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CHAPTER 4 Regulatory Control Preventing the entry and establishment of foreign plant and animal pests in a country or area and the eradication, containment, or suppression of pests established in limited areas are fundamental regulatory control principles. Early voyagers into newly opened countries brought in many insects that now infest homes, crops, and animals. International commerce accelerated such introductions. For many years, few legal restrictions on the introduction of plant and animal pests were in effect, and, as a result, many of the most important economic insect pests today are of foreign origin. In 1873, Germany passed the first regulatory measure prohibiting the entry of products that might spread the grape phylloxera, Phylloxera vitifoliae (Fitch), from America. The first important regulatory legislation in the United States was passed in 1877, when four states enacted legislation to afford protection against certain pest species. The initial federal law dealing with animal pests was passed by the United States Congress in 1884. In 1905, the Federal Insect Pest Act was passed, enabling the federal government, for the first time, to regulate the importation and interstate movement of articles that might spread insect pests. The Plant Quarantine Act, approved in 1912, authorized the Secretary of Agriculture to enforce necessary regulations to protect the agricultural economy of this country by preventing the introduc- tion of insects and plant diseases from foreign countries. At the same time, provisions were made for the establishment of quarantines to prevent the spread of pests within the United States. The savings to agriculture that are realized by preventing foreign pests from entering a country are difficult to determine. However, many important pests have been kept out of the United States since the establishment of quarantine 34
REGULATORY CONTROL 35 procedures, despite the marked expansion in international traffic and the accelerated speed of travel. An example is the injurious durra stalk borer, Sesamia cretica Lederer, which has been intercepted many times at United States ports of entry. In a single recent year, 38,461 foreign plant pests were intercepted at United States ports of entry-an average of 1 every 16 minutes. Also, 401,393 lots of prohibited plant material were prevented from entering the United States in a single year. The United Kingdom, through its enforcement of certain restrictions on the importation of apples from the United States, has prevented the artificial introduction of the destructive apple maggot, Rhagoletis pomonella (Walsh). These examples demonstrate that regulatory measures are often practical and successful. Even with the enforcement of quarantine procedures, however, some impor- tant pests, such as the cereal leaf beetle, Oulema melanopus (Linnaeus), and the face fly, Musca autumnalis De Geer, have recently been introduced into the United States The principle of preventing or retarding the spread of newly established pests by domestic regulatory and control measures has been used to protect agricultural crops against insect pests. For example, the Japanese beetle, Popillia japonica Newman, has been under continuous regulation in the United States since 1919. Established infestations still do not exist west of the Mississippi River, and they occur only in isolated areas in the south- eastern part of the country. The gypsy moth, Porthetria dispar (Linnaeus), which attacks many deciduous trees and shrubs, was first found in the United States in 1869. Control and quarantine programs have confined the pest to a few northeastern states, although there are some 100 million acres of forest west to the Mississippi River known to be susceptible to attack. The sheep scab mite, Psoroptes ovis (Hering), which once infested 50% of the sheep in the United States, is now confined to a few states in the Midwest. Domestic quarantines, combined with treatment programs, have eliminated several pests from the United States. Examples of these include the cattle tick, Boophilus annulatus (Say); red tick, Rhipicephalus evertsi Neumann, from Florida; parlatoria date scale, Parlatoria blanchardii (Targioni-Tozzetti), from Arizona and California; Hall scale, Nilotaspis halli (Green), from Cali- fornia; Mediterranean fruit fly, Ceratitis capitata (Wiedemann), from Florida and Texas; and the khapra beetle, Trogoderma granarium Everts, from the United States and also from Mexico. Many of the examples used to document and explain the various regulatory control principles are taken from the United States. However, comparable programs are active in most countries of the world. Although, in the United States, there are now adequate laws to serve as a basis for needed quarantine action and eradication or suppressive treatments, the success of publicly supported programs is materially affected by the
