U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Temperate Tree Fruit and Vegetable Research: Wapato, WA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Facilities
                        USDA Laboratory in Wapato, WA
                                    USDA Prosser Worksite
                                    USDA Moxee Farm
                    About UsSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Wapato, Washington Temperate Tree Fruit and Vegetable Research People







William  Walker    Research Geneticist (Insects) /ARSUserFiles/20920500/Walker/WWalker_Profile_Photo.png **Education:** BS, Michigan State University, Zoology and Genetics, 2001 Ph.D., Vanderbilt University, Neuroscience, 2008 **Research Interests:** The molecular biology, genetics, and genomics of insect pests of temperate tree fruit.  Primary focus is on the codling moth, *Cydia pomonella* and *Colladonus*leafhoppers that transmit the X-disease pathogen to cherry and other stone fruits. Topics include chemosensory and immune systems, insect vector and plant pathogen interactions, and biological control with entomopathogenic viruses. **Aims:** To improve our knowledge of the molecular genetics and genomics of tree fruit insect pests as it relates to their biology (physiology, biochemistry and behaviors) and ecological interactions.  To develop genetic resources, including sequenced genomes and transcriptomes, for insect pests where none previously existed. To apply these resources and knowledge towards the development of novel and sustainable genetics- or biomolecular-based/informed pest management strategies. **Background:** Tree fruit, including apple, cherry and pear are major orchard crop products in Central Washington and the Pacific North West. Pest insects of these fruit are a major economic concern. In the orchard environment, some insects cause direct damage by eating the fruit, while other insects spread microbial pathogens that cause disease in the fruits or their trees. During the past several decades, research on tree fruit pest insects has contributed to the development and implementation of sustainable management practices, but the problem persists. Further research is required to sustainably manage long established pests as well as recently invasive species. **Approach:** A genomics/transcriptomics approach in utilized to understand broadly the genetic makeup of target insects. Functional studies are carried out on specific candidate genes to understand their role in the physiology, behavior and ecological interactions of the insect. CRISPR gene editing is one molecular laboratory tool that is utilized specifically in codling moth that allows direct genetic studies. Knowledge gained from this approach is then used in the field, aimed at influencing or disrupting target genes to ultimately affect the physiology or behavior of the insect and control damage of the fruit orchard products. **Laboratory Personnel:** Jennifer Stout, Biological Science Technician (Molecular Genetics) Dan Hallauer, Biological Science Technician (codling moth virus) Janine Jewett, Biological Science Technician (codling moth diet kitchen) Katherine Easterling, Post Doc Associate     ProjectsIntegrated Approach to Manage the Pest Complex on Temperate Tree FruitsIn-House Appropriated (D)Accession Number:439454Genetic Insights into Leafhopper/Phytoplasma Interactions and Gene-Based Immunization for Plant Disease ControlReimbursable Cooperative Agreement (R)Accession Number:441249Genetic Insights into Leafhopper/Phytoplasma Interactions and Gene-based Immunization for Plant Disease ControlNon-Assistance Cooperative Agreement (S)Accession Number:441667USDA-ARS/Washington State University Little Cherry Disease Research PartnershipNon-Assistance Cooperative Agreement (S)Accession Number:442287Novel Control of Codling Moth with RNA InterferenceTrust Fund Cooperative Agreement (T)Accession Number:441748Genetic Engineering of Moth Viruses for Enhanced Insecticidal EfficacyTrust Fund Cooperative Agreement (T)Accession Number:440535
 ARS News ArticlesNo news articles listed for this employee.
 
