INTEGRATED PEST MANAGEMENT

by Beth Lindblom Patkus

Preservation Consultant

Walpole, MA

INTRODUCTION

A variety of insects and other pests attack binding materials, adhesives, and other substances in library and archival collections. Since some insects are attracted to the tight, dark places that abound in storage areas, and since many materials are handled infrequently, insects and other pests may do significant damage before they are discovered.

Libraries and archives have traditionally relied on pesticides for routine pest prevention and response to observed infestation. Pesticides often do not prevent infestation, however, and application of pesticides after the fact cannot correct the damage already done. Pesticides have also become less attractive because of a growing awareness that the chemicals in pesticides can pose health hazards to staff and damage paper-based collections. Newer extermination methods such as controlled freezing and oxygen deprivation have shown promise as alternatives for treatment of existing infestations, but like pesticides, they do not prevent infestation. Prevention can be achieved only through strict housekeeping and monitoring procedures.

Preservation professionals increasingly recommend a strategy called integrated pest management (IPM). This approach relies primarily on non-chemical means (such as controlling climate, food sources, and building entry points) to prevent and manage pest infestation. Chemical treatments are used only in a crisis situation threatening rapid losses or when pests fail to succumb to more conservative methods.

LIBRARY AND ARCHIVES PESTS

Most of the insect species likely to infest paper collections are attracted not by the paper itself but by sizes, adhesives, and starches, all of which are more easily digested than the cellulose that makes up paper. Some insects will also attack cellulose (i.e., paper and cardboard) and proteins (i.e., parchment and leather). Insect damage does not come solely from dining habits; collections are also damaged by tunnelling and nesting activities, and by bodily secretions.

Silverfish, firebrats, psocids (also called booklice), and cockroaches are among the most common library pests. Silverfish and firebrats can reach up to 12.5 mm in length; they feed on paper sizing, chew holes in paper (especially glossy paper), and damage book bindings and wallpaper to get to the adhesives underneath. They also feed on textiles, primarily rayon, cotton, and linen. They prefer dark, humid areas that are undisturbed for long periods of time. Psocids feed on microscopic mold growing on paper, and thus their presence usually indicates a humidity problem in the storage area. They are much smaller than silverfish and firebrats (about 1-2 mm), and may also feed on pastes and glues, but they do not produce holes in paper.

Cockroaches are omnivorous, but are especially fond of starchy materials and protein; they will eat book pages, bindings, adhesives, leather, and wallpaper. Cockroaches will chew holes in paper and bindings, but also can badly stain materials with their secretions. Cockroaches are thigmotactic, meaning that they like to contact a surface on all sides of the body; they seek very small crevices, between framed objects and the wall, etc.

The above discussion of library pests is far from exhaustive. Additional information on library and museum pests can be found in Harmon, Zycherman & Schrock, and Story, referenced at the end of this leaflet. Although other pests such as rodents may be encountered in libraries and archives, this leaflet will concentrate primarily on the prevention of insect infestations.

WHAT DO PESTS EAT?

All insects go through a metamorphosis during their life cycle; their growth proceeds in a series of steps until they reach adult stage. Other stages include egg, larva, pupa, and nymph; not all insects go through all stages. For many insects, the larva stage is the most damaging since that is when the most feeding takes place, but others (such as booklice) also inflict damage in the adult stage.

It is important to remember that collections themselves are not the only source of food for insects. There is a huge spectrum of foodstuffs for insects and other pests in library and archives buildings. The most obvious attractant is human food waste and stored food in offices and kitchens, but there are many other less obvious food sources.

Dermestid beetles may attack leather and wool, including rugs. They may also be attracted by dead birds and/or abandoned birds nests. Some species of beetles feed on the pollen and nectar from flowering plants, while others eat shed hair and skin cells from humans and other animals. Dust mites, which are numerous and almost invisible, feed on this human dander.

Although some insects may not be a direct threat to collections, their presence may attract insects that do pose a threat. Some insects feed on the bodies of other insects. Most pests (insect and otherwise) are attracted by debris from human or other animal activities.

Since most buildings and collections offer a seemingly endless supply of food for insects and other pests, it is clear that the first priority for effective pest prevention must be to eliminate sources of food and strongly emphasize strict housekeeping.

HABITATS AND BREEDING HABITS

Insect species require specific ranges of temperature, relative humidity, and other conditions in order to flourish. The first condition for their presence is the existence of openings in the building envelope through which they can enter. Once insects have entered a building, they seek out moisture, food sources, and undisturbed spaces for breeding.

Routes of entry

Inadequately sealed windows and doors, or windows and doors that are left open routinely, can provide an entry point for insects. Cracks and crevices in walls or foundations or openings around pipes can also be an entry route. Insects can squeeze through extremely small openings. Vents and air ducts can provide an entry point for birds, rodents, and insects. Plantings close to a building provide an excellent habitat for insects, which may then migrate into the building through various openings. Insects also can be brought into the building in books and papers themselves.

Climate

Optimum temperature for many insects is between 68-86°F. Most insects will die if exposed to temperatures below 28°F or above 113°F for a period of time. Optimum humidity levels for their proliferation are generally between 60%-80%. 1 Insects need moisture to survive, and some (such as psocids and silverfish) thrive on high humidity.

Water sources

Many insects are attracted to damp areas. Sources of water and potential insect habitats include water pipes running through collections, restrooms, kitchens, water fountains, custodial closets, and climate-control equipment. Standing water on a roof or in other locations can raise humidity levels and provide an excellent environment for insects.

Food sources

Food waste in kitchens and offices provides sustenance for insects, particularly if it remains in a building and uncovered for long periods of time. Potted plants and cut flowers, water in vases and over-watered plants, dead and dying plants, and the nectar and pollen of flowering plants all encourage the presence of insects.

Storage conditions

Some insect species that threaten collections thrive in small, dark, undisturbed spaces, in other words, in conditions that are common to storage areas. Insects will set up housekeeping inside dark, tight spaces (such as corrugated boxes), and are attracted to piles of boxes or other materials that are left undisturbed for long periods. Insects also live in quiet spaces like corners, the undersides of bookcases, and behind furniture. Dust and dirt help to provide a hospitable atmosphere for pests. Dead insects or insect debris can attract other insects. Dirt and clutter also make it difficult to see pests, so a problem may go unnoticed for some time.

Control of insect infestation requires elimination insofar as possible of potential insect habitats and food sources.

IPM STRATEGIES

Integrated pest management strategies encourage ongoing maintenance and housekeeping to insure that pests will not find a hospitable environment in a library or archives building. Activities include building inspection and maintenance; climate control; restriction of food and plants; regular cleaning; proper storage; control over incoming collections to avoid infestation of existing collections; and routine monitoring for pests.

It is best to begin a formal pest management program with an initial survey of the building and all collection storage areas. Have there been any pest problems in the past? If so, what type of pest was involved and what materials were affected? What was done to solve the problem? Any potential insect habitats should be eliminated. There are several steps that can be taken to reduce the number of insects in a library or archive.

Routes of entry

Windows and doors should be tightly sealed; weatherstripping may be necessary. Doors should not be propped open regularly. Openings around pipes should be sealed, as should cracks in the walls or foundation. Vents should be screened to keep out birds and rodents. A planting-free zone of about 12 inches should be maintained around buildings to discourage insects from entering. Plantings should be properly cared for and not over watered. The area around foundations should be graveled and graded away from a building to avoid basement flooding.

Climate

Climate should be moderate; conditions should be cool and dry; specifics depend on the needs of different materials. Temperature should be 68°F or lower, and relative humidity should be kept below a maximum of 50%. Maintaining climate conditions recommended for the preservation of books and paper will help to control insect populations.

Water sources

Pipes in collections areas and other sources of water such as restrooms, kitchens, or climate-control equipment should be inspected routinely to guard against water leakage. Wrap sweating pipes with insulating tape. Close off unused drains or drainpipe openings. Roofs and basements should be inspected periodically to insure that there is no standing water or flooding. Where problems recur, frequent inspections are necessary.

Food sources

Plants and cut flowers should be removed from the building. If this is impossible, plants should be well cared for and kept to a minimum; flowering plants should certainly be avoided. Avoid over watering and watch plants carefully for signs of infestation or disease. Food consumption should be confined to a staff lounge; staff should not eat at their desks. If functions that include refreshments are held in other spaces, all leftovers should be tightly sealed or removed by the caterers. Vacuuming and kitchen cleanup should be done immediately. All food should be stored in tightly sealed glass or metal containers or refrigerated, and a plastic garbage can with a tight-fitting lid should be provided for food waste. Trash should be removed from the building daily.

Housekeeping

Collection storage areas (and other areas) should be cleaned routinely and thoroughly, at least every 6 months. All areas should be checked for signs of pests at least once a month. Look at collections for stains and signs of insect grazing (small holes in paper, or areas of loss on the surface of paper or bindings). Check window sills; under bookcases and radiators; on and behind shelves; and inside boxes and drawers for signs of insect activity. Look for small piles of dust, insect bodies, frass (insect droppings), egg cases, and live insects; clean up any insect debris immediately.

Incoming collections

It is particularly important to develop strict procedures for dealing with newly acquired collections, since such collections have often been stored in attics or basements that are hospitable to pests.

Examine incoming material immediately to see if there is evidence of infestation. Work over a clean surface covered with blotter or other light paper. Remove all objects from storage or shipping enclosures and look at the binding, pages, and hollow (if any) in books. Examine frame backings and mats, wrappings, and other accompanying materials. Look for live creatures, insect droppings, larvae, or bodies.

Transfer materials to clean archival boxes until you can process them. If possible, isolate rehoused, incoming materials in a space away from other collections until processing. Space that will provide preservation conditions is cool, dry, clean, outfitted with shelving, etc., to discourage mold and insects. Throw the old boxes away unless they are archival quality and you are absolutely certain they are clean.

The clean archival boxes can be used over and over for this temporary holding use as long as the contents and boxes continue free of evidence of insects. Ideally, of course, incoming material should be processed and rehoused in its permanent enclosures promptly. Realistically, processing may be delayed, and the interior of boxes should be inspected routinely at least every few weeks. A tent or motel-type sticky trap can be placed on a side wall inside each box to improve monitoring.

If there is evidence of insects, talk to a preservation professional for detailed advice before proceeding further. Materials can be vacuumed thoroughly (assuming the objects are not deteriorated or fragile) through a nylon or other soft screen, using a high-filtration vacuum. Discard both filter and disposable bag outside the building or in a sealed container which is provided for food wastes and is emptied daily.

Pest monitoring

Effective implementation of a pest management program requires routine monitoring of pest activity. Routine monitoring using traps provides information about the type of insect(s), their entry points, the number of insects, where they are taking up residence, and why they are surviving. This information allows for identification of problem areas and development of a species-specific treatment program.

The most commonly used insect traps are sticky traps, available from most hardware and grocery stores. Several types are available: flat traps, rectangular box-shaped traps (motels), and tent-shaped traps. Many conservators recommend the tent traps as the easiest to handle. Whatever type and brand is chosen, consistency should be maintained so that data can be interpreted accurately.

The basic procedure for monitoring is as follows: 1) identify all doors, windows, water and heat sources, and furniture on a building floor plan; 2) identify likely insect routes, and mark trap locations on a floor plan; 3) number and date the traps; 4) place the traps in the area to be monitored, as indicated on the floor plan; 5) inspect and collect the traps regularly; and 6) refine trap placement and inspection as necessary, according to the evidence collected. Relocate traps (if initial results are negative) and try again.

If infestation is suspected in a particular area, place traps every 10 feet. Care should be taken to insure that traps do not come into contact with collection materials, since the adhesive can cause damage. Checking the traps 48 hours after placement will identify the area most seriously infested. Traps should be inspected weekly for at least three months and should be replaced every two months, when they are full, or when they lose their stickiness.

Documentation is essential; monitoring will be useless without it. The number of insects, the types of insects, and their stage of growth should all be recorded for each trap. Dates and locations of trap replacements should be noted. Detailed records should also be kept of any other evidence of activity, such as live or dead insects or their droppings.

Once insects have been trapped, they must be identified to determine what threat they pose to collections. There are several good books with drawings and descriptions of common library and archives pests; these are listed in the bibliography. An excellent resource for identification is the local or state Agricultural Extension agency, which will usually identify insects free of charge (the insect must be sent to them, and the entire body must be intact). Other potential resources include the biology department of a local university or a local history museum with an entomologist on staff.

TREATMENT METHODS

It is important to remember that sighting one or two insects is an occasion for monitoring to determine the extent of the problem; it is not necessarily a crisis situation. In the past, insect sightings often occasioned an indiscriminate use of pesticides.

If a serious insect infestation occurs, or if insect problems do not respond to the preventive techniques discussed above, direct treatment for insect infestation may be necessary. This strategy should be used as a last resort. Both chemical and non-chemical treatments are available; non-chemical means should be used wherever possible.

Chemical treatments

Pesticides are divided into categories, depending on the way they are used and their physical state.

Common chemical treatments used to control insects include aerosol sprays; attractants (which lure insects into traps, sometimes killing them); baits and pellets (which are eaten by the insects); contact and residual sprays (normally sprayed into cracks and crevices; these kill on contact and/or by absorption of the pesticide when the insect walks through the residue); dusts (e.g., boric acid or silica dust, which dehydrate insects or interfere with internal water regulation); fogging concentrates (these use equipment that suspends a pesticide and oil formulation in the air); fumigants (these expose infected material to a lethal gas); and residual and vapor pest strips (the insect absorbs pesticide by walking across residual pest strips, while pesticide evaporates from vapor pest strips to become a fumigant). Repellents (such as mothballs) are also sometimes used; these are meant to discourage rather than kill insects.

Fumigants are among the most toxic of pesticides; other pesticides are usually suspended in a liquid and sprayed, so that they tend to settle out of the air. Fumigant gases remain in the air and can easily spread over a wide area. Ethylene oxide (ETO), a gaseous fumigant, was commonly used in libraries and archives until the 1980s; many libraries had their own ETO chambers. ETO is effective against insect adults, larvae, and eggs. It poses serious health hazards to workers, and there is evidence that ETO can change the physical and chemical properties of paper, parchment, and leather. Acceptable limits on ETO exposure have been steadily lowered by the government, and most existing ETO chambers in libraries cannot meet these restrictions. Some residual ETO remains in treated materials, and little is known about the long-term risks to collections and staff from off-gassing toxins. ETO should be used only as a last resort; materials should be sent to a commercial facility and allowed to off-gas for at least several weeks before being returned to the library or archives.

In general, fumigants and other pesticides can cause long- and short-term health problems, ranging from nausea and headaches to respiratory problems to cancer. Many chemical treatments may cause no ill effects at the time of exposure, but may be absorbed into the body to cause health problems years later. Many of the chemicals also damage the treated materials and no chemical treatments provide a residual effect that will prevent reinfestation. Growing awareness of the risks has brought about increased emphasis on non-chemical pest-control methods.

Non-chemical treatments

A variety of non-chemical processes for exterminating insects have been explored. The most promising are controlled freezing and the use of modified atmospheres. Methods that have not proved as successful include the use of heat, gamma radiation, and microwaves.

Controlled freezing has been undertaken in various institutions over the past 15 years, and reports on its effectiveness have been largely favorable. Freezing is attractive because it involves no chemicals and thus poses no hazard to library staff. It can be used on most library materials and does not appear to damage collections (according to existing literature on experimental efforts), but research into this question is not yet complete. Very fragile objects, those made from a combination of materials, and artifacts with friable media should probably not be frozen; a conservator should always be consulted before any method is chosen.

Materials can be treated in household or commercial freezers, blast freezers, or controlled-temperature and humidity freezers. It is necessary to bag and seal items unless a freezer with specially controlled temperature and humidity is used. Bags must be sealed immediately to prevent insects from escaping. Some institutions box materials and then bag them. Bagging protects objects from changes in moisture content during defrost cycles and from condensation on cold books when they are removed from the freezer.

It is essential to guard against freeze resistance; some insects can acclimate to cold temperatures if they are kept in a cool area before freezing or if freezing happens too slowly. Research is incomplete in this area; it is not known if common library pests are able to develop freeze resistance.

In the absence of definitive data, material must be kept at room temperature until freezing begins. Items should not be packed too tightly within a freezer, since this can slow the freezing process. Most important, material should be frozen quickly. Freezer temperature should reach 0°C within 4 hours and -20°C within 8 hours. The most commonly reported successful treatments have been carried out at -29°C for a period of 72 hours. It is unknown whether higher temperatures for a shorter time would be equally effective; there are reports that 20°C for 48 hours has also been used with success.

Collections should be slowly thawed (brought up to 0°C over 8 hours) and brought up to room temperature. The entire process should then be repeated to insure effectiveness. Objects should remain bagged (some institutions leave them bagged for 6-8 months) until monitoring in the space indicates that the insect problem has been solved. Detailed documentation of each phase of treatment should be maintained. Like chemical treatments, freezing provides no residual benefits. If collections are not returned to a well maintained storage area, reinfestation will almost certainly occur.

Modified atmospheres have been used widely in the agricultural and food industries to control insect infestation. The term refers to several processes: decreased oxygen, increased carbon dioxide, and the use of inert gases, primarily nitrogen. Various experiments with modified atmospheres have been undertaken by cultural

institutions over the past 10 years, with generally successful results. Modified atmospheres show great promise, but additional research is needed to determine optimum exposure times and methods for particular types of insects. There appears to be no obvious damage to collections, but little research has been done on long-term effects. There is potential danger to staff from exposure to high levels of carbon dioxide, if that is used, but there are no residual effects on collections.

Modified atmospheres can be applied 1) in a traditional fumigation chamber or a portable fumigation bubble or 2) in low-permeability plastic bags. With a chamber or a bubble, materials are prepared for treatment (quarantined, documented, and loaded into the treatment chamber), air is evacuated from the chamber, and carbon dioxide (generally about 60% concentration) or nitrogen (to achieve an atmosphere of less than 1% oxygen) is introduced. Once the desired atmospheric concentration is reached, conditions are maintained at a specific temperature and relative humidity for the required amount of time.

Once treatment is finished, the vacuum is released, the carbon dioxide or nitrogen is removed, the chamber is aerated, and materials are removed to a quarantine area so that the effectiveness of treatment can be assessed. The process for treating materials in low-permeability plastic bags is similar, except that materials are sealed in bags with an oxygen scavenger that will reduce the oxygen level in the enclosure to less than what is needed for insect respiration. In some cases, the bags are purged with nitrogen before sealing.

In the tests conducted thus far, a variety of exposure times, temperatures, and relative humidities have been used. Since requirements for achieving an acceptable kill rate seem to vary according to the type of insect being exterminated and the type of process being used, there are not yet any generally-accepted guidelines for the application of modified atmospheres. Always contact a preservation professional for advice before proceeding with modified atmosphere treatment.

Heat can effectively exterminate insects; it has been used widely in food processing and medicine. A temperature of 140°F for at least one hour will kill most insects. Heat should not be used to eliminate insects from paper collections, however, because heat at the levels needed to kill insects greatly accelerates oxidation and paper aging; materials can become brittle and otherwise damaged.

Gamma radiation is used to sterilize cosmetics, food and agricultural products, medical supplies, and hospital and lab equipment. It poses some danger to personnel during treatment, but there is no residual radiation in the treated material. Gamma radiation can be effective against insects, but the minimum lethal dose for various species is still unknown and is affected by variables such as climate conditions and the nature of the infested material. Most important, research has shown that gamma radiation may initiate oxidation and cause scission of cellulose molecules; it has the potential to seriously damage paper-based materials. There is also a cumulative effect from repeated exposures. As a result, gamma radiation is not recommended.

Rumors about the effectiveness of microwaves for killing insects have circulated in the library community over the past several years. Microwaves are used successfully in the food, agricultural, and textile industries to control insects, but this strategy is not recommended for library collections. Microwaves have a limited penetration, and may not penetrate thick books. Their effectiveness also depends on the type of insect and the intensity and frequency of the radiation. Microwave ovens vary in intensity, so it is extremely difficult to determine standard times and temperatures for treatment. The primary argument against microwaves is the danger of damage to treated materials. Evidence from a variety of experiments indicates that pages and covers can scorch; metal attachments like staples can cause arcing; and adhesives can soften, causing pages to detach from their bindings in certain books.

Freezing and modified atmospheres currently show the most promise as alternatives to traditional pesticides. They remain experimental until more research has been done, however, so a preservation professional should be consulted before undertaking either treatment.

SUMMARY

Library and archival collections can be threatened by a variety of pests that damage paper-based and other materials. The method of pest control least damaging to collections and staff involves preventive measures and regular monitoring. If infestation does occur, treatment should be tailored to the specific insect species and the type of material that is infested. Chemical treatments should be avoided except as a last resort. Emerging technologies such as blast freezing and modified atmospheres have significant potential as alternatives to chemical control.

NOTES

Johanna G. Wellheiser, Nonchemical Treatment Processes for Disinfestation of Insects and Fungi in Library Collections. (Munich: K.G. Saur, 1992), p. 5. 3Wellheiser, p. 27

SOURCES FOR FURTHER INFORMATION

"A Virtual Exhibition of the Ravages of Dust, Water, Moulds, Fungi, Bookworms and other Pests." Available at http://www.knaw.nl/ecpa/expo.htm. A general introduction to the topic, prepared by the European Commission on Preservation and Access (ECPA).

"Integrated Pest Management." Audiovisual Department, Universite du Quebec a Montreal and Canadian Conservation Institute and Centre de Conservation du Quebec. 1995. Videotape, 22 minutes. A professionally produced video that provides good basic information for museums and archives. Comes with a short, informative booklet that gives the key points and suggests further reading.

Butcher-Younghans, Sherry, and Gretchen E. Anderson. A Holistic Approach to Museum Pest Management. American Association for State and Local History (AASLH) Technical Leaflet 191 (1990). Nashville, TN:

AASLH. Detailed, practical advice for controlling a range of pests commonly found in museums. This and other excellent publications can be ordered through their Web site, http://www.aaslh.org/, by writing to 530 Church Street, Suite 600, Nashville, TN 37219-2325, or by tel. 615/255-2971.

Canadian Conservation Institute. "Preventing Infestations: Control Strategies and Detection Methods," and "Detecting Infestations: Facility Inspection Procedure and Checklist." CCI Notes 3/1 and 3/2. Ottawa: CCI, 1996. 4 pp. and 3 pp. Short leaflets written primarily for museums providing general information about monitoring with traps and inspecting a building for infestation.