36 INSECT-PEST MANAGEMENT AND CONTROL knowledge and interest of all concerned. Quarantine officials solicit the cooperation of other state and federal agencies, commercial carriers, and prospective shippers in obtaining compliance with quarantine regulations. A fully informed public will abide by necessary laws; therefore, special emphasis is placed on an adequate public-information program. Obtaining compliance with regulations has largely replaced enforcement based on law alone. The public must also be adequately informed concerning the application of sup- pressive or eradicative treatments, particularly when aircraft are utilized. PLANT AND ANIMAL QUARANTINES PHILOSOPHY OF QUARANTINE ACTION The purpose of quarantine is to exclude potential pests, to prevent further dissemination of those already present, and to supplement eradication programs. Individual action cannot prevent the introduction and spread of plant and animal pests. Such protection must be provided through the adoption and enforcement of quarantines by government. Quarantines, therefore, have the protection of economy and welfare as their primary objective. Quarantines applied to commodities at ports of entry are considered to be the first line of defense against the introduction of new pests. Regulations apply to the introduction of pests carried by commercial transportation facil- ities. Adequate attention must also be given to other avenues of introduction, such as automobiles, privately owned aircraft, and watercraft. Looking to the future, quarantine measures may be needed in space travel. If a pest organism breaches the first line of defense, quarantines may be enacted to prevent a limited infestation from spreading throughout the ecological limits of the species. Such quarantine action is more effective when supported by control procedures to reduce the pest population. If the pest is confined to a limited area rather than distributed over a substantial portion of its ecological range, quarantine action is usually applied at the source of infestation. Conversely, if the pest is widely distributed, it may be more practical to apply regulations at the periphery of the infesta- tion or at the noninfested destination of the pest carrier. Under the provisions of a quarantine, procedures are developed to reduce or eliminate the risk of pest spread associated with the movement of potential pest carriers rather than to prohibit the movement. The degree of quarantine action depends on program goals. Fewer restrictions are necessary if the objective is to retard rather than prevent spread. It is essential that quarantines be constantly studied in order to make changes that may be necessary to attain objectives. They should be revoked when they no longer serve a useful purpose.
REGULATORY CONTROL 37 BIOLOGICAL BASIS FOR QUARANTINES Before a quarantine is considered, it must be determined that the pest is of economic importance and that action is warranted. Quarantines directed against specific foreign pests must not be based on their behavior in other lands. Since introduced pests are not usually accompanied by their natural enemies, they may become of major economic importance, even though they were of little or no concern in their native habitat. For this reason, domestic quarantines are sometimes invoked against pests that are not problems in other countries. Adequate protection by quarantine requires that knowledge be available concerning the identification and ecology of insects that are harm- ful to man, animals, crops, forests, ornamental plants, stored products, and structures throughout the world. Before a quarantine is invoked, other possible means of dealing with the problem are explored. There also must be reasonable expectation that the quarantine will be successful in preventing the introduction or spread of the pest and that the economic gain will exceed the cost of quarantine enforce- ment to government agencies and the public. If a quarantine is adopted, the habits of the pest are more fully explored, articles that may artificially spread the organism are determined, and pro- cedures are developed that will allow the safe movement of articles from regulated areas. Many articles besides hosts must be regulated, since pests may be spread in association with them. When treatments are being developed to eliminate pests associated with regulated articles, consideration is given to the length of time necessary to kill the pest. Some treatments, such as fumigation, render an article immediately free of pest risk, thereby allowing its safe movement at once. A time lapse is required following some treatments before the pest risk is eliminated; when this is necessary, quarantine action must be continued until the treatments become fully effective. Quarantines are imposed only on areas known to be infested or on those that have been exposed to infestation to such a degree that there is reasonable cause to presume that the area is infested. Constant surveillance is necessary to determine the extent of pest spread. The habits of the pest and its normal expected rate of natural spread are considered when the need for a quarantine is being decided. Continuous surveys are made in areas particularly vulnerable to invasion by specific foreign pests, as, for example, surveys in Florida for the Mediterranean fruit fly. MECHANICS OF QUARANTINE ACTION FOR NEWLY ESTABLISHED PESTS When a pest has been located and quarantine action appears desirable, certain procedures are usually followed: (1) The extent of infestation is
