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6 Implementing Management of Resistance to Pesticides PEST-CONTROL DECISIONS are influenced by many institutions, regula- tions, laws, and economics. This chapter focuses on the current status of efforts to manage development of resistance to pesticides and rec- ommends how strategies to manage resistance might be implemented. In- dividuals and single companies are limited in their ability to deal with resistance primarily because: (1) resistant pests move across property boundaries, (2) information on the current and prospective pesticide susceptibility levels of pest populations is expensive to assemble, (3) information on methods for managing resistance and actions to respond to resistance are often needed at many locations at the same time, involving several related compounds made by different companies, and (4) because of potential conflicts of interest, combined with companies' needs for proprietary secrets. In responding to these difficult challenges, we will assess the roles of public agencies, groups of private firms, and the market system in managing resistance. Once tactics for slowing pesticide resistance are developed and tested, technical progress will be achieved only if the tactics are properly, widely, and consistently applied. Four of the more important groups of organizations that affect implementation are: (1) the extension service, pest-management consultants, and farmers (considered here as a group); (2) regulatory agencies; (3) the pesticide industry; and (4) international organizations. This report focused on the biological and genetic bases of resistance and on tactics to manage resistance. The committee recognized that few of the standard institutional mechanisms and incentives are available to bring about changes needed to encourage use of these tactics, which are often specific to particular pests and/or crops. To coordinate activities to manage resistance, 371
372 MANAGEMENT OF RESISTANCE TO PESTICIDES it may be possible to build on existing initiatives such as the National Bio- logical Impact Assessment Program (NBIAP). EXTENSION, CONSULTANTS, AND PESTICIDE USERS Education The Cooperative Extension Service should take a leadership role in de- veloping educational programs in the area of management of resistance to pesticides, coordinating input from state agricultural experiment stations, pest-control advisers, the pesticide industry, commodity associations, reg- ulatory agencies, and end users. Factors to consider in a training program are · The known toxicological, genetic, biological, and operational factors that influence selection for resistance. Published studies should be used as the primary basis for anticipating situations where resistance might occur. · Identify and categorize pests and pesticides at high risk for developing resistance, particularly those that can develop cross-resistance. · Review integrated pest management-compatible tactics-such as re- ducing selection pressure- that delay resistance development. Stress inte- grating pesticide use with nonpesticidal control measures. Discuss the high value of retaining, for as long as possible, low-cost pesticides that are used successfully in integrated-pest-management (IPM) programs. · Emphasize the value of monitoring for resistance. Action thresholds should be established that determine the frequency of the population that is resistant at any time and above which it is advisable to switch to an alternative pesticide. Examples of action thresholds for development of resistance are described elsewhere in this volume (Fr~sbie et al.~. RECOMMENDATION 1. The Extension Committee on Organization and Pol- icy IPM Task Force should conduct a feasibility study for developing an educational program on management of pesticide resistance, coordinated through the Cooperative Extension Service. This committee should work with representatives from the state agricultural experiment stations, U.S. Department of Agriculture-Agricultural Research Ser- vice (USDA-ARS), Economic Research Service (ERS), Animal and Plant Health Inspection Service (APHIS), professional societies, industry, consultant orga- nizations, commodity organizations, public health agencies, and state depart- ments of agriculture to determine whether a program thrust in this area is needed and feasible, and, if so, what the form and function of the training program should be.
