Management (IPM)and Food Production” <http://www.epa.gov/pesticides/factsheets/ipm.htm> (accessed November 29, 2006).
Bill Freedman
Integrated Pest Management
Integrated pest management
Integrated pest management (IPM) is a newer science that aims to give the best possible pest control while minimizing damage to human health or the environment . IPM means either using fewer chemicals more effectively or finding ways, both new and old, that substitute for pesticide use.
Technically, IPM is the selection, integration and implementation of pest control based on predicted economic, ecological and sociological consequences. IPM seeks maximum use of naturally occurring pest controls, including weather, disease agents, predators and parasites . In addition, IPM utilizes various biological, physical, and chemical control and habitat modification techniques. Artificial controls are imposed only as required to keep a pest from surpassing intolerable population levels which are predetermined from assessments of the pest damage potential and the ecological, sociological, and economic costs of the control measures. Farmers have come to understand that the presence of a pest species does not necessarily justify action for its control. In fact, tolerable infestations may be actually desirable, providing food for important beneficial insects. Why this change in farming practices?
The introduction of synthetic organic pesticides such as the insecticide DDT, and the herbicide 2,4-D (half the formula in Agent Orange ) after World War II began a new era in pest control. These products were followed by hundreds of synthetic organic fungicides, nematicides, rodenticides and other chemical controls. These chemical materials were initially very effective and very cheap. Synthetic chemicals eventually became the primary means of pest control in productive agricultural regions, providing season-long crop protection against insects and weeds. They were used in addition to fertilizers and other treatments.
The success of modern pesticides led to widespread acceptance and reliance upon them, particularly in this country. Of all the chemical pesticides applied worldwide in agriculture, forests, industry and households, one-third to one-half were used in the United States. Herbicides have been used increasingly to replace hand labor and machine cultivation for control of weeds in crops, in forests, on the rights-of-way of highways, utility lines, railroads and in cities. Agriculture consumes perhaps 65% of the total quantity of synthetic organic pesticides used in the United States each year. In addition, chemical companies export an increasingly larger amount to Third World countries. Pesticides banned in the United States such as DDT, EDB and chlordane , are exported to countries where they are applied to crops imported by the United States for consumption.
For more than a decade, problems with pesticides have become increasingly apparent. Significant groups of pests have evolved with genetic resistance to pesticides. The increase in resistance among insect pests has been exponential, following extensive use of chemicals in the last forty years. Ticks, insects and spider mites (nearly 400 species) are now especially resistant, and the creation of new insecticides to combat the problem is not keeping pace with the emergence of new strains of resistant insect pests. Despite the advances in modern chemical control and the dramatic increase in chemical pesticides used on U.S. cropland, annual crop losses from all pests appear to have remained constant or to have increased. Losses caused by weeds have declined slightly, but those caused by insects have nearly doubled. The price of synthetic organic pesticides has increased significantly in recent years, placing a heavy financial burden on those who use large quantities of the materials. As farmers and growers across the United States realize the limitations and human health consequences of using artificial chemical pesticides, interest in the alternative approach of integrated pest management grows.
Integrated pest management aims at management rather than eradication of pest species. Since potentially harmful species will continue to exist at tolerable levels of abundance, the philosophy now is to manage rather than eradicate the pests. The ecosystem is the management unit. (Every crop is in itself a complex ecological system.) Spraying pesticides too often, at the wrong time, or on the wrong part of the crop may destroy the pests' natural enemies ordinarily present in the ecosystem. Knowledge of the actions, reactions, and interactions of the components of the ecosystems is requisite to effective IPM programs. With this knowledge, the ecosystem is manipulated in order to hold pests at tolerable levels while avoiding disruptions of the system.
The use of natural controls is maximized. IPM emphasizes the fullest practical utilization of the existing regulating and limiting factors in the form of parasites, predators, and weather, which check the pests' population growth . IPM users understand that control procedures may produce unexpected and undesirable consequences, however. It takes time to change over and determination to keep up the commitment until the desired results are achieved.
