2006 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter? Wheat is second only to maize in the United States in terms of total area planted and production at approximately 72 million acres and 2.2 billion bushels annually. Sorghum and barley are less widely planted but are also important to United States agriculture. The greenbug, Schizaphis graminum, is a key pest of wheat, sorghum, and barley while the Russian wheat aphid, Diuraphis noxia, is a key pest of wheat and barley. Widespread outbreaks of these pests occur frequently and cause losses in excess of $250 million per year. With the occurrence of greenbug biotypes that attacked sorghum in the late 1960s and the invasion of the Russian wheat aphid in 1986, coupled with the recent discovery of new U. S. Russian wheat aphid biotypes in 2003, insecticide use in wheat, sorghum, and barley increased markedly. The low profit margins associated with production of these crops make the frequent insecticide use required to mitigate yield losses caused by cereal aphids economically unsustainable. Environmental contamination, development of insecticide-resistant pests, and human health concerns also make insecticides unappealing as a principal integrated pest management (IPM) tactic. The preventive IPM paradigm involves building pest suppressive forces into agricultural ecosystems to reduce reliance on chemical insecticides and, as a consequence, to reduce the cost of crop production and improve environmental quality and human health. Preventive IPM systems rely on a variety of biorational tactics including insect-resistant cultivars and biological control by natural enemies and are, by their nature, knowledge intensive. The success of preventive IPM depends on sufficient understanding of the biology, ecology, and genetics of pests and their natural enemies, their interactions with their host plants, and their role and function in the agroecosystem to achieve a systems approach to IPM. One focus of this project is on the acquisition of the knowledge needed for effective preventive IPM centered on resistant cultivars, biological control by natural enemies, and other non-chemical IPM tactics. A second focus is on developing tools for immediate application to improve IPM practices in wheat, sorghum, and barley. In order to maximize the impact of the project, the knowledge accumulated and tools developed must be delivered to end-users in a form they can readily use. The third focus of the project is to develop an IPM Knowledge Based System by integrating the knowledge and tools developed during the project with previously existing knowledge and tools. The research to be conducted is relevant to National Program 304, Crop Protection & Quarantine, but contributes to National Program 301, Plant Genetic Resources, Genomics & Genetic Improvement. Accomplishments under this project contribute to the achievement of ARS Strategic Plan Goal 3, Objective 2, Performance Measure 5, in that project accomplishments contribute substantially to attainment of the Agency target of developing specific information and technology for producers to utilize in controlling pest outbreaks as they occur. The objectives of the project are a direct application of these program components to wheat, sorghum, and barley cropping systems. The proposed research addresses aspects of the biology, ecology, genetics, and management of cereal aphids and their natural enemies that represent critical gaps to development of environmentally and economically sound IPM programs. Attaining the project objectives will result in knowledge and tools to increase the role of natural enemies, host plant resistance, and other economical and environmentally beneficial control tactics in preventive IPM programs for the greenbug, Russian wheat aphid, and other cereal aphids in wheat, sorghum, and barley. Incorporating new IPM knowledge and tools into computer-based decision support systems will ensure that research results are delivered to pest managers in a form they can use. 2.List by year the currently approved milestones (indicators of research progress) Year 1 (FY 2005) Objective 1. Begin acquisition of field data to develop a life system model for the greenbug from which a natural enemy threshold for coccinellids can be derived. Begin acquisition of SSTCRIS data from greenbug infested winter wheat fields. Begin KBS development, incorporating information into the KBS rule base. Develop a preliminary greenbug life system model and coccinellid threshold and include it in the KBS. Objective 2. Establish, characterize, and sample conservation buffer plots. Collect greenbugs from noncultivated grasses and crops and initiate biotype evaluations. Objective 3. Begin spatially nested sampling of Russian wheat aphid populations. Develop microsatellite markers for Russian wheat aphid. Begin experiments to determine