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Pesticide Resistance: Strategies and Tactics for Management. 1986. National Academy Press, Washington, D.C. Pesticide Resistance Management: An Ex-Regulator's View EDWIN L. JOHNSON Regulatory officials can institute programs to deal with many aspects of pesticide resistance including information gathering, im- position of use instructions, and prohibitions designed to prolong the useful life of a pesticide. Another, probably more important consideration is whether one should undertake such programs, since they may present barriers to development and entry of new products and technology and impose additional costs on agricultural produc- ers and industry. There is also a substantial question concerning the electiveness of governmental regulatory intervention against coun- tervailing incentives in the private sector once the purpose moves beyond the data and information gathering and dissemination aspects of regulatory programs. Further, one must distinguish clearly be- tween socially valuable extensions of a pesticide's useful life and extensions that principally provide an extension of the marketability of old products for the sole benefit of the pesticide manufacturer. Technically trained individuals often see the future alternatives as limited illustrated by the decreased rate of success in chemical screening. Economists often see the future alternatives as limitless, based only on sufficient demand, such as the past development of several generations of chemicals and the incipient development of genetically engineered pest controls. The actual situation is most likely somewhere between these extreme views. We should not a priori presume the social desirability of extending the life of our existing pest controls through programs of pesticide resistance man- agement, particularly those of a regulatory nature. A large number offactors need to be weighed to make that determination. This paper attempts to lay out some items that need to be considered, as well as potential areas of regulatory intervention. 393
394 MANAGEMENT OF RESISTANCE TO PESTICIDES INTRODUCTION Regulatory agencies can and do deal with various aspects of the pesticide resistance problem, mostly at the national level. Their participation in im- plementing regulatory solutions for pesticide resistance management depends on many factors (as discussed by Hawkins, Dover and Croft, and Frisbie et al., this volume). It is not an easy task to synthesize these factors into a strategy. For example, should or can the effective life of a pesticide be extended? Continuing the market life of existing product lines has sometimes reduced industry's incentive to research and develop new product lines. Artificially extending the useful life may run contrary to a goal of encouraging the development of more effective and environmentally more desirable pest- control technologies, such as biologically derived controls. Extension of market life by delaying the onset of resistance may mean that less of a product is used, reducing the net return to the seller, who then defends the market share of older materials to meet return on investment objectives. Industry will generally be less than enthusiastic about participating voluntarily in such a program. The grower must also be considered. A pesticide resistance management program requires the grower to deal with complex pest-management strategies and decisions. For example, an integrated pest management (IPM) program may extend the useful life of a chemical and reduce chemical use and costs. Such programs would be in tune with the objectives of producers and en- vironmentalists but may be complex. INFORMATION GATHERING The regulatory agency, as well as other governmental agencies, can play an effective central role in gathering information and transfering it to those sectors affected by the outcomes of pesticide resistance problems. An agency could choose to collect data or to require data collection by other parties, principally pesticide producers. Given the limited funding of governmental activities worldwide, the focus should be to stimulate or require others to collect and react to data on pesticide resistance. The registrant generally has the best data on product performance, and the pesticide user has the greatest interest as the recipient. The agency, then, can be an effective facilitator of data collection. Predictive information a proactive approach-would en- able an orderly approach to designing or planning resistance management decisions early. Information gathered after the fact-a reactive approach- would require pesticide resistance strategies to be developed simultaneously with pesticide resistance.