An interdisciplinary systems approach is essential. Effective IPM is an integral part of the overall management of a farm, a business or a forest. For example, timing plays an important role. Certain pests are most prevalent at particular times of the year. By altering the date on which a crop is planted, serious pest damage can be avoided. Some farmers simultaneously plant and harvest, since the procedure prevents the pests from migrating to neighboring fields after the harvest. Others may plant several different crops in the same field, thereby reducing the number of pests. The variety of crops harbor greater numbers of natural enemies and make it more difficult for the pests to locate and colonize their host plants. In Thailand and China, farmers flood their fields for several weeks before planting to destroy pests. Other farmers turn the soil , so that pests are brought to the surface and die in the sun's heat.
The development of specific IPM program depends on the pest complex, resources to be protected, economic values, and availability of personnel. It also depends upon adequate funding for research and to train farmers. Some of the techniques are complex, and expert advice is needed. However, while it is difficult to establish absolute guidelines, there are general guidelines that can apply to the management of any pest group.
Growers must analyze the "pest" status of each of the reputedly injurious organisms and establish economic thresholds for the "real" pests. The economic threshold is, in fact, the population level, and is defined as the density of a pest population below which the cost of applying control measures exceeds the losses caused by the pest. Economic threshold values are based on assessments of the pest damage potential and the ecological, sociological, and economic costs associated with control measures. A given crop, forest area, backyard, building, or recreational area may be infested with dozens of potentially harmful species at any one time. For each situation, however, there are rarely more than a few pest species whose populations expand to intolerable levels at regular and fairly predictable intervals. Key pests recur regularly at population densities exceeding economic threshold levels and are the focal point for IPM programs.
Farmers must also devise schemes for lowering equilibrium positions of key pests. A key pest will vary in severity from year to year, but its average density, known as the equilibrium position, usually exceeds its economic threshold. IPM efforts manipulate the environment in order to reduce a pest's equilibrium position to a permanent level below the economic threshold. This reduction can be achieved by deliberate introduction and establishment of natural enemies (parasites, predators, and diseases) in areas where they did not previously occur. Natural enemies may already occur in the crop in small numbers or can be introduced from elsewhere. Certain microorganisms , when eaten by a pest, will kill it.
Newer chemicals show promise as alternatives to synthetic chemical pesticides. These include insect attractant chemicals, weed and insect disease agents and insect growth regulators or hormones. A pathogen such as Bacillus thuringiensis (BT), has proven commercially successful. Since certain crops have an inbuilt resistance to pests, pest-resistant or pest-free varieties of seed, crop plants, ornamental plants, orchard trees, and forest trees can be used. Growers can also modify the pest environment to increase the effectiveness of the pest's biological control agents, to destroy its breeding, feeding, or shelter habitat or otherwise render it harmless. This includes crop rotation, destruction of crop harvest residues and soil tillage, and selective burning or mechanical removal of undesirable plant species and pruning, especially for forest pests.
While nearly permanent control of key insect and plant disease pests of agricultural crops has been achieved, emergencies will occur, and all IPM advocates acknowledge this. During those times, measures should be applied that create the least ecological destruction. Growers are urged to utilize the best combination of the three basic IPM components: natural enemies, resistant varieties and environmental modification. However, there may be a time when pesticides may be the only recourse. In that case, it is important to coordinate the proper pesticide, the dosage and the timing in order to minimize the hazards to nontarget organisms and the surrounding ecosystems.
Pest management techniques have been known for many years and were used widely before World War II. They were deemphasized by insect and weed control scientists and by corporate pressures as the synthetic chemicals became commercially available after the war. Now there is a renewed interest in the early control techniques and in new chemistry.
Reports detailing the success of IPM are emerging at a rapid rate as thousands of farmers yearly join the ranks of those who choose to eliminate chemical pesticides. Sustainable agricultural practice increases the richness of the soil by replenishing the soil's reserves of fertility. IPM does not produce secondary problems such as pest resistance or resurgence. It also diminishes soil erosion , increases crop yields and saves money over the long haul. Organic foods are reported to have better cooking quality, better flavor and greater longevity in the storage bins. And with less pesticide residue , our food is clearly more healthy to eat.