variation within and between two Russian wheat aphid biotypes. Objective 4. Conduct studies on monitoring and characterizing Russian wheat aphid biotypes. Assist cereal breeders identifying resistance sources. Initiate studies on the seasonal dynamics of Russian wheat aphid biotype composition in the field. Initiate biological studies on the anholocycly and holocycly in Russian wheat aphid populations. Year 2 (FY 2006) Objective 1. Continue to acquire field data to develop the life system model. Continue to acquire SSTCRIS imagery of greenbug-infested fields. Continue KBS development. Objective 2. Continue to sample conservation buffer plots. Continue greenbug sampling and biotype evaluations. Objective 3. Continue spatially nested sampling of Russian wheat aphid populations. Begin assaying Russian wheat aphid populations for microsatellite polymorphisms. Complete experiments to determine variation within and between two Russian wheat aphid biotypes. Objective 4. Continue characterizing Russian wheat aphid biotypes, continue identification of Russian wheat aphid resistance in cereals, continue studies on the dynamics of Russian wheat aphid biotypes in the field, continue studies on holocycly and anholocycly in Russian wheat aphid populations. Add new biotypes to these studies if found. Year 3 (FY 2007) Objective 1. Complete acquisition of field data to develop a greenbug life system model and begin development the model. Complete acquisition of SSTCRIS imagery and begin development of a statistical model to extract the spatial pattern of altered reflectance in SSTCRIS imagery. Continue KBS development. Objective 2. Continue to sample conservation buffer plots. Complete greenbug biotype evaluations. Objective 3. Complete spatially nested sampling of Russian wheat aphid populations. Continue assaying Russian wheat aphid populations for microsatellite polymorphisms. Objective 4. Continue to characterize new Russian wheat aphid biotypes as they are found and the identification of resistance in cereals. Continue to characterize the biotype composition and seasonal dynamics in the field. Continue studies on holocycly and anholocycly in Russian wheat aphid populations. Year 4 (FY 2008) Objective 1. Finish development of the greenbug life system model, extract the coccinellid natural enemy threshold, and commence field studies to acquire validation data for the threshold. Complete development of the statistical model for identifying spatial pattern of greenbug infested fields and commence field validation studies. Interface the refined greenbug life system model with the KBS. Incorporate the coccinellid natural enemy threshold. Initiate an education program. Objective 2. Complete sampling of conservation buffer plots. Complete vegetative analysis of buffers. Complete biotypic evaluations and continue to identify insects and analyze data. Objective 3. Complete Russian wheat aphid population study, i.e. finish microsatellite and statistical analysis of data. Begin Russian wheat aphid genome study. Objective 4. Continue to characterize new Russian wheat aphid biotypes as they are found and the identification of resistance in cereals. Complete sampling of Russian wheat aphid biotype composition and seasonal dynamics in the field. Continue studies on holocycly and anholocycly in Russian wheat aphid populations. Year 5 (FY 2009) Objective 1. Finish field studies to acquire validation data, and iteratively test and refine the coccinellid threshold. Finish field validation studies and iteratively test and refine the statistical model to identify spatial signatures for greenbug infested fields. Modify the greenbug life system model and coccinellid threshold as necessary based on validation results and incorporate in the KBS. Incorporate the coccinellid natural enemy threshold. Continue the education program. Objective 2. Finish insect identification and data analysis from conservation buffer field study. Objective 3. Complete Russian wheat aphid genome study. Objective 4. Finish the analysis of Russian wheat aphid biotype composition and seasonal dynamics in the field. Finish the analysis of holocycly and anholocycly in Russian wheat aphid populations. Characterization of new Russian wheat aphid biotypes and assisting cereal breeders in identifying new sources of resistance in cereals will be an ongoing process. 