MANAGEMENT OF RESISTANCE TO PESTICIDES Formalize Procedures for Management of Resistance to Pesticides 373 There may be a need to formalize and standardize procedures for dealing with resistant pest populations, as discussed by Frisbie et al. (this volume). When a control failure occurs, farmers, agricultural consultants, chemical applicators, state agricultural experiment stations, and Cooperative Extension services should work with agricultural chemical companies to determine the basis for the failure. A series of questions need to be addressed in a logical order: was the most effective pesticide applied for the specific pest and life stage; was it applied at an appropriate rate; was it applied under favorable weather conditions; did the equipment function properly; is the toxic agent active. If any of these conditions were not met, corrective actions should be taken. If the control failure persists, a bioassay should then be used to determine whether the pest population is susceptible to the pesticide. When resistance is verified at a level sufficient to justify alternative control strat- egies, they should be used immediately, if possible. Additional research is needed to establish action thresholds for resistance for specific pests and crops, and to develop pest-specific rapid bioassay and monitoring techniques (see Chapters 2 and 4.) When appropriate management tactics (see Chapter 5) are developed and validated, they should be implemented by the appro- priate groups mentioned above. RECOMMENDATION 2. A formalized procedure or action plan should be developed to manage resistance to pesticides and to identify responsible individuals or agencies. The Cooperative Extension Service should take the leadership role in organizing work groups within state, regional, and na- tional IPM programs to implement management of resistance. REGULATORY AGENCIES This section concerns U.S. state and federal agencies. The committee focused on actions that could be undertaken to manage resistance without major legislative changes in state laws or in the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), the primary federal statute governing the registration and use of pesticides in the United States. When resistance occurs, what is the appropriate role of state and federal agencies currently regulating pesticide use? Use directions and prohibitions against certain practices might be added to pesticide labels to prolong the useful life of a pesticide. As reliable methods become available, "resistance- risk" data might be required as part of the pesticide registration process and used in developing educational materials for certifying and training users and sellers of pesticides. As a first step, the mode of action should be identified. The recent experience of applying biotechnology to herbicides suggests that
374 MANAGEMENT OF RESISTANCE TO PESTICIDES mode of action can be determined quite rapidly. Information on pesticide resistance often becomes available as part of other regulatory activities- reregistration, applications for emergency use exemptions, and regulatory actions taken to prohibit certain pesticide uses. Questions remain regarding what should be done with this information and how funds should be generated for regulatory activities, information collection, and research. Pesticide Resistance in Regulatory Decisions The committee agreed that resistance management is a legitimate activity for regulatory agencies when beneficial strategies and program opportunities arise, but recognized that there are strengths and weaknesses in each regu- latory initiative considered. At the present time, the committee does not recommend major changes in state or federal regulatory responsibilities as they relate to resistance. In the committee's judgment, there are compelling reasons why resistance is a difficult phenomenon to integrate more formally or routinely into reg- ulatory agency decision-making. These include (1) federal agencies cannot make or implement timely decisions for local management of resistance; (2) market participants, local groups, and extension services can monitor and more effectively direct management; and (3) regulatory agencies lack funding for new management initiatives because they have higher priority pesticide regulatory objectives to pursue. The U.S. Environmental Protection Agency (EPA) pesticide-use regula- tions under FIFRA do not explicitly direct the agency to consider resistance in carrying out its other responsibilities. In practice, though, the statute's basic risk-benefit balancing criterion requires consideration of pesticide ef- ficacy in determining benefits. To the extent resistance reduces actual or anticipated efficacy and hence benefits-EPA is already mandated to take it into account. Resistant pest populations, moreover, affect definitions of emergency use conditions, classification of pesticides, and reporting of "ad- verse effects" all part of the regulatory process. Any biological factor, such as resistance, that can substantially reduce the benefits from pesticide use could affect some regulatory decisions. Still, as a practical matter, it would be difficult to encourage use of strategies to manage resistance by specifying such strategies on pesticide product labels, the major instrument available to regulatory agencies for encouraging resistance management. Because most pesticide resistance events are localized and change rapidly, use of pesticide labels to help manage resistance will rarely be feasible (Johnson, Hawkins, this volume). Several approaches, however, do exist to encourage management of re- sistance. The practice of allowing market forces to reward product efficacy is well established for most pesticide products. (Johnson, this volume, dis