See also Sustainable agriculture
[Liane Clorfene Casten ]
RESOURCES
BOOKS
Baker, R. R., and P. Dunn. New Directions in Biological Control: Alternatives for Supressing Agricultural Pests and Diseases. New York: Wiley, 1990.
Burn, A. J., et al. Integrated Pest Management. New York: Academic Press, 1988.
DeBach, P., and D. Rosen. Biological Control By Natural Enemies. 2nd ed. Cambridge, MA: Cambridge University Press, 1991.
Pimentel, D. The Pesticide Question: Environment, Economics and Ethics. New York: Chapman & Hall, 1992.
PERIODICALS
Bottrell, D. G., and R. F. Smith. "Integrated Pest Management." Environmental Science & Technology 16 (May 1982): 282A–288A.
Integrated Pest Management
Integrated pest management
Integrated pest management (IPM) is a system that incorporates many methods of dealing with pest problems. IPM systems may include the use of pest-resistant crop varieties; the modification of habitat to make it less suitable for the pest; the use of pest-specific predators, parasites , herbivores, or diseases; and pesticides when necessary. However, because IMP systems do not have an exclusive reliance on the use of pesticides, they are a key element of any strategy to reduce the overall use of these chemicals, and thereby avoid the toxicological and ecological damages they cause.
Conventional pest control and its problems
Pests can be defined as any animals, plants, or microorganisms that interfere with some human purpose. For example, insects may be considered pests if they eat crop plants or stored foods, or if they are important vectors in the transmission of diseases of humans or domestic animals. Plants are considered to be pests, or weeds, if they excessively compete with crop plants in agriculture or forestry , or if they have an unwanted aesthetic, as is the case of weeds in grassy lawns. Microorganisms are regarded as pests if they cause diseases of humans, domestic animals, or agricultural plants. In all of these cases, humans may attempt to manage their pest problems through the use of pesticides, that is, chemicals that are toxic to the pest.
Very important benefits can be gained through the judicious use of pesticides. For example, agricultural yields can be increased, and stored foods can be protected. Human lives can also be saved by decreasing the frequency of diseases spread by arthropods ; malaria , for example, is spread through bites of a few species of mosquitoes . However, there are also some important negative consequences of the use of pesticides to achieve these benefits.
Pesticides are toxic chemicals, and they are rarely specifically poisonous only to the pests against which they may be used. The spectrum of pesticide toxicity is usually quite wide, and includes a diverse range of non-pest (or nontarget) species, in addition to the pest. Most insecticides , for example, are poisonous to a wide range of insect species, to other arthropods such as spiders and crustaceans, and often to fish , amphibians , birds , and mammals , including humans.
Moreover, the operational use of pesticides does not usually achieve a specific exposure of only the pest target—a large number of nonpest species is also exposed. This includes nonpest species occurring on the actual spray site, as well as species elsewhere that are exposed through offsite drift or other movements of the sprayed pesticide. Nontarget exposures are especially important when pesticides are applied as a broadcast spray over a large treatment area, for example, by an aircraft or tractor-drawn apparatus.
Some important ecological effects are caused by the typically broad spectrum of toxicity of pesticides, and the extensive exposures to non-pest species whenever broadcast sprays are used. For example, the extensive spraying of synthetic insecticides to manage epidemic populations of spruce budworm (Choristoneura fumiferana), an important defoliator of conifer forests in northeastern North America , results in huge nontarget kills of diverse arthropod species, and deaths of birds and other vertebrate animals. Similarly, the use of herbicides kills large numbers of plants, in addition to the few species that are sufficiently abundant to be considered weeds.