 Publications(Clicking on the reprint iconReprint Icon  will take you to the publication reprint.)Chemosensory receptor expression in abdomen tip of female codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae)-(Peer Reviewed Journal) Walker Iii, W.B., Cattaneo, A.M., Stout, J.L., Evans, M.L., Garczynski, S.F. 2023. Chemosensory receptor expression in abdomen tip of female codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae). Insects. 14(12):948. https://doi.org/10.3390/insects14120948.Salivary protein expression profiles of five species of Pentatomidae (Hemiptera)-(Peer Reviewed Journal) Marshall, A.T., Cooper, W.R., Walker Iii, W.B., Wildung, M., Northfield, T.D., Krey, K.L., Beers, E.H. 2023. Salivary protein expression profiles of five species of Pentatomidae (Hemiptera). Annals of the Entomological Society of America. 116:358-371. https://doi.org/10.1093/aesa/saad020.Bacterial endosymbionts identified from leafhopper (Hemiptera: Cicadellidae) vectors of phytoplasmas-(Peer Reviewed Journal) Cooper, W.R., Walker III, W.B., Angelella, G.M., Swisher Grimm, K.D., Foutz, J.J., Harper, S.J., Nottingham, L.B., Northfield, T.D., Wohleb, C.H., Stausbaugh, C.A. 2023. Bacterial endosymbionts identified from leafhopper (Hemiptera: Cicadellidae) vectors of phytoplasmas. Environmental Entomology. 52(2):243-353. https://doi.org/10.1093/ee/nvad015.Heterologous expression and functional characterization of Drosophila suzukii OR69a transcript variants unveiled response to kairomones and to a candidate pheromone-(Peer Reviewed Journal) Cattaneo, A.M., Witzgall, P., Kwadha, C., Becher, P.G., Walker III, W.B. 2022. Heterologous expression and functional characterization of Drosophila suzukii OR69a transcript variants unveiled response to kairomones and to a candidate pheromone. Journal of Pest Science. 96:1149-1171. https://doi.org/10.1007/s10340-022-01585-2.Comparative transcriptomic assessment of the chemosensory receptor repertoire of Drosophila suzukii adult and larval olfactory organs-(Peer Reviewed Journal) Walker III, W.B., Mori, B.A., Cattaneo, A.M., Gonzalez, F., Witzgall, P., Becher, P. 2022. Comparative transcriptomic assessment of the chemosensory receptor repertoire of Drosophila suzukii adult and larval olfactory organs. Comparative Biochemistry and Physiology, Part D: Genomics and Proteomics. 45. Article 101049. https://doi.org/10.1016/j.cbd.2022.101049.Status of organic fruit industry in the USA-(Proceedings) Walker Iii, W.B. 2022. Status of organic fruit industry in the USA. Proceedings. Volume 2022:133-134.Good to know: integrated research.  Entomologists at the USDA laboratory in Wapato, Washington, work to advance IPM for orchards-(Trade Journal) Cooper, W.R., Horton, D.R., Neven, L.G., Serrano, J.M., Walker Iii, W.B., Yee, W.L., Schmidt-Jeffris, R.A. 2022. Good to know: integrated research.  Entomologists at the USDA laboratory in Wapato, Washington, work to advance IPM for orchards. Good Fruit Grower. March 1, 2022 Issue.Chemical Ecology of Host and Mate Selection-(Literature Review) Lebreton, S., Saveer, A.M., Fandino, R.A., Walker Iii, W.B. 2021. Chemical Ecology of Host and Mate Selection. Frontiers in Ecology and Evolution. https://doi.org/10.3389/fevo.2021.780540.Stage-specific expression of an odorant receptor underlies olfactory behavioral plasticity in Spodoptera littoralis larvae-(Peer Reviewed Journal) Revadi, S.V., Gianuzzi, V., Rossi, V., Hunger, G.M., Conchou, L., Rondoni, G., Conti, E., Anderson, P., Walker III, W.B., Jacquin-Joly, E., Koutroumpa, F., Becher, P.G. 2021. Stage-specific expression of an odorant receptor underlies olfactory behavioral plasticity in Spodoptera littoralis larvae. BMC Biology. 19. Article 231. https://doi.org/10.1186/s12915-021-01159-1.RNA interference mediated knockdown of IAP in Lygus lineolaris induces mortality in adult and pre-adult life stages-(Peer Reviewed Journal) Walker III, W.B., Allen, M.L. 2011. RNA interference mediated knockdown of IAP in Lygus lineolaris induces mortality in adult and pre-adult life stages. Entomologia Experimentalis et Applicata. 138:83-92.Gene knockdown through RNAi  in  Lygus lineolaris-(Abstract Only)Expressed Sequence Reference Standards for Evaluating Stage-specific Gene Expression in Southern Green Lacewings, Chrysoperla rufilabris-(Peer Reviewed Journal) Allen, M.L., Walker III, W.B. 2010. Expressed Sequence Reference Standards for Evaluating Stage-specific Gene Expression in Southern Green Lacewings, Chrysoperla rufilabris. Biocontrol Science and Technology.   20: 6, 589-593, doi:  10.1080/09853151003657969.Gene Expression Studies in Lygus lineolaris-(Abstract Only) Walker III, W. B., Allen, M. L.  2009.  Gene Expression Studies in Lygus lineolaris. Entomological Society of America Annual Meeting.Lygus lineolaris polygalacturonase 4 (PG4) mRNA, partial cds FJ823132-(Other)Lygus lineolaris inhibitor of apoptosis IAP RACEd sequence-(Other)Expression and RNA interference of salivary polygalacturonase genes in Lygus lineolaris (Miridae: Hemiptera)-(Peer Reviewed Journal) Walker III, W.B., Allen, M.L. 2010. Expression and RNA interference of salivary polygalacturonase genes in Lygus lineolaris (Miridae: Hemiptera). Journal of Insect Science. 173(10):1-13.
 /ARSUserFiles/55746/William Walker_Photo-Credit-Aram Langhans.jpg


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov