W2185: Biological Control in Pest Management Systems of Plants
- October 01, 2007 to September 30, 2012
- Administrative Advisor(s):
David C. Thompson
- NIFA Reps:
Robert M. Nowierski
Statement of Issue(s) and Justification:Biological control has proven to be one of the most effective, environmentally sound, and cost-effective pest management approaches used to control pests. It is anticipated that biological control will play an increasingly important role in integrated pest management (IPM) programs as broad-spectrum pesticide use continues to decline. Moreover, biological control is a cornerstone of organic farming, and the production of organic commodities in the United States continues to increase at roughly 20% per year (USDA-ERS 2002). Organic farming is no longer considered a cottage industry since retail sales hit $14.6 billion in 2006. Biological control is the "the action of parasites, predators, and pathogens in maintaining another organism's density at a lower level than would occur in the absence of the natural enemies" (DeBach 1964). Two types of biological control, natural biological control and applied biological control, are often distinguished. Natural biological control is that brought about by indigenous natural enemies in the native range of a pest species. In contrast, applied biological control is achieved through human efforts or intervention, and consists of three main approaches - - importation, augmentation, and conservation. In the importation approach (generally referred to as classical biological control), exotic natural enemies are imported and released in a new area where the target pest occurs, while augmentation and conservation involve supplementing (or manipulating) natural enemies already in place, or modifying the environment, respectively, to improve the effectiveness of biological control. For a given arthropod pest or weed, a pool of natural enemies often exists which consists of vertebrates, invertebrates, and microorganisms. The fundamental problem in applied biological control is to select an appropriate species or combination of species from this pool that will bring about the desired level of pest suppression with minimal impact on nontarget species. The mission of this regional project is to facilitate research and implementation activities among the participating institutions and organizations in applied biological control.
The application is a renewal request for regional project W-1185 and involves biological control of both arthropod pests and weeds. Because biological control of arthropod pests and biological control of weeds are based upon many of the same ecological principles, researchers from the two fields benefit greatly from information exchange and research collaboration. Whereas the methodologies for controlling arthropod pests and weeds may differ, the scientific issues (e.g., introduction strategies, genetics of colonization, evaluation of natural enemy impact, etc.) overlap to a great extent. That some individuals involved in this project conduct research in both arthropod pest and weed systems is further evidence of the conceptual similarities between these two fields. In 2004, the USDA strengthened its commitment to pesticide reduction with its National Road Map to Integrated Pest Management (http:www.ipmcenters/IPMRoadMap.pdf). IPM programs based largely on biological control are of great benefit to agriculture, the quality of rural life, and the consumer. Reductions in insecticide, acaricide, and herbicide applications should allow farmers and ranchers to reduce production costs and make adjustments for a more sustainable agriculture. Reduced pesticide use will enhance the quality of rural life by decreasing ground and surface water contamination, reducing effects on nontarget species (including wildlife), and increasing safety of farm workers and other rural residents. These benefits also accrue at the interface of urban and agricultural environments, where there is increasing opposition to pesticide use by stakeholders. The reduction in pesticide residues in food is also desirable, although controversy remains over the extent and public health significance of such residues. Background Information and Justification: Despite many advances in recent years, our practical and conceptual understanding of success and failure in applied biological control fall short of meeting certain current and future requirements. For example, in classical biological control, the rate of establishment of natural enemies is relatively low in the case of arthropod pests (ca. 34%) (Kimberling 2004); further research into the genetics and ecology of colonization is clearly warranted. In the future, classical biological control should ideally be able to predict (1) the appropriate species (or biotype) or combination of species (and/or biotypes) to release for control of a target pest in a given situation; and (2) the environmental impact resulting from the introduction of an exotic enemy. Nontarget impacts to plants or insects from biocontrol agents are of great concern to conservation biologists, environmentalists, and federal agencies. Since 2000, regulations on natural enemy importation and introduction have increased and are enforced by USDA-APHIS using guidelines from the North American Plant Protection Organization (NAPPO). These guidelines require researchers to provide in-depth studies complete with rigorous data on the nontarget effects of biological control agents they wish to release (Mason et al. 2005). Currently, nontarget testing and regulations involved in releasing biological control agents are the subject of serious discussions by this workgroup at their annual meeting.