38 INSECT-PEST MANAGEMENT AND CONTROL determined as promptly as possible. (2) A public hearing is held to allow affected individuals and organizations, as well as representatives of noninfested areas, to express their opinions on the proposed quarantine. Emergency action, however, may be taken immediately prior to holding a hearing if such im- mediate action should be necessary to prevent the rapid spread of a pest. (3) Unless a different decision is made as a result of views expressed at the hearing, a quarantine is invoked. The quarantine specifies the pest, areas to be regulated, articles subject to regulation, and the basis under which pest carriers may be moved within and from regulated areas. Regulated areas in- clude known infestations and a marginal area based on the biology of the pest. (4) The hazard of spread associated with each of the regulated articles is carefully reviewed, and treatments based on research investigations are developed to allow the safe movement of regulated products. With some regulated articles, normal handling may eliminate the risk of artificial spread. Only slight adjustments in the handling procedures for some other articles will ensure a pest-free product. Exemption from treatment and certification requirements are allowed whenever possible to relieve any restrictions in keeping with good quarantine enforcement. Utilization of the exemption procedure expedites the move- ment of regulated articles and avoids imposing undue restrictions on industry. Regulated articles may be moved from infested areas on the basis of the following: (1) approved treatments are applied; (2) inspections are made indicating that the articles were produced in noninfested portions of the regulated area; (3) the articles have been examined and found to be free of the pest; and (4) the articles have been grown, produced, or handled in such a manner that no infestation will be transmitted. Movement may also be permitted if the articles are to be transported to designated processing plants where the pest risk is eliminated through processing, or if they are to be shipped to geographical areas where the pest cannot become established. In order to seek quarantine compliance, efforts are made to make the regu- lations known to the affected individuals and industries. Various means are employed to check on quarantine compliance. If the objective is to prevent spread, enforcement may involve the inspection of all types of traffic leaving regulated areas. If the objective is to retard spread, or if the regulated articles can be adequately checked at the source, such drastic action may not be necessary, and only spot checks are made. Regulated articles may also be checked at principal transportation centers, truck-weighing stations, and other similar points. EXPORT CERTIFICATION Certification of plant material for export is an important phase of foreign plant-quarantine activities. Phytosanitary laws of foreign countries are
REGULATORY CONTROL 39 translated, summarized, and made available to exporters. Whenever possible, plant material that meets the requirements of the country of destination is certified before it is exported. This procedure is sound and avoids the problems associated with treating infested materials after importation. LEGAL RESPONSIBILITY In the United States, the United States Department of Agriculture, under federal laws, has broad authority and responsibility to enforce quarantine regulations to prevent the entry or retard the spread of plant and animal pests, as well as to develop and carry out programs designed to eradicate, control, or suppress such pests. The so-called animal-quarantine legislation is encompassed principally in acts passed in 1884, 1890, 1903, 1905, and 1962. Authority for federal participation in the plant-quarantine field dates back to the Insect Pest Act of 1905 and the Plant Quarantine Act of 1912. Control and quarantine programs have been strengthened by the passage of a number of additional acts and amendments to these initial regulations. Work conducted under the provisions of these laws includes cooperative activities carried on jointly with state and local governments, other organiza- tions, and individuals. Since suppression and control programs must be handled in accordance with state laws and in cooperation with the states, the programs are effective only where the states concerned have a strong and continuing interest in the particular pest problem. Active cooperation between many countries in the enforcement of plant quarantines followed a conference called by the Food and Agriculture Organization of the United Nations and the adoption in 1951 of an agree- ment entitled "International Plant Protection Convention." All major nations now have plant-protection laws and regulations to guard against the introduc- tion of plant pests that could become established under their ecological con- ditions. For example, the Colorado potato beetle, Leptinotarsa decemlineata (Say), was introduced into Germany, and local infestations, discovered in 1874, were eradicated. A decree was issued by the German government in February 1875 forbidding the further importation of potatoes and potato sacks. France also imposed exclusion measures against the same pest in 1875. These two exclusion orders anteceded, by a few years, the Destructive Insects and Pest Act adopted by the United Kingdom in 1877. Many countries regulate the entry of host material that might introduce exotic, economic species of fruit flies. State agencies are responsible for enforcing quarantine regulations to prevent the spread of pests within a state. They may also enact legislation to prevent the introduction of pests of particular concern to them from either foreign or domestic sources, provided the federal government has not enacted quarantines against the specific pests.