Daniel, Vinod, Gordon Hanlon, and Shin Maekawa. "Eradication of Insect Pests in Museums Using Nitrogen." WAAC Newsletter 15.3 (September 1993): 15-19. Describes Getty Conservation Institute tests of low-oxygen atmospheres for treatment of pest-infested museum objects. Air was replaced with nitrogen in a bag encapsulating the infested object so that the oxygen concentration was reduced to less than 0.1%. Available online at: http://palimpsest.stanford.edu/waac/.

Elert, Kerstin, and Shin Maekawa. "Rentokil Bubble in Nitrogen Anoxia Treatment of Museum Pests." Studies in Conservation 42 (1997): 247-52. Describes tests conducted on a commercially available portable fumigation enclosure to determine its suitability for nitrogen fumigation. Addresses set-up, safety considerations, and limitations of the technology.

Goldberg, Lisa. "A History of Pest Control Measures in the Anthropology Collections, National Museum of Natural History, Smithsonian Institution." Journal of the American Institute for Conservation 35.1 (Spring 1996): 23-43. An interesting review of pest eradication techiques (particularly pesticides and fumigants) used at the National Museum of Natural History during the 19th and 20th centuries. Discusses the effects of such techniques on the collections.

Harmon, James D. Integrated Pest Management in Museum, Library, and Archival Facilities: A Step by Step Approach for the Design, Development, Implementation, and Maintenance of an Integrated Pest Management Program. Indianapolis: Harmon Preservation Pest Management (P.O. Box 40262, Indianapolis, IN 46240), 1993. 140 pp. A thorough, useful guide (in a three-ring binder) to IPM for collections-holding institutions. Covers monitoring, identification, and non-chemical and chemical strategies for pest control for insects and other pests like pigeons.

Hengemihle, Frank H., Norman Weberg, and Chandru J. Shahani. "Desorption of Residual Ethylene Oxide from Fumigated Library Materials." Washington, DC: Preservation Research and Testing Office, Preservation Directorate, The Library of Congress, November 1995. Preservation Research and Testing Series No. 9502. Describes studies undertaken to compare the relative capacity of selected library materials for offgassing of ethylene oxide. Useful for those concerned about exposure to collections that were fumigated with ethylene oxide in the past. Available at: http://lcweb.loc.gov/preserv/rt/fumigate/fume.html.

Jacobs, Jeremy F. "Pest Monitoring Case Study," in Storage of Natural History Collections: A Preventive Conservation Approach, Volume 1. Carolyn Rose, Catharine A. Hawks, and Hugh H. Genoways, eds. Society for the Preservation of Natural History Collections, 1995. A detailed description of the pest-monitoring activities undertaken by the Division of Mammals in the National Museum of Natural History.

Jessup, Wendy Claire. "Integrated Pest Management: A Selected Bibliography for Collections Care." February 1997. An excellent annotated bibliography that covers museum, library, and archival pests; integrated pest management methods; the effects of pesticides on collections; and occupational safety and health. Available at http: palimpsest.stanford.edu.

Odegaard, Nancy. "Insect Monitoring in Museums"; and Dale Paul Kronkright. "Insect Traps in Conservation Surveys." Both in WAAC Newsletter 13.1 (January 1991): 19-23. Both articles offer practical tips for monitoring insect populations using various types of traps. Available online at:

http://palimpsest.stanford.edu/waac/.

Parker, Thomas A. Study on Integrated Pest Management for Libraries and Archives. Paris: UNESCO, General Information Program and UNISIST, 1988. Publication number PGI-88/W3/20. 119 pp. Excellent publication covering the basics of pest management for cultural institutions.

Story, Keith O. Approaches to Pest Management in Museums. Washington, DC: Smithsonian Institution, 1985, 165 pp. Out of print. Some of the chemical-treatment information is outdated, but identification and IPM strategies are good.

Wellheiser, Johanna G. Nonchemical Treatment Processes for Disinfestation of Insects and Fungi in Library Collections. Munich: K.G. Saur, 1992, 118 pp. An excellent review of the various options for controlling pests in libraries; covers fumigants, freezing, gamma radiation, microwaves, and modified atmospheres. Includes information about treatment procedures; costs; results reported by various institutions; and benefits and risks of each treatment.

Zycherman, Linda A., and J. Richard Schrock, eds. A Guide to Museum Pest Control. Washington, DC: American Institute for Conservation and Association of Systematics Collections, 1988. 205 pp. Some information is outdated, but still a good basic text.

INTEGRATED PEST MANAGEMENT

Ki-Baik Uhm Entomology Division, National Institute of Agricultural Science & Technology Rural Development Administration 250, Seodun-Dong, Kwonseon-Ku, Suwon Kyungki-Do 441-707 Republic of Korea 1999-05-01

Integrated Pest Management (IPM) is accepted world-wide as the best way to protect crops with reduced pesticide use. However, IPM has several weak points with regard to ambiguous definitions, as well as difficulties in implementation. Several national IPM programs are discussed as case studies, and the needs of IPM in terms of policy, organization, research, extension, and evaluation. Case studies of successful IPM programs showed they were all good at defining their objectives and problems, and were able to harmonize policy, research, and extension in their implementation. To develop IPM programs for the 21st century, directional research and extension seems to be needed, rather than the development of new technology.

INTRODUCTION

For several decades, chemical pesticides have been considered the only reliable method of controlling pests. This was because most pesticides proved effective, while the cost of pesticides was only a small proportion of the total production costs. Consequently, growers, consumers and politicians did not pay much attention to an alternative approach — Integrated Pest Management (IPM). As a result, there have been relatively few successful cases of IPM.

Recently, however, the demand for IPM solutions have been increasing, rapidly due to the limitations now evident in chemical pesticides. First, the demand for food safety and conservation of the environment has been increasing, as the quality of public life improves with economic development. For example, articles in one of Korea's major daily newspapers dealing with pesticides appeared 134 times, or about once a week, during the period from 1995 to 1997. Of these articles, 70% were related to the adverse effect of pesticides and how to solve this problem (HYPERLINK "http://www.agnet.org/library/image/eb470t1.html" µTable 1§). Concern about the side effects of pesticides is not a new issue, and is now a global concern. Consequently, the reduction in pesticide use ranks as a top priority in many countries, including Korea.

Second, the average age of Korean farmers is increasing. Younger farm workers are trying to avoid spraying pesticides inside greenhouses to protect their health. As a result, the labor cost of pesticide applications has increased.

Third, it is not easy to find effective insecticides against new exotic insect pests such as greenhouse whitefly, (Trialeurodes vaporariorum), or thrips (Frankliniella occidentalis and Thrips palmi). There are only five pesticides registered in Korea for the control of greenhouse whitefly, and seven for the control of thrips. This is much fewer than the number of products available to control aphids and mites (HYPERLINK "http://www.agnet.org/library/image/eb470t2.html" µTable 2§). In 1995, 58 pesticides were tested to find those which were effective against Thrips palmi. Of these, only three were effective (Lee et al. 1995).

Furthermore, new pesticides are much more expensive, because many of them are extracted from soil-borne microorganisms. This lack of cheap, effective pesticides has led farmers to look for alternative methods to solve their pest problems.

Fourth, some endemic insect pests (e.g. two-spotted spider-mite and aphids) can develop pesticide resistance quickly, so that farmers apply excessive amounts of pesticide.

Finally, the increased use of insect pollinators in greenhouses is another reason why IPM is becoming more popular nowadays. Growers are increasingly using pollinating insects such as bumblebees in their greenhouses, and must be careful about using pesticides in order to protect them. These five reasons are the principle catalysts of change, and are why IPM is increasingly being seen as an alternative system of pest management.

DEFINITION OF IPM

There are 64 definitions of integrated control, pest management, or integrated pest management that have been made since the early 1930s (Bajwa & Kogan 1996). In simple terms, IPM can be defined as a procedure to manage pest populations by harmonizing control methods such as natural enemies, pesticides and cultural practices. The purpose of IPM is not eradication or removal of the pest, but management of pest populations so that economic damage and harmful environmental side-effects are minimized.

Rational decision-making is the basis of the IPM concept to avoid overuse of pesticides. Furthermore, IPM provides a safe environment, sustainable agriculture, and superior agricultural products for world trade. IPM can be a remedy for the problems caused by pesticides, such as increased food prices and increased public costs for water purification and medical services. Thus, IPM can increase the real income of farmers, maintain productivity, improve the environment, and protect the health of consumers and farmers. These are the reasons why IPM is now welcomed by everyone, and called "all things to all people". Nowadays, the IPM approach is the central theme for combating pests that affect human and animal health.

HISTORICAL REVIEW

The theory and principles supporting IPM have been developed over the last 40 years. Prior to World War II, pest control was accomplished primarily through cultural practices such as tillage and rotation, and mechanical removal of pests. After World War II, DDT and other organic insecticides came into use worldwide to control insect pests. The period from the late 1940s through to the mid-1960s has been called the "Dark Ages" of pest control (Newsom 1980).

The regular use of pesticides was the basis of pest control practices on almost all farms in industrialized countries in the early 1950s. Most early researchers focused on the development and application of pesticides.

By the 1970s, farmers had come to rely on pesticides, and other control methods were not even considered. Regular spray programs were developed on a routine preventive basis, which provided a shield of pesticide protection whether the pest was present in damaging numbers or not.

Shortly after the introduction of control programs based on pesticides, however, resistance, resurgence, and residual problems began to emerge. Some farmers experienced disaster because they could not cultivate crops any more, since no pesticide could control the pests on their farms, or the cost became too high. Perhaps the most alarming example of this is the cotton fields in Peru, Egypt, Central America, and Texas (USA). In an effort to control pests in cotton, some farmers increased the application of highly toxic pesticides to 60 applications during the growing season. Under these conditions, the cost of pest control made the production of cotton profitless, and the industry collapsed in some areas.

Integrated control (IC), the term first applied to IPM, was developed and introduced as a concept in the United States in the late 1950s. IC was developed to harmonize chemical control and biological control. It was Smith and Allen (1954) who established IC as a new trend in economic entomology. The early concept was based on the premise that pesticides could have a minimum impact on the natural enemies of the pest if applied at the correct time and under the correct conditions.

"Economic threshold", another important concept in IPM, was introduced at that time. It is based on the knowledge that pest populations fluctuate naturally. Control measures should only be used to prevent an increasing pest population from reaching the economic injury level. The "economic injury level" was defined as the lowest density that will cause economic damage. These concepts remained the major theme of IPM throughout much of the 1970s.

The focus of IPM began to shift to non-pesticidal tactics in the 1980s, including expanded use of cultural controls, introduction of resistant plants, and biological control. Although a mass of research results on the effectiveness of IPM were published during the 1970s and 1980s, IPM was not implemented by farmers on a large scale before the 1990s. One of the major reasons was the lack of extension support.

In the 1990s, extension techniques and policy have been emphasized strongly in the development of IPM. The characteristics of IPM in each decade are summarized in HYPERLINK http://www.agnet.org/library/image/eb470t3.html Table 3§.

DEVELOPING AN IPM SYSTEM

The IPM process begins with finding current pest problems in the local cropping system, and seeks to develop a solution to these. Next, IPM is systematically combined with other tactics, extension plans and implementation programs to provide an integrated system of pest control. Some might say that IPM is more likely to succeed early if countries import and adopt IPM models which have worked well elsewhere. However, an IPM model from abroad cannot necessarily be applied directly, because each IPM system is developed to solve problems specific to local conditions. Thus, an IPM system should be set up for a specific area, and developed in target fields by trial and error. Other IPM systems cannot be a solution, merely a good reference.

In general, the major components that deserve consideration in preparing any IPM system include: Defining the target or goal of the system; Setting up a program, including organization and budget; Research and development, including a review of knowledge and technology developed previously; Extension to farmers and implementation by farmers in their own fields; Analysis and evaluation of the impact of the program; and Feedback to solve any problems appearing during evaluation.

Defining Target and Policy

A reduction in pesticide use is considered to be one of the most important policies in the world, from both the economic and environmental point of view. IPM has now been adopted by most countries as a way of achieving this goal. However, the strategy is different in each country. In general, policies of most countries are aimed at reducing pesticide use by 50% within a certain period of time.

In the Netherlands, the main problem was that the use of pesticides expressed as input per hectare per year was very high compared to other countries. Scientists in the Netherlands concluded that the environment had been polluted and that underground water sources were endangered. Nature had tended to lose its self-regulating capacity, while agriculture itself was wrestling with an ever-increasing number of resistant pests (Baerselman 1991). With this diagnosis, they started to prepare a long-term policy plan for crop protection in 1987. Their Multi-Year Crop Protection Plan was presented in June 1991. The aim of this plan was to halve the use of pesticides by the year 2000.

In Ontario, Canada, the reduction of pesticides was adopted as policy even though Canada's consumption of pesticides was very low compared to other countries. The motivation was mainly political. Public opinion polls in Ontario had indicated that the public were concerned about pesticides from the perspective of both health and the environment. The electorate made their choice in the late summer of 1987. Quite simply, the party which won the election and became the ruling party had as one of their platforms a promise to reduce pesticides by 50% by the year 2002. Why 50%? It had a nice ring to it, as did other programs. The public doesn't want terms such as 37% or 63%, even if these are logical reductions determined by scientists.

Ten million Canadian dollars were made available for the first five years. Three broad areas of effort were identified. These were: the education of farmers ($C1 million), research ($C 5.6 million), and infrastructure of

pest management and education personnel ($C3.4 million). The funds were made available at a rate of $2 million per year (Surgeoner and Roberts 1993).

In the United States, the national goal of implementing IPM methods on 75% of the nation's cropland was announced in September 1993 (Sorensen 1994). This goal represents a commitment by the federal government to work with its state and private sector partners to help farmers implement pest management approaches that rely less on pesticides, are more sustainable, are equally efficient economically, and still provide people with a cheap, safe and plentiful food supply.

Thirteen countries in Southeast Asia have begun national IPM programs with the support of the FAO Inter-country Program. This international IPM program started in 1980, and many countries in this group developed their own programs based on their own national research and extension systems. Commitment and changes in national policies followed. This program has shown that farmers can be trained by extension staff to master IPM field skills, apply them in their own fields, reduce their use of pesticides, increase profits and maintain and increase their yields. It designed widespread training programs in member countries, thereby creating confidence in IPM as a way of improving yields and reducing costs.

Many countries have tried to adopt policies which restrict pesticide utilization. Such rules have stimulated the implementation of IPM and research into alternative methods of pest control. Sweden established a pesticide reduction policy in 1986. This was the first in the world, and was very successful. Sweden's approach was to adopt a more stringent registration policy for new pesticides, and to renew the license for all previously registered pesticides with stricter criteria (Kroeker 1991). This strict registration policy was subsequently adopted in many other European countries, including Denmark and the Netherlands. In Indonesia, the key to the IPM program's success was the banning of insecticides by presidential decree in 1987, following an outbreak of the brown planthopper (Kenmore 1996).

Implementing IPM

National IPM programs can usually operate effectively by harnessing the cooperation of existing organizations such as universities, national research institutes and the national extension system. In some cases, however, new organizations were established specifically to implement IPM programs. An example of this approach is the Center for Tropical Pest Management (CTPM) in Australia. CTPM is a joint venture involving four organizations: the Queensland Department of Primary Industries, the CSIRO Division of Entomology, the University of Queensland and the Queensland Department of Lands. About 80 staff are involved in this joint venture, providing a range of disciplines to tackle a series of problems (Norton 1995).

In the United States, the National IPM Plan redirects existing and new resources of the Department of Agriculture and its land grant university partners into a single coordinated effort to address important pest control problems for different cropping systems and crop production regions.

In the case of Italy, there are few experimental stations for agriculture. Most of those which do exist belong to the Ministry of Agriculture, while regional governments manage the extension service. Regional governments fund the research done by universities and other institutions. Extension officers are employed by Farmers' Associations, with a contribution from the regional government. Collaboration between these different organizations is the key factor in successful implementation of IPM (Briolini 1991).

The European IPM Working Group was set up in 1992 to strengthen policy and research, and give Europe more impact within the international IPM effort. The activities of the European Group have been sustained by European Commission funding, together with support from participating institutions.

Basically, the common factors in the organization of national IPM programs are planning, research and development, extension, education, and general support. These elements are universal, whether the program has a new organization or not.

Developing of Tactics for IPM

The specific pattern of IPM is dependent on local cropping systems. Any IPM program has to be both practical and highly specific, in order to meet the social and environmental requirements which growers and scientists perceive as important. However, to some extent countries are likely to have much the same general strategy in developing IPM programs. In USA, considerable attention has been given, first to basic research (which is most important for the development of the applied sciences), and secondly to interdisciplinary work, with specific research groups solving problems of implementation and tactical matters. Finally, all the information is compiled into a comprehensive program.

Recently, the National IPM Program provided $US500,000 to those projects which provide specific objectives related to technology development (including specific mission-linked or basic research) and transfer, as well as for the demonstration, information management and assessment of the project in economic, social, environmental and public health terms. In addition, funds have been supplied to invetigate alternative methods of pest management.

In Canada, the first emphasis has been on a literature review to avoid over-investment at the beginning of the IPM program. Canada has also concentrated on the study of spraying technology, biological control, and environmentally sound cultural practices. Host plant resistance is also an essential component in their research program.

In Italy, emphasis has been placed on developing alternative measures, as well as pest records for every crop, determination of the economic injury level, and optimized pest forecasting models. Monitoring of insecticide resistance is also important, along with the risk assessment of chemicals in the environment.

In general, there has been lot of research into IPM. For example, the number of research articles dealing with IPM which could be retrieved from AGRIS, a literature database, was 699 articles published between 1975 and 1997 ( HYPERLINK "http://www.agnet.org/library/image/eb470f1.html" µFig. 1§). We should note that the rate at which research articles were published was greatest in the first half of the 1990s. One of the main reasons why there are many research articles in recent years is the increased world-wide concern about the environment.

Most of the IPM research published before 1990 seems to have been conducted independently of IPM implementation. In other words, it lacked an interdisciplinary approach. In the 1990s, research has focused particularly on methods of implementation. To accelerate IPM research in Asian countries, experience and information should be shared more frequently, either by exchanges between scientists or on the basis of national programs.

Extension and Farmers' Use of IPM

The end user of IPM is the crop grower. IPM coordinators, therefore, should be able to develop fine-tuned education programs and keep encouraging growers to adopt IPM techniques. To achieve those goals, IPM experts need to develop dissemination programs that farmers find easy to understand. One way commonly used in many industrialized countries is demonstrations farms that are run by farmers themselves.

Extension services run by Ministries of Agriculture have also played a major role in the education and dissemination of IPM to farmers. Extension serves as a bridge connecting farmers and researchers. In general, extension staff should be aware of who has a pest problem, where it is, and what kind of problem is involved. Extension workers advise farmers in situ, by electronic communication and/or by phone. Therefore, an effective extension service is the most important component on which the success of any IPM program depends.

In the United States, only 165 entomologists were working for the extension service in 1972, before extension IPM programs were initiated on a widespread basis. By 1985, this number had grown to 298 (Allen and Rajotte 1990).

In the greenhouse IPM of the Netherlands and England, a close relationship among researchers, development and extenstion workers, and growers has resulted in the rapid transfer and use of information about biological control in greenhouses. Commercial producers of natural enemies served as a private extension service, since natural enemies are essential in the greenhouse IPM (van Lenteren 1989, Wardlow 1991).

Key to the success of the Inter-country Rice IPM Program was showing how closely outbreaks of brown planthopper are related to overuse of broad-spectrum insecticides. Field demonstrations and training in Farmers' Field Schools used innovative approaches to give farmers the needed IPM skills. By the end of 1995, 35,000 trainers and 1.2 million farmers had been exposed to IPM through these programs (Kenmore 1996).

In Korea, a pilot IPM Program was established in 1993 to promote training, development and implementation of IPM. Since 1993, 92 IPM trainers have been trained in summer field programs which emphasize hands-on training in how to manage pests and diseases. Topics discussed include yield loss impact levels in relationship to infection rates, and weather factors which are favorable for epidemics. Discussions of insect pests cover recognition, migration and development patterns, yield loss impact levels in relationship to pest densities, the role of alternative hosts, and natural enemies. Natural enemies are an important topic, including recognition, predation rates and prey, as well as susceptibility to herbicides, fungicides and insecticides.

IPM training for farmers is conducted in "Farmer Field Meetings" (FFM) that are held in a farmer's field over the entire cropping season. Defoliation and detillering studies are conducted in the field. At each meeting, farmers practice field management methods using the agroecosystem method which is re-reforced with specific studies of diseases, insects, and natural enemies predominant at the meeting time. The FFM usually meet four times each season, with each meeting held at a critical control points in the cropping cycle. By the end of the training period, most farmers can evaluate their field in a few minutes, and make appropriate management decisions based on their field's specific situation. This is a major move away from conventional spray calendars that often include several pesticide compounds in one spray.

So far, the IPM program in Korea has operated under relatively low pressure from immigrating pests. There is still a need for continuous field verification, training, and more data collection over a greater number of years to deal with variations according to annual migrations and temperature conditions. However, we feel confident that the present understanding of the rice ecosystem, plant compensation, role of natural enemies, and migration periods will allow farmers to assess their own fields for appropriate management of pests.

The importance of extension work in IPM has increased since the mid-1980s. There are many techniques that can be used for extension work in pest management. However, they are not all suited to the same situation. It is therefore important to analyze each situation and then to identify appropriate extension objectives, before techniques can be selected and put into practice.

Evaluation of IPM

The economic effects of IPM are realized both by individual farmers and by society at large. Depending on how IPM programs are structured, they can put different emphasis on factors such as the cost of pest control, the level and variability of producer income, and the health of those applying the pesticides. The program can also affect

food safety and water quality for human and wildlife, and the long-term sustainability of agricultural systems. IPM programs can be evaluated on the basis of acceptance by farmers, reductions in pesticide use, or economic benefits.

In Queensland, 80% of citrus growers have adopted IPM in the form of monitoring for insect pests, spraying chemicals and/or releasing beneficial insects when pests are above a threshold, and utilizing classical biological control agents (Smith 1990).