Where success has been achieved in classical biological control, the underlying ecological mechanisms are not always clear. After 100 years of effort, we still do not fully understand the mechanisms by which a successful natural enemy operates in nature, or why a particular organism is successful in one situation and unsuccessful in another. Basic research in augmentation and conservation of natural enemies is also needed. In augmentation, we urgently need a coherent theory of inundative/inoculative release as well as basic efficacy data in order to more readily incorporate commercially available predators and parasitoids of arthropod pests into IPM systems. The genetics of mass production must be evaluated experimentally so that quality control procedures can become a regular practice in the commercial production of natural enemies. Advances in the nutrition of parasitoids and predators are needed. Continued commitment to conservation of natural enemies is required, including innovative ways of integrating pesticides and cultural controls with key natural enemy species. Global warming has now been accepted as a serious threat to our natural and agroecosytems (Intergovernmental Panel on Climate Change 2007). It will be imperative that biological control scientists watch for the effects of climate change on arthropod pests that have been kept in check by natural enemies. Products of biotechnology designed for pest control must also be assessed and incorporated (where appropriate) into IPM programs. In the past five years, W-1185 scientists have examined interactions between transgenic crops and biological control species, and these studies will increase as more such crops are approved. Finally, biological control scientists are providing management professionals with the sustainable and effective tools with which to manage the relentless pressure of invasive species on natural and agricultural ecosystems.
Regional Character of Project: Exotic pests continue to arrive in the western U.S., and many of these will become permanently established. For such pests, the use of classical biological control should remain a high priority. At the same time, our IPM programs must be continuously evaluated, refined, and adjusted in response to changes in newer and more specific control technologies and production practices. The most effective way to address these new pests that become quickly established and spread to other states is through regional collaboration of state and federal scientists. Experiment Stations and non-Land Grant institution members to this project accrue timely and relevant benefits to participation. Regionality is essential to implementing biological control-based solutions to our pest problems for the following reasons: 1) numerous target pests occur in three or more western states or territories; for these pests, the research effort must be coordinated and duplication minimized to effectively utilize very limited resources; 2) regional importation/quarantine facilities are critical for a coordinated response to exotic arthropod pests and weeds. These facilities are finite, there are no plans to expand them in the foreseeable future, and they serve the needs of all states and territories in the region; and 3) interstate exchange of information and exotic species/biotypes is facilitated through a regional approach. Sharing the cost of foreign exploration and quarantine is essential, as is sharing of methodological advances and our knowledge base. Without a regional project in biological control, the Western states and territories will not be able to rapidly share current information on controlling new and existing pest species, many of which have ranges over multiple states. Additionally, this group discusses emerging pest threats and forms collaborations and networks that anticipate and plan for pest arrival. Besides state to state (Experiment Station) collaborations, active participants include scientists from USDA-ARS, USDA-APHIS, USFS, and state departments of agriculture, all of which benefit from rapid information transfer and shared projects.
Transcending the coordination and cooperation on a given pest is an important shared need for advances in regulatory policy, general methodologies for release and evaluation of natural enemies, and the need to develop sound ecological theory concerning pest population dynamics, predator-prey interactions, and the genetics of colonization in biological control. For example, theoretical and experimental studies of the actual ecological mechanisms that underpin pest population regulation are being addressed in several states and among pest systems. Our members and Federal Advisors, serve on key committees that are steering efforts to minimize nontarget effects through policy management, and a website developed in 2004 for this project, serves to maintain real-time communication and continuity in this group of scientists that include members outside the western region.
Related, Current, and Previous Work:The previous W-1185 project proposal has been revised to condense four of the 15 objectives into two objectives. Additionally, while outreach has always been an important component of Land Grant programs, this proposal is formalizing its outreach commitment as a new official Objective. Over the past 5 years, new pests have arrived in the western U.S., and others have gained in importance. These have been incorporated into a revised species target list. Twelve arthropod pests have been added to the work list, (minimum of 72 arthropod pests), and 6 new weeds (minimum of 52 weed species) [see Appendix A]. Aphids, whiteflies, tephritid fruit flies, scales and mealybugs, thrips and leafhoppers have all added new species to the region during the past 5 years. Additional weeds include, but are not limited to, Russian olive, common tansy, common reed, puncture vine and a hawkweed. Additionally, the target pest groups for this proposal reflect changes to the classification of some groups. Arthropod categories now include Aphids, Beetles, Hemiptera, sessile Hemiptera, Lepidoptera, Fruit flies, Whiteflies, and Other Arthropods. Weed groups now include Brassicas, Gorse and Broom, Purple Loosestrife, Saltcedars, Spurges, Thistles, Tumbleweeds and Other Weeds. Previous work (2002-2006): Substantial progress was made in the utilization of biological control for the suppression of both arthropod and weed pests through introduction (classical), conservation, and augmentation approaches. Measures of progress for the W-1185 group detailed in Appendix B include 580 professional publications produced as a result of research conducted under project objectives. These breakdown as follows; 361 peer reviewed journal articles, 27 technical papers, 101 book chapters/contributed sections, 5 books, 50 proceedings papers, 20 peer reviewed extension articles, Masters theses, and trade journal articles. This list is a conservative reporting of the overall output, as many members did not include their trade and extension publications. Other measures of progress are the impact of the research on managing invasive and native pests, and fundamental biological discoveries, or changes in conceptual frameworks that influence biological control research. The past 5 years has also seen the continued development of new methods that influence how biological control research is conducted. Underlying these many accomplishments were the critical interactions and collaborations that transcended state and institutional boundaries and were made possible through this regional research project. As one example, a comprehensive reference book on the biological control of invasive plants in the United States was produced in 2004 (Coombs et al. 2004), and the 17 participating W-1185 members represented the Oregon Dept. of Agriculture, Washington State University, Oregon State University, Montana State University, the University of Idaho, USDA-ARS, USDA-ARS (European Biological Control Lab.), CABI Biosciences (Switzerland), and the California Dept. of Food and Agriculture.
