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Suggested Citation:"SUMMARY." National Research Council. 1981. Cotton Boll Weevil: An Evaluation of USDA Programs : a Report. Washington, DC: The National Academies Press. doi: 10.17226/18570.
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Suggested Citation:"SUMMARY." National Research Council. 1981. Cotton Boll Weevil: An Evaluation of USDA Programs : a Report. Washington, DC: The National Academies Press. doi: 10.17226/18570.
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Suggested Citation:"SUMMARY." National Research Council. 1981. Cotton Boll Weevil: An Evaluation of USDA Programs : a Report. Washington, DC: The National Academies Press. doi: 10.17226/18570.
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Suggested Citation:"SUMMARY." National Research Council. 1981. Cotton Boll Weevil: An Evaluation of USDA Programs : a Report. Washington, DC: The National Academies Press. doi: 10.17226/18570.
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Suggested Citation:"SUMMARY." National Research Council. 1981. Cotton Boll Weevil: An Evaluation of USDA Programs : a Report. Washington, DC: The National Academies Press. doi: 10.17226/18570.
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Suggested Citation:"SUMMARY." National Research Council. 1981. Cotton Boll Weevil: An Evaluation of USDA Programs : a Report. Washington, DC: The National Academies Press. doi: 10.17226/18570.
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Suggested Citation:"SUMMARY." National Research Council. 1981. Cotton Boll Weevil: An Evaluation of USDA Programs : a Report. Washington, DC: The National Academies Press. doi: 10.17226/18570.
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SUMMARY Since the early years of this century, efforts to control the boll weevil and other insect pests of cotton have been the combined responsibility of the federal government, state governments, and cotton growers themselves. In the laboratories of USDA, of state universities in the Cotton Belt states, and of private chemical companies, scientists in a number of disciplines have continually sought better ways of controlling the boll weevil and other cotton pests, placing most of their emphasis on the development of chemical insecticides. As new insecticides have been created in the labora- tories and then manufactured on a commercial scale by chemical com- panies, the USDA and state agricultural extension services have advised cotton growers—often with the assistance of cotton growers' councils—on how to use these insecticides in the most effective and efficient ways, and to supplement them with other tactics such as cultural practices. This method of dealing with cotton pests is referred to in this report as "current insect control," or CIC. This method, of course, has required cotton growers to spend vast sums of money to purchase and apply the insecticides. One major problem has been that the boll weevil, Anthonomus grandis, has shown remarkable ability in developing biological resis- tance to each new insecticide over a period of time. Although many of the insecticides developed over the last 40 years were able to reduce boll weevil infestations substantially when first used, none has demonstrated the ability to do so indefinitely. A related prob- lem has been that reductions in boll weevil populations through the use of the newest pesticides have often been accompanied by increases in the populations of other cotton plant pests, such as the bollworm and the tobacco budworm. Furthermore, efforts to control these pests and the many others that also attack the cotton plant have been hampered by the practical difficulties involved in carrying out coordinated control programs among thousands of cotton growers spread out over large geographic areas. As the demand for cotton has gradually declined in the United States, as each new insecticide has lost its effectiveness against the boll weevil, and as the costs of growing cotton have increased,

cotton growers and other interested persons from the Cotton Belt states afflicted by the boll weevil have urged the federal government to assume the responsibility of managing the boll weevil on a coor- dinated national basis. Those in the cotton industry, as well as many members of Congress from the southern states, have generally advocated an all-out effort to eradicate the boll weevil from the entire United States. Others, however, including a substantial number of scientists, have expressed reservations about the probabil- ity of success of any attempt to eradicate—that is, to totally eliminate—the boll weevil population in the United States. Their view is that any federal program should be directed at keeping boll weevil populations below the levels at which they cause economically significant damage to cotton. Between l978 and l980, USDA conducted concurrent three-year trials of these two strategies. One, the boll weevil eradication (BWE) program in North Carolina and Virginia, was intended to reduce the boll weevil population to zero. The other, called the optimum pest management (OPM) program, in Panola County, Mississippi was designed to keep the populations of boll weevils and other cotton pests below economically damaging levels. The BWE trial area increased from l5,500 acres in l978 to 32,500 acres of cotton in l980, and the OPM trial in Mississippi involved treatment of cotton acreage that increased annually from approximately 32,000 acres in l978 to 39,000 acres in l980. The principal purpose of this report is to review the conclu- sions reached from the two experiments as to the probable biological, economic, and environmental effects that might result from federal implementation of either a BWE or OPM program throughout the Cotton Belt. Chapter l of the report provides an overall description of cotton culture in the United States and of the insect pests which attack cotton, while Chapter 2 summarizes the various efforts that have been made to reduce the economic damage caused by these pests. Chapter 3 has two parts, one reviews the legislative background for publicly supported pest control programs in general, the other concentrates on federal programs toward the control of the boll weevil in particular. Chapter 4 discusses the OPM and BWE trials in more detail and outlines how they would be implemented if a decision was made to use either one throughout the Cotton Belt. It also touches upon alternative control strategies. Chapter 5, the longest chapter in this report, is an extensive appraisal of the two experi- mental trials themselves—how they were conducted, the conclusions drawn from them, and the extrapolations of those conclusions made by USDA to determine the probable biological, economic, and environ- mental effects if either an insect management or eradication program was carried out throughout the Cotton Belt. The USDA identified six alternative beltwide boll weevil/cotton insect management programs. The definitions of these alternative programs are given in Appendix A.