In the United States, 61 economic evaluations of IPM programs in cotton, soybeans, vegetables, fruits, peanuts, tobacco, corn, and alfalfa have been published (Norton and Mullen 1994). These evaluations indicate that pesticide use, on average, has decreased for seven out of eight commodities. Costs of production decreased or remained unchanged in four out of the five commodities. Yields increased for six out of the seven, and net returns increased for all seven commodities. Monetary risks to farmers decreased in all three cases in which this was evaluated. A national study of IPM programs over the three-year period ending in 1985 reported a total economic benefit of $578 million per year in nine commodities (Fajotte et al. 1987).

The success of IPM programs has often been measured in terms of the overall reduction in the volume of pesticides used to control pests. Although a reduction in pesticide use is a desirable consequence of IPM, it cannot be the only measure of success. There are special circumstances in which, even following IPM guidelines, it may be necessary to use more, not less, pesticide. The issue is pesticide use within the principles of IPM, i.e., selective use after maximizing the effectiveness of natural controls (Kogan 1998).

A study by Pimental et al. (1980) provided rough estimates of the environmental and social costs associated with pesticide use in the United States. The implications for IPM benefits are that if pesticide use is reduced by IPM programs, then the benefits may be realized in proportion to the pesticide reduction. They estimated that the environmental and social costs of pesticides in the United States amounted to $830 million each year. This total was based on the costs of human exposure (US$184 million), livestock poisoning and product contamination (US$12 million), a reduction in the number of natural enemies and increased pesticide resistance of pests (US$287 million), honeybee poisonings and reduced pollination (US$135 million), losses of crops and trees due to pesticide drift (US$70 million), fishery and wildlife losses (US$11 million), and the cost of government pollution controls (US$140 million).

In general, major factors affecting the success of IPM are: A policy environment that encourages IPM; The participation of growers and other end users, in the whole research and development process; and A system that provides research and decision support to facilitate the adaptation of IPM to changes in

production practices, pest status and control technology (Norton 1995).

PROSPECTS FOR THE 21ST CENTURY

IPM is widely accepted as being "all things to all people". It has become an integral part of global policy for the conservation of the environment. Farmers expect IPM to reduce the costs of their pest control and the danger to their health from pesticides. Environmentalists expect IPM to replace chemical pesticides in agriculture. Chemical companies expect it to permit the continued use of pesticides, under conditions that will reduce their potential hazards to people and environments. Regulatory agencies see IPM as precise prescriptions for pest control actions which can replace present application schedules. Scientists see IPM as a way to integrate the specific information of their individual research projects into a system which increases the predictability of optimum crop production, while reducing the risk to the environment. Politicians welcome the concept of IPM because almost no-one opposes it.

Looking ahead, it is new IPM technology, including both plant and insect products of genetic engineering, which are generally seen as most significant. However, there has been no absolute and exclusive measure for pest management so far, and nothing of the kind is likely to eventuate, even if genetic engineering is emphasized over all other technologies. IPM has proven to be a robust construct. Opportunities to be creative within the confines of the IPM formula are limitless. Success has come mainly from a better understanding of the ecology of crop/pest interactions, and only rarely from a new control method.

Better communication among specialists between regions and countries would not only improve, the efficiency of implementation, but also avoid duplication of research efforts. IPM acts as a unifying force to stimulate interdisciplinary problem-solving, and to promote understanding of the social and economic impact of pest management and the creation of IPM-oriented farmer groups. The ease and speed of information dissemination through the Internet will certainly have an impact on IPM in the next century. The promise of reliable predictive models based on real-time weather data may finally become a reality, as software and weather information become more widely available. Extension information and educational programs via the Web are already available and, when cleverly used, have given positive results.

To conclude, IPM has played a key role in plant protection, and will continue to play a major role in the next century. The development of new tactics is not the only goal we must pursue. Expanding the implementation of IPM farmers by strengthening extension is even more important.

REFERENCES

Allen, W.A. and E.G. Rajotte. 1990. The changing role of extension entomology in the PM era. Annual Review of Entomology 35: 379-397.

Baerselman, F. 1991. The Dutch Multi-Year Crop Protection Plan (MJP-G): A contribution towards sustainable agriculture. In: Proceedings of an IOBC conference, "Biological control and integrated crop protection: towards environmentally safer agriculture", Van Lenteren, J.C. and O.M.B. de Ponti (Ed.), pp. 141-147.

Bajwa, W.I., and M. Kogan. 1996. Compendium of IPM Definitions (Electronic database). Corvallis, Oregon, USA, Integrated Plant Protection Center.

Briolini, G. 1991. IPM in Italy with particular reference to the Emilia-Romagna region. In: Proceedings of an IOBC conference, "Biological control and integrated crop protection; towards environmentally safer agriculture", Van Lenteren, J.C. and O.M.B. de Ponti (Eds.), pp. 76-97.

Kenmore, P.E. 1996. Integrated pest management in rice. In: Biotechnology and Integrated Pest Management, Persley, G.J. (Ed.) Wallingford, UK: CAB International. 475 pp.

Kogan, M. 1998. Integrated pest management: Historical perspectives and contemporary developments. Annual Review of Entomology 43: 243-270.

Kroeker, G. 1991. Crop protection policy in Sweden: A retrospective view and some thoughts for the future. In: Proceedings of an IOBC conference, "Biological control and integrated crop protection: Towards environmentally safer agriculture", Van Lenteren, J.C. and O.M.B. de Ponti (Eds.), pp. 159-163.

Lee, G.S., J.K. Yoo, J.O. Lee, S.H. Kang and S.Y. Hong. 1995. Experiments on the selection of insecticide and pesticide application systems against Thrips palmi. Annual Research Report of NIAST 538-545. (In Korean).

Van Lenteren, J.C. 1989. Implementation and commercialization of biological control in Western Europe. In: International Symposium on Biological Control Implementation". NAPPO. Bulletin No. 6. pp. 50-70.

Newsom, L.D. 1980. The next rung up the integrated pest management ladder. Bulletin of Entomological Society of America 26: 369-374.

Norton, G. 1995. Cooperative strategies for pest management: Making it happen. In: Proceedings of the International Workshop on Pest Management Strategies in Asian Monsoon Agroecosystems, N. Hokyo, and G. Norton (Eds.), pp. 21-28.

Norton, G.W., and J. Mullen. 1994. Economic Evaluation of Integrated Pest Management Programs: A Literature Review. Virginia Cooperative Extension Publication 448-120. 112 pp.

Pimentel, D., D. Andow, R. Dyson-Hudson, D. Gallaham, S. Jacobson, M. Irish, S. Kroop, A. Moss, I. Schreiner, M. Shepard, T. Thompson, and B. Vinzant. Environmental and social costs of pesticides: A preliminary assessment. Oikos 4: 1260140.

Rajotte, E.G., R.F. Kazmierczak, Jr., G.W. Norton, M.T. Lambur, and W.A. Allen. 1987. The National Evaluation of Extension's Integrated Pest Management Programs. Virginia Cooperative Extension Publication 491-010. 123 pp.

Smith, D. 1990. Integrated pest management in Queensland citrus. Australian Citrus News, (December): 6-12.

Smith, R.F., and W.W. Allen. 1954. Insect control and the balance of nature. Scientific American 190: 38-92.

Sorensen, A.A. 1994. Proceedings of the National Integrated Pest Management. Forum, Arlington, VA, June 17-19, 1992. DeKalb, Illinois, USA. America: Am. Farmland Trust. 86 pp.

Surgeoner, G.A. and W. Roberts. 1993. Reducing Pesticide Use by 50% in the Province of Ontario: Challenges and Progress. In: The Pesticide Question, Environment, Economics, and Ethics, Pimentel, DH. Lehman (Eds.) pp. 206-222.

Wardlow, L.R. 1991. The role of extension services in integrated pest management in glasshouse crops in England and Wales. In: Proceedings of an IOBC conference, "Biological control and integrated crop protection: towards environmentally safer agriculture". Van Lenteren, J.C. and O.M.B. de Ponti (Eds.) pp. 193-199.

Yoo, J.K., K.W. Kwon, H.M. Park, and H.R. Lee. 1984. Studies on the selective toxicity of insecticides for rice insect pests between some dominant rice insect pests and a predacious spider, Pirata subpiraticus. Korean Journal of Applied Entomology 23; 166 - 171.

Integrated pest management - the good, the bad and the genetically modified

Just as there is more than one way to skin a cat, fry an egg or eat an ice-cream, there are many ways to beat agricultural pests. Combining different pest control strategies is the basis of integrated pest management (Box 1). It can be applied, in theory at least, to any kind of pest - vertebrate, invertebrate, plant, bacteria, fungi or virus.

In part, the development of integrated pest management (IPM) is a response to the failure of many chemical pesticides to provide long-term solutions to pest problems. While some pesticides have dramatic effects when first applied, many pests develop resistance to the chemical over time and often re-emerge to plague an industry. It can become a vicious circle - the farmer increases the rate of pesticide application, producing increasingly resistant 'super-bugs'. Large quantities of the poisons enter the soils and waterways of the region, with sometimes unforeseen and devastating effects on the environment and human health.

Pest resistance in the Ord

When large plantations of cotton were established in Western Australia's Ord River valley in the 1960s, the caterpillars (larvae) of two species of heliothis moth moved in. These destructive pests were controlled initially by pesticides, but, pretty soon, they started developing resistance. Farmers kept increasing the dosage, but they were fighting a losing battle. Eventually, as landholders went broke, switched to other crops or simply abandoned their properties, the industry collapsed.

Now, 25 years later, researchers are trialling an integrated pest management strategy to see if commercial cotton can again be grown in the Ord River valley. Many elements of the strategy were first developed in the Namoi Valley in New South Wales, another cotton-growing area. The strategy includes:

* Vastly improved understanding of the ecology and biology of pests and the crop itself.* Monitoring the increase in insect pest numbers. This, combined with an understanding of their life cycles,

allows pesticide spraying at the most effective times, reducing the need for large amounts of pesticide.* Using different types of insecticides to reduce the likelihood of resistance to any one chemical building up.* Increasing the numbers of natural predators. One of the side effects of high rates of pesticide use is that

insects and other small animals that might otherwise feed on cotton pests are killed. As application rates decline, more of these beneficial animals survive and are able to play a more active role in suppressing insect pests.

* Cotton plant varieties that have been genetically engineered. They now include a gene taken from a bacterium (Bacillus thuringiensis, or Bt) that produces a protein which is toxic to heliothis caterpillars.

The key components of integrated pest management

Successful integrated pest management usually has several key components.

1. Knowledge. Understanding the biology and ecology of the pest, and the crop (or livestock) is essential. Information about interactions within agricultural ecosystems is also important. IPM draws on the fundamental knowledge of plant and insect biology accumulated by biologists.

2. Monitoring. Farmers can use relatively simple techniques to keep track of what pests are where. This information, combined with knowledge of pest life cycles, can enable farmers to implement control measures at the most effective times.

For example, the pyrgo beetle is a major defoliating insect pest of tea tree in Australia. In the past, growers have used large quantities of chloropyrifos spray to control the beetle, but this chemical has been showing up as an undesirable residue in tea-tree oil products. Clearly, better ways are needed. Field trials have demonstrated that the placement of yellow sticky traps within tea-tree plantations gives growers an accurate picture of beetle distribution at an early stage of their life cycle, enabling better targeted control programs. These would reduce both the need for and the cost of applying chemical sprays.

Monitoring on a broader scale can also be used to predict pest outbreaks and forewarn farmers to take action. For example, scientists at the Cooperative Research Centre for Tropical Pest Management have developed a computer model that can predict the migration of the heliothis moth using information on wind patterns and satellite data about the status of host plants and breeding sites.

3. Economic threshold. This takes into account the revenue losses resulting from pest damage and the costs of treatment to prevent the damage. Below the economic threshold, the presence of the pest is tolerated. Only when pest numbers increase above the threshold does the farmer take action.

4. Adaptability. Farmers must keep informed about what is happening in their paddocks so that they can adapt their strategies to changing circumstances. Research scientists, too, must aim to keep at least one step ahead of the pest, which is also undoubtedly changing and adapting over time.

Control techniques

A wide range of pest control techniques is available to farmers. Some of them are as old as agriculture itself - rotating a crop, for example, to avoid a build-up of host-specific pests. Some are new - in recent years, genetic engineering has opened up many possibilities in pest control that were unavailable to agriculturalists even a decade ago.

Integrating techniques

But farmers using integrated pest management don't hang their hats on any single technique. The simple philosophy is that control will be more effective, and resistance will be less likely to build up, when a range of measures is deployed against a pest (Box 2). Wherever possible, different pest control techniques should work together rather than against each other. In some cases, this can lead to synergy - where the combined effect of different techniques is greater than would be expected from simply adding the individual effects together.

Fighting the good fight

Our knowledge of agricultural systems and their associated pests will continue to expand, enabling management efforts to become increasingly subtle, increasingly effective and increasingly benign to the environment.

Farmers should benefit too, from reduced handling of potentially toxic chemicals and from the increased satisfaction that comes with a heightened awareness of the farm ecosystem. They may feel less pain in the hip pocket, because the savings from the reduced use of pesticides will often outweigh the cost of integrated control measures. And the long-term sustainability of the farming systems may also be enhanced.

Pest control is a continuing struggle, because rarely are pests totally eradicated (and, in the case of native pests, this may not even be desirable). The ways are many, but the aim is the same: to find a balance, precarious though it may be, between the impact of the pest and the effort needed to suppress it.

Biointensive Integrated Pest Management (IPM)

Fundamentals of Sustainable Agriculture

ATTRA--National Sustainable Agriculture Information Service

PO Box 3657 Fayetteville, AR 72702 Phone: 1-800-346-9140 --- FAX: (479) 442-9842

By Rex Dufour NCAT Agriculture Specialist

July 2001 The PDF version of this document is available at http://attra.ncat.org/attra-pub/PDF/ipm.pdf

52 pages — 866 kb

Abstract

This publication provides the rationale for biointensive Integrated Pest Management (IPM), outlines the concepts and tools of biointensive IPM, and suggests steps and provides informational resources for implementing IPM. It is targeted to individuals interested in agriculture at all levels.

Contents

Part One

"Conventional" and "Biotensive" IPMWhy Move to Biointensive IPM? Components of Biotensive IPMHow to Get StartedThe Pest Manager/Ecosystem ManagerProactive Strategies (Cultural Controls)Biological Controls Mechanical ControlsPest IdentificationMonitoringEconomic Injury & Action LevelsSpecial ConsiderationsCosmetic Damage and AesthetcisRecord-keepingChemical ControlsSpecial ConsiderationsIntegrated Weed Management SystemsCurrent Status of IPMCrops with Developed IPM ProgramsGovernment PolicyThe Future of IPMFood Quality Protection ActNew OptionsMore Weed IPMOn-farm ResourcesIPM On-lineIPM Certification and MarketingSummaryReferences

"Conventional" and "Biotensive" IPM

Pest management is an ecological matter. The size of a pest population and the damage it inflicts is, to a great extent, a reflection of the design and management of a particular agricultural ecosystem. We humans compete with other organisms for food and fiber from our crops. We wish to secure a maximum amount of the food resource from a given area with minimum input of resources and energy. However, if the agricultural system design and/or management is faulty—making it easy for pests to develop and expand their populations or, conversely, making it difficult for predators and parasites of pests to exist—then we will be expending unnecessary resources for pest management. Therefore, the first step in sustainable and effective pest management is looking at the design of the agricultural ecosystem and considering what ecological concepts can be applied to the design and management of the system to better manage pests and their parasites and predators.

The design and management of our agricultural systems need re-examining. We’ve come to accept routine use of biological poisons in our food systems as normal. But routine use of synthetic chemicals represents significant energy inputs into the agricultural system, and carries both obvious and hidden costs to the farmer and society.

Attempting to implement an ecology-based discipline like IPM in large monocultures, which substitute chemical inputs for ecological design, can be an exercise in futility and inefficiency. IPM, as it was originally conceived, proposed to manage pests though an understanding of their interactions with other organisms and the environment. Most of the 77 definitions for IPM listed in The Database of IPM Resources (DIR) website, <http://www.ipmnet.org/DIR/>, despite some differences in emphasis, agree with this idea and have the following elements in common:

» A conception of a managed resource, such as a cropping system on a farm, as a component of a functioning ecosystem. Actions are taken to restore and enhance natural balances in the system, not to eliminate species. Regular monitoring makes it possible to evaluate the populations of pest and beneficial organisms. The producer

can then take steps to enhance natural controls (or at least avoid or limit the disruption of natural controls) of the target pest(s).» An understanding that the presence of a pest does not necessarily constitute a problem. Before a potentially disruptive control method is employed, appropriate decision-making criteria are used to determine whether or not pest management actions are needed.» A consideration of all possible pest management options before action is taken. » A philosophy that IPM strategies integrate a combination of all suitable techniques in as compatible a manner as possible; it is important that one technique not conflict with another (1).

However, IPM has strayed from its ecological roots. Critics of what might be termed “conventional” IPM note that it has been implemented as Integrated Pesticide Management (or even Improved Pesticide Marketing) with an emphasis on using pesticides as a tool of first resort. What has been missing from this approach, which is essentially reactive, is an understanding of the ecological basis of pest infestations (see first bullet above). Also missing from the conventional approach are guidelines for ecology-based manipulations of the farm agroecosystem that address the questions:

» Why is the pest there?» How did it arrive?» Why doesn’t the parasite/predator complex control the pest?

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Why Move to Biointensive IPM?

Biointensive IPM incorporates ecological and economic factors into agricultural system design and decision making, and addresses public concerns about environmental quality and food safety. The benefits of implementing biointensive IPM can include reduced chemical input costs, reduced on-farm and off-farm environmental impacts, and more effective and sustainable pest management. An ecology-based IPM has the potential of decreasing inputs of fuel, machinery, and synthetic chemicals—all of which are energy intensive and increasingly costly in terms of financial and environmental impact. Such reductions will benefit the grower and society.

Prior to the mid-1970s, lygus bugs were considered to be the key pest in California cotton. Yet in large-scale studies on insecticidal control of lygus bugs, yields in untreated plots were not significantly different from those on treated plots. This was because the insecticides often induced outbreaks of secondary lepidopterous larvae (i.e., cabbage looper, beet armyworm, and bollworm) and mite pests which caused additional damage as well as pest resurgence of the lygus bug itself. These results, from an economic point of view, seem paradoxical, as the lygus bug treatments were costly, yet the treated plots consistently had lower yields (i.e., it cost farmers money to lose money). This paradox was first pointed out by R. van den Bosch, V. Stern, and L. A. Falcon, who forced a reevaluation of the economic basis of Lygus control in California cotton HYPERLINK "http://attra.ncat.org/attra-pub/ipm2.html" \l "5"

Over-reliance on the use of synthetic pesticides in crop protection programs around the world has resulted in disturbances to the environment, pest resurgence, pest resistance to pesticides, and lethal and sub-lethal effects on non-target organisms, including humans (3). These side effects have raised public concern about the routine use and safety of pesticides. At the same time, population increases are placing ever-greater demands upon the “ecological services”—that is, provision of clean air, water and wildlife habitat—of a landscape dominated by farms. Although some pending legislation has recognized the costs to farmers of providing these ecological services, it’s clear that farmers and ranchers will be required to manage their land with greater attention to direct and indirect off-farm impacts of various farming practices on water, soil, and wildlife resources. With this likely future in mind, reducing dependence on chemical pesticides in favor of ecosystem manipulations is a good strategy for farmers.

Consumers Union, a group that has carried out research and advocacy on various pesticide problems for many years, defines biointensive IPM as the highest level of IPM: “a systems approach to pest management based on an understanding of pest ecology. It begins with steps to accurately diagnose the nature and source of pest problems, and then relies on a range of preventive tactics and biological controls to keep pest populations within acceptable limits. Reduced-risk pesticides are used if other tactics have not been adequately effective, as a last resort, and with care to minimize risks.” (2) This “biointensive” approach sounds remarkably like the original concept of IPM. Such a “systems” approach makes sense both intuitively and in practice.

The primary goal of biointensive IPM is to provide guidelines and options for the effective management of pests and beneficial organisms in an ecological context. The flexibility and environmental compatibility of a biointensive IPM strategy make it useful in all types of cropping systems.

Even conventional IPM strategies help to prevent pest problems from developing, and reduce or eliminate the use of chemicals in managing problems that do arise. Results of 18 economic evaluations of conventional IPM on cotton showed a decrease in production costs of 7 percent and an average decrease in pesticide use of 15 percent (4). Biointensive IPM would likely decrease chemical use and costs even further.

Components of Biointensive IPM

An important difference between conventional and biointensive IPM is that the emphasis of the latter is on proactive measures to redesign the agricultural ecosystem to the disadvantage of a pest and to the advantage of

its parasite and predator complex. At the same time, biointensive IPM shares many of the same components as conventional IPM, including monitoring, use of economic thresholds, record keeping, and planning.

How To Get Started With IPM

PLANNING

Good planning must precede implementation of any IPM program, but is particularly important in a biointensive program. Planning should be done before planting because many pest strategies require steps or inputs, such as beneficial organism habitat management, that must be considered well in advance. Attempting to jump-start an IPM program in the beginning or middle of a cropping season generally does not work.

When planning a biointensive IPM program, some considerations include:• Options for design changes in the agricultural system (beneficial organism habitat, crop rotations)• Choice of pest-resistant cultivars• Technical information needs• Monitoring options, record keeping, equipment, etc.

Blocks on the Pesticide Treadmill

Resistance: Pesticide use exerts a powerful selection pressure for changing the genetic make-up of a pest population. Naturally resistant individuals in a pest population are able to survive pesticide treatments. The survivors pass on the resistance trait to their offspring. The result is a much higher percentage of the pest population resistant to a pesticide. In the last decade, the number of weed species known to be resistant to herbicides rose from 48 to 270, and the number of plant pathogens resistant to fungicides grew from 100 to 150. Resistance to insecticides is so common — more than 500 species — that nobody is really keeping score HYPERLINK "http://attra.ncat.org/attra-pub/ipm2.html" \l "2" µ(2)§.

Resurgence: Pesticides often kill off natural enemies along with the pest. With their natural enemies eliminated, there is little to prevent recovered pest populations from exploding to higher, more damaging numbers than existed before pesticides were applied. Additional chemical pesticide treatments only repeat this cycle.

Secondary Pests: Some potential pests that are normally kept under good control by natural enemies become actual pests after their natural enemies are destroyed by pesticides. Mite outbreaks after pesticide applications are a classic example.

Residues: Only a minute portion of any pesticide application contacts the target organism. The remainder may degrade harmlessly, but too often water, wind, and soil will carries pesticides to non-target areas and organisms, affecting the health of human and wildlife populations. Public concerns over residues are deepened by the lack of research and knowledge about possible synergistic interactions between pesticide residues and the hundreds of other synthetic chemical residues now found in the environment.

The Pest Manager / Ecosystem Manager

The pest manager is the most important link in a successful IPM program. The manager must know the biology of the pest and the beneficial organisms associated with the pest, and understand their interactions within the farm environment. As a detailed knowledge of the pest is developed, weak links in its life cycle become apparent. These weak links are phases of the life cycle when the pest is most susceptible to control measures.

The manager must integrate this knowledge with tools and techniques of biointensive IPM to manage not one, but several pests. A more accurate title for the pest manager is “ecosystem doctor,” for he or she must pay close attention to the pulse of the managed ecosystem and stay abreast of developments in IPM and crop/pest biology and ecology. In this way, the ecosystem manager can take a proactive approach to managing pests, developing ideas about system manipulations, testing them, and observing the results. IPM options may be considered proactive or reactive. Proactive options, such as crop rotations and creation of habitat for beneficial organisms, permanently lower the carrying capacity of the farm for the pest. The carrying capacity is determined by factors like food, shelter, natural enemies complex, and weather, which affect the reproduction and survival of a species. Cultural controls are generally considered to be proactive strategies. The second set of options is more reactive. This simply means that the grower responds to a situation, such as an economically damaging population of pests, with some type of short-term suppressive action. Reactive methods generally include inundative releases of biological controls, mechanical and physical controls, and chemical controls.

Proactive Strategies (Cultural Control)· Healthy, biologically active soils (increasing belowground diversity)· Habitat for beneficial organisms (increasing aboveground diversity)· Appropriate plant cultivars

Cultural controls are manipulations of the agroecosystem that make the cropping system less friendly to the establishment and proliferation of pest populations. Although they are designed to have positive effects on farm ecology and pest management, negative impacts may also result, due to variations in weather or changes in crop management.

Carrying Capacity of Farm Systems for Pest Populations

In a non-farmscaped system, where pests have fewer natural controls and thus reach higher average populations, they are more likely to approach or exceed the economic threshold level for the crop, making pesticide treatments likely. In a farmscaped system, greater and more consistent populations of beneficial organisms put more ecological pressure on the pests, with the result that pest populations are less likely to approach the

economic threshold. In other words, the ecological carrying capacity for a pest will probably be lower in a farmscaped system. For more on farmscaping, see p. 11.

Maintaining and increasing biological diversity of the farm system is a primary strategy of cultural control. Decreased biodiversity tends to result in agroecosystems that are unstable and prone to recurrent pest outbreaks and many other problems (5). Systems high in biodiversity tend to be more “dynamically stable”—that is, the variety of organisms provide more checks and balances on each other, which helps prevent one species (i.e., pest species) from overwhelming the system. There are many ways to manage and increase biodiversity on a farm, both above ground and in the soil. In fact, diversity above ground influences diversity below ground. Research has shown that up to half of a plant’s photosynthetic production (carbohydrates) is sent to the roots, and half of that (along with various amino acids and other plant products) leaks out the roots into the surrounding soil, providing a food source for microorganisms. These root exudates vary from plant species to plant species and this variation influences the type of organisms associated with the root exudates (6).

Factors influencing the health and biodiversity of soils include the amount of soil organic matter; soil pH; nutrient balance; moisture; and parent material of the soil. Healthy soils with a diverse community of organisms support plant health and nutrition better than soils deficient in organic matter and low in species diversity. Research has shown that excess nutrients (e.g., too much nitrogen) as well as relative nutrient balance (i.e., ratios of nutrients—for example, twice as much calcium as magnesium, compared to equal amounts of both) in soils affect insect pest response to plants (7, 8). Imbalances in the soil can make a plant more attractive to insect pests (7, 8), less able to recover from pest damage, or more susceptible to secondary infections by plant pathogens (8).

Soils rich in organic matter tend to suppress plant pathogens (9). In addition, it is estimated that 75% of all insect pests spend part of their life cycle in the soil, and many of their natural enemies occur there as well. For example, larvae of one species of blister beetle consume about 43 grasshopper eggs before maturing (10). Both are found in the soil. (Unfortunately, although blister beetle larvae can help reduce grasshopper populations, the adult beetles can be a serious pest for many vegetable growers.) Overall, a healthy soil with a diversity of beneficial organisms and high organic matter content helps maintain pest populations below their economic thresholds.

“When we kill off the natural enemies of a pest we inherit their work” — Carl Huffaker

Genetic diversity of a particular crop may be increased by planting more than one cultivar. For example, a recent experiment in China (11) demonstrated that disease-susceptible rice varieties planted in mixtures with resistant varieties had 89% greater yield and a 94% lower incidence of rice blast (a fungus) compared to when they were grown in monoculture. The experiment, which involved five townships in 1998 and ten townships in 1999, was so successful that fungicidal sprays were no longer applied by the end of the two-year program. Species diversity of the associated plant and animal community can be increased by allowing trees and other native plants to grow in fence rows or along water ways, and by integrating livestock into the farm system. Use of the following cropping schemes are additional ways to increase species diversity. (See ATTRA’s Farmscaping to Enhance

Biological Control for more information on this topic.)

Crop rotations radically alter the environment both above and below ground, usually to the disadvantage of pests of the previous crop. The same crop grown year after year on the same field will inevitably build up populations of organisms that feed on that plant, or, in the case of weeds, have a life cycle similar to that of the crop. Add to this the disruptive effect of pesticides on species diversity, both above and below ground, and the result is an unstable system in which slight stresses (e.g., new pest variety or drought) can devastate the crop.

An enforced rotation program in the Imperial Valley of California has effectively controlled the sugar beet cyst nematode. Under this program, sugar beets may not be grown more than two years in a row or more than four years out of ten in clean fields (i.e., non-infested fields). In infested fields, every year of a sugar beet crop must be followed by three years of a non-host crop. Other nematode pests commonly controlled with crop rotation methods include the golden nematode of potato, many root-knot nematodes, and the soybean cyst nematode.

When making a decision about crop rotation, consider the following questions: Is there an economically sustainable crop that can be rotated into the cropping system? Is it compatible? Important considerations when developing a crop rotation are:• What two (or three or several) crops can provide an economic return when considered together as a biological

and economic system that includes considerations of sustainable soil management?• What are the impacts of this season’s cropping practices on subsequent crops?• What specialized equipment is necessary for the crops?• What markets are available for the rotation crops?

A corn/soybean rotation is one example of rotating compatible economic crops. Corn is a grass; soybean is a leguminous broadleaf. The pest complex of each, including soil organisms, is quite different. Corn rootworm, one of the major pests of corn, is virtually eliminated by using this rotation. Both crops generally provide a reasonable return. Even rotations, however, create selection pressures that will ultimately alter pest genetics. A good example is again the corn rootworm: the corn/bean rotation has apparently selected for a small population that can survive a year of non-corn (i.e., soybean) cropping (12).

Management factors should also be considered. For example, one crop may provide a lower direct return per acre than the alternate crop, but may also lower management costs for the alternate crop (by reducing weed pressure, for example, and thus avoiding one tillage or herbicide application), with a net increase in profit.

Other Cropping Structure Options

Multiple cropping is the sequential production of more than one crop on the same land in one year. Depending on the type of cropping sequence used, multiple cropping can be useful as a weed control measure, particularly when the second crop is interplanted into the first.

Intercropping French beans with cilantro —a potential control for symphylans. Multiple cropping is the sequential production of more than one crop on the same land in one year. Depending on the type of cropping sequence used, multiple cropping can be useful as a weed control measure, particularly when the second crop is interplanted into the first.

Interplanting is seeding or planting a crop into a growing stand, for example overseeding a cover crop into a grain stand. There may be microclimate advantages (e.g., timing, wind protection, and less radical temperature and humidity changes) as well as disadvantages (competition for light, water, nutrients) to this strategy. By keeping the soil covered, interplanting may also help protect soil against erosion from wind and rain.

Intercropping is the practice of growing two or more crops in the same, alternate, or paired rows in the same area. This technique is particularly appropriate in vegetable production. The advantage of intercropping is that the increased diversity helps “disguise” crops from insect pests, and if done well, may allow for more efficient utilization of limited soil and water resources. Disadvantages may relate to ease of managing two different crop species— with potentially different nutrient, water, and light needs, and differences in harvesting time and method—in close proximity to each other. For a detailed discussion, request the ATTRA publication, Intercropping: Principles and Production Practices.

Strip cropping is the practice of growing two or more crops in different strips across a field wide enough for independent cultivation (e.g., alternating six-row blocks of soybeans and corn or alternating strips of alfalfa and cotton or alfalfa and corn). It is commonly practiced to help reduce soil erosion in hilly areas. Like intercropping, strip cropping increases the diversity of a cropping area, which in turn may help “disguise” the crops from pests. Another advantage to this system is that one of the crops may act as a reservoir and/or food source for beneficial organisms. However, much more research is needed on the complex interactions between various paired crops and their pest/predator complexes.

The options described above can be integrated with no-till cultivation schemes and all its variations (strip till, ridge till, etc.) as well as with hedgerows and intercrops designed for beneficial organism habitat. With all the cropping and tillage options available, it is possible, with creative and informed management, to evolve a biologically diverse, pest-suppressive farming system appropriate to the unique environment of each farm.

Other Cultural Management Options

Disease-free seed and plants are available from most commercial sources, and are certified as such. Use of disease-free seed and nursery stock is important in preventing the introduction of disease.

Resistant varieties are continually being bred by researchers. Growers can also do their own plant breeding simply by collecting non-hybrid seed from ealthy plants in the field. The plants from these seeds will have a good chance of being better suited to the local environment and of being more resistant to insects and diseases. Since natural systems are dynamic rather than static, breeding for resistance must be an ongoing process, especially in the case of plant disease, as the pathogens themselves continue to evolve and become resistant to control measures (13).

Sanitation involves removing and destroying the overwintering or breeding sites of the pest as well as preventing a new pest from establishing on the farm (e.g., not allowing off-farm soil from farm equipment to spread nematodes or plant pathogens to your land). This strategy has been particularly useful in horticultural and tree-fruit crop situations involving twig and branch pests. If, however, sanitation involves removal of crop residues from the soil surface, the soil is left exposed to erosion by wind and water. As with so many decisions in farming, both the short- and long-term benefits of each action should be considered when tradeoffs like this are involved.

Spacing of plants heavily influences the development of plant diseases and weed problems. The distance between plants and rows, the shape of beds, and the height of plants influence air flow across the crop, which in turn determines how long the leaves remain damp from rain and morning dew. Generally speaking, better air flow will decrease the incidence of plant disease. However, increased air flow through wider spacing will also allow more sunlight to the ground, which may increase weed problems. This is another instance in which detailed knowledge of the crop ecology is necessary to determine the best pest management strategies. How will the crop react to increased spacing between rows and between plants? Will yields drop because of reduced crop density? Can this be offset by reduced pest management costs or fewer losses from disease?

Altered planting dates can at times be used to avoid specific insects, weeds, or diseases. For example, squash bug infestations on cucurbits can be decreased by the delayed planting strategy, i.e., waiting to establish the cucurbit crop until overwintering adult squash bugs have died. To assist with disease management decisions, the Cooperative Extension Service (CES) will often issue warnings of “infection periods” for certain diseases, based upon the weather.

In some cases, the CES also keeps track of “degree days” needed for certain important insect pests to develop. Insects, being cold-blooded, will not develop below or above certain threshold temperatures. Calculating accumulated degree days, that is, the number of days above the threshold development temperature for an insect pest, makes the prediction of certain events, such as egg hatch, possible. University of California has an excellent website that uses weather station data from around the state to help California growers predict pest emergence: <http://www.ipm.ucdavis.edu/WEATHER/ddretrieve.html>.

Some growers gauge the emergence of insect pests by the flowering of certain non-crop plant species native to the farm. This method uses the “natural degree days” accumulated by plants. For example, a grower might time cabbage planting for three weeks after the Amelanchier species (also known as saskatoon, shadbush, or serviceberry) on their farm are in bloom. This will enable the grower to avoid peak egg-laying time of the cabbage maggot fly, as the egg hatch occurs about the time Amelanchier species are flowering (14). Using this information, cabbage maggot management efforts could be concentrated during a known time frame when the early instars (the most easily managed stage) are active.

Optimum growing conditions are always important. Plants that grow quickly and are healthy can compete with and resist pests better than slow-growing, weak plants. Too often, plants grown outside their natural ecosystem range must rely on pesticides to overcome conditions and pests to which they are not adapted.

Mulches, living or non-living, are useful for suppression of weeds, insect pests, and some plant diseases. Hay and straw, for example, provide habitat for spiders. Research in Tennessee showed a 70% reduction in damage to vegetables by insect pests when hay or straw was used as mulch. The difference was due to spiders, which find mulch more habitable than bare ground (15). Other researchers have found that living mulches of various clovers reduce insect pest damage to vegetables and orchard crops (16). Again, this reduction is due to natural predators and parasites provided habitat by the clovers. Vetch has been used as both a nitrogen source and as a weed suppressive mulch in tomatoes in Maryland (17). Growers must be aware that mulching may also provide a more friendly environment for slugs and snails, which can be particularly damaging at the seedling stage.

Mulching helps to minimize the spread of soil-borne plant pathogens by preventing their transmission through soil splash. Mulch, if heavy enough, prevents the germination of many annual weed seeds. Winged aphids are repelled by silver- or aluminum-colored mulches (18). Recent springtime field tests at the Agricultural Research Service in Florence, South Carolina, have indicated that red plastic mulch suppresses root-knot nematode damage in tomatoes by diverting resources away from the roots (and nematodes) and into foliage and fruit (19).

Biotech Crops. Gene transfer technology is being used by several companies to develop cultivars resistant to insects, diseases, and herbicides. An example is the incorporation of genetic material from Bacillus thuringiensis (Bt), a naturally occurring bacterium, into cotton, corn, and potatoes, to make the plant tissues toxic to bollworm, earworm, and potato beetle larvae, respectively. Whether or not this technology should be adopted is the subject of much debate. Opponents are concerned that by introducing Bt genes into plants, selection pressure for resistance to the Bt toxin will intensify and a valuable biological control tool will be lost. There are also concerns about possible impacts of genetically-modified plant products (i.e., root exudates) on non-target organisms as well as fears of altered genes being transferred to weed relatives of crop plants.

Whether there is a market for gene-altered crops is also a consideration for farmers and processors. Proponents of this technology argue that use of such crops decreases the need to use toxic chemical pesticides.

Biological Control

Beneficial organisms should be viewed as mini-livestock, with specific habitat and food needs to be included in farm planning. Biological control is the use of living organisms —parasites, predators, or pathogens—to maintain pest populations below economically damaging levels, and may be either natural or applied. A first step in setting up a biointensive IPM program is to assess the populations of beneficials and their interactions within the local ecosystem. This will help to determine the potential role of natural enemies in the managed agricultural ecosystem. It should be noted that some groups of beneficials (e.g., spiders, ground beetles, bats) may be absent or scarce on some farms because of lack of habitat. These organisms might make significant contributions to pest management if provided with adequate habitat.

Natural biological control results when naturally occurring enemies maintain pests at a lower level than would occur without them, and is generally characteristic of biodiverse systems. Mammals, birds, bats, insects, fungi, bacteria, and viruses all have a role to play as predators and parasites in an agricultural system. By their very nature, pesticides decrease the biodiversity of a system, creating the potential for instability and future problems. Pesticides, whether synthetically or botanically derived, are powerful tools and should be used with caution.

Creation of habitat to enhance the chances for survival and reproduction of beneficial organisms is a concept included in the definition of natural biocontrol. Farmscaping is a term coined to describe such efforts on farms. Habitat enhancement for beneficial insects, for example, focuses on the establishment of flowering annual or perennial plants that provide pollen and nectar needed during certain parts of the insect life cycle. Other habitat features provided by farmscaping include water, alternative prey, perching sites, overwintering sites, and wind protection. Beneficial insects and other beneficial organisms should be viewed as mini-livestock, with specific habitat and food needs to be included in farm planning.

The success of such efforts depends on knowledge of the pests and beneficial organisms within the cropping system. Where do the pests and bene- ficials overwinter? What plants are hosts and non-hosts? When this kind of knowledge informs planning, the ecological balance can be manipulated in favor of beneficials and against the pests.

It should be kept in mind that ecosystem manipulation is a two-edged sword. Some plant pests (such as the tarnished plant bug and lygus bug) are attracted to the same plants that attract beneficials. The development of beneficial habitats with a mix of plants that flower throughout the year can help prevent such pests from migrating en masse from farmscaped plants to crop plants.

See ATTRA’s Farmscaping to Enhance Biological Control for a detailed treatment of this subject.

Applied biological control, also known as augmentative biocontrol, involves supplementation of beneficial organism populations, for example through periodic releases of parasites, predators, or pathogens. This can be effective in many situations—well-timed inundative releases of Trichogramma egg wasps for codling moth control, for instance.

Most of the beneficial organisms used in applied biological control today are insect parasites and predators. They control a wide range of pests from caterpillars to mites. Some species of biocontrol organisms, such as Eretmocerus californicus, a parasitic wasp, are specific to one host—in this case the sweetpotato whitefly. Others, such as green lacewings, are generalists and will attack many species of aphids and whiteflies.

Information about rates and timing of release are available from suppliers of beneficial organisms. It is important to remember that released insects are mobile; they are likely to leave a site if the habitat is not conducive to their survival. Food, nectar, and pollen sources can be “farmscaped” to provide suitable habitat.

The quality of commercially available applied biocontrols is another important consideration. For example, if the organisms are not properly labeled on the outside packaging, they may be mishandled during transport, resulting in the death of the organisms. A recent study by Rutgers University (20) noted that only two of six suppliers of beneficial nematodes sent the expected numbers of organisms, and only one supplier out of the six provided information on how to assess product viability.

While augmentative biocontrols can be applied with relative ease on small farms and in gardens, applying some types of biocontrols evenly over large farms has been problematic. New mechanized methods that may improve the economics and practicality of large-scale augmentative biocontrol include ground application with “biosprayers” and aerial delivery using small-scale (radio-controlled) or conventional aircraft (21).

Inundative releases of beneficials into greenhouses can be particularly effective. In the controlled environment of a greenhouse, pest infestations can be devastating; there are no natural controls in place to suppress pest populations once an infestation begins. For this reason, monitoring is very important. If an infestation occurs, it can spread quickly if not detected early and managed. Once introduced, biological control agents cannot escape from a greenhouse and are forced to concentrate predation/parasitism on the pest(s) at hand.

An increasing number of commercially available biocontrol products are made up of microorganisms, including fungi, bacteria, nematodes, and viruses.

Mechanical and Physical Controls

Methods included in this category utilize some physical component of the environment, such as temperature, humidity, or light, to the detriment of the pest. Common examples are tillage, flaming, flooding, soil solarization, and plastic mulches to kill weeds or to prevent weed seed germination.

Heat or steam sterilization of soil is commonly used in greenhouse operations for control of soil-borne pests. Floating row covers over vegetable crops exclude flea beetles, cucumber beetles, and adults of the onion, carrot, cabbage, and seed corn root maggots. Insect screens are used in greenhouses to prevent aphids, thrips, mites, and other pests from entering ventilation ducts. Large, multi-row vacuum machines have been used for pest management in strawberries and vegetable crops. Cold storage reduces post-harvest disease problems on produce.

Although generally used in small or localized situations, some methods of mechanical/physical control are finding wider acceptance because they are generally more friendly to the environment.

Pest Identification

A crucial step in any IPM program is to identify the pest. The effectiveness of both proactive and reactive pest management measures depend on correct identification. Misidentific-ation of the pest may be worse than useless; it may actually be harmful and cost time and money. After a pest is identified, appropriate and effective management depends on knowing answers to a number of questions. These may include:

• What plants are hosts and non-hosts of this pest?• When does the pest emerge or first appear?• Where does it lay its eggs? In the case of weeds, where is the seed source? For plant pathogens, where is the source(s) of inoculum?• Where, how, and in what form does the pest overwinter?• How might the cropping system be altered to make life more difficult for the pest and easier for its natural

controls?

Monitoring

Monitoring involves systematically checking crop fields for pests and beneficials, at regular intervals and at critical times, to gather information about the crop, pests, and natural enemies. Sweep nets, sticky traps, and pheromone traps can be used to collect insects for both identification and population density information. Leaf counts are one method for recording plant growth stages. Square-foot or larger grids laid out in a field can provide a basis for comparative weed counts. Records of rainfall and temperature are sometimes used to predict the likelihood of disease infections.

Specific scouting methods have been developed for many crops. The Cooperative Extension Service can provide a list of IPM manuals available in each state. Many resources are now available via Internet.

The more often a crop is monitored, the more information the grower has about what is happening in the fields. Monitoring activity should be balanced against its costs. Frequency may vary with temperature, crop, growth phase of the crop, and pest populations. If a pest population is approaching economically damaging levels, the grower will want to monitor more frequently.

Economic Injury and Action Levels

The economic injury level (EIL) is the pest population that inflicts crop damage greater than the cost of control measures. Because growers will generally want to act before a population reaches EIL, IPM programs use the concept of an economic threshold level (ETL or ET), also known as an action threshold. The ETL is closely related to the EIL, and is the point at which suppression tactics should be applied in order to prevent pest populations from increasing to injurious levels.

In practice, many crops have no established EILs or ETLs, or the EILs that have been developed may be static over the course of a season and thus not reflect the changing nature of the agricultural ecosystem. For example, a single cutworm can do more damage to an emerging cotton plant than to a plant that is six weeks old. Clearly, this pest’s EIL will change as the cotton crop develops.

ETLs are intimately related to the value of the crop and the part of the crop being attacked. For example, a pest that attacks the fruit or vegetable will have a much lower ETL (that is, the pest must be controlled at lower populations) than a pest that attacks a non-saleable part of the plant. The exception to this rule is an insect or nematode pest that is also a disease vector. Depending on the severity of the disease, the grower may face a situation where the ETL for a particular pest is zero, i.e., the crop cannot tolerate the presence of a single pest of that particular species because the disease it transmits is so destructive.

Special Considerations - Cosmetic Damage and Aesthetics

Consumer attitudes toward how produce looks is often a major factor when determining a crop’s sale price. Cosmetic damage is an important factor when calculating the EIL, since pest damage, however superficial, lowers a crop’s market value. Growers selling to a market that is informed about IPM or about organically grown produce may be able to tolerate higher levels of cosmetic damage to their produce.

Record-keeping: “Past is prologue” Monitoring goes hand-in-hand with record-keeping, which forms the collective “memory” of the farm. Records should not only provide information about when and where pest problems have occurred, but should also incorporate information about cultural practices (irrigation, cultivation, fertilization, mowing, etc.) and their effect on pest and beneficial populations. The effects of non-biotic factors, especially weather, on pest and beneficial populations should also be noted. Record-keeping is simply a systematic approach to learning from experience. A variety of software programs are now available to help growers keep track of—and access—data on their farm’s inputs and outputs.

Time and Resources

A successful biointensive IPM program takes time, money, patience, short- and long-term planning, flexibility, and commitment. The pest manager must spend time on self-education and on making contacts with Extension and research personnel. Be aware that some IPM strategies, such as increasing beneficial insect habitat, may take more than a year to show results.

A well-run biointensive IPM system may require a larger initial outlay in terms of time and money than a conventional IPM program. In the long run, however, a good biointensive IPM program should pay for itself. Direct pesticide application costs are saved and equipment wear and tear may be reduced.

Chemical Controls

Included in this category are both synthetic pesticides and botanical pesticides. Synthetic pesticides comprise a wide range of man-made chemicals used to control insects, mites, weeds, nematodes, plant diseases, and vertebrate and invertebrate pests. These powerful chemicals are fast acting and relatively inexpensive to purchase.

Pesticides are the option of last resort in IPM programs because of their potential negative impacts on the environment, which result from the manufacturing process as well as from their application on the farm. Pesticides should be used only when other measures, such as biological or cultural controls, have failed to keep pest populations from approaching economically damaging levels.

If chemical pesticides must be used, it is to the grower’s advantage to choose the least-toxic pesticide that will control the pest but not harm non-target organisms such as birds, fish, and mammals. Pesticides that are short-lived or act on one or a few specific organisms are in this class. Examples include insecticidal soaps, horticultural oils, copper compounds (e.g., bordeaux mix), sulfur, boric acid, and sugar esters (23).

Biorational pesticides. Although use of this term is relatively common, there is no legally accepted definition (24). Biorational pesticides are generally considered to be derived from naturally occurring compounds or are formulations of microorganisms. Biorationals have a narrow target range and are environmentally benign. Formulations of Bacillus thuringiensis, commonly known as Bt, are perhaps the best- known biorational pesticide. Other examples include silica aerogels, insect growth regulators, and particle film barriers.

Particle film barriers. A relatively new technology, particle film barriers are currently available under the tradename Surround® WP Crop Protectant. The active ingredient is kaolin clay, an edible mineral long used as an anti-caking agent in processed foods, and in such products as toothpaste and Kaopectate. There appears to be no mammalian toxicity or any danger to the environment posed by the use of kaolin in pest control. The kaolin in

Surround is processed to a specific particle size range, and combined with a sticker-spreader. Non-processed kaolin clay may be phytotoxic.

Surround is sprayed on as a liquid, which evaporates, leaving a protective powdery film on the surfaces of leaves, stems, and fruit. Conventional spray equipment can be used and full coverage is important. The film works to deter insects in several ways. Tiny particles of the clay attach to the insects when they contact the plant, agitating and repelling them. Even if particles don’t attach to their bodies, the insects may find the coated plant or fruit unsuitable for feeding and egg-laying. In addition, the highly reflective white coating makes the plant less recognizable as a host. For more information about kaolin clay as a pest management tool, see ATTRA’s publications Kaolin Clay for Management of Glassy-winged Sharpshooter in Grapes and Insect IPM in Apples: Kaolin Clay.

Sugar Esters. Throughout four years of tests, sugar esters have performed as well as or better than conventional insecticides against mites and aphids in apple orchards; psylla in pear orchards; whiteflies, thrips, and mites on vegetables; and whiteflies on cotton. However, sugar esters are not effective against insect eggs. Insecticidal properties of sugar esters were first investigated a decade ago when a scientist noticed that tobacco leaf hairs exuded sugar esters for defense against some soft-bodied insect pests. Similar to insecticidal soap in their action, these chemicals act as contact insecticides and degrade into environmentally benign sugars and fatty acids after application. AVA Chemical Ventures of Portsmouth, NH hopes to have a product based on sucrose octanoate commercially available by the end of 2001. Contact: Gary J. Puterka, ARS Appalachian Fruit Research Station, Kearneysville, WV, (304) 725-3451 ext. 361, fax (304) 728-2340, e-mail <gputerka@afrs.ars.usda.gov>.

Because pest resistance to chemical controls has become so common, susceptibility to pesticides is increasingly being viewed by growers as a trait worth preserving. One example of the economic impact of resistance to insecticides has been documented in Michigan, where insecticide resistance in Colorado potato beetle was first reported in 1984 and caused severe economic problems beginning in 1991. In 1991 and following years, control costs were as high as $412/hectare in districts most seriously affected, in contrast to $35-74/hectare in areas where resistance was not a problem (25). The less a product is applied, the longer a pest population will remain susceptible to that product. Routine use of any pesticide is a problematic strategy.

Botanical pesticides are prepared in various ways. They can be as simple as pureed plant leaves, extracts of plant parts, or chemicals purified from plants. Pyrethrum, neem formulations, and rotenone are examples of botanicals. Some botanicals are broad-spectrum pesticides. Others, like ryania, are very specific. Botanicals are generally less harmful in the environment than synthetic pesticides because they degrade quickly, but they can be just as deadly to beneficials as synthetic pesticides. However, they are less hazardous to transport and in some cases can be formulated on-farm. The manufacture of botanicals generally results in fewer toxic by-products.

Compost teas are most commonly used for foliar disease control and applied as foliar nutrient sprays. The idea underlying the use of compost teas is that a solution of beneficial microbes and some nutrients is created, then applied to plants to increase the diversity of organisms on leaf surfaces. This diversity competes with pathogenic organisms, making it more difficult for them to become established and infect the plant.

An important consideration when using compost teas is that high-quality, well-aged compost be used, to avoid contamination of plant parts by animal pathogens found in manures that may be a component of the compost. There are different techniques for creating compost tea. The compost can be immersed in the water, or the water can be circulated through the compost. An effort should be made to maintain an aerobic environment in the compost/water mixture. ATTRA has more information about compost teas, available on request.

Pesticide application techniques

As monetary and environmental costs of chemical pesticides escalate, it makes sense to increase the efficiency of chemical applications. Correct nozzle placement, nozzle type, and nozzle pressure are very important considerations. Misdirected sprays, inappropriate nozzle size, or worn nozzles will ultimately cost the grower money and increase the risk of environmental damage.

If the monitoring program indicates that the pest outbreak is isolated to a particular location, spot treatment of only the infested area will not only save time and money, but will conserve natural enemies located in other parts of the field. The grower should also time treatments to be least disruptive of other organisms. This is yet another example where knowledge about the agroecosystem is important. With the increasing popularity of no-till and related conservation tillage practices, herbicide use has increased. One way to increase application efficiency and decrease costs of herbicide use is through band application. Another example of bait-insecticide technology is the boll weevil bait tube. It lures the boll weevil using a synthetic sex pheromone. Each tube contains about 20 grams of malathion, which kills the boll weevil. This technique reduces the pesticide used in cotton fields by up to 80% and conserves beneficials. It is most effective in managing low, early-season populations of the boll weevil.

Integrated Weed Management Systems

Weeds as competitors in crops present a number of unique challenges that need to be recognized when developing management strategies. The intensity of weed problems during a growing season will be influenced by weed population levels in previous years. The axiom “one year’s seeding equals seven years’ weeding” is apt.

Weed control costs cannot necessarily be calculated against the current year’s crop production costs. Weeds present a physical problem for harvesting. Noxious weed seed mixed with grain reduces the price paid to growers. If the seed is sold for crop production the weed can be spread to new areas. For example, the

perennial pepperweed, thought to have been introduced to California in sugar beet seed, now infests thousands of acres in the state. In addition, weed economic thresholds must take into account multiple species and variable competetive ability of different crops. For example, 12.7 cocklebur plants in 10 sq. meters of corn cause a 10% yield loss. Only 2 cockleburs in the same area planted to soybeans will cause the same 10% crop loss (12).

Sustainable Agriculture and IPM

Sustainable agriculture is a system of agriculture that is ecologically, economically, and socially viable, in the short as well as long term. Rather than standing for a specific set of farming practices, a sustainable agriculture represents the goal of developing a food production system that:

yields plentiful, affordable, high-quality food and other agricultural products does not deplete or damage natural resources (such as soil, water, wildlife, fossil fuels, or the

germplasm base) promotes the health of the environment supports a broad base and diversity of farms and the health of rural communities depends on energy from the sun and on natural biological processes for fertility and pest management can last indefinitely

IPM and sustainable agriculture share the goal of developing agricultural systems that are ecologically and economically sound. IPM may be considered a key component of a sustainable agriculture system. A premise common to IPM and sustainable agriculture is that a healthy agroecosystem depends on healthy soils and managed diversity. One of the reasons modern agriculture has evolved into a system of large monocultures is to decrease the range of variables to be managed. However, a system with few species, much like a table with too few legs, is unstable.

Tactics that can be integrated into weed management systems include:

“Rotation crops, when accompanied by care in the use of pure seed, is the most effective means yet devised for keeping land free of weeds. No other method of weed control, mechanical, chemical, or biological, is so economical or so easily practiced as a well-arranged sequence of tillage and cropping.”

Source: Leighty, Clyde E. 1938. Crop Rotation. p. 406-429. In: Soils and Men, 1938 Yearbook of Agriculture. U.S. Govt. Print. Office, Washington, DC.

• Prevention — The backbone of any successful weed management strategy is prevention. It is important to prevent the introduction of seeds into the field through sources like irrigation water or manure.

• Crop rotation —A practical and effective method of weed management (discussed in previous sections).• Cultivation — Steel in the Field: A Farmer’s Guide to Weed Management Tools shows how today’s

implements and techniques can handle weeds while reducing or eliminating herbicides (26).• Flame weeding — good for control of small weeds.• Delayed planting — Early-germinating weeds can be destroyed by tillage. And with warmer weather, the

subsequently planted crop (depending on the crop, of course) will grow more quickly, thus competing better with weeds.

• Staggered planting schedule — This will allow more time for mechanical weed control, if needed. This also lessens the weather risks and spaces out the work load at harvest time.

• Surface residue management — As mentioned earlier, a thick mulch may shade the soil enough to keep weed seeds from germinating. In addition, some plant residues are allelopathic, releasing compounds that naturally suppress seed germination.

• Altered plant spacing or row width — An example is narrow-row (7–18" between rows compared to conventional 36–39" between rows) soybean plantings. The faster the leaves shade the ground, the less weeds will be a problem.

WEED PREVENTION

Have a long, diverse rotation

Sow clean seedPrevent weed seed formationAvoid imported feeds or manuresCompost all manure thoroughlyControl weeds in field bordersDelay planting the crop (for faster crop growth and quicker ground coverage)

Maintain good soil quality

Herbivores — Cattle, geese, goats, and insects can be used to reduce populations of specific weeds in special situations. Cattle, for example, relish Johnson grass. Weeder geese were commonly used in cotton fields before

the advent of herbicides. Musk thistle populations can be satisfactorily reduced by crown- and seed-eating weevils. Goats may be used for large stands of various noxious weeds.

• Adjusting herbicide use to situation — Herbicide selection and rate can be adjusted depending upon weed size, weed species, and soil moisture. Young weeds are more susceptible to chemicals than older weeds. By integrating a variety of tactics, farmers can reduce or eliminate herbicide use. For more information about weed management options see ATTRA’s publication, Principles of Sustainable Weed Management for Croplands.

Current Status of IPM - Crops with Developed IPM Programs

In the last twenty years or so, IPM programs have been developed for important pests in corn, soybeans, cotton, citrus, apples, grapes, walnuts, strawberries, alfalfa, pecans, and most other major crops. These programs are constantly being revised or fine-tuned, and occasionally undergo a significant overhaul as the introduction of a ew technology or new pest makes the present IPM program obsolete.

The best source of information on conventional IPM is the Cooperative Extension Service (CES) associated with the land-grant university in each state. Booklets and fact sheets describing IPM programs and control measures for a wide range of crops and livestock are available free or for a small charge. For the address of a state IPM coordinator, refer to the Directory of State Extension Integrated Pest Management Coordinators. A free copy can be obtained from the Cooperative State Research, Education, and Extension Service (27), or through the world wide web at <http://attra.ncat.org/www.reeusda.gov/ipmdirectory.pdf>. (Adobe Acrobat Reader must be loaded on your computer in order to access this page.)

Government Policy

In 1993, leaders from USDA, EPA, and FDA announced a goal of placing 75% of U.S. crop acreage under IPM by the year 2000. The IPM Initiative described three phases:

1. Create teams of researchers, Extension personnel, and growers to propose projects to achieve the 75% goal.

2. Fund the best of those projects.

3. Facilitate privatization of IPM practices developed in the process.

Highlights.

The primary goal of biointensive IPM is to provide guidelines and options for the effective management of pests and beneficial organisms in an ecological context. This requires a somewhat different set of knowledge from that which supports conventional IPM, which in turn requires a shift in research focus and approach. Recommended actions to better facilitate the transition to biointensive IPM are:

• Build the knowledge/information infrastructure by making changes in research and education priorities in order to emphasize ecology-based pest management

• Redesign government programs to promote biointensive IPM, not “Integrated Pesticide Management”

• Offer consumers more choices in the marketplace

• Use the market clout of government and large corporations

• Use regulation more consciously, intelligently, and efficiently

The Future of IPM

As this publication has highlighted, IPM in the future will emphasize biological and ecological knowledge in managing pests. Beyond that, specific areas are described here that will impact research and implementation of IPM in the future.

Food Quality Protection Act (FQPA)

“A convergence of technical, environmental and social forces is moving agriculture towards more non-pesticide pest management alternatives like biological control, host plant resistance and cultural management.”

Michael Fitzner, National IPM Program Leader, USDA Extension Service The FQPA, the amended Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), requires the EPA to review all federally registered pesticides in the next 10 years and to use a more comprehensive health standard when allowing re-registration. The ultimate impact is unknown, but FQPA will most likely result in stricter regulations concerning pesticide residues in food, particularly with respect to organochlorines, organophosphates, and carbamates. Some of the most toxic pesticides have already been “de-registered” with respect to some of their former uses. These regulations may provide incentive for more widespread adoption of IPM. More information, including implementation status (from an August 1999 Progress Report) can be found at the FQPA homepage: <http://www.epa.gov/opppsps1/fqpa/>.

New Options

Pest control methods are evolving and diversifying in response to public awareness of environmental and health impacts of synthetic chemical pesticides and resulting legislation. The strong growth of the organic foods market—20% annual expansion for the past several years—may also be a factor in the accelerated development of organic pest management methods. Agricultural pests are developing resistance to many synthetic agrichemicals,

and new synthetic chemicals are being registered at a slower rate than in the past. This situation has helped open the market for a new generation of microbial pesticides.

Research is proceeding on natural endophytes —fungi or bacteria that have a symbiotic (mutually beneficial) relationship with their host plant—and their effects on plant pests. This research might yield products that could be used to inoculate plants against certain pests. Problems associated with soil erosion and water quality are generally the result of weed control measures like tillage, herbicides, cultivation, planting date and pattern, etc. (30). In the future, research will focus not on symptoms, such as soil erosion, but on basic problems such as how to sustainably manage soils. Weeds, as an important facet of sustainable soil management, will consequently receive more emphasis in IPM or Integrated Crop Management (ICM) programs.

On-farm Resources

As farm management strategies become increasingly fine-tuned to preserve a profitable bottom line, the conservation, utilization, and development of on-farm resources will take on added importance. In the context of IPM, this will mean greater emphasis on soil management as well as on conserving beneficial organisms, retaining and developing beneficial habitats, and perhaps developing on-farm insectaries for rearing beneficial insects.

IPM On-line

There is an increasing body of information about production, marketing, and recordkeeping available to growers via the Internet. The Internet is also a good source of information about IPM, beneficial insects, products, and pest control options for individual crops. IPM specialists are generating high-quality websites as a modern educational delivery tool, and many Extension Service leaflets are now being made available in electronic format only.

IPM Certification and Marketing

Certification of crops raised according to IPM or some other ecology-based standards may give growers a marketing advantage as public concerns about health and environmental safety increase. For example, since 1995, Wegmans has sold IPM-labeled fresh-market sweet corn in its Corning, Geneva, Ithaca, Syracuse, and Rochester, New York stores. Wegmans has also added IPM-labeled corn, beets, and beans to its shelves of canned vegetables. One goal of the program, in addition to being a marketing vehicle, is to educate consumers about agriculture and the food system. Another goal is to keep all growers moving along the “IPM Continuum.” Growers must have an 80% “score” on the IPM program elements within three years, or face losing Wegmans as a buyer.

These “ecolabels,” as they’re known, are becoming more popular, with over a dozen brands now in existence. They may provide for a more certain market and perhaps a price premium to help growers offset any costs associated with implementing sustainable farming practices. A possible downside to implementing such programs is that they require additional paperwork, development of standards and guidelines, and inspections. There is concern from some quarters that IPM labeling will cause consumers to raise more questions about pesticide use and the safety of conventional produce. Some advocates of organic farming worry about consumer confusion over the relationship of the ecolabel to the “Certified Organic” label.

Mothers & Others for a Livable Planet, a national, non-profit, consumer advocacy and environmental education organization, has partnered with apple farmers in the Northeast region to create a supportive market environment for farm products that are locally grown and ecologically responsible. The result is the Core Values eco-label: A CORE Values Northeast apple is locally grown in the Northeast (New York and New England) by farmers who are striving to provide apples of superior taste and quality while maintaining healthy, ecologically balanced growing environments. Growers whose apples bear the CORE Values Northeast seal are accredited in knowledge-based biointensive Integrated Pest Management (IPM) production methods. For more information about this program, visit: <http://www.corevalues.org/cvn/home.html>.

The ecolabel to the right is a result of a collaboration between the World Wildlife Fund (WWF), the Wisconsin Potato and Vegetable Growers Association (WPVGA), and the University of Wisconsin. Raising consumer demand for biology-based-IPM farm products is the goal of the program.

There has been an IPM labeling program casualty in 2000. Massachusetts’s “Partners with Nature” marketing program closed its doors after losing funding support from the Massachusetts Department of Food and Agriculture. The program, which included IPM production guidelines, had operated since 1994, with 51 growers participating in 1999.

A bibliography of IPM Certification, Labeling, and Marketing can be found at:

<http://www.ipminstitute. org/ipm_bibliography.htm>.

Back to Top of Page Go to Biointensive IPM Part Two. By Rex Dufour NCAT Agriculture Specialist, July 2001

ATTRA is the national sustainable agriculture information service operated by the National Center for Appropriate Technology under a grant from the Rural Business-Cooperative Service, U.S. Department of Agriculture. These organizations do not recommend or endorse products, companies, or individuals. NCAT has offices in Fayetteville, Arkansas (P.O. Box 3657, Fayetteville, AR 72702), Butte, Montana, and Davis, California.

ANALISIS AGROEKOSISTEM DALAM PENGENDALIAN HAMA TERPADU

PENDAHULUAN

Pengendalian Hama Terpadu (PHT) adalah suatu sistem pengelolaan hama dengan memadukan lingkungan dan dinamika populasi hama, memanfaatkan semua teknik dan metoda yang cocok seharmonis mungkin, dan mempertahankan populasi hama di bawah ambang kerusakan ekonomi.

Pada saat awal dilontarkan gagasan konsep PHT oleh Stern et al. (1959), terpikir oleh mereka untuk memadukan pengendalian yang merupakan potensi biologis yang dapat mengatur kehidupan serangga yang dianggap sebagai hama dengan pengendalian yang bertujuan membunuh serangga hama (pestisida). Namun dalam perkembangan selanjutnya konsep PHT berprinsip dasar sebagai pengendalian yang secara ekonomis harus menguntungkan, ekologis dapat dipertanggungjawabkan, dan sosiologis dapat diterima.

Pendekatan ekologis dalam PHT berarti pengetahuan tentang hama, tanaman dan lingkungan merupakan dasar untuk mengembangkan strategi dan taktik pengendalian.

Pendekatan konsep adalah spesifik sasaran, spesifik tempat, dan waktu secara interdisipliner dan lintas sektoral.

Strategi PHT adalah menahan populasi hama, bukan memusnahkannya, dengan tujuan mengoptimalkan hasil pengendalian, dan bukan semata-mata produksi yang tinggi. Tujuan tersebut dapat dicapai melalui pemanfaatan kekuatan pengendali alami seperti cuaca, ketahanan tanaman inang, dan musuh alami. Cuaca tidak dapat dimanipulasi secara langsung, sedangkan ketahanan inang dan pemanfaatan musuh alami dapat dianggap sebagai landasan bagi usaha yang dapat ditempuh. Pemanfaatan maksimal dari faktor-faktor mortalitas di alam tersebut hanya dapat dicapai apabila perusakan zat-zat racun terhadap lingkungan berada pada tingkat minimum.

AGROEKOSISTEM

Agroekosistem merupakan suatu unit yang tersusun oleh total komplek organisme dalam suatu daerah pertanian bersama-sama dengan lingkungan pendukungnya, yang kemudian lingkungan tersebur dimodifikasikan oleh manusia melalui berbagai kegiatan pertanian, industri, rekreasi, dan sosial.

Ilmu yang mengembangkan dan mengaplikasikan pendekatan-pendekatan agroekosistem disebut analisis agroekosistem (Agroecosystem Analysis). Analisis ini menggambarkan hubungan antar komponen-komponen kegiatan manusia yang saling tindak (interaction), dan hubungan timbal balik antara sub sistem yang satu dengan sub sistem lainnya, yang secara keseluruhan akan mempengaruhi sub sistem lingkungan alami (ecology).

Melalui mekanisme sistem pengelolaan lingkungan, maka rekomendasi yang diberikan selalu didasarkan pada model pengelolaan lingkungan yang bersifat lintas disiplin atau lintas sektoral. Oleh karena itu pengambilan keputusan penggunaan suatu sistem memerlukan pengkajian tentang realitas secara menyeluruh dari masing-masing sub sistem, sehingga sistem yang digunakan merupakan sistem yang benar-benar dapat menunjang keberhasilan kerja untuk mencapai tujuan secara optimal, tanpa menimbulkan dampak negatif terhadap organisme, ekosistem maupun agroekosistemnya.

Ekosistem tanaman pertanian merupakan komplek unit ekologi dengan berbagai faktor yang saling berinteraksi. Tanaman pertanian bukan merupakan suatu unit yang terisolasi, namun merupakan bagian dari suatu sistem ekologi yang meliputi hubungan antara beberapa tipe lahan pertanian, perkayuan, sungai, gulma atau lahan yang tidak ditanami.

Komponen utama tanaman pertanian meliputi tanaman itu sendiri, gulma atau tanaman lainnya, tanah dan biotanya, keseluruhan kondisi lingkungan fisik dan kimiawi, species hama dengan faktor mortalitas alaminya, termasuk penyakit dan species bermanfaat, artropoda kompetitor terhadap pakan dan ruang, dan keseluruhan kegiatan manusia, termasuk di dalamya adalah usaha manusia dalam mengelola sistem.

Landasan pengelolaan hama didasarkan pada pengetahuan yang rinci tentang ekosistem pertanaman. Pernyataan tersebut tampak mudah dan sederhana, namun dalam kenyataannya sangat komplek dan kemungkinan tidak akan pernah dapat difahami secara lengkap. Kajian tentang ekosistem tanaman pertanian pada suatu wilayah (daerah, negara) dapat dipakai sebagai acuan, namun belum tentu dapat diterapkan pada wilayah lainnya. Setiap wilayah mempunyai variasi tingkat perbedaan, antara lain disebabkan oleh perbedaan varietas yang ditanam dalam sistem pengelolaan yang berbeda, perbedaan lingkungan fisik dan lingkungan tanaman suatu wilayah, dan bahkan dalam kenyataannya pada wilayah yang sama mungkin terdapat variasi tingkat perbedaan.

Entomologist telah berusaha mengembangkan pengetahuan tentang agroekosistem tanaman pertanian dan keterkaitan-keterkaitan yang ada di dalam sistem tersebut, namun pemahaman tersebut dianggap masih kurang lengkap. Meskipun serangga-serangga bermanfaat telah banyak dikenal, namun perlu dilengkapi data tentang hubungan antara populasi total komplek species-species bermanfaat terhadap populasi hama (Reynold et al., 1975).

ANALISIS AGROEKOSISTEM DAN KEPUTUSAN PENGENDALIAN

Modifikasi sebagai akibat perlakuan irigasi atau pemupukan, penggunaan varietas yang berbeda, jarak tanam, cara bercocok tanam, waktu tanam dan umur tanaman, akan berpengaruh terhadap populasi hama dan species bermanfaat.

Agroekosistem pola tanam (mixed cropping) di daerah tropika memiliki diversitas vegetasi yang cukup tinggi, keberadaan tanaman relatif permanen di lapangan, stabilitas iklim cukup tinggi dan tingkat isolasi relatif rendah.

Pendekatan tradisional untuk strategi pengendalian hama dalam pola tanam tersebut adalah penekanan terhadap biologi dan perilaku hama, pemantauan populasi hama, dan pendugaan tingkat kerusakan ekonomi.

Pratanam.- Sisa tanaman lain sebelumnya dapat merupakan sumber infeksi serangga hama bagi tanaman berikutnya, oleh karena itu sebelum tanam tanaman pertanian (yang sedang diupayakan) sebaiknya dilaksanakan sanitasi.

Meledaknya populasi dan seranga hama tanaman di beberapa daerah pengembangan tanaman budidaya diduga karena faktor sanitasi yang kurang diperhatikan.

Sisa tanaman sebelumnya sebaiknya dicabut kemudian dibakar karena merupakan sarang yang baik bagi serangga hama.

Saat Tanam.- Pengaturan waktu tanam berdasarkan zona iklim.

Cara Bercocok Tanam.- Beberapa modifikasi pada tanaman pertanian dapat sebagai pengendalian dengan cara bercocok tanam (cultural control) pada hama-hama tertentu (Reynold et al., 1975).

Kebijakan umum yang dapat ditempuh antara lain memaksimumkan penggunaan tanaman inang resisten yang sinergis dengan tiga pendekatan pengendalian yang umum dikenal, yaitu:

(a) Penekanan.- Menekan populasi hama pada pertanaman dengan menurunkan daya tarik tanaman terhadap hama dan menghalangi perpindahan hama di dalam tanaman. Taktik yang dapat digunakan adalah menanam tanaman penutup tanah, menanam tanaman perangkap, dan menanm dengan pola strip cropping atau campuran antara tanaman yang resisten dengan yang rentan.

(b) Pengaturan.- Peningkatan keragaman tanaman ditujukan untuk mengkonservasi dan memaksimumkan aksi musuh-musuh alami, terutama untuk hama yang berstrategi intermediate (antara r dan K). Kondisi yang menunjang bagi musuh alami dapat diciptakan dengan cara pemakaian mulsa, menanam tanaman liar yang dapat menyediakan makanan (madu, nektar, tepungsari) bagi musuh alami dewasa, dan inang atau mangsa alternatif bagi musuh alami.

(c) Pembatasan sumber daya untuk meningkatkan kompetisi intraspecies diantara serangga hama. Misalnya memilih tanaman yang secara alami memiliki carrying capacity (K) rendah, sehingga mendorong terjadinya kanibalisme diantara serangga hama.

Contoh:

Tanaman jagung dapat digunakan sebagai perangkap bagi penggerek buah kapas H. armigera. Rambut jagung segar merupakan tempat yang menarik bagi ngengat H. armigera untuk meletakkan telur (Sjafaruddin et al., 1990). Apabila dikaitkan dengan upaya untuk memilih tanaman jagung yang secara morfologis tahan terhadap H. armigera, sementara itu pada umumnya larva H. armigera bersifat kanibalisme, maka serangan hama tersebut akan semakin kecil jauh di bawah ambang pengendalian.

Tumpangsari tanaman kapas dengan kacang hijau, ternyata kacang hijau dapat berfungsi sebagai perangkap kutu daun Aphis gossypii Glover, dan merupakan tempat yang baik bagi perkembang biakan populasi musuh alami Aphis, misalnya kumbang predator dari famili Coccinellidae, Laba-laba, dan semut merah.

Tanaman Tahan Hama. Ketahanan tanaman terhadap serangga hama juga dipengaruhi oleh pemupukan. Dosis pupuk nitrogen (N) sangat berpengaruh terhadap populasi serangga di lapangan. Tanaman yang terlalu banyak dipupuk N, pertumbuhannya akan rimbun dan hal ini akan menarik serangga hama tertentu. Selain itu gizi tanaman berubah sehingga lebih disukai serangga.

Tanaman tahan hama mempunyai arti penting dalam Pengelolaan Hama Terpadu antara lain pada situasi sebagai berikut:

a. Siklus hama terlemah untuk dapat dikendalikan (Weakest Link) pendek.b. Tanaman mengalami penurunan nilai ekonomi (harga jual).c. Hama selalu ada dan merupakan faktor pembatas dalam usaha memperbaiki keberhasilan tanaman untuk

areal yang luas.d. Cara pengendalian yang lain tidak ada atau tidak mungkin dilakukan.e. Pada daerah terisolir dan transportasi sulit.f. Masyarakat belum mengadopsi penggunaan pestisida.

Musuh Alami Hama.- Konsep IPM antara lain meliputi aspek ekologi, yaitu lingkungan musuh alami dan jaring-jaring makanan di lingkungan tersebut, dan aspek teknologi, yaitu praktik bercocok tanam yang disesuaikan kondisi lingkungan setempat. Pengetahuan tentang jaring-jaring makanan pada komoditas suatu tanaman pertanian sangat bermanfat bagi keberhasilan pengendalian hayati, karena dapat mengetahui berbagai species musuh alami setempat yang berpotensi menekan perkembangan populasi hama. Disamping itu juga dapat diketahui keterkaitan antara komoditas suatu tanaman dengan komplek komoditas tanaman lainnya, ditinjau dari segi hama. Dimungkinkan adanya hama-hama suatu tanaman yang dapat menyerang komoditas lain, yang berarti terdapat keterkaitan antara musuh alami pada hama suatu tanaman dengan hama komoditas lain.

Dalam hubungannya dengan musuh alami ini, maka perlu diketahui peranan musuh alami dalam menekan populasi hama, sehingga dapat mengkonservasi dan memanipulasi, agar lebih efektif.

Kedudukan Pengendalian Hayati dalam Pengelolaan Hama

a. Pengendalian Hayati yang mandiri :

Yaitu apabila suatu hama mempunyai beberapa musuh alami yang menyerang fase tumbuh yang berbeda.

Contoh: Pemakan daun jeruk (Papillo memmon-memmon): telurnya diparasitir oleh Oencyrtus sp., dan larva serta kepompongnya diparasitir oleh Tetrastichus sp.

b. Pengendalian Hayati sebagai komponen Pengelolaan Hama :

Contoh pada kelapa : Oryctes rhinoceros : larva dapat dikendalikan oleh jamur Metarrhizium anisopliae; larva, kepompong, dan dewasanya dapat dikendalikan Baculovirus (Rhabdion) oryctes.

Cara Pengendalian Non-Pestisida Lainnya Yang ditempuh.- Pengendalian secara mekanis perlu diterapkan pada beberapa jenis serangga. Ulat yang telah melampaui instar keempat pada umumnya sulit dikendalikan dengan insektisida, maka perlu dikendalikan dengan cara mekanis, yaitu dengan cara memungut ulat tersebut, kemudian dimatikan. Cara ini dapat juga dilakukan pada kelompok telur S. litura dengan cara memencet kelompok telur tersebut yang umumnya diletakkan pada permukaan daun bagian bawah, atau memetik daun tersebut untuk dimusnahkan. Demikian juga ulat S. litura instar pertama sampai ketiga yang pada umumnya masih hidup berkelompok di sekitar bekas paket telur. Terhadap ulat dan pupa S. derogata serta pupa S. flava dapat juga dilakukan dengan cara seperti di atas.

Kumbang Hypomeces squamosus (hama tanaman kapas) dapat dikumpulkan dengan cara menggoyang-goyangkan tanaman kapas, karena sifat serangga tersebut senang menjatuhkan diri apabila terjadi getaran yang keras. Serangga yang jatuh ditampung dalam ember yang berisi larutan insektisida. Sehingga penggunaan insektisida dapat lebih hemat dan relatif lebih aman.

Cara Pengendalian genetik.- Pada umumnya dilakukan teknik pemandulan serangga hama (KB hama). Teknik yang umum dilakukan adalah penyinaran sinar gamma dari Cobalt 60. Walaupun secara kimia, yaitu dengan menggunakan Chemosterilant juga dapat dilakukan, namun cara tersebut lebih banyak dampak negatifnya terhadap organisme lain yang bermanfaat dan termasuk pada manusia.

Persyaratan yang harus dipenuhi agar pengendalian genetik melalui teknik pemandulan serangga hama dapat berhasil dengan baik, yaitu :

a. Harus mempunyai cara pembiakan yang murah dan cepat (efisien).

b. Pemandulan tidak berpengaruh terhadap perilaku serangga, misal : daya saing dengan jantan normal masih tetap sama.

c. Akan lebih berhasil jika kopulasi betina hanya satu kali.

d. Jantan mandul harus dilepas pada saat populasi rendah, karena jumlah yang dilepas akan semakin efisien.

e. Dikaitkan dengan cara pengendalian yang lain (misal dengan insektisida), populasi rendah baru pelepasan jantan mandul.

Cara Pengendalian Dengan Pestisida (Pengendalian Kimiawi).-

Keuntungan penggunaan pestisida dalam Pengelolaan Hama :

1. Pestisida merupakan satu-satunya cara pengendalian yang praktis untuk menekan populasi hama yang mendekati ambang ekonomi.

2. Pestisida memiliki tindakan kuratif untuk menghindarkan terjadinya kerusakan ekonomik.

3. Pestisida menawarkan berbagai kisaran dalam sifat, cara penggunaan dan yang lain untuk berbagai keadaan hama.

4. Pestisida harganya relatif masih rendah sehingga dapat memberikan pendapatan petani yang tinggi, sehingga usaha taninya tetap menguntungkan.

Keterbatasan penggunaan pestisida dalam Pengelolaan Hama :

1. Terjadinya ketahanan hama/serangga terhadap pestisida.

2. Terjadinya letusan hama kedua.

3. Terjadinya perbesaran hayati melalui rantai makanan.

4. Adanya pengaruh merugikan bagi species bukan sasaran.

5. Bahaya residu pestisida bagi lingkungan.

6. Bahaya langsung bagi si pemakai dan bagi keselamatan manusia.

Tiga prinsip penggunaan pestisida dalam Pengelolaan Hama :

1. Prinsip 100% pembunuhan tak diperlukan.

2. Mengganti kebiasaan penggunaan pestisida berdasarkan kalender dengan perlakuan berdasarkan ambang ekonomik.

3. Penggunaan pestisida harus dapat didukung oleh analisis ekologi dan ekonomi.

DAFTAR PUSTAKA

Bacheler, J. S. (2000) Managing Insect Cotton. North Carolina Cotton Production Guide. Center for IPM, NC State University. http://ipmwww.ncsu.edu/Production_Guides/cotton/chptr11.html. Internet Version.

Luckmann, W. H. and R. L. Metcalf. (1975) The Pest Management Concept. In Introduction To Insect Pest Management (Eds. R. L. Metcalf and W. H. Luckmann), p. 3-35.. John Wiley and Sons, New York.

Reynold, H. T., P. L. Adkisson, and Ray F. Smith. 1975. Cotton Insect Pest Management. p. : 379 - 439. In Metcalf, R.L and W.H. Luckman (Eds.). Introduction to Insect Pest. Management. Plennum Press. New York.

Stern, V. M., Ray F. Smith, Robert van den Bosch and Kenneth S. Hagen. (1959) The integrated control concept. Hilgardia, 1959, vol. 29, p. 81-101.

Selayang Pandang Pengendalian (Pengelolaan) Hama Tanaman Perkebunan

Pada umumnya tanaman keras dibudidayakan sebagai tanaman perkebunan.

Keadaan stabil pertanaman perkebunan di daerah tropik menunjukkan bahwa kegiatan sejumlah besar hama potensial sangat ditekan berat oleh musuh-musuh alaminya, sehingga memungkinkan untuk pengembangan pengendalian hayati terutama dengan teknik konservasi dan augmentasi.

Konservasi musuh alami adalah upaya melestarikan musuh alami hama yang telah ada di suatu wilayah dengan menjaga keberadaannya dan melindungi dari kepunahan.

Musuh alami akan tetap berada pada suatu ekosistem, apabila :

Ekosistem cukup stabil

Ketersediaan inang cukup

Inang tidak bergejolak terlalu kuat

Telah tercatat beberapa contoh keberhasilan dan peranan upaya konservasi dan augmentasi dalam penerapan pengelolaan hama.

Kita semua telah sepakat menerima konsep pengelolaan hama (pest management) yang bukan hanya pemaduan cara atau taktik pengendalian, atau sebagai konsep yang juga memadukan disiplin ilmu, kegiatan, sarana dan dana dalam suatu program pengendalian hama.

Contoh Kasus : Pada Perkebunan Kelapa Sawit

Pengganggu Utama adalah :

Hama : Ulat Api Thosea bisura Moore

Ulat Kantong Cremastopsyche pendula Joanis

Gulma

Pengendalian dengan :

penggunaan insektisida berspektrum luas yang intensif

pengendalian gulma yang intensif terutama dengan herbisida

Justru :

Sering terjadi eksplosi kedua hama utama tanaman kelapa sawit tersebut

Mengapa hal tersebut dapat terjadi ?

Ternyata :

Penggunaan herbisida mengakibatkan mengeringnya gulma di bawah pertanaman kelapa sawit, disamping itu penggunaan insektisida berakibat banyak parasit kedua jenis hama tersebut terbunuh atau mati. Salah satu penyebab yang nyata adalah bahwa parasit tersebut kekurangan pakan tambahan yangberupa nectar yang dihasilkan gulma berbunga, seperti : Euphorbia geniculata dan E. prunifolium.

Disamping itu juga diketahui bahwa parasit-parasit seperti : Apantelas sp., Aulosaphes sp., Eozenilla equatorial, Aphadnus rifipes, Echthromorpha agrestoria, Xanthopimpla sp., sering dijumpai mengunjungi kedua jenis tersebut di atas untuk mendapatkan nectar yang dihasilkannya. Sementara itu Xanthopimpla sp. dan Sarcophaga sp. sering beristirahat pada Ageratum conyzoides dan A. maxinacum.

Jadi :

Pembersihan gulma tidak selalu memberi manfaat, dan hal ini sebagai bukti bahwa Dirty Farming (Pertanian Yang Kotor) bermanfaat sebagai upaya konservasi musuh alami.

Catatan singkat mengenai hama dalam contoh kasus :

Ulat Api Thosea bisura Moore

Merupakan salah satu keluarga Limacodidae, ordo Lepidoptera, berbentuk oval, dengan bulu gatal dalam berkas-berkas kecil berderet di bagian tepi (lateral) tubuhnya. Berwarna hijau atau kebiru-biruan dengan strip kuning pada bagian dorsal, sedangkan pada sisinya terdapat dua strip merah atau becak-becak berwarna lila.

Banyak species dari keluarga Limacodidae yang disebut juga sebagai ulat srengenge, karena ulat tersebut mempunyai bulu gatal yang jika terkena kulit manusia akan terasa panas dan nyeri, seperti terbakar terik matahari.

Pada umumnya merusak daun-daun kelapa sawit yang agak muda atau daun-daun yang belum terlalu tua. Gigitan ulat srengenge menyebabkan luka pada daun yang tidak teratur. Dalam tingkat serangan yang hebat daun-daun kelapa sawit sering tinggal lidinya.

Sifat khas dari anggota keluarga Limacodidae, kecuali berbulu sangat gatal, juga ulat yang hampir menjadi kepompong membuat kepompong yang berbentuk bulat telur atau lonjong. Kokon dibuat dari pintalan benang liurnya, berwarna coklat atau coklat hitam, dengan lapisan luar kadang-kadang berwarna putih atau tidak berwarna. Pada umumnya kokon-kokon tersebut diletakkan secara berkelompok pada pangkal daun, pelepah atau tempat-tempat lain. Kupu keluar dari salah satu ujung dengan meninggalkan lubang berbentuk bulat, seakan-akan seperti tong dengan tutupnya. Kokon tersebut sering dipakai untuk mainan anak-anak, yaitu untuk peluit.

Kupu keluarga Limacodidae berbentuk seperti tudung sesaji, aktif pada sore/malam hari dan berwarna kelam.

Ulat Kantong Cremastopsyche pendula Joanis

Termasuk salah satu species dari keluarga Psychidae, ordo Lepidoptera. Disebut ulat kantong karena ulat tersebut berada dalam kantong atau “rumah” yang dibuat dari sisa-sisa daun yang dimakan dan benang liurnya.

Suatu keistimewaan pada ulat kantong yaitu bahwa pada umumnya kupu betina tidak bersayap. Kupu tersebut tetap tinggal dalam kantong. Yang belum diketahui secara pasti yaitu cara kupu jantan mengawini kupu betina, sebab boleh dikata bahwa sejak ulat sampai menjadi kupu dan kemudian mati, kupu betina tetap berada dalam kantong. Sementara itu kupu jantan tumbuh secara wajar/normal lengkap dengan dua pasang sayapnya dan dapat terbang.

Penggunaan Insektisida Dalam Pengelolaan Hama Perkebunan

Sistem Pengendalian Dini

Pada prinsipnya Sistem Pengendalian Dini (Early Warning System) adalah mendeteksi hama seawal mungkin pada sumbernya yang segera diikuti penyemprotan insektisida secara terbatas (Spot Spray).

Tujuan sistem ini yaitu meningkatkan efisiensi pengendalian hama melalui penggunaan insektisida yang sehemat mungkin, tanpa terjadi eksplosi hama. Sistem ini harus dilaksanakan secara kontinyu.

Faktor yang menentukan keberhasilan pelaksanaan Sistem Pengendalian Dini adalah :

Pengorganisasian : struktur dan diskripsi tugas para pelaksana.

Survey dan pemetaan serangga hama

Pelaksanaan pengamatan yang terus-menerus dan periodik/reguler.

Teknik pengendalian yag meliputi pemilihan jenis insektisida dan cara aplikasi yang tepat.

Penggunaan Insektisida Pyethroid Sintetis (L-Cyhalothrin / Matador) berperan sangat penting dalam pelaksanaan Sistem Pengendalian Dini, karena :

Bekerja cepat mengendalikan hama (Rapid Knockdown), sehingga hama belum meluas.

Hemat

Sangat aktif pada penggunaan dosis rendah

Aktifitas cukup luas terhadap berbagai species hama perkebunan dari ordo : Lepidoptera, Hemiptera, Coleoptera, Diptera maupun Acarina, sehingga tidak perlu menyediakan insektisida dengan bahan aktif yang beragam.

Sistem Spot yang dilakukan akan menjamin keberhasilan dengan jumlah individu pohon yang disemprot lebih sedikit. Apalagi adanya sifat repelensia (menolak serangga hama), maka tidak hanya mengendalikan hama pada petak yang disemprot, akan tetapi juga menurunkan populasi hama pada petak sekelilingnya.

Toksisitas rendah terhadap serangga penyerbuk, seperti lebah madu.

Bekerja ganda sebagai racun perut dan kontak, sehingga disamping sesuai sebagai Spot Spray pada Sistem Pengendalian Dini, juga cocok untuk Overall Spray pada tahap persiapan memasuki Sistem Pengendalian Dini.

Insektisida Baru Penghambat Pembentukan Chitin (Chlorfluazuran, contoh : Atabron)

Penghambat pembentukan chitin (Chitin Inhibitor) atau Insektisida Pengatur Tumbuh (Insecticide Growth Regulator) kulit luar larva, sehingga tidak terjadi perubahan fase dari suatu instar ke instar berikutnya, maka terjadi kematian larva atau berperan sebagai larvisida.