The detailed research accomplishments by W-1185 scientists from 2002-2006 are presented in condensed form in the annual reports. The group is simply too large, and the accomplishments too diverse, to present these findings in detail below (W-1185 participants work on approximately 124 different pest species). For detailed information, individual reports (by year) can be found on the W-1185 website. Therefore, selected projects representing the contributions of many members are highlighted below.
Pest management impacts. Substantial impacts were made on many pests targeted in the previous period. Over 400,000 natural enemies (individuals) were released or relocated for use against at least 23 pest arthropods or weeds in western states in 2006 alone. Many more programs are evaluating non-target effects of potential biological control agents, and applying for release permits. Additionally, these ongoing projects are assessing environmental consequences of former releases and documenting ecosystem impacts. The introduction of parasitoids for control of the pink hibiscus mealybug has resulted in a greater than 98% decline of populations of this pest in California. The predator Rodolia limbata suppresses the breadfruit pest Icerya seychellarum to less than 1% of its previous density on Ofu and Olsega Islands in American Samoa. The red gum lerp psyllid is in decline in coastal areas of California, and the Eugenia psyllid is under significant control in warmer areas of that state. Reduction of purple loosestrife due to biological control in Oregon is mitigating the adverse effects on urban wetlands. The biological control of saltcedar (Tamarix spp.), one of the worst noxious weeds in the U.S., is a good example of a collaborative project, as saltcedar is a problem in at least 11 western states. W-1185 researchers (CO, CA, MT NV, NM, OR, TX, WA and WY) are evaluating biotypes of Diorhabda elongata, some of which are defoliating large acreages of saltcedar, assessing its impact on the ecology of select ecosystems, or are screening other natural enemies for potential future releases.
Development of the conceptual framework for biological control research. Several projects involving development or tests of theory provided new insights in basic biology, or improved our understanding of the evolutionary relationships between groups of pest or natural enemy groups. These include a population genetic analysis of introduced and native European populations of hoary cress, which provided insight into the role of The Enemy Release hypothesis vs. the Evolution of Increased Competitive Ability Hypothesis in the invasion of this noxious weed. Research using ragwort biological control as a model system, targeting of weed vulnerabilities and integrated management of disturbance, plant competition, and natural enemy regime are improving both theory and practice of weed biological control. In another set of studies, a facultative bacterial symbiont of pea aphids, Hamiltonella defensa, was shown to confer resistance to parasitism by the dominant parasitoid Aphidius ervi. Different symbiont genotypes conferred from about 40% to virtually 100% resistance to parasitism, and symbiont genotype appeared to represent most of the variation in resistance. This result suggests bacterial symbionts sometimes mediate interactions between pests and natural enemies, and symbionts may explain some instances of variation in the ability for natural enemies to regulate particular pest populations. Lastly, conceptual advances in the systematic relationships of various important pest and natural enemy groups will enable more effective and safer implementation of biological control. These groups include Leucochrysa, a green lacewing genus, aphids in the Aphis gossypii complex, and the important chalcidoid parasitoid groups of the Aphelinidae and Trichogrammatidae.
New methods. W-1185 researchers continue to lead in the development and use of cutting edge tools in biological control. New methods include the development of host range testing protocols for arthropod natural enemies in many current projects. The use of molecular techniques have increased our ability to conserve and monitor natural enemies in cotton. In one example, ELISA immunoassays and PCR are being increasingly used to quantify the predation rates of an entire arthropod assemblage. Novel advances in protein marking of very small parasitoids has allowed mark/recapture experiments to monitor agent movement. Improved rearing systems for the glassy winged sharpshooter and its natural enemies have improved the implementation of biological control for this important pest. Projects have used GIS and airborne hyperspectral remote sensing technologies, and population genetics and systematics studies have been aided by use of microsatellite mtDNA variations and COI sequencing to distinguish species. Lastly, the use of pathogens for classical biological control has not been achieved before, but in the last project period, the rust disease Puccinia jaceae var. solstitialis was approved for release against yellow starthistle, thus hopefully paving the way for greater use of pathogens against weeds in the future.
Outreach. Many project members made contributions in biological control outreach. A few examples are included here. In conjunction with numerous contributors (seventeen W-1185 participants) a reference book on the biological control of invasive plants in the United States was published (Coombs et al. 2004). This book covered 39 total invasive plants in the continental U.S. and discussed the origin, biology, habitat, impacts and range of 94 biological control agents. In Micronesia, quarantine personnel from four Western Pacific countries, were trained in aphid and aphid natural enemy collection and identification. Further, a workshop on invasive crop pests was held on Pohnpei with participants from local universities and national and state government agencies. In addition to biological control extension programs on olive fly, eucalyptus pests, and the glassy winged sharpshooter, Daane (UC-Berkeley) produced 26 extension publications and 33 proceedings papers in addition to his 33 peer reviewed publications. Of note is a Spanish language extension book on vine mealybug he co-authored in 2005 (212 pp). The University of Idaho and the Nez Perce Tribe Bio-Control Center conducted 12 one-day technology transfer workshops and a three-day youth camp for state, federal, tribal land managers, private landowners, and high-school students. The workshops, providing education on how to release and monitor natural enemies, were conducted in the Pacific Northwest, Nevada and North Dakota.
In 2004, W-1185 participants from UC-Berkeley and UC-Riverside launched an information-intensive website for the project that is updated routinely. This site includes web links to all members and collaborators, posts individual annual reports by institution, background information on biological control, and all annual meeting agendas and subsequent presentations. With approximately 100 separate PDF files of detailed progress reports, it provides a wealth of information to our stakeholders on W-1185 research output, and also serves as a communication vehicle to W-1185 members and institutions. Areas Needing Further Investigation. Biological control programs require a) identifying a country of pest origin, b) locating and successfully importing a natural enemy, c) rearing the natural enemy and testing for non-target impacts, d) applying for release of promising agents and waiting for approval, and finally, e) releasing the agent and evaluating field efficacy. These steps take time, therefore, additional work needs to be done on most of the pest groups for which current research is ongoing. This group is very instrumental in the development of procedures for host range testing of arthropod natural enemies. Symposia sections were added to the annual W-1185 meetings to discuss specific on-going cases and to debate the details of how to perform nontarget testing.
An invaluable function of W-1185 to the Western Region, is information exchange on emerging pests. Many W-1185 participants operate globally, engage in foreign exploration, speak at international symposia, and collaborate with scientists in other states and countries. This group provides a network of resources with which to anticipate and plan for the inevitable arrival of an arthropod or weed pest that will appear without its natural enemies.
Another area of concern to the group as a whole is the increasingly burdensome regulatory structure for classical biological control programs. In the past 5 years, lengthy delays before permitting, rules prohibiting hand carrying of biological control organisms, problems with shipping live organisms worldwide, and other regulations mandated by the Department of Homeland Security, have represented significant constraints on project research. While we support regulation promoting environmentally sustainable and ethical practices in biological control, we also strive to maintain research projects that will control devastating arthropod and weed pests. In the past 5 years we have addressed these concerns at our annual meetings, and worked with our National Program Leaders in biological control in USDA-ARS, USDA-CSREES, and USDA-APHIS-PPQ to resolve these constraints. We intend to continue to be a voice for a regulatory process that provides the needed oversight of biological control research to ensure it is safe and effective, but does not impede progress on what is often the most ecologically benign method of pest suppression.
- Goal A: Import and Establish Effective Natural Enemies (Classical Biological Control). Goal A includes 6 specific objectives: Objective 1. Survey indigenous natural enemies.Objective 2. Conduct foreign exploration and ecological studies in native range of pest.Objective 3. Determine systematics and biogeography of pests and natural enemies.Objective 4. Determine environmental safety of exotic candidates prior to release.Objective 5. Release, establish and redistribute natural enemies.Objective 6. Evaluate natural enemy efficacy and study ecological/physiological basis for interactions.
- Goal B: Conserve Natural Enemies to Increase Biological Control of Target Pests. Goal B has 3 specific objectives: Objective 7. Characterize and identify pest and natural enemy communities and their interactions. Objective 8. Identify and assess factors potentially disruptive to biological control. Objective 9. Implement and evaluate habitat modification, horticultural practices, and pest suppression tactics to conserve natural enemy activity.
- Goal C: Augment Natural Enemies to Increase Biological Control Efficacy. Goal C has 3 specific objectives: Objective 10. Assess biological characteristics of natural enemies. Objective 11. Develop procedures for rearing, storing, quality control and release of natural enemies, and conduct experimental releases to assess feasibility. Objective 12. Implement augmentation programs and evaluate efficacy of natural enemies.
- Goal D: Evaluate environmental and economic impacts and raise public awareness of biological control. Goal D has 2 specific objectives: Objective 13. Evaluate the environmental and economic impacts of biological control agents. Objective 14. Develop and implement outreach activities for biological control programs.
Goal A: Import and Establish Effective Natural Enemies.