MANAGEMENT OF RESISTANCE TO PESTICIDES 375 cusses efficacy waivers under FIFRA.) There are possibilities, as well, for the extension service, agricultural consultants, and pesticide firms to monitor for and recommend management strategies in local areas. Finally, in considering the regulatory approach to managing resistance to pesticides, the constraints on available resources must be recognized. For a regulatory approach to be effective, it must be timely and specific as to location, crop, and pests. Consideration of mixtures and multiple compounds so that rotations might be used would require considerable manpower, which is not currently available in the EPA. Health and environmental risks could increase if EPA and state resources were shifted from pesticide safety to managing resistance and maintaining pesticide product life. The economic conditions under which individual pesticide firms, groups of firms, or farmers can profitably act to reduce resistance are limited by pest mobility and market structure. The following conditions are thought to favor mandatory or government programs in resistance management (Mir- anowski and Carlson, this volume): (1) when noncooperation by one or more chemical firms can jeopardize a regional program to manage resistance; (2) when antitrust considerations make certain cooperative efforts between firms difficult, and perhaps illegal; (3) when coordination between firms is costly, such as might occur when many companies or farmers with widely different interests in managing a pest population are involved; or (4) when a govern- ment unit is directly responsible for pest control, such as for public health pests or on public lands managed by the Forest Service. The increasing number of pesticide resistance incidents (i.e., human health- related pests in hospitals, malaria mosquitoes, isolated rat populations, and certain agricultural pests such as the Colorado potato beetle) is frequently cited as a reason for government regulations in risk management. The in- creased cost of synthesizing new chemicals to replace those chemicals made obsolete by resistance also affects the availability and cost of chemical pes- ticides. Increased safety testing has increased pesticide registration time and costs of bringing new pesticides to market (CAST, 19811. Cross-resistance can also make it more difficult to develop new chemicals; there is concern in some quarters that we may be running out of biochemical or physiological target sites in pests that can be attacked by new chemicals. New biological techniques, however, are expected to enable us to identify additional target sites not heretofore recognized. Pesticide companies and growers are con- cerned about the very limited set of products in many cases, just one or two registered compounds available to control many major pests. On the other hand, indicators of future scarcity of pesticides such as pesticide prices in broad classes of pesticides do not give signals of increasing rates of resistance development. Pesticide prices have been falling relative to the prices of other agricultural inputs over the past 15 years (Miranowski and Carlson, this volume). Pesticide prices are an important indicator of
376 MANAGEMENT OF RESISTANCE TO PESTICIDES resource scarcity in the future even in the presence of market imperfections. One is cautioned, however, that examining changes in pesticide prices prob- ably will not reveal and correlate with high levels of resistance on minor crops and/or pests. Also not revealed are important pest resistance episodes (rodenticides, dipter~cides) in poor regions or countries. Frequently, government agencies can assist in resistance management by carrying out other regulatory and research functions. For example, the EPA has had a program supporting IPM research; as a part of IPM, efforts to manage resistance to pesticides is clearly a legitimate function of government. California and a few other states have been active in funding research to understand resistance to pesticides, with a goal of developing practical pro- grams to reduce its buildup (Hawkins, this volume). In cases where pesticides are approved only for experimental or emergency use, evaluation of pesticide use ideally should precede approval for com- mercial registration or at least be in progress while the application is being considered. Monitoring is critical to evaluation of both experimental and emergency pesticide-use programs. While accurate monitoring is expensive and virtually impossible to administer on a global scale (see Chapter 4, this volume), it should be possible on a smaller scale; it should include regular estimates of densities and distribution of pest, extent of pest-related damage, and frequencies of resistant pest genotypes. The latter should be obtained for pests in the surrounding area as well. Programs to obtain similar estimates should also be instituted for a few representative areas where pesticides are already being applied. RECOMMENDATION 3. Departments of agriculture within each state, in considering whether to request emergency use permits to respond to pest- control needs that have arisen because of resistance to another compound, should seek advice on whether the conditions governing the emergency use permit are consistent with validated tactics for the management of resis- tance. The EPA, in approving such requests, should also consider the con- sequences for managing resistance, especially when cross-resistance is thought to be a possibility. The committee agreed that the idea of requiring data on "resistance risk" as part of the pesticide registration requirements is currently inappropriate. Con- siderable research is needed before the feasibility of such data requirements can be established, and such a regulatory response would require significant resource commitments at the EPA. Whenever such data exist, however, regulatory agen- cies should use them in discussing potential pesticide benefits (Dover and Croft, this volume). RECOMMENDATION 4. Major reforms in regulatory programs do not ap- pear justified or feasible at this time to advance the management of resistance