In addition, some pesticides are toxic to humans, and people may be poisoned as a result of exposures occurring through the normal use of these chemicals. The most intense exposures involve accidents, and in rare cases people may be killed by pesticide poisoning. Usually, however, the exposure is much smaller, and the toxic response is milder, and often not easily measurable. Generally, people who are employed in the manufacturing or use of pesticides are subject to relatively intense exposures to these chemicals. However, all people are exposed to some degree, through the food, water , and air in their environments. In fact, there is now a universal contamination of animals, including humans, with certain types of pesticides, most notably the persistent chlorinated hydrocarbons , such as DDT.
Other ecological effects of pesticide use occur as a result of habitat changes. These effects are indirect, and they can negatively influence populations of wildlife even if they are not susceptible to direct toxicity from the pesticide. For example, the use of herbicides in forestry causes large changes in the abundance and species composition of the plant community. These changes are highly influential on the wildlife community, even if the herbicide is not very toxic to animals.
Obviously, it is highly desirable that alternative methods of pest management be discovered, so that our reliance on the extensive use of pesticides can be diminished.
Integrated pest management
Compared with reliance on the broadcast use of pesticides, integrated pest management is a preferable system of pest control. Through IPM an acceptable degree of pest control can be achieved by using a variety of complementary approaches. These include the following components: (1) Development and use of varieties of crop species that are resistant to the pest or disease . If there is genetically based variation for susceptibility to the pest or disease, resistant crop varieties can be developed using standard breeding practices. (2) Attacking the pest biologically, by introducing or enhancing the populations
of its natural predators, parasites, or diseases. (3) Changing other ecological conditions to make the habitat less suitable for the pest. (4) Undertaking careful monitoring of the abundance of pests, so that specific control strategies can be used efficiently, and only when required. (5) Using pesticides as a last resort, and only when they are a necessary component of an integrated, pest-management system.
If a system of integrated management can be successfully designed and implemented to deal with a pest problem, the reliance on pesticides can be greatly reduced, although the use of these chemicals is not necessarily eliminated. For example, a system of integrated pest management has been developed for the control of boll weevil (Anthonomus grandis) in cottonfields in Texas. The widespread use of this system has allowed large reductions in the use of insecticides for this purpose. About 19 million lb (8.8 million kg) of insecticides were used against boll weevil in 1964, but only 2.4 million lb (1.1 million kg) in 1976 after an IPM system became widely used.
Biological control of pests
A very beneficial aspect of integrated pest management is the use of control methods that are highly specific to the pest, whenever this is biologically or ecologically possible. This is important because it allows nontarget damages to be avoided or greatly reduced.
Often, the most useful pest-specific control methods involve the utilization of some sort of biological-control agents, such as a disease, predator , or herbivore that specifically attacks the pest species. The use of biological agents has been most successful in the case of invasive pests that have been introduced from another continent , and that are thriving in the absence of their natural control agents. The utility of biological control is best appreciated by considering some examples.
In the late nineteenth century the cottony-cushion scale insect (Icyera purchasi) was accidentally introduced from Australia to the United States, where it became a serious threat to the developing citrus industry of California. In one of the first triumphs of biological control, this pest was successfully managed by the introductions of an Australian lady beetle (Vedalia cardinalis) and parasitic fly (Cryptochetum iceryae).
Because it is toxic to cattle, the klamath weed (Hypericum perforatum) became a serious problem in pastures in southwestern North America after it was introduced from Europe . However, this weed was controlled by the introduction of two European beetles that eat its foliage. A similar success is the control of European ragwort (Senecio jacobea) in pastures in western North America through the introduction of three of its insect herbivores.
The common vampire bat (Desmodus rotundus) of subtropical parts of the Americas bites cattle and other animals in order to obtain a meal of blood , which may weaken the victims or cause them to develop diseases. This serious pest of livestock can now be controlled by capturing individual bats , treating them with petroleum jelly containing a pesticide, and then setting the animals free to return to their communal roosts in caves, where the poison is transferred to other bats during social grooming. This treatment is specific, and other bat species are not affected.