40 INSECT-PEST MANAGEMENT AND CONTROL MOVEMENT OF SCIENTIFIC SPECIMENS Under the provisions of federal and state regulations, approval may be granted to import or move living pests interstate to specific locations for scientific purposes. Such approval is based on a careful review of each case by the state and federal agencies concerned. It is desirable to conduct scientific studies in areas where the pest is known to occur. If this is not possible, the next choice is an area well removed from those in which the pest could become established if it escaped. If the research must be conducted in areas where the pest is not known to occur and might become established, first consideration is given to determining whether adequate safeguards can be maintained to eliminate any possibility of escape. Other considerations include the type of studies to be made, the potential biotic range of the pest, and its relative importance, as well as the possibility that it may represent a new race or strain that is not present in the area where the investigations are to be conducted. Issuance of a permit depends on this review. It is important that everyone abide by laws regulating the movement of living pests and recognize his responsibilities in preventing escape or illegal transport of the pests. REGULATORY CONTROL PROGRAMS Publicly supported regulatory control programs are an essential part of the over-all effort to protect crops and livestock from pests. These programs are based on the results of the best available research information, and research should be continued as long as the programs are operated, so that improve- ments may be made. There are three main types of organized publicly supported pest-control programs: eradication, containment, and suppression. Eradication and con- tainment programs also involve regulatory activities to prevent reinfestation or spread to new areas. The type of program to be conducted depends on the objectives. Various methods are used in eradication, containment, and suppression programs; these include chemical, cultural, and biological measures. Chemical- control procedures for eradication have been effective and economical, but the chemicals must be used in such a way as to cause minimal adverse side effects. An important consideration in the use of toxicants in organized publicly supported programs is the assurance that the materials are applied under the direction of employees trained in the proper application of pesti- cides. The total amount of chemical required for the control of a pest in programs of this type is usually less than the quantity that would be utilized
REGULATORY CONTROL 41 by the general public should the pest be allowed to spread throughout its ecological range. Cultural-control procedures are used whenever possible, but they usually cannot be relied on to attain eradication unless combined with other treat- ments. Over the years, numerous biological-control organisms have been of considerable benefit in containing but not eradicating serious pests. However, there have been a few instances where biological procedures have been responsible for pest elimination. An example is the eradication of the melon fly, Dacus cucurbitae Coquillett, from the island of Rota near Guam in the South Pacific by the male-sterilization technique, in which gamma radiation is used. With other pest-control programs, it is possible to utilize cultural and biological procedures in combination with chemical control and attain the desired objective. ERADICATION Eradication programs are those conducted for the purpose of eliminating the target organism from a geographical area. Although no plant pest has been eradicated from the entire area where it is known to occur throughout the world, many species have been eradicated from limited geographical areas. Eradication programs are usually applied against pests that have recently gained entry and are not established over a large portion of their potentially favorable ecological range. If adequate control methods are not known when the pest problem is discovered, even though eradication is desirable, such a program may not be undertaken until new procedures are developed. At times, new technology makes it feasible to eliminate pests even though they are firmly established over a sizable geographical area. An excellent example is the eradication of the screw-worm, Cochliomyia hominivorax (Coquerel), from the southeastern United States, which resulted from the application of the sterile-male technique explained in detail in Chapter 15. Although there may not be sufficient data to develop procedures assuring eradication when a new pest is found, eradication programs may be tried to reduce actual or potential crop losses. For example, white-fringed beetles, Graphognathus spp., were seriously damaging crops in southern Alabama and northwestern Florida when first identified; therefore, it was the consensus of state and federal workers and others that every effort should be made to attempt elimination with the tools available. When it was demonstrated that the pest could not be eliminated with known methods, the program objective was changed to one of containment. Some newly introduced pests cannot be eradicated or contained with any known procedures. An example is the spotted alfalfa aphid, Therioaphis maculata (Buckton), which first appeared in New Mexico in 1954. By the
42 INSECT-PEST MANAGEMENT AND CONTROL end of that year it had moved to 7 additional states, and in 1967 it existed in 36 states - nearly every place where alfalfa is grown commercially in the United States. Eradication of a pest is difficult and sometimes must be repeated, as in the case of the Mediterranean fruit fly, first found in the United States in central Florida in 1929, after it had spread over a considerable area. An intensive eradication effort against this important fruit and vegetable pest was promptly initiated. It required approximately 18 months and $7 million to eradicate the infestation. The insect was not found again in the United States until 1956. This reinvasion, similarly, was widespread before being detected by a homeowner in Miami, Florida. In the second eradication program, the same length of time was required to eliminate the pest, at a cost of approxi- mately $11 million. Following the 1956 outbreak, an intensive trapping program was initiated to detect new invasions as quickly as possible. A third infestation, found in 1962, was eradicated by the end of 9 months, with an expenditure of $1 million. A fourth invasion was discovered in 1963 and was eradicated at a cost of $300 thousand within 3 months. A fifth invasion was discovered in the Brownsville, Texas-Matamoros, Mexico, area in June 1966. Following eradication treatments, no further specimens were found after a lapse of 44 days, and all quarantine restrictions were removed within 6 months. A malathion poison-bait spray formulation was used to eradicate the 1956, 1962, and 1963 invasions. This demonstrates the value of constant surveillance for foreign pests. CONTAINMENT Containment programs against plant or animal pests that have not reached their full ecological limits are conducted when eradication cannot be accom- plished, either because the best has become firmly established or because eradicative treatments are not available. For example, when the Japanese beetle was discovered in the United States, sufficient information was not available on control treatments to make eradication practical. Consequently, the beetle has spread over a considerable area. State and federal governments are still conducting a program designed to contain the pest. It is often ad- visable to expend public and private funds in an effort to retard the spread of a pest rather than allow it to move unimpeded throughout its ecological range. In containment programs, there is usually no attempt to reduce or eliminate populations throughout the infested areas; control is generally confined to selected portions of infested areas from which the pest may be artificially spread. It also may be practical to apply measures to suppress the population along the periphery of the infested area to retard natural spread. An example
REGULATORY CONTROL 43 is the program to contain the gypsy moth in the United States. Suppressive pesticidal sprays have been applied along the periphery of the infestation to retard natural spread to the south and west. Such treatments have been largely responsible for restricting this pest to a small portion of its potential range within the country. In some containment programs, the control effort is aimed at reducing populations throughout the infested area, with the hope that a research break- through will make eradication practical at a later date. An example is the recent development of effective soil-fumigation procedures in which a mixture of dichloropropenes and dichloropropanes was used against the golden nematode, Heterodera rostochiensis Wollenweber. A progressive eradication program against this pest is being conducted in the only known infested area in the United Statesâon Long Island and in Steuben County, New York. Prior to the development of the fumigation procedures, the golden nematode had been confined to small areas and kept, or contained, at low populations throughout the infested area by utilizing cultural-control measures. Containment programs are reviewed at frequent intervals to make sure that the objectives are being attained. Control of the Dutch elm disease, Ceratocystis ulmi (Buisman) C. Moreau, in the United States, and its associated bark beetle vectors of the causal fungus, is an example of a program turned over to prop- erty owners after eradication and containment efforts no longer appeared feasible. SUPPRESSION State and federal agencies in the United States also cooperate with private individuals and grower organizations on programs against some pests capable of periodic sudden outbreaks over such wide areas that control cannot be accomplished by individual effort. These pest-control programs are mostly applied against widely distributed plant or animal pests. Examples of publicly supported suppression programs designed to control populations of pests occurring over extensive areas are those conducted against several species of grasshoppers or locusts; the torsalo or human hot fly, Dermatobia hominis (Linnaeus, Jr.); and the Mediterranean fruit fly. In the United States, grasshoppers in the western states are subject to control annually by state and federal agencies with participation by farmers. Coopera- tive locust-control programs have been conducted in 13 countries in the Near East, South Asia, and Africa; namely, Afghanistan, Ethiopia, India, Iran, Iraq, Jordan, Lebanon, Libya, Morocco, Pakistan, Sudan, Tunisia, and Turkey. Central American countries and Mexico cooperate in suppression programs conducted against the torsalo and the Mediterranean fruit fly. The work is