AN EX-REGULATOR'S VIEW 395 Premarketing Data The action closest to the theoretical ideal that a regulatory agency could take would be to require regulatory data on predicted or continuing effi- cacy, prior to registration, with resistance buildup as a specific parameter. The United States has lowered its requirements for premarketing efficacy data to reduce regulatory intervention in areas thought to be regulated by the market. Other countries, however, routinely require efficacy data gen- erated in that country. Requirements could perhaps be modified to obtain data relevant to forecasting the onset of resistance. Product performance over time is what is needed, not merely demonstrated efficiency at the time of registration. But are test methods available to predict, before actual use, the time- dependent relationships of resistance development? I can only pose this ques- tion to the appropriate scientific disciplines. The answer I have received to date from within the United States and from a few foreign experts is that current methods allow us to only speculate about which pesticide chemicals are likely to create pest resistance problems. If methods can be developed does forecasting resistance development provide the necessary information for the development of resistance management strategies? Postmarketing Data After-the-fact resistance information is easier to obtain, but may be sub- stantially less useful than pre-use information, which can provide the basis of an anticipatory resistance management strategy. It is easier for regulatory officials to adopt an after-the-fact surveillance system. New premarketing testing requirements will increase pesticide development costs and potentially delay marketing of new compounds. Postmarketing survey strategies, how- ever, provide less time to adapt to observed resistance problems, particularly from a regulatory position that requires a legal change in the label or in regulations, compared with the initial approval action. By the time data become available it may be too late to introduce remedial measures in many areas already showing resistance. I have been told that pest-control experts are aware of the places in the world where resistance may develop first because of particular environmental circumstances. Perhaps these areas could be monitored to alert the rest of the world to resistance development in time to develop effective management strategies elsewhere. Most governments with registration programs require the periodic rereg- istration of products, and they reserve the right to request additional data as a part of that process. Producers of all, or of critical, products especially
396 MANAGEMENT OF RESISTANCE TO PESTICIDES those with health significance-could be required to provide new efficacy data at specified anniversaries. A less-formal alternative might be to initiate efficacy networks of a wide range of users to exchange observed data on the current performance of registered pesticides. An example is the Environmental Protection Agency (EPA)-National Pest Control Association agreement to share information on ineffective pesticides and new products. A private-sector example is the meetings and publications of control recommendations by the National Cotton Council. International networks would be useful. The EPA has proposed that user networks be created to provide such information for dissemination to users and pesticide producers and for re- viewing use instructions and the risk/benefit posture of the pesticide. Net- working, however, will require a further breakdown of the notion that certain functions are the purview of a specific organization. Although networks provide after-the-fact information for some areas, they can provide predictive information to regions where resistance has not pro- gressed as rapidly. Networks to date have focused on alternatives to the ineffective product and not explicitly on pesticide resistance management strategies for the affected chemical. Other sources of information can be scanned for indications or patterns of resistance, including an organized clipping service to provide clues from scientific literature. In the United States, sources uniquely available to the regulatory program include requests for emergency exemptions based on ineffectiveness of the currently registered alternatives. Although available, in the absence of other data these approaches are hit or miss, often result in data that are hard to interpret, are late in identifying a problem, and lead to no clear solution except to remove the ineffective product from the market- place. EDUCATION Education is always an important aspect of program success. A regulatory authority has a limited role in education, however, beyond making available data and resistance strategies and promulgating a clear regulatory policy. Resistance prevention strategies identifying IPM approaches are probably best conveyed through applicator certification, training, and extension activ- ities. Labeling could perhaps communicate resistance information to users. In some developing countries the regulatory agency plays a more direct role in the training of farmers and pesticide dealers; thus it could incorporate resistance information into those programs.
AN EX-REGUC4TOR'S VIEW 397 REGULATORY STRATEGY When the registration of a pesticide is governed by its risks compared with benefits, the case for registration becomes weaker as the efficacy (benefit) decreases. At some point the deterioration in benefits would dictate that the compound be removed from the market. There are two problems with this if it is the sole regulatory approach. First, rather than extending the useful life of a product, this process removes the product after it has lost its value. Second, regulatory agencies around the world share both a common shortage of resources and a universal thrust toward human health and environmental effects of a pesticide rather than efficacy. Thus, few pesticides would be banned in such a regulatory environment, unless there was a clear health or environmental hazard. As resistance develops several things may change simultaneously. First, the pesticide becomes virtually useless against specific pests in some geo- graphic areas, causing a shift to a presumedly more costly alternative. This reduces the total benefit of the product as well as the risk from its use. Net risk may either increase or decrease, depending on the safety of the substituted compound. Usually, newer products may be more safely used than older ones if the registration process is inducing the proper incentives into the pesticide development process. Second, marginal benefits may be unchanged or reduced, depending on whether efficacy is reduced in areas where the pesticide is still useful. The normal scenario is that more applications or mixtures of chemicals become necessary to control a pest infestation. Such actions increase both the costs of control and the potential risk at the margin. The combination of these two circumstances may or may not provide sufficient justification for canceling or restricting a product under U.S. pes- ticide law. Although there may be a shift in marginal benefits and risks, total benefits may continue to outweigh risks at sites of continuing use of the product. Cancellation would be difficult to justify, particularly if users con- tinued to believe that further use was beneficial in their particular circum- stance; users already reacting to resistance will be disinterested in the proceedings, having already shifted to alternatives. Countries without a risk/benefit test, but that require a separate efficacy test, may be more successful in removing products when the compound's efficacy decreases below some standards of absolute performance. In the United States the courts have determined that a product may not be denied registration merely because it does not meet a predetermined level of efficacy (Cowley v. EPA, 1980~; rather, it must only perform as claimed on its label. Therefore, claims such as "Aids in the control of. . ." or "Provides ben- eficial reduction in. . ." are enough to make it difficult to demonstrate that a compound did not meet these requirements in the absence of complete