MANAGEMENT OF RESISTANCE TO PESTICIDES 377 to pesticides. Administrators of regulatory agencies should, however, for- mally enunciate policy statements that indicate awareness of, and respon- siveness to, resistance management issues, to the extent that such factors can and must be considered when implementing regulatory activities. Ac- tivities to manage resistance should not be pursued to the extent that they divert program resources from high priority safety responsibilities. R,?.vi.~tance Management Information in Regulatory Agencies The committee does feel strongly that a legitimate function of regulatory agencies is the collection and dissemination of information on resistance to pesticides. Information on the efficacy of particular pesticides is critical for making informed pesticide-use decisions. Because of their contact with farmers, extension service personnel and other local groups are in the best position to help producers formulate de- cisions to manage resistance. Given the frequent necessity for quick responses to resistance development by farmers, consultants, and chemical firms, how- ever, the reporting of a resistance episode to regulatory agencies could prob- ably not be acted on fast enough for a regulatory agency to initiate steps to foster resistance management, at least in the current production year. It is very costly to monitor and determine the geographical boundaries of a resistant pest population. A company often may not even know that resis- tance exists. Sometimes, firms may be reluctant to reveal diminution of pesticide effectiveness, but it is very difficult to conceal resistance in the United States for long. On the other hand, though, the desire for repeat sales of a pesticide product, and for sales of other products in the company's product line, generally leads companies to respond quickly to assess and report the extent of resistance to pesticides. Nevertheless, regulatory agencies can help foster solutions to pesticide resistance by compiling and disseminating accurate information. Various EPA functions, such as granting of emergency use registrations and the "adverse effects" activities, currently have important impacts on information flow. Resistance to available pesticides is reported in about 30 percent of the documents filed with the EPA by state agencies requesting emergency use registrations (section 18 of FIFRA). Compiling information on resistance in an easy-to-access computer file and disseminating this to a repository within the USDA, such as the National Pesticide Information Retrieval System, could be useful. Because of the local nature, variable severity, and important time dimensions of resistance, it is difficult at present for state and federal programs to obtain information and respond quickly. Furthermore, there is no reliable mechanism in place to validate the accuracy of resistance information. Therefore, any steps to com
378 MANAGEMENT OF RESISTANCE TO PESTICIDES pile and publish resistance data should proceed only in conjunction with an effective mechanism to update and confirm its accuracy. RECOMMENDATION 5. Information collection and dissemination on pesti- cide resistance is an important function of federal agencies involved with agriculture. A new initiative in carrying out this function should be pursued. The EPA, the USDA, and state regulatory agencies should cooperate in building a permanent repository for such information, including a mecha- nism to confirm the accuracy of resistance data. Reports published by the Food and Agricultural Organization (FAO) and the World Health Organization (WHO) validate resistance episodes and could per- haps serve as a useful model in establishing a repository for resistance data. Funding Funding constraints must be confronted in structuring new initiatives to manage resistance. The EPA and state regulatory agencies appear to have little flexibility to reduce or adjust other program responsibilities in pesticide regulation. As stated earlier, the committee feels that safety-related pesticide regulatory activities should retain higher priority than resistance management. Therefore, public funds through regulatory channels for resistance manage- ment are limited. Resistance monitoring, information dissemination, and research activities will require both public and private programs. One idea advanced at the convocation for raising new funds to advance resistance management is imposition of a national sales tax on pesticides. In supporting such a tax, proponents argue that the pesticide industry and users of pesticides will be the primary beneficiaries of successful resistance man- agement and that they should defray through such a tax the costs to develop and maintain programs to manage resistance. There is no indication that pesticide companies or farmers feel that resis- tance development and management needs are critical enough in the United States to justify such a tax. Pesticide firms have been surveyed and are nearly unanimously opposed to such a tax. No careful assessment of farmers is available, although the committee suspects that farmers without resistance problems will probably not be eager to bear the brunt of such a tax through higher pesticide prices since the tax would finance research and extension related to resistance for other regions or countries. Many resistance problems have only local impacts, and these can usually be met with new pesticides or nonpesticide approaches, including wider adoption of integrated pest management. Farmers may approve localized user fees for managing resistance, as occurs with community pest-management user fees used to fund integrated pest management, pest eradication, and management of resistance to pesticides for mosquitoes. Such fees are assessed