Another serious pest of cattle is the screw-worm fly (Callitroga ominivorax), whose larvae feed on open wounds and can prevent them from healing. This pest has been controlled in some areas by releasing large numbers of male flies that have been sterilized by exposure to gamma radiation . Because females of this species will only mate once, any copulation with a sterile male prevents them from reproducing. The sterile-male technique works by overwhelming wild populations with infertile males, resulting in few successful matings, and a decline of the pest to an economically acceptable abundance.
The future of pest management
Clearly, it is highly desirable to use integrated pest management systems, especially in comparison with broadcast sprays of conventional, synthetic pesticides. This is particularly true of those relatively few pests for which effective biological controls have been discovered, because these methods have few nontarget effects.
It is unfortunate that in spite of ongoing research into their development, effective integrated systems have not yet been discovered for most pest management problems. Because it is important to manage pests, their control must therefore continue to rely heavily on synthetic pesticides. Regrettably, the toxicological and ecological damages associated with a heavy reliance on pesticides will continue until a broader range of integrated tools is available to pest managers.
Integrated pest management is the key for reducing the reliance on pesticides in intensively managed systems in agriculture, forestry, horticulture , and public health.
Resources
books
Briggs, S.A. Basic Guide to Pesticides. Their Characteristics and Hazards. Washington, DC: Taylor & Francis, 1992.
Freedman, B. Environmental Ecology. 2nd ed. San Diego: Academic Press, 1994.
Bill Freedman
KEY TERMS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .- Agroecosystem
—A agricultural ecosystem, comprised of crop species, noncrop plants and animals, and their environment.
- Drift
—Movement of sprayed pesticide by wind beyond the intended place of treatment.
- Nontarget effects
—Effects on organisms other than the intended pest target of pesticide spraying.
Integrated Pest Management
Integrated Pest Management
Integrated pest management (IPM) refers to strategies used to minimize the application of chemical pesticides and to combat plant pests, such as insects and other arthropods , pathogens, nematodes , weeds, and certain vertebrates, without incurring economic plant damage. All plant pests (as well as other life-forms) have natural enemies, and the use of such biological control agents is commonly thought to form the basis of IPM. Biological control can be practiced through the introduction, encouragement, and/ or release in high numbers of appropriate natural enemies of plant pests. However, in many cases, particularly those involving pests other than insects, biological control may be insufficient to provide economic management of pests on crops or other plants valued by humans. Therefore, IPM utilizes an arsenal of additional strategies to accomplish its goals. These tactics may include periodic sampling of plants to determine if and when pesticides must be used to avoid economic damage, and when the target pests are most susceptible to the least amount of pesticidal treatment. Elements of cultural or physical management, such as crop rotation, destruction of infested plant material which may serve as a source of subsequent pest problems (sanitation), or use of high temperatures or moisture (flooding) to destroy pests. Most of these strategies can be used by home gardeners, as well as by farmers, and are site or situation specific to a particular plant environment.
There are many variants of IPM philosophy. These differences form a continuum from simply using knowledge of pest biology to apply pesticides with timing that is optimal for managing pests, while minimizing applications of pesticides, to the total exclusion of "hard" pesticides in favor of "soft" or naturally derived materials that are less disruptive to nontarget organisms and the environment ("bio-intensive" or "bio-based" IPM).
This type of bio-intensive IPM is not much different from some forms of organic or ecological plant culture. Like IPM, organic growing philosophy has many variants, and most of these allow the use of certain naturally derived, as opposed to synthetic, pesticides. However, many of these types of natural materials can also become pollutants, if used unwisely or in large quantities.
see also Agriculture; Pesticides; Sustainable Development.
Bibliography
flint, mary louise, and dreistadt, steven h. (1998). natural enemies handbook: the illustrated guide to biological pest control. berkeley, ca: university of california press.
stapleton, james j. (1995). "evolving expectations for integrated disease management: advantage mediterranea." journal of turkish phytopathology 24(2):93–98.
reuveni, reuven, ed. (1995). novel approaches to integrated pest management. boca raton, fl: lewis publishers.
internet resource
university of california statewide integrated pest management program. "what is ipm?" available from http://www.ipm.ucdavis.edu/ipmproject.
James J. Stapleton