4a.List the single most significant research accomplishment during FY 2006. New Russian wheat aphid biotype genetically characterized. The Russian wheat aphid has been a major economic pest of small grains in the western United States since its introduction in 1986. During FY 2006, scientists at the USDA-ARS Wheat, Peant and Other Field Crops Research Unit, Stillwater, Oklahoma, conducted pioneering genetic studies characterizing Russian wheat aphid biotypes and determined that the two predominant Russian wheat aphid biotypes, designated RWA1 and RWA2, are homogeneous and cannot be separated by any molecular markers. They appear to be a single, out-breeding population with gene flow between biotypes; however, clonal diversity was detected by micro-satellite DNA fingerprints within biotypes, therefore each biotype does not represent the asexual proliferation of a single aphid. Because no evidence of a second introduction was found, it appears that the origin of RWA2 is from within the extant population that emigrated from Central America into Texas. (NP 304, Component II) 4b.List other significant research accomplishment(s), if any. Two new Russian wheat aphid biotypes discovered. A collaborative effort between USDA-ARS Wheat, Peanut and Other Field Crops Research Unit, Stillwater, OK, and Colorado State University was undertaken to evaluate the five designated and two putative Russian wheat aphid biotypes on extant and potential sources of resistance in wheat, barley, and triticale. During FY 2006, 25 plant entries were screened using the Russian wheat aphid biotypes to determine their resistance status to each biotype. From this study it was determined that there are now seven unique biotypes of the Russian wheat aphid. Additionally, we have now identified wheat and triticale entries that are resistant to all 7 biotypes. (NP 304, Component II, III, and V) Accuracy for pest-treatment decisions improved. There exists a need to develop effective decision support tools to help growers manage key pests of wheat, such as the greenbug. At the USDA-ARS Wheat, Peanut, and Other Field Crops Research Unit, Stillwater, OK, in conjunction with collaborators from Oklahoma State University, we continued research to develop a predictive model for the predatory impact of coccinellidae on the greenbug. During FY 2006, we conducted field and laboratory studies to quantify the spatially explicit population dynamics of cereal aphids in relation to predation by coccinellidae and initiated development of a preliminary model. The research has potential to improve pest management practices for the greenbug in wheat because treatment decisions will be more accurate and based on knowledge of potential for biological control. (NP 304, Component III, V, and VI) Remote sensing technology economically and environmentally improves pest management. There exists a need for improved methods for monitoring greenbug infestations in wheat fields for purposes of making control decisions. At the USDA-ARS Wheat, Peanut, and Other Field Crops Research Unit, Stillwater, OK, in conjunction with collaborators from the Texas Agricultural Experiment Station and SST Development Group Inc., we are developing remote sensing technology to detect and monitor greenbug infestations in winter wheat. During FY 2006, we documented that multi-spectral remote sensing differentiated stressed areas in production winter wheat fields caused by greenbug infestation from non-stressed areas. Remote sensing technology has the potential to markedly improve pest management practices for the greenbug in winter wheat because infestations in fields will be efficiently detected and delineated at an early stage, which could result in more economically and environmentally sound management. (NP 304, Component V and VI) 4c.List significant activities that support special target populations. None. 5.Describe the major accomplishments to date and their predicted or actual impact. Discovered and described three new Russian wheat aphid biotypes and quickly disseminated this information to plant breeding programs so they could immediately incorporate the new biotypes into their screening and evaluation process. This research has helped to ensure the future success of plant resistance as an important management tool for Russian wheat aphids. Developed species-specific DNA markers to detect and identify hyperparasitoids in primary parasitoids developing in aphids. This pioneering research provides a valuable tool for studying the tritrophic relationships, ecology, and impact of parasitic Hymenoptera that attack aphids. Developed improved barley screening protocols that take into account all newfound Russian wheat aphid biotypes, and identified STARS 9301B as the primary resistant control. This research has alerted breeding programs to the need of screening for new biotypes and provided new protocols for identifying resistance. Developed improved economically sound and environmentally responsible decision support tools to help growers manage key pests of wheat such as the greenbug. This decision support system will greatly improve pest management practices in small grains. Determined that greenbug infestations can be monitored by multi-spectral and hyper-spectral radiometry. This remote sensing technology has the potential to substantially improve greenbug control measures because growers