MANAGEMENT OF RESISTANCE TO PESTICIDES 379 on crop acreage (for example, cotton insect eradication programs), land area (property tax), and production level (cotton bale taxes), with local growers having a direct role in controlling how the funds are used. Pesticide manufacturers have incentives to join with other pesticide firms, university researchers, and the extension service to provide research and information on resistance. Industry is expanding voluntary efforts to report resistance. To date there have been no major financial assessments. RECOMMENDATION 6. Redirection of EPA funding or imposition of a na- tional pesticide tax are not recommended. Pesticide taxes collected by local pest-control districts can be used to manage resistance and should be en- couraged. PESTICIDE INDUSTRY Most major pesticide firms are active in many countries, and actions taken in one country reflect its unique crops, pests, social institutions, and laws. In recent years, pesticide companies in groups and individually have increased actions to reduce the rate of resistance buildup and to prolong the market lives of pesticides. Several organizations of pesticide firms have come into existence over the past 4 or 5 years with management of resistance as their major purpose. A currently successful example of this voluntary cooperative program among companies occurred in Australia with the goal of managing development of resistance to synthetic pyrethroids by cotton bollworms (He- liothis armigera) (Davies, 19841. Economically, the willingness of a particular company to take actions to reduce resistance development for a given pesticide is related to market structure, pest mobility, and cost and returns of employing resistance man- agement tactics. The value of protecting a pesticide from resistance is affected by: number, effectiveness, and costs of existing and prospective, competitive pesticides; expense of nonchemical controls; ease of production of the com- pound; and effectiveness in controlling major pestles) on major coopts). Groups of pesticide firms have joined together, with some successes, to prevent or forestall the emergence of resistance for certain classes of pro- prietary pesticides. Such action has been possible only where coordinated activities are not costly or illegal, and when coordination across pesticide products was mutually recognized as essential to prevent resistance to val- uable products. With cross-resistance, or production of a single compound by several companies, cooperative efforts between firms may be used for monitoring, research, and in deployment of control tactics such as use of mixtures, recommendations for use of selective pesticides, and rotation of pesticides. The basic notion is that by joining efforts areas large enough to
380 MANAGEMENT OF RESISTANCE TO PESTICIDES treat mobile pest populations effectively can be combined (Miranowski and Carlson, this volume). Antitrust Concerns Agreements between firms to divide up territories, customers, or time periods are usually considered illegal, especially in developed countries with mature market economies. Even if the intent of a group of firms is to regulate sales of a class of pesticides to prevent development of resistance, such group actions could be ruled anticompetitive, although the committee is aware of no such case. Companies are reticent to try collaborative activities, but individually or jointly they can take action that is not anticompetitive in order to reduce selective pressure on a pest population. Three actions that have either been tried or considered are (1) recommendations in addition to label directions by a firm on use patterns of its product to prevent resistance (such recommendations would, though, have to be consistent with labels or risk a violation of FIFRA), (2) joint recommendations to end users (farmers, public health agencies) by a group of firms on pesticide-use patterns over time and space, and (3) attempts by a firm or firms to influence or amend the regis- tration of products by regulatory agencies (discussed below). Recommendations on rotation or mixtures of pesticides can either be issued directly by the company or funneled through the extension service, a local government agency, or private consultants. Because such a program is only a recommendation to users, who still have the right to buy and use any registered compound at any time in a manner consistent with its label direc- tions, recommendations to rotate or mix pesticides are not considered to be anticompetitive. Such a program requires considerable cooperation among users and sellers of pesticides. RECOMMENDATION 7. After consultation with the EPA; university, state, and federal researchers; and industry trade associations, the U.S. Justice Department should consider issuing a voluntary ruling that clarifies the anti-trust consequences (if any) of joint pesticide use recommendations by groups of pesticide companies offered for the purpose of reducing devel- opment of resistance to pesticides. Registering Pesticide Mixtures Pesticide registration decisions can affect resistance. For example, there are occasions when mixtures are a valid management strategy, and such a strategy can be recommended with confidence for use over a wide area. Indeed, mixtures of pesticides are routinely used, consistent with EPA-ap- proved labels on existing products, on some crops to control pest complexes