Objective 1: Survey indigenous natural enemies. The scientific literature will be reviewed to determine prior records and geographic distributions of potential natural enemies of arthropod pests and weeds. A survey and collection of natural enemies will be conducted throughout the geographic area of infestation of each target pest. Parasitized pests and natural enemies will be held in the laboratory to allow natural enemy emergence, identification and determination of levels of parasitism and hyperparasitism. For herbivores, specific types of plant injury will be catalogued and plant species closely related to the target weed will be surveyed.
Objective 2: Conduct foreign exploration and ecological studies in native range of pest. The purpose of foreign exploration is to find, select, and obtain natural enemies from abroad which show promise as biological control agents. Ecological studies conducted on candidate natural enemies in their native range provide information that allows selection of the safest and most effective candidates, and facilitates their establishment and impact on the target pest in the U.S. Natural enemies will be collected and studied abroad in multiple locations throughout the native range of the respective pests. Live materials will be shipped to quarantine facilities listed under Objective 4 and will be shared among scientists/institutions as discussed under Objective 5. The overseas activities will be conducted by a) U.S.-based federal and state scientists from this project; b) other federal and state scientists based at domestic and foreign laboratories; c) scientists participating in USDA programs for exchange of science and technology with countries such as Japan, China, and Russia; and d) scientists operating under contracts with overseas institutions such as BBCA (Italy), and CABI Biosciences (Switzerland). The network of foreign cooperators that project scientists collaborate with is extensive, and provides critical support in foreign exploration efforts.
Objective 3: Determine systematics and biogeography of pests and natural enemies. Correct identification of a target pest and associated natural enemies provides a link with the work carried out in the past and represents a key to obtaining information in the scientific literature on biogeography, ethology, and ecology of a species. Many target pests and natural enemies belong to taxonomic groups for which the evolutionary relationships are poorly understood, and some groups are only now being modernized. Detailed systematic studies of target pests and natural enemies will involve modern systematic approaches including molecular, biosystematic, morphometric, and numerical taxonomic techniques. Initial analysis of the biogeography of target host and natural enemy species will be based on results of geographical surveys and information in the scientific literature. More detailed analyses will be based on crossing studies, and molecular genetic analyses. It is noteworthy that this regional project contains scientists with systematic and molecular genetic expertise in many of the natural enemy groups critical to biological control. Expertise essential for natural enemy studies planned for the next five years is represented in the following participating agencies: CA-AES (Phytoseiidae, Coccinellidae, Encyrtidae, Braconidae, Aphidiidae, Pteromalidae); ID-AES (Chrysopidae, Hemerobiidae, Coccinellidae); HI-AES (Encyrtidae, Eucoilidae); NY-CUAES (Chrysopidae, Hemerobiidae); and WA-AES (Chamaemyiidae, Syrphidae). Additional assistance is available through an extensive network of collaborators for taxonomic determinations among the Agricultural Experiment Stations, USDA, and other institutions (e.g., Bishop Museum, Honolulu; USNM; British Museum).
Objective 4: Determine environmental safety of exotic candidates prior to release. The environmental safety of classical biological control has been called into question by conservation biologists and others concerned about the direct and indirect nontarget impacts of exotic natural enemies. This has resulted in a need for more in-depth study of the environmental safety of candidate agents. Much of this additional work will be done in U.S. quarantine facilities (as well as overseas, see Objective 2). Traditionally, work in U.S. quarantines has focused on the exclusion of undesirable pathogens, parasitoids, hyperparasitoids, and predators from natural enemy shipments. Also, much host specificity testing of weed agents has been conducted in U.S. quarantines. With enhanced emphasis on assessing the environmental safety of candidate agents prior to release, U.S. quarantines will become an increasingly important resource and of vital importance to serving many of this projects objectives. Exotic biological control agents will be received, processed, and studied in quarantine facilities at CA-B-AES (Albany), CA-R-AES, HI-SDOA, WA-AES, and WA-ARS for the management of arthropod pests. Biological control agents of weeds will be handled through quarantine facilities at CA-ARS, MT-AES, WA-AES, and HI-FS. A few projects will utilize quarantine facilities in other regions (TX-AES, DE-ARS, VA-SDA, FL-AES). Quarantine and enhanced pre-release studies of environmental safety will be conducted for exotic natural enemies attacking pests in 11 target pest groups by 12 participating agencies
Objective 5: Release, establish, and redistribute natural enemies. Key steps in the implementation of classical biological control are the initial release, establishment and redistribution of approved natural enemies. The initial numbers of natural enemies available for field release or redistribution are often limiting, requiring laboratory or field propagation. Facilities for mass production exist at CA-ARS, CA-DFA, MT-AES, MT-ARS, WA-AES, and WA-ARS. Many weed biological programs initiate field insectaries that ultimately produce large numbers of individuals for redistribution. However, even with sufficient numbers for release, establishment does not always occur. Consequently, studies are being conducted by project members that examine various factors that might influence colonization. A noteworthy feature of this regional project is the high degree of natural enemy sharing among participants for initial release in new habitats and for redistribution.