398 MANAGEMENT OF RESISTANCE TO PESTICIDES ineffectiveness. One solution is for regulatory agencies to require labels to be as unambiguous and useful to the user as possible by including resistance management information. Any such restrictive action will probably be challenged, given the different perspectives of the affected parties. Growers dependent on the product will check crop yield (or its value) against the cost of pest control. If they are continuing to use the product in question, they probably believe it is bene- ficial, and they will attempt to retain it. Industry will be viewing the product from a profitability viewpoint. A product developing resistance is usually an older product that has recouped most, if not all, of its development costs. As such it will usually be worth spending money on an appeal to prolong its market life and profits. Finally, the government will be looking at the social costs of the compound, comparative production costs, returns to grow- ers, and potential risks to the public and the environment, with available alternatives. All sides will differ on what the ultimate fate of the chemical should be. Given the uncertainty of predicting resistance, market introduction and cost-effectiveness of alternatives, uncertainty of benefit estimates, almost certain legal challenge to a proposed ban, and health and safety issues, it is unlikely that strong legal action to ban an ineffective chemical would be initiated. If it were, it would simply accelerate what nature has started: the demise of the chemical as an effective pest-control agent. Since a ban would be unlikely and would not achieve pest resistance management, can a benefit/risk regulation be used to force use patterns that would extend the period of effectiveness? Perhaps such changes could be forced with skillful use of the threat of cancellation; a convincing case might be made that new use instructions would prevent loss by creating a favorable risk/benefit picture from an unfavorable one. A formal approach in the United States would require an extensive risk/benefit analysis equivalent to the Spe- cial Review process for cancellation, a procedure that typically takes several years to complete. The effect must first be noted and documented, a full risk/benefit analysis conducted, and a pest resistance management strategy developed and implemented on the label of the pesticide, all in the face of likely objections from manufacturers, users, and those more concerned with competing health and environmental safety priorities. How effective is this approach in dealing with progressing pest resistance? Presuming that a regulatory resistance management strategy could be im- posed and that it would be timely and effective, several issues must be explored. Is the market more effective than the government regulatory ma- chinery? Is resistance prevention or management a valid regulatory policy objective? Can regulatory strategies with any rationality and feasibility be developed? The regulatory mechanism is cumbersome. The EPA, for example, can regulate product labels by offering the alternative of cancellation if the label
AN EX-REGUL4TOR'S VIEW 399 is not modified in some specific way. This can be done ( 1 ) through negotiation if the producer believes the costs of the change are not too high, (2) through a risk/benefit analysis showing that the change is necessary to prevent an unreasonable adverse effect, (3) by issuing a regulation requiring a change or defining areas where the product may not be used, or (4) by restricting use to certified applicators trained in special circumstances of use. Other than negotiation, which could get labels changed in a year or so, these procedures take from two to five years to accomplish plenty of time for further resistance to develop. Private-sector organizations in the United States, as well as government bodies engaged in training and extension, however, regularly review the effectiveness of current pest control by crop or region. Broadly disseminating the conclusions of these reviews should provide the timely information each farmer needs to decide whether current practices should be changed. Pro- ducers marketing alternative products are likely to reinforce information on the relative effectiveness of that company's product over the product of a competitor. Customer loyalty is important. Therefore, the producer will prob- ably recommend ways to use the questionable product to minimize the like- lihood of absolute pest-control failure. Here, the incentives appear to push government, associations, individual farmers, the producer of the product, and his competitors all in the same general direction. Whether this would result in a resistance management approach to extend the life of the product or simply a shift to alternative controls would be a function of the alternatives, benefits, and costs of each approach as viewed by each of the operators involved. This marketplace mechanism, aided by governmental training and information, might react more quickly and more selectively than the regulatory process. The question now becomes, Is resistance management a valid regulatory objective? The 1910 pesticide law and the 1947 Federal Insecticide, Fungicide and Rodenticide Act (FIFRA) emphasized protecting the farmer from inef- fective products. Gradually, Congress modified the regulatory framework to consider potential risks of pesticide use. The 1980 amendments allowed EPA to waive efficacy data for pesticides because users, especially farmers, were believed to be highly educated and markets were sensitive enough to respond to ineffective products. It seems that regulatory objectives are not consistent with regulatory agencies expending resources on prolonging product life. If industrial, agricultural, or any other groups bring in proposals for la- beling to extend the useful life of a product, however, regulatory officials must respond and quickly review the proposals, approving them if there is no increase in hazard. Extending the useful life of a needed pesticide differs from extending its marketing life, which would only benefit the manufacturer. This distinction must be made, since it affects the risk/benefit balance for the chemical.