MANAGEMENT OF RESISTANCE TO PESTICIDES 381 that are not controllable with any single pesticide. Regulatory agencies need to be flexible and to review the merits of new label application and warning proposals quickly. Use of labels to mandate specific use patterns should be discouraged because such recommendations are not appropriate in all regions where a given pesticide is used. At the same time, industry representatives should not attempt to use the registration process to conceal changes in pesticide efficacy from pesticide users or competitors. If a label is obtained that only allows a mixture of two compounds to be applied for a given pest, and if resistance has been developed to one of these compounds in some locales, then farmers in the areas with resistance may be induced to use an ineffective compound. In addition, a requirement that only mixtures be used could increase the amount of pesticide released in the environment. Research on the use of pesticide mixtures to reduce development of re- sistance is in progress, but is not sufficiently advanced to support definitive recommendations at this time. Compatibility of pesticides as mixtures and selectivity of pesticides in controlling pests and pest complexes continue to be important topics for research. Coordination of the research, use recommendations, and regulation of pesticide mixtures is needed. Requiring use of mixtures by only selling pesticides in this form is a severe restriction, and it should only be adopted if research demonstrates the mixture's desirability in managing resistance. RECOMMENDATION 8. The EPA should adopt a flexible policy on registra- tion of pesticide mixtures. Coordination among regulatory agencies, re- search groups, and pesticide companies is needed when requests for registration of mixtures are proposed. Minor-Use Pesticides Resistance can exacerbate shortages of pesticides in crops with small acreages and specialized pests. New pesticide introductions have been encouraged in minor-use groups by a program known as Interregional Project-4 (IR-41. The JR-4 program encourages input by universities and other groups in developing residue chemistry, efficacy, and phytotoxicity data for obtaining tolerances and product registrations. The program strives to lower the cost of registration for minor uses so that these markets are not bypassed when a chemical firm is expanding the crops and pests included on its label. In several instances, the JR-4 program has been successful in supporting minor-use registrations needed because of resistance to pesticides. The JR-4 program can serve as a model for new efforts to encourage public sector activity in resistance management programs. If a pesticide firm has particular use instructions it wishes to include on the label, then the firm can
382 MANAGEMENT OF RESISTANCE TO PESTICIDES provide authorization and financial support for university research so that a prescribed program to manage resistance is available to farmers. Efforts on the part of the USDA and universities need not be limited to residue analysis and short-term efficacy tests. Longer-term efficacy studies related to resis- tance management could also be included. The JR-4 program has been effective over the past 20 years because it shares data across regions and facilitates close cooperation between the pes- ticide industry, grower organizations, and state and federal laboratories. The EPA has assisted by providing financial support, handling JR-4 petitions as priority actions, and promulgating specific guidelines for the registration for food and nonfood uses. Efforts to address minor-use problems faced outside of agriculture have been extremely limited. There is interest on the part of industry to include rodenticides, disinfectants, and other human health pests in this program. Resistance problems are particularly severe in some non- agricultural pests, so new approaches and funding are both needed and jus- tified. RECOMMENDATION 9. Expansion is encouraged of the JR-4 activities to include pesticide registration activities related to resistance. Expanding the JR-4 concept to nonagricultural minor uses should be pursued by state and federal agencies. INTERNATIONAL CONSIDERATIONS Pesticide resistance is a global problem. Resistant pest populations are not restricted by geographical boundaries, and major pesticide manufacturers operate in all parts of the world, often selling comparable products to control the same pestles) on four continents. Large-scale movement of people and goods among countries increases the likelihood that resistant pest populations become internationally established. This is especially true in developing regions where quarantine and inspection services are often lacking or inef- fective. The less-developed countries are particularly vulnerable to disease and severe economic losses from pesticide resistance. Agricultural devel- opment efforts, although often constrained by resistance in agricultural pest populations, have not generally received the attention directed toward resis- tance problems due to failures in disease vector control programs that affect public health programs. Because the United States plays a large role in world agriculture, and U.S. policies are highly visible, management actions taken by the U.S. to limit resistance to pesticides can affect the global development of resistance. Global consequences should be considered in developing legislative and adminis- trative changes in U.S. pesticide-use policy.
MANAGEMENT OF RESISTANCE TO PESTICIDES Roles of International Organizations 383 FAO and WHO These U.N. organizations are made up of member coun- tries. Their roles in managing resistance to pesticides are to · Encourage and assist member countries to develop and use effective, accurate monitoring systems to detect resistance. · Provide member countries with technical assistance to analyze and in- terpret existing information to determine the significance of resistance epi- sodes that are detected, and potential implications for field-level programs. · Facilitate the collection and dissemination of information on resistance to pesticides. · Assist all countries to carry out research on countermeasures for resis- tance by directly funding or by stimulating relevant research projects. · Assist in training and education for effective management of resistance to pesticides. The FAO regards resistance problems and related strategies as an inherent part of IPM programs. It can neither intervene nor interfere with national policies of member countries on pesticide registration or other regulatory matters. If requested, though, it can provide available guidelines and assist in securing external expertise. An international Code of Conduct on the Distribution and Use of Pesticides, now under preparation, will provide further international guidance on appropriate responses to pesticide resistance problems. For 30 years, management of resistant disease vectors has been a high priority of WHO, which considers vector resistance the greatest technical impediment to control of these diseases. The problem has become even more critical in recent years as human pathogens have developed resistance to major drugs. Where no vaccine or effective drugs are available for mass treatment, WHO's public health programs must rely on vector control. Ac- cordingly, WHO has developed 13 standardized tests for the susceptibility of major disease vectors to important pesticides. The WHO program for detecting and monitoring resistance involves interpreting and analyzing test results, feedback, periodic reporting, and follow-up advisement to member countries. All monitoring and detection information is stored on computer files; incidence and distribution trends are summarized and reported every 5 years at meetings of WHO's Expert Committee on Insecticide Resistance. Countries where resistance is detected receive an alert and are advised to study the epidemiological picture to see if resistance is impeding progress of disease-control efforts. This action may ultimately lead to the development of new methods or new materials for vector control. WHO's current focus on training and education is designed to alleviate a lack of trained profes- sionals in many member countries.
384 MANAGEMENT OF RESISTANCE TO PESTICIDES The World Bank This institution may affect resistance to pesticides through its investments in agricultural development or public health projects that provide funds for pesticide purchase. World Bank officials have issued guide- lines to determine whether projects with major pesticide purchases are likely to provide a positive return on investment and encourage sound safety and pest-management practices. Development of these guidelines is an important step for pest-control investments in developing countries, and the World Bank should be encouraged to apply them in addressing likely pesticide resistance problems. CGIAR International Research Centers The international research cen- ters are autonomous, commodity-oriented, and focus primarily on methods for increasing productivity through germ plasm research. While it is not within the mandate of these centers directly to address resistance issues, the importance of good pesticide management is recognized within many of the centers' model or better programs. IPM strategies are used in these programs partly as a measure to prevent development of resistance. Need for U.S. Support While the concerns and programs of a number of international organizations contribute to greater global integration of man- agement of resistance to pesticides, several problems constrain their effec- tiveness: · A lack of data on pesticide use and pesticide performance in less- developed countries limits opportunities to assess the likelihood of resistance to specific materials developing in specific pest populations. Lack of such information makes it difficult to develop criteria for pesticide-dependent investments or to make wise selections of pesticide materials for use in development and public health programs. · Information on the incidence of resistance needs to be more effectively collected and summarized, better targeted, and more broadly disseminated. · Appropriate decision-making based on accurate information requires well-trained people. The current level of training is inadequate in many less- developed countries, and training opportunities are limited by a lack of resources. Private and public decision-making in the United States is affected by inadequate information on global incidence of resistance to pesticides. As part of the international community, the United States depends on the main- tenance of global pest susceptibility to important pesticides. The U.S. Agency for International Development (AID) provides some assistance in the areas of pesticide management, training, and improved pest management to less- developed countries and regions with which it deals. The AID policy on pesticides requires that AID projects minimize pesticide use and encourage