44 INSECT-PEST MANAGEMENT AND CONTROL coordinated through OIRSA (Organismo Internacional Regional de Sanidad Agropecuaria) and is financed by Nicaragua, Guatemala, El Salvador, Costa Rica, Honduras, Panama, and Mexico. MONITORING THE EFFECT OF CONTROL PROGRAMS ON THE ENVIRONMENT The pesticide-monitoring responsibility in large-scale control operations may be defined as a surveillance activity designed to assure high operational per- formance and adherence to safety precautions in the application of substantial amounts of pesticides to areas under treatment. Its goals are maximum protec- tion of public health, the applicators, domestic animals, fish, wildlife, and other organisms. It is axiomatic that most biological, cultural, or chemical-control procedures applied against a specific pest have some effects on other organisms, referred to as side effects. This is true whether the selected control procedures are applied by rural or urban individuals or by public agencies. The extent of such effects on other organisms is largely dependent on the size of the control operation. Since the initiation of organized pest-control programs, scientists have attempted to utilize procedures that would have the least detrimental side effects. Initially, evaluation of side effects was made principally by research workers who were at the same time determining whether the treatments would be effective for control of the target organism. Studies on the side effects of heptachlor treatments for the control of the imported fire ant, Solenopsis saevissima richteri Forel, in the United States, especially the residue problems associated with food and feed crops and wild- life, brought widespread attention to large-scale use of persistent pesticides. The combination of studies on the impact of the programs conducted against the imported fire ant led to changes in control procedures. A specific insecti- cide bait was developed that, under the conditions of use, is not hazardous. Side effects associated with large-scale eradication, containment, or sup- pression programs can be beneficial. For example, chlorinated hydrocarbon insecticides mixed with agricultural soils for the control of Japanese beetle, white-fringed beetle, or European chafer, Amphimallon majalis (Razoumowsky), larvae also provide control of numerous other soil-inhabiting pests, including certain wireworms, rootworms, and root aphids. Fumigation treatments to eradicate the khapra beetle also eliminate other grain-inhabiting insects and rodents. Certain storage-insect pests are controlled as side effects to treatments applied to fields of small grains for cereal leaf beetle control in the United States. Monitoring assumed a major role in control programs in the United States in May 1963, following release of the President's Science Advisory Committee report on "Use of Pesticides." In the committee's recommendations the sub-
REGULATORY CONTROL 45 ject was referred to directly, as follows: "Provide as a part of the operating budget of federal control and eradication program funds to evaluate the effi- ciency of programs and their effects on nontarget organisms in the environ- ment. Results of these studies should be published promptly." Monitoring, from the standpoint of large-scale control programs, is concerned with the gross or immediate impact of a disruption in the environment brought about by direct application of a pesticide. It deals with the acute and more- dramatic effects of a single or a few pesticide applications, on an area a few- hundred to several-thousand acres in size. Results of monitoring investigations may establish or point to the need for research studies on long-term chronic effects of a pesticide program on the biota. A decision to initiate large-scale plant-pest control or eradication programs is reached after careful consideration of all factors involved. First, the impor- tance of the pest to agriculture or public health must be appraised. Then, all that might be adversely affected by the procedures to be used must be reviewed. When pesticides are employed in the total effort, the following factors must be considered before initiating the program: 1. Effectiveness against the target organism. 2. Possible hazards to applicators and to people residing in treated areas. 3. Residues on food or feed crops. 4. Hazards to fish and wildlife. 5. Danger to the honey bee, Apis mellifera Linnaeus, and other pollinators, or possible detrimental upset in the balance of beneficial insect complexes. 6. Effects on soil organisms or on plants grown in the treated soil. 7. Water pollution, with special reference to: endangering public and private water supplies for use by man and domestic animals, including con- tamination of soil by water used for irrigation; residues in fish and other aquatic organisms; and effect on food-chain organisms. 8. Possible contamination of surrounding areas through air drift or water movement. 9. Possible absorption and translocation of the pesticide by the plants. 10. The mechanism of action and persistence in soils. The decision to monitor a control program is based on many considera- tions. The most important are: (1) the type of pesticide to be used; (2) the type and size of the area to be treated; (3) residues already in the environment; and (4) possible hazard to plant and animal life in the area. SUPPORTING ROLE OF RESEARCH AND METHODS IMPROVEMENT Control and quarantine programs usually involve pests of foreign origin that have been recently introduced. Consequently, research data for developing