Selektif

Mengendalikan larva khususnya dari golongan Lepidoptera, Diptera dan Coleoptera, yang umumnya merupakan hama utama perusak daun dan buah pada tanaman perkebunan.

Serangga dewasa dari jenis hama-hama tersebut di atas apabila terkena semprotan akan menghasilkan telur yang tidak sempurna/tidak menetas.

Kerja lambat, namun aktif memberantas hama yang resisten terhadap organofosfat, karbamat dan pyrethroid.

Mengendalikan hama tertentu (sangat efektif untuk ulat api pada perkebunan kelapa sawit), tanpa mempengaruhi populasi parasit, predator dan serangga berguna yang lain.

Mode Of Action,- hanya bekerja katif setelah melalui saluran pencernaan, walaupun pada dosis tinggi juga bekerja sebagai racun kontak.

Toksisitas terhadap golongan mamalia (binatang berdarah panas) sangat rendah, sehingga sangat aman penggunaannya, baik bagi tenaga penyemprot maupun lingkungan

Jadi :

Chlorfluazuran mempunyai prospek yang baik untuk digunakan dalam Pengelolaan Hama Tanaman Perkebunan.

PENGENDALIAN HAMA PASCA PANEN (HAMA GUDANG/HAMA BAHAN DALAM SIMPANAN)

Pengantar

Tanaman atau produksinya sering mengalami kerusakan-kerusakan di lapangan. Setelah dipanen kadang-kadang produksi tersebut masih mengalami kerusakan-kerusakan di dalam simpanan. kerusakan tersebut dapat disebabkan oleh hama (serangga, tikus, burung, dan sebagainya), maupun penyakit (terutama jamur) dan penyebab lain.

Dalam kaitannya dengan hama gudang, produksi tidak terbatas pada produksi tanaman, namun termasuk produksi suatu industri, seperti simpanan bahan dari tulang, dendeng keju dan lain-lain. Sementara itu produksi tanaman hendaknya dipandang dalam arti luas, tidak terbatas pada buah atau biji yang dapat disimpan lama, namun juga meliputi bahan-bahan yang berupa daun kering, kayu dan lain-lain.

Dalam hal ini istilah gudang tidak hanya berupa bangunan yang dapat ditutup rapat, akan tetapi termasuk pula setiap tempat yang dapat dipakai untuk menyimpan barang. Tempat-tempat tersebut tanpa memperdulikan bentuk, ukuran, dan letaknya, dalam kaitannya dengan hama pasca panen dapat dianggap sebagai gudang.

Beberapa kasus telah menunjukkan besarnya kerugian akibat serangan hama gudang. Secara teknis kerugian hama gudang meliputi dua aspek, yaitu kuantitas dan kualitas. Secara kuantitas sudah jelas, yaitu bahwa hama tersebut merusak/makan bahan dalam simpanan, sehingga volume berkurang, sedangkan secara kualitas yaitu mengotori bahan dalam simpanan, yang pada akhirnya dapat menimbulkan bau yang tidak enak (bahasa Jawa : apek), demikian pula rasa juga akan berkurang atau berubah sama sekali, apalagi apabila terjadi komplikasi serangan antara hama dengan penyakit (terutama cendawan). Pengertian rasa enak itu memang subyektif, akan tetapi dapat dibuktikan secara obyektif dari sektor perdagangan.

Tujuan utama mempelajari hama bahan dalam simpanan adalah mengetahui cara pengendaliannya. Untuk mencapai tujuan tersebut diperlukan pengetahuan tentang hubungan antara faktor luar dengan hama itu sendiri. Ilmu pengetahuan tersebut disebut Ekologi hama gudang. Faktor-faktor lingkungan yang berpengaruh terhadap hama gudang, baik sendiri-sendiri maupun bersama-sama, yang utama adalah : faktor makanan, faktor iklim, faktor musuh alami, faktor kegiatan manusia.

Usaha Untuk Mengatsi Hama Gudang

Pada dasarnya usaha tersebut dibagi menjadi dua cara, yaitu preventif dan kuratif.

Usaha preventif : usaha-usaha pencegahan sebelum terjadi serangan hama pasca panen, antara lain :

Karantina : merupakan peraturan yang melarang masuknya bahan dari suatu negara ke negara atau dari suatu daerah ke daerah lain, apabila belum mendapat ijin dari yang berwenang lebih dahulu. Dikenal dua macam karantina, yaitu (1) karantina luar negeri (foreign quarantine), merupakan karantina antar negara. Pada umumnya suatu negara telah mempunyai Dinas Karantina, yang melarang ke luar-masuknya bahan sebelum mendapat sertifikat yang menerangkan bahan tersebut telah bebas hama. Namun sering terjadi penyimpangan, misal karena adanya Kekebalan Diplomatik, adanya stadia hama yang tidak terdeteksi, yang kemudian dalam pengiriman akan dapat berkembang, prioritas kebutuhan akan bahan pangan (kondisi kemajuan ekonomi suatu negara), (2) Karantina dalam negeri (domestic quarantine), lebih mudah diterobos, terutama di negara-negara yang kacau politik maupun ekonominya. Pengendalian hama gudang dengan karantina memang sulit dilaksanakan.

Pembungkusan : dengan kaleng, poliester (semacam plastik). Di pedesaan penyimpanan jagung sekaligus dengan klobotnya akan lebih tahan disimpan lebih lama daripada tanpa klobot.

Sanitasi : terutama sanitasi gudang, dapat menggunakan bahan kimia beberapa hari sebelum digunakan.

Fisik,- dengan menurunkan kadar air bahan yang akan disimpan baik dengan penjemuran (natural drying), maupun pemanasan dengan menggunakan bahan bakar atau tenaga listrik, hal-hal tersebut umum dilakukan; pengaliran udara panas (bahasa Jawa : diomprong), misal pada perusahaan rokok dan juga sering dilakukan pada pabrik kopi; penggunaan suhu rendah (ruang pendingin), misal pada kapal pengangkut untuk menyimpan daging, buah-buahan, sayur-sayuran.

Kimia,- yang umum dilakukan adalah fumigasi dengan Phostoxin.

Usaha Kuratif : merupakan usaha pengendalian yang dilakukan setelah terjadi serangan. Secara fisik antara lain dengan penjemuran, misal terhadap kedelai yang terserang Doloessa viridis, ternyata sebagian besar ulat akan mati atau melarikan diri, dan dengan penjemuran yang berulang-ulang menyebabkan telur banyak yang tidak dapat menetas. Secara mekanik antara lain : dengan sinar X dapat membunuh telur dan imago Tribolium castanuem (menyerang tepung), Sitophilus spp. (menyerang beras maupun gabah); penggunaan lampu perangkap (light trap), misal penggunaan cahaya lampu merah/jingga pada pabrik-pabrik rokok untuk memantau dan sekaligus mengendalikan hama Lasioderma serricorne yang menyerang tembakau atau daun tembakau kering dalam simpanan; dengan lem perekat, misal untuk lalat dan tikus; dengan membuat shock, misal dengan melempar/membanting bahan dengan mesin pelempar, namun akan menurunkan daya dan kecepatan kecambah bahan tersebut. Secara kimia, prinsipnya adalah melakukan fumigasi ulang setelah ada serangan, namun harus diperhatikan untuk bahan yang mampu mengabsorpsi bahan kimia dalam waktu yang lama. Secara hayati, dengan memelihara musuh alami, misal kucing untuk mengendalikan tikus.

ISSN: 1063-262X

Integrated Pest Management-Biological Control: Natural Enemies

AFSIC Notes no. 3

March 1992

Prepared By Jane Potter Gates, Coordinator

HYPERLINK http://www.nal.usda.gov/afsic/index.html. Alternative Farming Systems Information Center, Information Centers Branch National Agricultural Library, Agricultural Research Service, U. S. Department of Agriculture Beltsville, Maryland 20705-2351

Definition and History

Integrated pest management (IPM) is an ecologically based, environmentally conscious method that combines, or integrates, biological and nonbiological control techniques to suppress weeds, insects, and diseases ("Integrated Pest Management Systems: Protecting Profits and the Environment", by Raymond E. Frisbee and John M. Luna, Farm Management : The 1989 Yearbook of Agriculture, p 226. NAL Call No. lAg84y 1989).

Interest in developing IPM into crop management systems began in the 1960s. Credit for the IPM concept is given to Dr. Roy F. Smith and Dr. Harold T. Reynolds, of the University of California (op.cit.)

Integration of multiple pest suppression techniques has the highest probability of sustaining long-term crop protection ("Integrated Pest Management, a Sustainable Technology", by T.J. Henneberry et.al, Agriculture and the Environment: The 1991 Yearbook of Agriculture, p 151. NAL Call No. lAg84y 1991). An array of technologies and data analysis procedures have been developed about those strategies and tactics most appropriate for use in implementing specific IPM systems. These include economic thresholds, sampling technology, modeling, natural controls, geographic distribution, effects of pest migration and movement, host resistance, and pesticides (op.cit., p 152).

IPM's basic framework is acknowledged to be natural controls. These include natural enemies, weather, climate, and food resources. Natural enemies play an important role in regulating populations of all pest classes (op.cit., p 154).

Biological Control: Natural Enemies

Biological control utilizes natural enemies such as parasites, predators, pathogens or competitors, deriving its energy directly from the pests themselves. It is acknowledged to be the best type of pest control ("Biological Control" by Lloyd A. Andres, Research for Tomorrow: The 1986 Yearbook of Agriculture, p 15 1. NAL Call No. lAg84y 1986).

The biological control strategy was born in a citrus grove in 1889, in what is now the city of Los Angeles, California ("Biological Control Turns 100 This Year" by Jessica Morrison, Agricultural Research, V 37 (Mar 1989) n 3, p 4. NAL Call No. 1.98 Ag84). The release of 129 imported Australian vedalia beetles resulted in dramatic reduction of the cottony cushion scale which had threatened California's citrus industry. The technique of releasing an imported organism that establishes itself and spreads to permanently control a pest is today known as the classical biological control concept (op.cit.). Successful classical biocontrol means that no further costs are required to keep the pest under control.

Natural Enemies: Problems

Although simple in concept, the process of locating the place of origin of the non-native pest and then finding and introducing natural enemies from its place of origin presents obvious ecological and logistical challenges. For example, any introduced pest predator or parasite must undergo exhaustive testing before being released to be sure it will not harm non-target organisms. Even when challenges are successfully met, projects can fail because of problems relating to such factors as climate differences, prior or current pesticide use, disturbances of the habitat by other agricultural operations, and/or the removal of noncrop vegetation that might otherwise offer food and shelter to the natural enemies.

Natural Enemies: Strategies

Planting of cover crops, providing nectar-producing plants and sources of alternate hosts in and around fields, and interplanting different crops to provide habitat diversity are all management techniques that lead to the build-up of natural enemy populations and result in enhanced biological control of pests.

IPM: Prevailing Practice

Today virtually all land-grant universities, as well as USDA and the private sector, have implemented IPM systems for most agricultural crops ("Altering Insect Brain Chemistry" by Michael E. Adams, Research for Tomorrow : The 1986 Yearbook of Agriculture, p 142. NAL Call No. lAg84y 1986). In California, professional pest control advisers (PCAS) are licensed by the state to give pest management advice to growers. At the University of Minnesota, researchers are developing what may become known as the first biological herbicide (Joumal of Soil & Water Conservation v. 46 (2): p.231; 1991 Mar/Apr. NAL Call No. 56.8 J822). And in Florida, Sarasota County has become that state's first government entity to adopt integrated pest management on

all its properties, calling it the wave of the future (American Nurseryman v. 147 (3): p.69; 1991 August 1. NAL Call No. 80 AM371).

Selected Readings

"Before You Buy Botanical Pest Controls..." by Bob Hofstetter. The New Farm v. 13 (7): p.36-39; 1991 Nov/Dec. NAL Call No. Sl.N32

"Biological Control: The Second Century" by M. R. Nelson. Plant Disease v. 73 (8): p.616; 1989 August. NAL Call No. 1.9P69P

"Insecticide resistance management: an integral part of IPM" by J.B. Graves, B.R. Leonard, G. Burris, et.al. Proceedings -Beltwide Cotton Conferences, 1991 v.l: p.23-24. NAL Call No. SB249.N6

"Insects & Diseases: Friends or Enemies". California Grower v. 15 (4): p.20-32; 1991 April. NAL Call No. SB379.A9A9

"IPM and Beyond: Biological Pest Control in the Conservatory" by Kristine Ciombor. The Public Garden v. 6 (2): p.29-32; 1991 April. NAL Call No. QK71.P83

"IPM in Turf' by James B. Beard. Grounds Maintenance v. 26 (3): p.26,28; 1991 March. NAL Call No. SB476.G7

"Principles, Definitions, and Scope of Integrated Pest Control" by R.F. Smith & H. T. Reynolds, U.N. Food and Agriculture Organization, Symposium on Integrated Pest Control, Oct.11-15, 1965, Rome Proceedings v. 1: p. 11-17. NAL Call No. SB951.FG2

"Scout Crops Now to Protect Yields". Conservation Impact v. 9 (6): p. 1; 1991 June. NAL Call No. S604.C66

[Series] by John A. Davidson and Charles F. Cornell. American Nurseryman. NAL Call No. 80 AM371.

"In the Beginning..." v. 167 (5): p. 76-77,79-89; 1988 March 1.

"Changing Philosophies" v. 167 (7): p. 115-117,120-121; 1988 April 1.

"IPM: Parts and Parcel" v. 167 (8): p. 81-91; 1988 April 15.

"Making the Pilot FLY" by Davidson, Cornell, Mary E. Zastrow and Dona C. Alban. 1988 June 1. v. 67 (10): p 51-60; 1988 May 15.

"The Untapped Alternative" by Davidson, Cornell & Alban. v. 167 (1 1): p 99-109;

Farmscaping to Enhance Biological Control

Pest Management Systems Guide

ATTRA National Sustainable Agriculture Information Service

P.O. Box 3657

Fayetteville, AR 72702

Phone: 1-800-346-9140 --- FAX: (479) 442-9842

The PDF version of this document is available at

http://attra.ncat.org/attra-pub/PDF/farmscaping.pdf

39 pages - 988 kb

Abstract: This publication contains information about increasing and managing biodiversity on a farm to favor beneficial organisms, with emphasis on beneficial insects. The types of information farmscapers need to consider is outlined and emphasized. Appendices have information about various types and examples of successful "farmscaping" (manipulations of the agricultural ecosystem), plants that attract beneficials, pests and their predators, seed blends to attract beneficial insects, examples of farmscaping, hedgerow establishment and maintenance budgets, and a sample flowering period table.

Hedgerow of insectary plants at Fong Farms Ltd. in Woodland, CA.

Contents

Introduction

Farmscape Planning

Other Considerations

Weather

Perennial vs. Annual

Healthy Soil Ecology

Insectary Plant Characteristics

Mulches & Trap Crops

Farmscaping for Birds and Bats

Bat Housing

A Recap: Steps to Farmscaping

Federal Cost Share Programs

Summary

References

Introduction

“Farmscaping” is a whole-farm, ecological approach to pest management. It can be defined as the use of hedgerows, insectary plants, cover crops, and water reservoirs to attract and support populations of beneficial organisms such as insects, bats, and birds of prey.

In some respects, beneficial organisms should be considered—and managed as—mini-livestock. The larger varieties of livestock are healthier and reproduce more readily when provided an adequate and nutritious diet. Likewise, “mini-livestock” require adequate supplies of nectar, pollen, and herbivorous insects and mites as food to sustain and increase their populations. The best source of these foods is flowering plants. Flowering plants are particularly important to adults of the wasp and fly families, which require nectar and pollen sources in order to reproduce the immature larval stages that parasitize or prey on insect pests.

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However, using a random selection of flowering plants to increase the biodiversity of a farm may favor pest populations over beneficial organisms. It is important to identify those plants, planting situations, and management practices that best support populations of beneficial organisms.

Farmscaping, like other components of sustainable agriculture, requires more knowledge and management skill on the part of the grower than conventional pest management. The investment in knowledge and management may yield such benefits as:

A reduction in pesticide use

Savings in pesticide costs

Reduced risk of chemical residues on farm products

A safer farm environment and more on-farm wildlife.

However, farmscaping is not a magical cure for pest problems. It is simply an ecological approach to pest management that can be an integral component of a biointensive integrated pest management (IPM) program.

The use of farmscaping to increase beneficial organism habitat must be understood and practiced within the context of overall farm management goals. For example, when considering planting a perennial hedgerow the producer should evaluate the various costs and benefits likely to be associated with a hedgerow. Growers with farmscaping experience will likely be the best source for this kind of information.

Farmscape Planning

There are probably as many approaches to farmscaping as there are farmers. Some growers, after observing a cover crop harboring beneficial insects, plant strips of it in or around their crop fields. The advantages of this kind of approach are:

It is simple to implement

It is often very effective

The farmer can modify the system after observing the results.

Problems arise when the beneficial insect habitat, unbeknownst to the grower, also harbors pest species. (For a more detailed discussion of this topic, visit:

HYPERLINK "http://www.lib.uconn.edu/CANR/ces/ipm/general/htms/cvercrop.htm" \t "_blank" µhttp://www.lib.uconn.edu/CANR/ces/ipm/general/htms/cvercrop.htm§). In other instances the beneficials may not exist in numbers sufficient to control pest populations during the time when pest populations generally increase. Predator/prey population balances are influenced by the timing of availability of nectar, pollen and alternate prey/hosts for the beneficials. Therefore, there is a strong argument to be made for having year-round beneficial organism habitat and food sources. The “beneficial habitat season” may be extended by adding plants that bloom sequentially throughout the growing season or the whole year.

When contemplating farmscaping, consideration should be given to the cost of developing beneficial habitat and maintenance of the habitat as well as the cost of any land that might be taken out of production. In any case, a more systematic, research-oriented approach to farmscaping can often help the grower avoid mistakes and develop desirable habitats that match the needs of the beneficial organisms as well as the pest management needs of the farm.

The following are key considerations in crafting a farmscaping plan:

1. Ecology of Pests and Beneficials

What are the most important (economic) pests that require management?

What are the most important predators and parasites of the pest?

What are the primary food sources, habitat, and other ecological requirements of both pests and beneficials? (Where does the pest infest the field from, how is it attracted to the crop, and how does it develop in the crop? Where do the beneficials come from, how are they attracted to the crop, and how do they develop in the crop?)

2. Timing

When do pest populations generally first appear and when do these populations become economically damaging?

When do the most important predators and parasites of the pest appear?

When do food sources (nectar, pollen, alternate hosts, and prey) for beneficials first appear? How long do they last?

What native annuals and perennials can provide habitat?

3. Identification of Strategies

Reduction of pest habitat (i.e., reduce/alter overwintering pest sites, or reduce/alter locations from which pest invades.)

Augmentation of beneficial habitat (insectary establishment; consider both perennial options—permanent plantings such as hedgerows—and annual options.)

Trap Crops—planted specifically to be more attractive to the pest than is the crop to be harvested. This is due to the timing of the appearance of the trap crop or the fact that it is physiologically more attractive to the insect. (Please see appendices HYPERLINK "http://attra.ncat.org/attra-pub/farmscaping/fsappendixd.html" µD§ and HYPERLINK "http://attra.ncat.org/attra-pub/farmscaping/fsappendixg.html" µG§ for descriptions of planting systems that can be used in farmscaping.)

4. Insectary Establishment

Seed and plant sources

Cost of ground preparation, planting and maintenance (irrigation, weeding, etc.) for:

at least one year following establishment of perennials

needed number of plantings per season of beneficial habitat (remember that many annuals provide pollen or nectar for only a few weeks during the cropping season, so that either relay plantings or plant species mixes may be needed for beneficial habitat.)

Equipment needs.

Other Considerations

Weather

Weather variations from year to year may cause a particular management practice to be beneficial one year and problematic the next. A flexible approach is needed in order to adjust beneficial habitat according to weather variations. An observant eye is the grower’s most valuable tool in this respect.

Perennial vs. Annual

The type of cropping system, perennial vs. annual, is an important factor in farmscaping. Perennial systems such as orchards possess an inherent ecological stability derived from the variety of tree-based habitats, which are not harvested or destroyed as in annual systems. Adding a cover crop to an orchard can increase and complement the biodiversity of the system.

Ideally, cover crops (CCs) in orchard systems should be selected and managed for the following attributes (1) :

CCs should not harbor important orchard pests

CCs should have some ability to divert generalist pests from the orchard crop

CCs should confuse specialist pests visually or olfactorily (by smell) and thus reduce their colonization of orchard trees

CCs should be capable of altering host-plant nutrition (without negatively impacting the crop) and thereby reduce pest success

CCs should reduce dust and thereby reduce spider mite outbreaks

CCs should change the microclimate and thereby reduce pest success

CCs should increase natural enemy abundance or efficiency, thereby increasing biological control of arthropod pests.

Studies of commercial pecan orchards in Oklahoma (2) and almond plantations in California (3) have demonstrated the efficacy of managing cover crops for pest control in orchard systems. In all instances, this farmscaping technique resulted in significant reductions in pesticide applications.

Annual cropping systems are much less stable than perennial ones. Depending on the amount of tillage involved, the ecology of annual systems, both above and below ground, is dramatically altered every year. To help anchor the ecology of an annual system, consider planting “permanent” insectary strips or hedgerows in or along an annual crop field.

The idea of undisturbed beneficial habitat distributed at intervals in or around crop fields is a theme common to many farmscaping techniques. Depending on the plant species, these “perennial islands” provide food resources for beneficial organisms as well as overwintering sites from which crops can be colonized in the spring. Kenny Haines, a vegetable grower in North Carolina who practices farmscaping, notes that his insectary strips provide a “meetin’ place” for the beneficials. Springtime environments of annual cropping systems are characterized by extremes of temperature, sunlight and humidity—conditions in which colonization and survival of beneficials is unlikely without good habitat nearby. For details on how some farmers (including Kenny Haines) incorporate a “permanent” component into their annual fields.

Healthy Soil Ecology

Many organisms, including pest insects associated with both perennial and annual crops, spend part of their life cycle in the soil. A diverse soil ecology maintained with regular additions of organic matter helps to regulate populations of both pest and beneficial organisms (4, 5, 6).

Insectary Plant Characteristics

Experimentation is the key to finding a successful combination of planting systems, ground covers/mulches, and management practices that work best for the unique soil and environmental conditions of a particular farm and crop.