3 CONCLUSIONS Overview The NRC Committee applauds the advances in insect control tech- nology and management that have taken place under the direction of the USDA during the course of the trials such as diapause control, pheromone traps for monitoring population of weevils, and plant breeding. The NRC Committee recognizes the important contribution to the understanding of cotton insects made by the technical monograph on cotton insect management (SEA l98l) and also commends USDA for the imaginative approach and creative efforts to project future impacts of the various programs. More than 80 years of experience with programs intended to eradicate such pests as the gypsy moth, the fire ant, and the mosqui- toes that transmit malaria and yellow fever have demonstrated that the future effects and costs of eradication programs cannot be accu- rately predicted. Eradication programs must therefore remain open- ended. Since difficulties are likely to appear, eradication efforts may have to be intensified, new technologies may have to be used, and legislative action may be required to enforce full participation by cotton producers. An acceptable beltwide program for managing cotton pests must be one that allows cotton growers to produce cotton efficiently and causes minimum harm to the environment. Since the biological conse- quences, environmental effects, and economic costs of an eradication program cannot be predicted with any degree of certainty, specific probabilities should be attached to alternative estimates of public costs and benefits. The probability of success of each level of program effort should be stated, and it is necessary to compare a realistic range of potential benefits with a realistic range of possible costs. After reviewing the USDA evaluation team reports, the NRC Committee came to the following conclusions about the BWE and OPM trials and the USDA evaluation teams' extrapolation of the data from the trials to beltwide programs: USDA Biological Evaluation Team Report The USDA biological evaluation was based only on data from the two trial areas; therefore, the biologists were unable to make probabilistic extrapolations about the possible effects of either method on the entire boll weevil belt. The implic- it inference that these data apply to the entire area inhab- ited by the boll weevil is statistically invalid. The cotton insect complex, the environmental characteristics, the cotton production practices, the insect management prac- tices, and perhaps the boll weevil populations vary consider- ably from year to year across the Cotton Belt. Yet the OPM

and BWE trials and the USDA plans for implementing each one on a beltwide basis provide little information on this heter- ogeneity or how to deal effectively with it. The evidence does not demonstrate that migration was the reason for the discovery of an individual weevil or the discovery of a reproducing weevil population in the BWE trial area. Therefore, the BWE trial did not conclusively demon- strate that eradication was achieved. Even if no weevils had been found, the trial as designed could not have proved conclusively that eradication had been accomplished. The migration and dispersal potential of the boll weevil are incompletely understood. There are risks in assuming that the boll weevil is incapable of "jumps" of a much longer distance than what is now accepted as the maximum. It is not possible to judge the prospects for eradication and their costs without more knowledge of boll weevil migration. The effectiveness of efforts to sterilize male boll weevils has not been demonstrated. Since the original plan of the BWE trial was based on male sterilization as a basic tech- nique, there is a need to reexamine the role of this tech- nique in future boll weevil control and eradication programs. The proposed pheromone trap densities and the length of time they would be operational for monitoring the effectiveness of a beltwide eradication program would be inadequate, particu- larly for detecting low level infestations. USDA Economic Evaluation Team Report The specific costs for full implementation of the OPM program that would be necessary prior to eradication were not includ- ed in projecting the overall costs of the eradication program (OPM-BWE, see definitions in Appendix A), and the regulatory and organizational responsibilities in efforts to eradicate were not defined. The NRC Committee believes that the net consumer benefits as well as the loss of net income to producers as calculated in the USDA Economic Evaluation Team Report are inflated (See Table 5.2 that reproduces the table from the USDA report, Economics and Statistics Service l98lb). The NRC Committee agrees that if eradication of the boll weevil is adopted as a joint policy and financial responsi- bility of the federal and state governments and cotton growers, the short-range costs of cotton insect control, both economic and environmental, will rise relative to continua- tion of current insect control practices. However, the long