Objective 6: Evaluate natural enemy efficacy and study ecological/physiological basis for interactions. The establishment of a natural enemy species does not always result in effective control of the target pest, as many ecological and environmental factors may influence the degree of control achieved. Hence, ecological studies must accompany the release of biocontrol agents to evaluate natural enemy impact, improve efficacy, and determine the ecological/physiological basis for natural enemy-host interactions. Experimental techniques used to quantify natural enemy efficacy include natural enemy inclusion, exclusion and interference. These consist of adding, excluding or interfering with natural enemies in experimental settings and comparing these to unmanipulated controls. Standard techniques will be used to study the influence of environmental variables (e.g., temperature and humidity) on life-history characteristics of the natural enemies and on predator-prey and parasite-host interactions. A key aspect of this regional project is that valuable comparative data from the wide range of habitats found in the Western Region is often obtained through collaboration among participants.
Goal B: Conserve Natural Enemies to Increase Biological Control of Target Pests.
Objective 7: Characterize and identify pest and natural enemy communities and their interactions. Two critical first steps in the conservation of natural enemies are determination of the identity of the species involved and characterization of the ecological communities in which they reside. This information is fundamental to developing an understanding of how perturbations such as pesticide applications will influence pest and natural enemy densities. Much of the methodology needed to address this objective is the same as for Objective 1.
Objective 8: Identify and assess factors potentially disruptive to biological control. Conservation biological control involves the alteration or modification of the environment to favor natural enemies, either by reducing adverse factors or by providing missing requisites. Thus, specific factors that impede or reduce the efficacy of biological control agents must be identified and quantified as to their impact. For many of the target pest species, this involves the identification of agricultural practices (mainly broad spectrum pesticide applications) that impact biological control agents, including the impact of herbicides on weed biological control agents. Many studies have focused on laboratory surveys and bioassays of various pesticides and subsequent large-scale field tests involving these "softer" compounds. Other factors, such as climatic extremes, indigenous natural enemies, cultural management practices, etc., can also be disruptive to the natural enemies.
Objective 9: Implement and evaluate habitat modification, horticultural practices, and pest suppression tactics to conserve natural enemy activity. As mentioned above, the conservation approach to biological control seeks to enhance the effectiveness of natural enemies, but may also target the pest as well. Examples of the conservation approach include maintaining weedy borders around fields or intercropping with nectar/pollen producing species to increase longevity and reproduction in the natural enemies; providing nesting boxes or shelters to improve reproduction or create refugia from environmental extremes; and using various agronomic approaches to increase the effectiveness of the natural enemies and/or hinder the target pest (e.g., plant spacing, cover crops, polycultures, strip crops, strip-cutting, crop rotation, trap crops, early/late planting and harvesting, etc.). These approaches may help conserve natural enemies while still controlling the target pest. The utilization of selective pesticides (especially microbials), including their selective use (e.g., reduced dosages and frequency of application, and selective timing of pesticide application) may help conserve natural enemies while still controlling the target pest. Research studies will focus on the implementation of these approaches and especially field-scale evaluation of the impact on host/prey diversity, natural enemy activity, and pest suppression.
Goal C: Augment Natural Enemies to Increase Biological Control Efficacy.
Objective 10: Assess biological characteristics of natural enemies. Natural enemy species and biotypes may show differences with regard to their biological characteristics (e.g., developmental thresholds and rates, fecundity, behavior, host specificity, cold tolerance, etc.) and these differences may influence their effectiveness as biological control agents. Research will be conducted to develop criteria for selecting biotypes, species, and combinations of beneficial species for use against a given pest to ensure that the most suitable natural enemy species are selected for each specific augmentative release program..
Objective 11: Develop procedures for rearing, storing, quality control and release of natural enemies, and conduct experimental releases to assess feasibility. The success of mass-rearing programs for experimental and commercial augmentation is highly dependent on the procedures used for rearing, storing, distribution, and release of natural enemies. Large-scale rearing of arthropod natural enemies usually requires the production of host plants, the arthropod host, and the natural enemy. Changes in colonies can occur due to genetic or environmental influences that can reduce the effectiveness of the natural enemy after release. Prior to release, it is desirable to increase the shelf-life of natural enemies for subsequent delivery and distribution. During storage, aspects of natural enemy quality such as viability and fecundity may be significantly reduced resulting in decreased efficacy of the biological control agent. Determination of the best natural enemy stage(s) for release and effective release methods are prerequisite for the timely suppression of the target pest. Research will be conducted to develop rearing and storage techniques for a variety of natural enemies for both inundative and inoculative release programs. Work will also focus on genetic improvement of natural enemies and assessing their value for pest suppression in various agricultural systems. Further, an understanding of the relationship between the numbers of natural enemies released, the resulting impact on the pest population, and the level of protection provided to the commodity is required. The development of management and economic models based on an understanding of such population processes will aid in characterizing the benefits of augmentation. Research will involve characterizing the interactions between the host, the natural enemies used in augmentation, and their biotic and abiotic environment, and will also include the development of optimal release strategies (i.e., timing of release, optimal numbers for release, rates of release, etc.).