400 MANAGEMENT OF RESISTANCE TO PESTICIDES The question now becomes whether a pesticide management strategy can be susceptible to regulatory imposition. Regulatory schemes, to be enforce- able, must be unambiguously stated on a label or in a regulation. The type of statement is difficult to visualize and even more difficult to specify. Resistance management could be implemented through a requirement that users follow IPM practices or that pesticides be mixed or rotated with other chemicals. The latter is susceptible to label instructions, and with sufficient information may be differentiated for geographical areas. As more flexible or complex options are needed to cope with resistance problems, the less practical the label becomes for conveying unambiguous, enforceable instruc- tions. The label is probably not suited for conveying complex strategies, and it is questionable whether it should. For example, a debate in Congress on whether a label can detail IPM approaches concluded that EPA and the U.S. Department of Agriculture (USDA) should make IPM information available to applicators through the applicator training program but EPA should not dictate practices on labels. In countries with great diversity in cropping practices and environmental circumstances, effective and enforceable label statements are not practicable, thus the regulatory process is limited in ef- fecting pesticide resistance strategies. One option would be to specify that compounds be used under permit. Pesticides posing resistance problems would be used only by direction of a professional pest-management con- sultant. California is currently the only state that has the authority to imple- ment this approach. A regulatory agency can require that a pesticide be used within the structure of a resistance management program. The question becomes that of timeliness of regulatory versus other approaches, the level of priority and resources that a regulatory agency ought to spend, and its ability in the United States to implement enforceable, workable strategies without additional authority. INDUSTRY Industry could effectively manage the useful life of its products. The incentives, however, to foster the adoption of any strategy are lacking in the United States. For example, extending useful life may imply less use, which is often counterproductive to marketing motivations and rate-of-return ob- jectives for industry. These are generally of a short-term nature and do not accommodate giving up sales now for uncertain future, and perhaps lower, revenues. To some degree the incentives mentioned under private-sector approaches versus regulatory approaches can benefit farmers when resistance threatens. Competition and the desire to retain customer loyalty to a product line can provide growers with necessary information on what to use. Creating strategies to extend useful life is more complex. Assuming that
AN EX-REGULATOR'S VIEW 401 a company did want to express a resistance management strategy on its label, several impediments or disincentives arise. For example, the simple solution of reducing the number of applications runs against marketing and financial incentives, but could be changed by company policy. Another example is that of specifying mixtures with other products, perhaps those of competitors. Unless the competitor agrees, such a label addition can be stopped. Prior consultation with some firms, thus excluding other competitors, could lead to antitrust charges. One interesting case of collaboration to extend useful life is the Japanese fungicide experience (Delp, 19841. In countries with less vigorous antitrust enforcement and more tolerance for cartels, such joint solutions are easier to implement. The fungicide industry has organized itself to cope with the issue of pes- ticide resistance. Here regulatory agencies can be receptive to industry pro- posals for modifying use instructions that will contribute to resistance management. Agencies can foster industry cooperative ventures, especially in strong antitrust countries, by requiring cooperation under such procedures as the 3(c)~2~(B) authority to require data to support continued registration. Regulatory agencies can also provide the necessary requirements to generate data on development of resistance to assure equitable treatment of all man- ufacturers for data requirements. An organized approach by industry could include governmental and pes- ticide user organizations to provide real assistance in solving some of the questions. An industrial forum could be created to provide resistance research in both forecasting techniques and resistance management strategies. Such a program has the potential to minimize costs and antitrust concerns while developing feasible approaches for predicting and coping with pest resistance problems. CONCLUSION Regulatory agencies can help to reduce the onslaught of pesticide resis- tance. The most useful role is that of facilitator to foster data gathering and private-sector efforts to cope with resistance issues, including timely response to label-change requests. Regulatory mechanisms do not appear to be a primary vehicle for forcing resistance management strategies. Indeed, there are some important questions about the appropriateness of regulatory solu- tions and tinkering with the marketplace implicit in such an undertaking. The cost of pursuing a strong resistance management policy by regulation would be high and could hamper the development of new and more desirable pest-control tools. The conditions for embarking on such a course must be carefully thought through before regulated resistance management is adopted as a solution.
402 MANAGEMENT OF RESISTANCE TO PESTICIDES ACKNOWLEDGMENTS I thank William Currie, Anne Lindsay, Richard Michell, Bernard Schnei- der, and James Touhey for their helpful ideas and comments on this paper REFERENCES Cowley v. EPA, 615 Federal Reporter 2nd 1312 (1980). Delp, C. J. 1984. Industry's response to fungicide resistance. Crop Prot. 3:3-8. .