MANAGEMENT OF RESISTANCE TO PESTICIDES 385 an integrated approach to pest management, but availability of funds can limit the extent to which this policy is implemented. RECOMMENDATION 10. The United States should support increased in- volvement and larger-scale organized efforts to coordinate information sys- tems and research on resistance to pesticides. To the extent possible, the United States should provide funding and personnel to achieve increased training and education on pesticide management and pesticide resistance in less-developed countries. The potential benefits of these courses of action for the United States are a decreased rate of global development of resistance and an increased ability to react rapidly to accurate information about new cases of resistance in domestically important pest species. The USDA-OICD (Office of International Cooperation and Development) and AID should take a lead role in providing personnel and funding in pursuit of this goal. impact of U.S. Policy No international organization or institution has regulatory authority for pesticide use. The influence of U.S. policymaking on pesticide-regulating programs in other nations is thus critical. Both U.S. domestic pesticide use and international aid policies can affect perceptions or use of specific pesticide materials in other countries. The EPA registration process sends signals to other countries regarding U.S. judgment on benefits and risks of particular pesticides. Regulation 16 of the Code of Federal Regulations (part 216, Pesticide procedures; also codified in Section 118 of the Foreign Assistance Act) requires that any AID international as- sistance project involving pesticides be reviewed through an environmental impact statement (EIS). The preparation of an EIS, and its outcome, are based partly on the EPA's registration status of proposed pesticides. The process is more stringent for materials that are not registered for use in the United States. FAO and WHO programs, and the public health and agricultural control programs in less-developed countries, rely heavily on inexpensive, practical, and effective pesticides. Actions taken by the United States on pesticide use or management of resistance can affect this reliance, especially when such actions tend to limit access in the developing nations to older, cheaper, generic chemicals that have retained efficacy for decades of use in the developed world. · Actions that conserve the susceptibility of important pests to major pesticides aid third world goals by decreasing the global rate of resistance development.
386 MANAGEMENT OF RESISTANCE TO PESTICIDES · Policies that limit the global availability of particular pesticides can constrain less-developed countries' abilities to manage resistance. Constraints on global availability of certain pesticides have come about because of cancellation or suspension actions taken in the United States. U. S. pesticide regulations are based on national priorities and relatively strict environmental standards. Some materials banned in the United States are considered essential for achieving public health or agricultural development goals in less-developed countries possessing different national priorities. Additionally, the United States must be aware that less-developed countries may adopt U.S. regulations with little or no analysis or modification, even in cases where such regulations are inappropriate. Vast differences in insti- tutions, agricultural systems, and cultural and political factors, however, can make U.S. policies on pesticide use or management of resistance to pesticides inappropriate or counterproductive for other countries. RECOMMENDATION 11. U.s. policy recommendations or policies specific to U.S. priorities should contain qualifications that clearly limit their ap- plicability to the current domestic situation. Assistance should be provided by AID and EPA in helping less-developed countries formulate pesticide · ~ po Icles. REFERENCES CAST (Council for Agricultural Science and Technology). 1980. Impact of government regulations on the development of chemical pesticides for agriculture and forestry. Report No. 87. Ames, Iowa: CAST. Davies, R. A. H. 1984. Insecticide resistance: An industry viewpoint. Pp. 593-600 in Proc. 1984 Br. Crop Prot. Conf., Pests and Dis. WORKSHOP PARTICIPANTS Implementing Management of Resistance to Pesticides GERALD A. CAR~soN (Leader), North Carolina State University ARNo~D AsPE~N, U.S. Environmental Protection Agency CHARLES M. BENBROOK, National Research Council Lungs CHIARAPPA, Food and Agriculture Organization of the United Nations CHAR~Es J. DELP, E. I. duPont de Nemours and Company MICHAEL J. DOVER, World Resources Institute STAN FERTIG, U.S. Department of Agriculture RAYMOND E. FR~ss~E, Texas A&M University NORMAN GRATZ, World Health Organization, Switzerland LYNDON S. HAwK~Ns, California Department of Food and Agriculture
MANAGEMENT OF RESISTANCE TO PESTICIDES RICHARD HERRErr, ICI Americas, Inc. MAUREEN HINKEE, National Audubon Society EDWIN L. JOHNSON, U.s. Environmental Protection Agency JOHN A. MIRANOWSKI, U.s. Department of Agriculture KATHERINE REICHEEDERFER, U.s. Department of Agricultur PATRICK WEDDEE, Weddle, Hansen and Associates KEN WEINSTEIN, McKenna, Conner and Cuneo 387 e