Objective 12: Implement augmentation programs and evaluate efficacy of natural enemies. The successful suppression of pest populations through augmentative releases of natural enemies is often dependent on a clear understanding of appropriate times and numbers for natural enemy release, and mitigating problems associated with pesticide disruption or cultural management approaches that might be harmful to the natural enemies involved in the augmentation. Augmentation programs must be evaluated to determine the impact of the natural enemies on the target pest using different release strategies, or under varying environmental conditions. The economic feasibility of such programs also needs to be determined. Augmentative releases will be compared in small and large field trials with conventional control methods (e.g., pesticide applications) and untreated controls to assess natural enemy efficacy and the economic feasibility of such releases. Natural enemy exclusion or inclusion approaches may be needed to ensure that observed impacts are due to the inoculative or inundative releases, and not to indigenous natural enemies responding to more suitable conditions following the modification of agricultural practices (e.g., limited pesticide applications).
Goal D. Evaluate environmental and economic impacts and raise public awareness of biological control.
Objective 13: Evaluate the environmental and economic impacts of biological control agents. Although we as a community of scientists are well aware of the benefits of a successful biological control program, economic and environmental impacts are often not thoroughly evaluated. With community concern about potential negative impacts of biological control, it is more important than ever that both positive and negative environmental impacts be documented. Research will be conducted to determine patterns of non-target host utilization by natural enemies of weeds and arthropod pests, and the population-level consequences of non-target attack. Research will also be initiated to evaluate the genetic potential for specialized natural enemies to expand their host ranges. The evaluation of a natural enemy's potential for host range expansion will be accomplished by surveying closely related taxa or species that share the same or similar ecological niches to the target species. Field plots will be established in areas where the natural enemies are active or have been released, and the non-target hosts will be sampled periodically based on the life cycles of the organisms involved. If transfers are detected, the impact of the agents on the non-target host will be measured by determining the frequency, geographical, and taxonomic extent of attacks. The loss of growth and viable seed production (plants), rates of mortality, or changes in abundance of non-target host populations will be determined using replicated check and treatment plots coupled with exclusion or other appropriate techniques. Further, the economic return on research dollars spent on biological control is well known to scientists but not widely appreciated by the public. Declining resources and state/federal initiatives towards more accountability make it imperative that benefit/cost ratios of biological control be determined. Such information will help encourage the greater adoption of biological control in pest control programs, and will foster increasing interest and support for biological control at the state and federal levels. Our charge in this objective is to carefully document benefit/cost ratios of biological control programs for both insect and weed pests. The costs of obtaining, processing, propagating, releasing, and evaluating introduced biological control agents will be obtained from the respective project records. Using treatment thresholds, the cost of chemical treatment or other control tactics will be determined by querying pest control operators, growers, or by determining the cost of materials, labor, and operation of the application equipment. Using the production values associated with the current land use, the economic and environmental benefits of biological control will be determined. The economic value of conservation and/or augmentation of natural enemies will be assessed along with the long- term costs of using the natural enemies. These costs will be compared with the economic inputs of alternative conventional control methods, or total absence of controls.
Objective 14: Develop and implement outreach activities for biological control programs. This new objective seeks to encourage greater development of outreach programs among our participants as well as to document current outreach efforts that have not been easy to report under our current set of objectives. Well-documented, and highly visible outreach activities include 1) publication of our research findings in international journals, and 2) an outreach website which debuted in 2004. This W-1185 web site has general information about biological control, a list of the contributing members to W-1185, their contact information and individual reports, project annual reports, and links to upcoming events, jobs and funding, and other relevant information. This web site will continue to serve as a public face to the W-1185 group. Less well-documented in the past have been talks to constituent groups such as grower groups, ranchers, forest managers, and Master Gardener groups, as well as the development of educational materials about biological control programs for the public. We expect that the record of this activity will improve dramatically with this new mechanism for recording outreach.
Measurement of Progress and Results:
- The results of the proposed research activities will consist of: new or improved natural enemy species or biotypes for biological control of major arthropod and weed pests in the western U.S.;
- improved methods for incorporating biological control into IPM programs for key agricultural resources in the western U.S.
- data addressing the ecological basis of success and failure of biological control;
- and data addressing the environmental and economic impacts of biological control.
- The publications, presentations and website will continue to provide the state and federal agencies, and grower industry clientele with both technical and practical information on a timely basis.
Outcomes or projected Impacts:
- The availability of new or improved biological control options for major pest species in the western U.S. will result in reduced pesticide usage, increased sustainability of agricultural production systems, and economic benefits to both agricultural producers (in the form of reduced pest management costs) and consumers (in the form of reduced food costs).