range economic and environmental costs of a BWE program or CIC cannot be predicted from either the trial data, which do not address the heterogeneity across the Cotton Belt, or the Delphi panel data, which are subjective projections and estimates obtained from pest control experts and cotton producers. The NRC Committee agrees if an OPM program, implemented area by area, was adopted as a coordinated public responsibility, this strategy would reduce the economic and environmental costs to below the costs of current insect control. The short run management costs of an OPM program could be expect- ed to be much below the short run cost of eradication. A decision on which strategy should be implemented beltwide should not be made on the basis of the reported differences among benefit-cost ratios or "normalized" economic predic- tions. The data generated by the Delphi process and the program cost projections simply are not precise enough and fail to show enough recognition of the risks of changing to a BWE or an OPM program. USDA Environmental Evaluation Team Report The USDA environmental evaluation focused on the two trial areas, and no estimates were made of the changes in environ- mental quality that might result from beltwide implementation of eradication or optimum pest management programs. Since no beltwide data were provided on the existing levels of pesticide residues or on the residues that would be added by implementing either an OPM or a BWE program, the NRC Committee was unable to evaluate the projected environmental impact. Any beltwide conclusions extrapolated from environ- mental effects during the OPM or BWE trials are unjustified. The NRC Committee believes that a BWE or OPM program would increase pesticide concentrations initially by adding substantial amounts of insecticides (5 or more additional applications per season) to the l0 to l2 applications per season now made in some areas. The duration of this inten- sive application period in any given area cannot be predict- ed. However, it would obviously have to be continued as long as weevils were captured in traps. At least l6 different insecticides have been employed in the OPM and BWE trials. The environmental effects of some of these insecticides over extended areas and extended periods of time are little known. Several important pesticide concentration rates, and the beltwide environmental impacts of the insecticide applica- tions proposed in the USDA's OPM and BWE programs, have not

been estimated adequately. Areas of particular concern are: (l) the effects of diflubenzuron on estuarine and coastal Crustacea, (2) the effects of inhalation of the highly toxic methyl parathion, EPN, and azinophosmethyl upon human health, (3) the effects of these three insecticides upon honeybees and other pollinators, (4) the general effects of an intensi- fied insecticide load on natural enemies of secondary cotton insect pests and the possible resurgence of these pests as a consequence, (5) the effects of an intensified insecticide load, especially of pyrethroids, on game and cultivated fish populations, and (6) the effects of an intensified insecti- cide load on endangered species. • The "modular indices" used in the USDA environmental evalua- tion are misleading and are based on insufficient or inade- quate data. The only wildlife parameter used, for example, was the population of white-tailed deer, estimated from hunter kills. It was also reported that insufficient data were gathered on fish populations in the trial areas to calculate population changes. As a consequence of this paucity of data, no indices were determined for either fish or wildlife in the OPM and BWE trials. Despite this lack of critical information, calculations based entirely on limited spray drift and residue were made and led to the assumption that an eradication program (OPM-BWE as defined in Appendix A) would have much less of an environmental impact than an OPM program or CIC. • No attempt was made to monitor the effects of either an OPM, CIC, or BWE program upon the health of persons directly exposed to insecticides. An excellent opportunity existed to monitor the impact of the insecticides on the exposed person- nel involved in the trials, but no studies appear to have been made. A minimum list of the clinical evaluations that should have been made during the trials would include: (l) excretion of urinary metabolites from parathion, methyl parathion, azinophosmethyl, diflubenzuron, etc.; (2) neuro- logical and behavioral evaluations including blood acetyl- cholinesterase levels; and (3) blood chemistries for an analysis of pesticide residues. Operational and Sociological Considerations The NRC Committee believes that a precondition for implemen- tation of any eradication program would be a commitment by Cotton Belt states to establish the necessary regulatory authority and to appropriate the necessary financial support. No evidence was presented that such commitments have been made or can be obtained.

A beltwide appraisal of the attitudes of cotton growers toward an OPM or BWE effort was not undertaken. The NRC Committee believes that such a survey to determine the extent of grower cooperation and opposition would be essential before a federal and state commitment to any kind of program could be made. The USDA evaluation did not try to assess the attitude that private pest consultants or agribusiness firms might take toward either an OPM or BWE program. It is the NRC Commit- tee's opinion that the positive support of both groups would raise the probability of success. The USDA evaluation fails to include any technical plans for maintaining a barrier along the border with Mexico to prevent a reinvasion of U.S. cotton by the boll weevil. Also missing are plans for coping with plants outside cotton fields which may be boll weevil hosts. RECOMMENDATION The NRC Committee unanimously recommends that integrated pest management (IPM) practices—that is, the use of all available tech- nology and methods integrated into a holistic approach to pest control—be the thrust of boll weevil and other cotton pest control programs for the next several years. During the past l0 years, integrated pest management has made tremendous progress in reducing both insecticide use and cotton losses. Through continued research, education, and the adoption of new practices, cotton insect management should continue to improve. The rapid adoption of new techniques in recent years demonstrates that current insect control practices are dynamic. A truly integrated management program is still evolving and probably will vary from year to year and area to area, depending on the variables in each region's cotton crop, ecology, and economy. As cotton insect control technology continues to evolve, the potential for eradication should be periodically reevaluated. The NRC Committee therefore recommends an indefinite postponement of both the OPM and BWE programs, and we encourage the private sector, the academic community, and government agencies to assist the development and adoption of private integrated pest management so that its poten- tial is more fully realized.

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