will be able to detect infestations at a much early stage of development. Discovered new Russian wheat aphid biotypes that damage all currently deployed resistant wheat. This information has been disseminated to plant resistance breeding programs so they can incorporate these new biotypes into their screening and evaluation process. Evaluated the response of previously identified Russian wheat aphid resistant barleys to five newly designated Russian wheat aphid biotypes and found STARS 9301B to be resistant to all, and is recommended for use as a primary resistance source for breeding programs. The methods developed for biotypic evaluations will provide a standardized means for plant breeders to assess biotypic variation. All accomplishments made under this project are fully consistent with relevant milestones listed in the Project Plan, and with the relevant research components as defined in the National Program 304 and 301 Action Plans. Accomplishments under this project contribute to the achievement of ARS Strategic Plan Goal 3, Objective 2, Performance Measure 5, in that project accomplishments contribute substantially to attainment of the Agency FY 2007 target of developing specific information and technology for producers to utilize in controlling pest outbreaks as they occur. 6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products? An improved version of a web-based greenbug management decision support system was made available in the public domain for use by wheat growers and others involved in pest management in wheat. The system was also made available in compact disk format as the result of an identified need to provide the system to users who do not have access to the internet or who have slow internet connection, which is a substantial fraction of potential users. The decision support system is available for use now. The primary constraint to adoption is educating end-users on how to use the system and its advantages over current pest management decision-making approaches. We are currently engaged in educational activities. 7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below). Burd, J.D. 2006. Population ecology of greenbugs and Russian wheat aphids in the Great Plains. 17th Biennial International Plant Resistance to Insects Workshop, West Lafayette, Indiana. Burd, J.D., Merchant, M.L. 2005. The 60-year war against greenbug. Entomological Society of America, Ft. Lauderdale, Florida. Burd, J.D., Porter, D.R. 2006. Biotypic diversity of greenbugs. 17th Biennial International Plant Resistance to Insects Workshop, West Lafayette, Indiana. Burd, J.D., Porter, D.R., Puterka, G.J., Haley, S.D., Peairs, F.B. 2006. New found biotypic variation among North American Russian wheat aphid populations. 7th Biennial International Plant Resistance to Insects Workshop, West Lafayette, Indiana. Payton, T.L., Shufran, K.A., Puterka, G.J. 2005. Genetic variation of Russian wheat aphid (Homoptera: aphididae) biotypes found in the US. Entomological Society of America, Ft. Lauderdale, Florida. Puterka, G.J., Mornhinweg, D., Burd, J.D. 2006. The response of RWA1 resistant and susceptible barley to five RWA biotypes. 17th Biennial International Plant Resistance to Insects Workshop, West Lafayette, Indiana. Shufran, K.A., Puterka, G.J., Burd, J.D., Chen, Y., Payton, T.L. 2005. Genetic relatedness of world populations of Russian wheat aphid. Entomological Society of America, Ft. Lauderdale, Florida. Elliott, N.C. 2006. Getting a grip on greenbugs. Agricultural Research, Science Update, September 2006. p. 23. Review Publications Shufran, K.A., Rangaswamy, V., Burd, J.D., Porter, D.R. 2005. Single strand conformation polymorphism analysis discriminates greenbug (Homoptera: Aphididae) mtDNA haplotypes. Journal of Agricultural and Urban Entomology. 22(1):49-54. Chen, Y., Pike, K.S., Greenstone, M.H., Shufran, K.A. 2006. Molecular markers for identification of the hyperparasitoids Dendrocerus carpenteri and Alloxysta xanthopsis in Lysiphlebus testaceipes parasitizing cereal aphids. Biocontrol. 51(2):183-194. Giles, K.L., Dillwith, J.W., Berberet, R.C., Elliott, N.C. 2005. Survival, development, and growth of Coccinella septempunctata fed Schizaphis graminum from resistant and susceptible winter wheat. Southwestern Entomologist 30(2):113-120. Elliott, N.C., Tao, F.L., Giles, K.L., Royer, T.A., Greenstone, M.H., Shufran, K.A. 2006. First quantitative study of rove beetles in Oklahoma winter wheat fields. Biocontrol. 51:79-87. Elliott, N.C., Tao, F.L., Giles, K.L., Kindler, D., French, B.W., Greenstone, M.H., Shufran, K.A. 2006. Ground beetle density in Oklahoma winter wheat fields. Southwestern Entomologist. 31(2):121-128. Burd, J.D., Porter, D.R. 2006. Biotypic diversity in greenbug (Hemiptera: Aphididae): characterizing new virulence and host associations. Journal of Economic Entomology. 99(3):959-965.