- The attendant benefits of reducing pesticide usage include reduced food, soil and water contamination, reduced impacts on nontarget species including wildlife, and reduced human exposure to potentially harmful chemicals.
- Enhanced knowledge of the ecological mechanisms underlying biological control will increase success rates.
- Enhanced knowledge of the environmental and economic impacts of biological control will improve the environmental safety of biological control and foster its adoption in current and new pest management programs.
(2012): The sequence of objectives for Goals A, B and C define a typical progression for classical, augmentative and conservation biological control programs, respectively. The numerous, specific biological control programs that comprise this proposal are at different points along these progressions. For the most part, initiation of Objectives 13 and 14 (Goal D) will require completion of Goals A, B and C.
Projected Participation:Include a completed Appendix E form
Outreach Plan:Traditional outlets for disseminating project results, including peer-reviewed articles, annual progress reports, presentations at scientific meetings, websites created for specific projects, and extension publications and presentations, will continue to be heavily utilized. The publishing effort of this group is both prolific, and of very high quality. In the last five years, our group has published in excess of 580 publications [Appendix B]. A measure of multidisciplinary research, 57% of peer-reviewed publications in the past 5 years have been in non-arthropod pest management journals. This effort will clearly continue. Our members do not list submitted and invited talks that do not include a paper, however, these would number in the upper hundreds over the past 5 years. The annual meeting of W-1185 members and collaborators is well attended and includes presentations on timely projects. Of the 55 attendees to the 2006 meeting, 17 Land Grant Experiment Stations were represented, and 7 different state or federal institutions participated. The meeting also includes presentations by selected members on relevant topics, and these are added to the website as downloadable Powerpoint® presentations. Another goal for improving the website is to add impact/informational reports for the general public on high profile pests. While several participants have extension appointments, most of the others also participate in extension and other outreach activities. A unique feature of biological control research is that many of the research activities are conducted in close cooperation with end users. This is especially true in classical biological control where large or multiple areas infested by the target pest are required when introducing new agents. Researchers work with public and private land managers to access these lands. For example, researchers in the saltcedar biocontrol program are cooperating with private, local (county weed departments), state (game and fish departments, water commissions) and federal agencies (USDI-NPS, BLM, BOR, FWS, USDA-NFS). Researchers working on conservation and augmentative biological control also work hand-in-hand with producers and other beneficiaries. The addition of a project objective (Obj. 14) for outreach will help document both the formal development of outreach programs and the informal efforts of many participants to include constituent groups in their programs.
Organization and Governance:The Technical Committee will be comprised of representatives designated by the directors of various participating state agricultural experiment stations, state departments of agriculture, and federal agencies. This project is considered a Western Regional Research Project administratively, but because this regional project embraces research topics and biological control tactics of national scope and interest, participation by scientists from other regions of the United States is encouraged. The administrative advisor will be selected by the Western Association of Agricultural Experiment Station Directors and will serve the committee without vote. The Technical Committee officers will consist of a Chair, Secretary, and Representative at Large elected from the regional project membership. These elected officials, plus the administrative advisor, comprise the Executive Committee. The Chair will prepare technical and executive meeting agenda, preside at meetings, and prepare an annual progress report on the research activities of the regional project. The Secretary will record the minutes of technical and executive committee meetings and perform other duties as necessary. The Representative at Large, who will be elected annually, will succeed the Secretary who will in turn succeed the Chair. Subcommittees, composed of Technical Committee members, may be appointed by the Chair to assist with project needs. The Technical Committee will meet annually, unless otherwise planned, at a place and on dates designated by majority vote of the Technical Committee members.
Literature Cited:DeBach, P. 1964. Biological control of insect pests and weeds, ed. P. DeBach. London: Chapman & Hall. 844 pp.
Coombs, E. M., Clark, J. K., Piper, G. L. and Cofrancesco, A. 2004. Biological control of invasive plants in the United States. Western Soc. Weed Sci. Oregon State Univ. Press, Corvallis. 467 pages.
Intergovernmental Panel on Climate Change. 2007. Climate Change 2007: the physical science basis (the Fourth Assessment Report (AR4). Summary at http://www.ipcc.ch
Kimberling, D. N. 2004. Lessons from history: predicting successes and risks of intentional introductions for arthropod biological control. Biological Invasions 6: 301-318.
Mason, P. G., Flanders, R. G. and Arrendondo-Bernal, H. A. 2005. How can legislation facilitate the use of biological control of arthropods in North America? Proceedings, 2nd International Symposium of Biological Control of Arthropods, Davos, Switzerland. Sept. 2005. U.S.D.A. Forest Service Publication FHTET-2005-08, vol. 1. pp. 701-714.
USDA-Economic Research Service. 2002. Recent growth patterns in the U.S. organic foods market. Agriculture Information Bulletin No. (AIB777) 42 pp.
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