46 INSECT-PEST MANAGEMENT AND CONTROL control and regulatory measures may not be available. Even when there is basic laboratory-research information about the particular pest, the adaptation of these data to large-scale quarantine or control operations requires consider- able expansion and field evaluation. Basic-research accomplishments must be rapidly transposed into workable action programs. Several special-methods improvement laboratories have been established in the United States. The laboratories are staffed by personnel who work in close collaboration with other research scientists to develop practical regula- tory and control procedures. An example of cooperative research and methods improvement illustrates the value of this type of approach and how it can be used to minimize or eliminate some of the adverse side effects associated with large-scale suppres- sion programs. During the early stages of the imported fire ant program in the United States, a single application of heptachlor, a chlorinated hydrocarbon insecticide, was the only known means to control the ants effectively. How- ever, there were adverse effects of the insecticide on fish and wildlife. A program to develop alternate control procedures was accelerated, and intensive screening of materials led to the development of a bait formulation consisting of soybean oil, corncob grits, and a minute quantity of the insecticide mirex. When this bait is applied at the recommended rate, only 1/7 oz of the insecti- cide is distributed per acre. The bait has no adverse effect on fish and wildlife and does not create harmful residues. The development of this formulation made it possible to continue the large-scale suppression operation. A significant advance in the field of chemical pest control through methods improvement was the development of the ultra-low-volume-treatment tech- nique. This involves the application of minute quantities of undiluted or highly concentrated technical insecticide. Some chemicals applied in this manner, even at a reduced per-acre dosage, control pests more effectively than when applied in a diluted form. Application costs are lowered because of the increased acreage that can be treated per application unit, particularly when aircraft are utilized. There are also savings in costs associated with mixing and transporting the chemicals. Since the need for mixing is eliminated, there is a reduction in the hazard involved in handling the toxicants; and in aircraft application there is greater safety to the pilot, since the material may be applied at a higher flight level. The low-volume-treatment technique has been used effectively in publicly supported suppressive programs in the United States against pests such as grasshoppers; the boll weevil, Anthonomus grandis Boheman; and the cereal leaf beetle. Although the goal of pest-control programs is to develop an effective treatment entirely free of objectionable side effects, this is seldom possible. There are exceptions, howeverânotably the eradication of the screw-worm fly in the southeastern United States through the release of sterile insects of
REGULATORY CONTROL 47 this species. The elimination of the screw-worm from the southeast has been of untold benefit to the livestock industry, and there have been no complaints from farmers about the eradication method used. In addition, increases in deer populations have occurred in the area, and this has been commented on favorably by those interested in wildlife. The sterility principle also shows considerable promise against certain fruit fly species and is being investigated as a means of controlling other important plant and animal pests. BIBLIOGRAPHY Federal Plant Pest Act, approved May 23, 1957 (Title 7 of U.S. Code, sections ISOaa- 15QJJ). Food and Agriculture Organization of the United Nations International Plant Pro- tection Convention. 1951. Viale Delle Terme Di Caracalla, Rome. Food and Agriculture Organization of the United Nations Plant Protection Bulletin, issued bimonthly by the World Reporting Service, Rome. McCubbin, W. A. 1954. The plant quarantine problem. Ejnar Mucksgaard, Copenhagen. 255pp. Mexican Border Act of 1942, as amended (Title 7 of U.S. Code, section 149). Plant Quarantine Act of 1912, as amended (Title 7 of U.S. Code, sections 151-165, and 167). President's Science Advisory Committee. 1963. Use of pesticides. Report. U.S. Govern- ment Printing Office, Washington, D.C. 26 pp. Smith, H. S., E. O. Essig, H. S. Fawcett, G. M. Peterson, H. J. Quayle, R. E. Smith, and H.R. Tolley. 1933. The efficacy and economic effects of plant quarantines in California. Calif. Univ., Coll. Agr., Berkeley. Agr. Exp. Sta. Bull. 553. 276 pp. The Terminal Inspection Act of March 4, 1915, as amended (Title 7 of U.S. Code, section 166). United States Department of Agriculture. 1958. Locust and other insect control. U.S. Dep. Agr. Misc. Pub. 770. 147 pp. United States Department of Agriculture, Agricultural Research Service, Plant Pest Con- trol Division. Cooperative Economic Insect Report, issued weekly. Weber, B. A. 1930. The plant quarantine and control administration; its history, activi- ties, and organization. Service Monograph of the U.S. Government 59. Brookings Institution, Washington, D.C. 198 pp.