As a first step, the producer should choose plants that provide good habitat for the desired predators or parasites, and at the same time, do not harbor insects that are likely to become pests. For example, subterranean clover harbors many beneficials like big-eyed bugs, and also harbors relatively few Lygus species. pests. Avoid aggressive, invasive plants and those that may act as reservoirs for diseases that attack surrounding crops.

Cover crops that are good insectary plants include buckwheat, sweet clover, faba beans, vetch, red clover, white clover, mustards, and cowpeas. Herbaceous plants that are good insectary plants and which may be planted in strips include species in the carrot (Apiaceae=Umbelliferae), sunflower (Asteraceae=Compositae), and mint (Lamiaceae) families. (Refer to appendices A, B, and C for detailed information on pests, beneficials, and seed blends for plants that attract beneficials.)

In many instances, floral structure is an important consideration. Beneficials with short mouthparts, such as the tiny parasitic wasps, find it easy to obtain nectar and pollinate plants in the parsley and sunflower families because of the small, shallow flowers these species provide. Plants that possess extrafloral nectaries (nectar sources outside the flower), such as faba beans, cowpeas, vetch, and several native ground covers, provide beneficials with easy access to an important food source in addition to the nectar and pollen of their flowers.

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Recent work in Georgia investigated the importance of different food sources—extrafloral nectaries, honeydew (a liquid emitted by whiteflies, aphids, scales, and leafhoppers, composed of unused portions of plant sap as well as certain waste products of the insects), sucrose, or no food sources—on Microplitis croceipes, a parasitoid of the corn earworm in cotton (7). Important findings included:

Retention of the wasp and parasitization rates were highest in cotton plots in which wasps were able to feed on extrafloral nectar.

Retention of the wasp and parasitization in patches with honeydew was comparable to patches without food—probably due to the rapid decrease in quality of honeydew as it dries, combined with low quantity per site and general low detectability of this food by the parasitoid. Honeydew is scattered about randomly within a field and on a plant. Extrafloral or floral nectaries, on the other hand, are always found at the same location on a particular plant, making it easier for beneficials to locate this food source.

Important characteristics of an ideal food source in the field are high quality, high quantity per site, high detectability, and high predictability of the food location. Nectar sources possess all these qualities.

To summarize this research, some species of parasitic wasps will stay in an area with nectar sources—either floral or extrafloral—and this results in a higher parasitization rate of host pests in that area. This makes sense, because the wasp can spend more time hunting for hosts and less time hunting for food. Many crop plants do not provide sufficient food for hungry parasitoids. As a consequence, parasitoids will disperse from target areas in search for food. After feeding, parasitoids may not return to original target areas, especially when the distance between food and host locations is too great or when the food locations also harbor hosts (7). Because nectar sources are so important to many beneficials, non-invasive plants with floral or extrafloral nectaries might be considered prime candidates for use in farmscaping.

A study in California (8) revealed that beneficials in fact do feed on nectar and pollen provided by insectary plants, and will move up to 250 feet into adjacent crop lands. Further research is needed to determine the optimum spacing of insectaries within a particular crop and ecosystem so that parasites spend most of their time controlling pests (as opposed to searching for food) and producers know how much land insectaries will require and where they are most effectively placed.

The appearance of beneficials should be timed to coincide with peak need for biological control of pests associated with the main crop. Another way of looking at this is that an insectary crop should grow and bloom at a time that best meets the needs of beneficials for pollen, nectar, or alternate hosts. Strategies to prolong bloom include planting cover crops in strips on successive planting dates. Planting a mix of plants, particularly perennials, that bloom in succession and that meet the habitat needs of desired beneficials is another farmscaping option. It may be helpful to develop a diagram, when planning habitat that will have something in flower year-round.

The migration of certain species of beneficials from the cover crop(s) to the main crop is sometimes associated with senescence (or post-bloom period) of the cover crop. In these instances, mowing the cover crops in alternate strips may facilitate their movement while the remaining strips continue to provide refuge for other beneficial species. Sickle-bar mowers are less disruptive to beneficials than flail mowers and rotary mowers.

Mulches

Although this publication generally focuses on living habitat, clearly some beneficial organisms, such as spiders and ground beetles, benefit from mulches (or a habitat that mimics some of the effects of mulches, such as that found in “no-till” fields). Much of the benefit lies in the fact that mulches provide overwintering habitat for these organisms in a moderated microclimate (9).

Trap Crops

A related strategy in farmscaping is the selection of plants that attract pests. These “trap crops” can then be plowed down or managed in some fashion that takes advantage of a vulnerable stage in the crop pest life cycle.

Farmscaping for Birds and Bats

Birds and bats are important insect predators, particularly during the spring when they are raising young. Their activities complement each other. Birds are generally active during the day and feed on caterpillars and other insects, while bats feed during dusk and into the night on mosquitoes, moths, and other nocturnal insects.

Birds and bats are both amenable to living in artificial shelters—free-standing or attached to a building. This could be a slightly modified structural component of a building, such as nest shelves along eaves for barn swallows (10) or a spaced board attached to a beam for bat habitat. Bats, frequently found in man-made structures, prefer places that are warm, dry, and protected from disturbance (11).

Both birds and bats will benefit from having a small pond or body of water on the property or nearby. Bats require a watering area ideally 10 feet long, as they drink “on the fly.” Birds will be content with birdbath-size and larger water bodies.

One difficulty in farmscaping for birds is that some birds’ diets change from insects to seeds (or to fruit) after they have finished rearing their young. The following table lists some bird species that may be considered for farmscaping efforts.

Bird Species

Comments (10, 12, 13)

Bluebird

Nest boxes should be located 5-6' above the ground-best facing a tree or artificial perch. Place multiple houses 30 yards apart to allow individual birds to establish territories. The opening should be 1.5" in diameter.

Chickadees

Feed mostly in hedgerows and wooded borders. Nest boxes best located near or in trees, hedgerow, etc., 5-15' above the ground. Will overwinter.

Wrens

Feed on insects on ground and plants. Locate nest box close to stick piles and garden. Generally a summer resident only. Opening should be .75" in diameter

Barn Swallow

Attracted by nest shelves under eaves or other structures. Beware of droppings. Opening should be 1.5" in diameter

Robin

Common insectivore, but consumes small fruits and cherries.

Starling

Common insectivore, but will eat small fruit and hollow out large fruit (apples). May forage in large flocks.

Bats not only eat insects that are a nuisance to humans (a small brown bat can devour up to 600 mosquitoes in an hour), but can provide significant agricultural pest control services. In one season, a typical colony of about 150 big brown bats in the Midwest eats 50,000 leafhoppers, 38,000 cucumber beetles, 16,000 June bugs, and 19,000 stink bugs (11)—not to mention thousands of moths such as adult cornborers, earworms, and cutworms.

 

Bat Housing

The easiest way to construct bat housing is to simply add a sheet of plywood to a barn or house wall with ¾” spacers between the sheet and wall. Placing the long axis of the plywood vertically will allow for greater temperature variation in the bat space. (See HYPERLINK "http://attra.ncat.org/attra-pub/farmscaping/fscontacts.html" µUseful Contacts§ for contacts who know about bat habitat and housing.)

Other construction considerations include (11):

Use exterior-grade plywood with exterior-grade staples and bolts.

Minimum bat house dimensions are 32” tall, 14” wide, with 3–6” landing pad below the opening.

Provide 1–4 roosting chambers, spaced at ¾”. Landing pad and roosting chamber should be roughened or have a durable textured surface for the bats to grasp—no sharp points to tear bat wings!

Front and side venting should be appropriate for local climate.

All seams should be caulked to avoid leaks.

Treating bat houses with diluted bat guano or allowing some weathering of a new bat house may help attract new “renters”.

Considerations when locating a bat house (11):

Any place that already has bats is best, particularly agricultural areas (vs. urban areas) due to insect abundance and habitat variety.

Place the bat house near water—within a quarter mile is ideal.

Place it near some sort of protective cover like a grove of trees—don’t place houses in a grove of trees, but 20–25 ft. away due to predator concerns, and at least 10 ft. above the ground.

Don’t place bat houses near barn owl boxes—the barn owl is a bat predator. Place the two types of boxes a fair distance from each other facing in opposite directions.

Do not mount bat houses on metal buildings (too hot for bats) or in locations exposed to bright lights.

In California, bat houses in barns and on the north and west sides of buildings have had the greatest rate of occupancy. This may not be true for locations in other parts of the country.

Paint the exterior with three coats of outdoor paint. Available observations suggest that the color should be black where average high temperatures in July are 80–85° F, dark colors (such as dark brown or gray) where they are 85–95° F, medium or light colors where they are 95–100° F, and white where they exceed 100° F. Much depends upon amount of sun exposure; adjust to darker colors for less sun. (14)

A Recap: Steps to Farmscaping

Habitat enhancement for beneficial organisms can provide the foundation for a biologically intensive Integrated Pest Management (IPM) program. The steps presented below may help when attempting to increase the “directed diversity” of an agricultural ecosystem:

Keep good records of where, when, and what pests occur on the farm.

Obtain as much information as you can about both the pest’s and the beneficial organism’s life cycle and habitat requirements. Where are eggs laid and when do they hatch? Where does the pest/beneficial feed and how long does it need to develop into an adult? Where does the pest/beneficial overwinter and in what form? This information will not only aid in farmscaping, but will also aid pest management.

Make a list of tools that are available to create a friendlier habitat for the beneficials (or a more unfriendly habitat for pests). This may include various combinations of: insectary plants, crop rotations, hedge rows, intercropping schemes, planting or harvesting time and methods, etc. Beware of aggressive insectary or hedgerow plants.

Select those tools listed in #3 that best fit into your cropping system, rotation, equipment, and labor availability. Remember, permanent plantings will require maintenance during the first few years after planting.

Experiment, observe the results, fine tune the system, and experiment again. Try something new—a variation on something that’s already being done.

Start simple and small, then develop the farmscaping as experience and observations dictate.

Summary

The goal of farmscaping is to prevent pest populations from becoming economically damaging. This is accomplished primarily by providing habitat to beneficial organisms that increase ecological pressures against pest populations. Farmscaping requires a greater investment in knowledge, observation, and management skill than conventional pest management tactics, while returning multiple benefits to a farm’s ecology and economy.

However, farmscaping alone may not provide adequate pest control. It is important to monitor pest and beneficial populations so that quick action can be taken if beneficials are not able to keep pest populations in check. Measures such as maintaining healthy soils and rotating crops are complementary to farmscaping and should be integrated with farmscaping efforts. Biointensive Integrated Pest Management (IPM) measures, such as the release of commercially-reared beneficials (applied biological control) and the application of “soft” pesticides (soaps, oils, botanicals) can be used to augment farmscaping efforts.

References

Bugg, R.L. and C. Waddington. 1994. Managing cover crops to manage arthropod pests of orchards. Agricultural Ecosystems & Environment. Vol. 50. p. 11–28.

Bugg, R.L., M. Sarrantonio, J.D. Dutcher, and S.C. Phatak. 1991. Understory cover crops in pecan orchards: Possible management systems. American Journal of Alternative Agriculture. p. 50–62

Anonymous. 1995. Bios: a growing success. Farmer to Farmer. May–June. p. 8–9

Akhtar, Mohammad and M.M. Alam. 1993. Utilization of waste materials in nematode control: A review. Bioresource Technology. Vol. 45. p. 1–7.

Trankner, Andreas. 1992. Use of agricultural and municipal organic wastes to develop suppressiveness to plant pathogens. p. 35–42. In: E.S. Tjamos (ed.) Biological Control of Diseases. NATO ASI Series, Vol. 230, Plenum Press, New York, NY

Hoitink, Harry A.J. and Peter C. Fahy. 1986. Basis for the control of soilborne plant pathogens with composts. Annual Review of Phytopathology. Vol. 24. p. 93–114.

Stapel, J.O. and A.M. Cortesero. 1997. Importance of nectar sources for adult parasitoids in biological control programs. Midwest Biological Control News. May. p. 1, 7.

Long, R.F., A. Corbett, C. Lamb, C. Reberg-Horton, J. Chandler, M. Stimmann. 1998. Beneficial insects move from flowering plants to nearby crops. California Agriculture, September-October. p. 23–26.

Riechert, S.E. 1998. The role of spiders and their conservation in the agroecosystem. In: Pickett, C.H. and R.L. Bugg (eds). 1998. Enhancing Biological Control: Habitat Management to Promote Natural Enemies of Agricultural Pests. University of California Press, Berkeley, CA.

Thalmann, Dan. 2000. Attract a pest-control air force. Growing for Market. Vol. 9, No. 3. March. p. 11–13.

Long, R.F. 1999. Use of bats to enhance insect pest control. p. 67–70. In: Bring Farm Edges Back to Life! Yolo County Resource Conservation District, Woodland, CA. 105 p.

Duval, Jean, S. Sobkowiak. 1995. Birds and bats: The orchard pest patrol. Sustainable Farming, Vol. 6 No. 1. p. 6, 7.

Brittingham, M.C. 1992. Controlling birds on fruit crops. Northland Berry News. September. Vol. 6, No. 3. p. 7, 8.

Bat Conservation International Website. 2000 http://www.batcon.org/bhra/bhcriter.html

Robins, P. 1999. Cost share programs for resource conservation and wildlife habitat development. p. 89–91. In: Bring Farm Edges Back to Life! Yolo County Resource Conservation District, Woodland, CA. 105 p.

Ent 312 - Use of Computers in IPM Syllabus - modified 4 March 1998

Winter term 1998 - 3 hr credit

Prerequisites: Ent 311 Introduction to Insect Pest Management or consent of Instructor;

Basic knowledge of spreadsheets and statistics recommended

Leonard Coop, Ralph Berry, and Brian Croft

Dept. Entomology and Integrated Plant Protection Center

Oregon State University

This class is designed to teach computer skills and hands-on experience regarding ecological and systems/management concepts to support development and implementation of Integrated Pest Management programs, with emphasis on insect pest management. Main topic areas to include decision making, population dynamics, phenology, crop loss, modeling, and implementation considerations. Tools to be used as part of the instruction include desktop computers, spreadsheet software, internet related software, special-purpose modeling software programs, and specific decision support software such as IPMP, PETE, APPLESCAB, FMS, and HOPPER. The format will emphasize a broad survey of concepts and techniques rather than an in-depth knowledge of a few topic areas. Optional student-selected topics will provide flexibility in catering to individual student's interests. Scientific written reporting of students' investigations will receive a major emphasis in this class.

Class Structure: Full quarter class: 1 hr lecture (Monday 11 am),

2 hr lab (sec. 1 Tuesday 10-noon, sec. 2 Monday 1-3 pm),

1 hr lecture/recitation (Fri. 11 am)

Instructor: Leonard Coop, Dept Entomology and Integrated Plant Protection Center (IPPC),

541-737-5523 work - office Cordley 4038, office hours TBA

541-737-3080 fax

HYPERLINK "mailto:coopl@bcc.orst.edu" µcoopl@bcc.orst.edu§ email

Computers used:

various web servers including

ipm-dd.orst.edu (Windows NT), ipm-models.orst.edu (Linux),

ippc.orst.edu (Windows NT). Class notes and other info will be posted at

http://ippc2.orst.edu

 

At the completion of the course, participants will have developed the knowledge and skills to:

View pest management problems from a systems perspective.

Organize a problem area by decomposing it into modular, linked, quantifiable components.

Put ecological theory and concepts into practical use.

Write laboratory exercise reports in the format of scientific investigations, with Introduction, Objectives, Methods, Results, and Discussion.

Use a computer spreadsheet as a general purpose analytical tool for simple as well as complex questions.

Understand the utility and differences between many types of research and implementation models, expert systems, and decision support systems.

Use several of the more specialized IPM software programs to understand technical and management aspects of IPM decision making.

Text: Handouts from various sources

Primary references and recommended readings:

Gutierrez, A. P. 1996. Applied Population Ecology: a supply-demand approach. John Wiley and Sons, NY. 305 pp.

Hilborn, R. and M.Mangel. 1997. The Ecological Detective - Confronting Models with Data. Monographs in Population Biology no. 28. Princeton University Press. Princeton, NJ. 315 pp.

Horn, D. J. 1988. Ecological approach to Pest Management. The Guilford Press, NY. 285 pp. Keen, R. E. and J. D. Spain. 1992. Computer Simulation in Biology. A BASIC Introduction. Wiley-Liss. New York. 498 pp + diskette.

Norton, G. A., and J. D. Mumford [eds.]. 1993. Decision Tools for Pest Management. CAB International. Wallingford, Eng. 279 pp.

Pedigo, L. P., and M. R. Zeiss. 1996. Analyses in Insect Ecology and Management. Iowa State Univ. Press. 168 pp + diskette.

Week:

1. Overview + Introduction to IPM modeling

- Introductory concepts, background, expectations

- Systems concepts for IPM

- Intro to flow charting

Lab exercise 1: Spreadsheet analysis I: Cocoa pod borer simulation model (a spreadsheet model of pod borer development, survival, crop injury, and control economics). Reference: Chapter 10 in Norton and Mumford 1993.

Classroom exercise 1: Flow charts used in conceptual modeling (a target problem area to be individually selected by each student).

2. Modeling techniques, curve fitting techniques

- Problem solving techniques: Scientific method, and conceptual modeling techniques. Reference: Alternative views of the scientific method and modeling - chapter 2 in Hilborn and Mangel, pp. 12-38.

- Problem solving techniques: Top-down design, stepwise refinement

Classroom exercise 2: Structuring problems hierarchically using top-down design, stepwise refinement, outlining and Warnier-Orr diagrams.

Lab exercise 2: Spreadsheet analysis II: Simple regression and curve fitting, Using BASIC programs to fit curves to data: routines for transformation and and curve fitting by linear and polynomial regression. Reference: Handout on how to fit curves and display them with Lotus 123, Keen and Spain pp. 49-67, 393-407, 453-461.

3. IPM on the World Wide Web - I

- Searching for on-line IPM resources

- Learning IPM concepts and principles via the web

Lab exercise 3: Searching for IPM information using general search engines, Database of IPM Resources (DIR), World of IPM Web Class (U. Minn.), Basics of building a web page.

4. IPM on the World Wide Web - II

- Building web pages: modifying pages from remote links, and building pages from original content.

Lab exercise 4: Advanced web page building: developing original content from word processor and spreadsheets.

5. Population dynamics modeling I: Life table and matrix models

- Life table parameters used for modeling purposes, stage-frequency data analysis - estimating development time, survival rates, and recruitment rates. References: Horn pp. 62-88, Southwood and Jepson 1962.

Lab exercise 5: Spreadsheet analysis III: Developing population models from life-table data, with improvements including logistic growth; Using spreadsheet macros to control model execution. References: Keen and Spain pp. 137-144, Horn 1988 pp. 62-93, class handouts on basic life table analysis, 2 pp.

6. Population dynamics modeling II: Modeling predator-prey dynamics

Lab exercise 6: Spreadsheet analysis IV: The Nicholson-Bailey predator-prey model and improvements including logistic pest population growth, type two functional response, and decreased search efficiency with increased parasitoid density. References: Norton and Mumford pp. 101-117, Keen and Spain pp. 113-116.

7. Modeling insect, crop and disease development

- Temperature effects on development

- Linear and degree-day models

- Non-linear development models

- Representing developmental variation in models

Lab exercise 7: Using and interpreting on-line degree-day models, using x-intercept and lowest CV methods to determine developmental requirements, phenology modeling with the PETE model - a generic phenology model. A classroom parameterization and calibration exercise will be conducted.  References: Taylor 1981 (summary of insect development a using non-linear model), Wilhoit, Stinner, and Axtell 1991 (FMS description), Zalom et al. 1983 (Use of Degree-days), Chmiel and Wilson 1979 (lowest CV method), Van Kirk and Aliniazee 1981 (determining lower thresholds from constant temperature data), Welch et al. 1978 (PETE model), Coop et al. 1993 (subpopulations to represent developmental variation).

8. Sampling issues related to IPM

- Spatial dispersion, Taylor's power law, binomial sampling plans, sequential sampling plans

Lab exercise 8: Spreadsheet analysis V: From sample data to sequential sampling plans: a step by step spreadsheet example, with demo of Javascript IPMP sampling calculator for strawberry root weevil.

Demo: Application of GIS and geostatistical analysis tools for IPM. References: Kogan and Herzog 1980, Liebhold et al. 1993, Johnson 1993 - Chapter 14 in Norton and Mumford, lecture handout, Variowin geostatistical analysis software .

9. Crop loss, economic thresholds, and injury equivalents

- Definitions, relationship between ET and EIL

- Use of injury equivalents

Lab exercise 9: Spreadsheet analysis VI: Economic injury levels and injury equivalents for grasshoppers in West Africa.

References: Poston, Pedigo and Welch 1983, Pedigo et al. 1986, Pedigo and Zeiss 1996, Coop and Croft 1993, Capinera et al. 1983, Bardner and Fletcher 1978, Kogan and Turnipseed 1980, spreadsheet template on EILs and IEQs (injury equivalents).

10. Decision making software, evaluating Decision Support Systems

- IPMP peppermint DSS

- HOPPER grasshopper management DSS

- Crop disease resistance: RESISTAN

- Computer simulation games: SCAB, Lateblight

References: Jones 1989, Stone and Schaub 1990, Stone 1989, Beck et al. 1989. Johnson et al. 1987, Johnson and Radcliffe 1991,

Lab exercise 10: Using computer simulation games to learn about disease management principles as applied to apple scab and lateblight of potato. Using Hopper to evaluate the need for treatment and control alternatives for rangeland grasshoppers.

11th Week topics - options (to be selected by each student)

- Disease modeling basics: modeling disease infections, modeling the spatial spread of diseases.

- Crop modeling basics, Liebig's law models and stress factors, DSSAT models

- Databases in IPM: structure, storage, delivery techniques

- Quantifying additional factors affecting EIL and ETs

- Stella and other tools for conceptual and computer modeling

- Pesticide efficacy and residual activity

- Pesticide resistance modeling approaches

- Pesticide risk environmental impact ranking systems (Kovatch approach)

- Disease modeling II - using real-time weather data

- Dispersal Processes: Diffusion processes,  island models, stepping stone models, backtrack models

- Modeling crop-weed interactions

- Weather simulation and forecasting techniques

- The Web: Javascript, CGI and Database IPM projects

- Decision analysis/advanced matrix techniques