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Associate Professor, Extension Entomologist
Department of Horticulture
Oregon Wine Research Institute
4017 Ag and Life Sciences BldgCorvallis, OR 97331-7304
- Mating disruption
- Entomopathogenic/Biorational pest control agent
- Biological control
- Herbivore-induced plant volatiles
- Perennial food crops
My work at OSU work focuses to resolve key entomological industry needs in the Pacific Northwest with current focus on Spotted Wing Drosophila, Brown Mamorated Stink Bug, mealybugs and sustainable pest managment in hazelnut orchards. Previously I studied mites in Oregon vineyards .
The aim of my work is to provide environmentally sustainable and minimal impact pest management strategies for agriculturalists in Oregon and further afield. This is done with knowledge obtained from detailed insect physiological, biological, behavioral, ecological and environmental studies. I have a strong focus to develop monitoring tools and determine economic and action thresholds. This knowledge is then used to apply treatments timed to occur during periods when pests are at their most vulnerable. I have knowledge and experience using alternative pest control methods including various modes of biological control, mating disruption and conventional synthetic pesticides. It is believed that use of a combination of these pest management strategies will minimize environmental impact and optimize sustainable agriculture.
In the past, my work focused on the development of an Integrated Control Program of Vine Mealybug, a cosmopolitan and invasive pest more recently along the grape-growing areas along the west coast of the USA. The invasive characteristics of VMB and pending future colonization into new areas in this region may require focus in my current position at Oregon State University.
Ph.D., Entomology, University of Stellenbosch, South Africa, 2003
M.Sc., Integrated Pest Management, University of Stellenbosch, 1998
H.E.D., (Higher Education Diploma), University of Stellenbosch, 1993
B.Sc., Botany and Zoology, University of Stellenbosch, 1992
2012-Present: Associate Professor, Department of Horticulture, Oregon State University, Corvallis, Oregon
2006-2012: Assistant Professor, Department of Horticulture, Oregon State University, Corvallis, Oregon
2003-2005: Postdoctoral Researcher, Department of Environmental Science, Policy, and Management, University of California, Berkeley, California
2003-2005: Research Associate, Department of Conservation Ecology & Entomology, University of Stellenbosch
1999-2003: Research and Extension Entomologist, Agricultural Research Council (ARC)
1997-1998: Senior Research Technician, Agricultural Research Council (ARC)
1996: Research Technician, Agricultural Research Council (ARC)
1995-1996: Secondary School Teacher, Buren High School, Cape Town
1994: Secondary School Teacher, Calitzdorp High School
I accept graduate students for Horticulture
Outreach and Extension
Selected Extension Journal and Outreach Publications
Walton, V.M., 2007. Seasonal Vine Mealybug phenology in different grape-growing areas in the Western Cape, http://www.wynboer.co.za/recentarticles/200706mealy.php3
Walton V. M., Olsen, J., Lambrinos, J, Bruck D, 2007. Identifying new Invasive and Re-emerging pests on Hazelnuts in the Pacific Northwest. http://oregonstate.edu/dept/hort/faculty/Walton-NewAndReemergingPestsOnHazelnutsInThePNW.
Reitmajer, M., Walton V.M., Skinkis, P., and Chambers U., Seasonal Phenology and Symptoms of Rust mite infestations in Oregon vineyards, Pacific Entomology Branch Meeting, Portland Oregon
Walton V. M., James, D., Pscheid, J., William, R, Sandrock, J., 2007. Short Shoot Syndrome of Grapes in the Pacific Northwest. Practical Winery and Vineyard Magazine (Submitted).
Walton V.M., Pscheid, J., William, R, Sandrock, J., 2006. Short Shoot of Grapes. http://oregonstate.edu/dept/hort/faculty/Walton-ShortShootVersion6.pdf
Walton, V.M., Rosetta, R., DeFrancesco,, J., Yang, W. Q., Strik, B. 2006. Scale Insects on Blueberries, what you should know, http://oregonstate.edu/Dept/nurspest/Azalea_Bark_Scale.pdf
Daane K. M., Walton, V. M., Bentley W.J., Millar, J., G., Cooper, M.L., Biscay P. J. & Yokota G. Y. 2006. Developing a Pheromone Based Mating Disruption Program for the Vine Mealybug. UC Plant Protection Quarterly, Vol. 16, No.1.
Walton, V.M., 2004. Degree day estimation as a warning tool for vine mealybug infestation in vineyards. Wynboer, Technical guide for wine producers December 2004.
Walton, V.M., 2004. Protocol for control of mealybug in Vineyards (Production blocks). Wynboer, Technical guide for wine producers September 2004.
Walton, V.M., 2003. Research Strategies for olive pests in South Africa. In: ARC guide for olive production (Olive producers' booklet).
Walton, V.M., 2003. Degree Day Estimation, a new warning tool for vine mealybug infestation in vineyards, Wynboer, Technical guide for wine producers September 2003.
Daane, K.M., Bentley, W.J., Macmillan, C., and Walton, V.M., 2003. New control programs for the vine mealybug. Wine Business Monthly 10(8), 24-28.
Walton, V.M., Pringle, K.L., & Daane, K.M., 2003. Integrating vine mealybug (Planococcus ficus) control with the use of pheromone trapping in South African vineyards. Wynboer: A Technical Guide for Wine Producers 8, 22-27.
Walton, V.M., 2002. Mealybug on grapevines. Pamphlet for DFPT.
Walton, V.M. & Addison, P., 2002. Protocol: Control of mealybugs and ants. Poster pamphlet for Winetech, the South African Wine Industry Technical Organization.
Miller B., Bruck D. J., Walton, V. M., 2012. Relationship of Black Vine Weevil Egg Density and Damage to Two Cranberry Cultivars. HortSci 47(5): 1–7.
Gadino A. N, Walton V. M., 2012. Temperature-related development and population parameters for Typhlodromus pyri (Acari: Phytoseiidae) found in Oregon vineyards. Exp Appl Acarol DOI 10.1007/s10493-012-9562-9.
Chambers U., Walton V.M. and S. A. Mehlenbacher 2011. Susceptibility of Hazelnut Cultivars to Filbertworm, Cydia latiferreana. HortSci 46: 1377-1380.
Gadino A. N., Walton V. M. and J. Lee. 2011. Olfactory response of the predatory mite Typhlodromus pyri (Acari: Phytoseiidae) to methyl salicylate in laboratory bioassays. J Appl Entomol DOI 10.1111/j.1439-0418.2011.01670.x
Daane K. M., Middleton, M. C., Sforza, R., Cooper, M. L., Walton, V. M., Walsh, D. B., Zaveio, T., and R.P.P. Almeida. 2011. Development of a multiplex to distinguish mealybug species found in North American vineyards. Environ Entomol. DOI: http://dx.doi.org/10.1603/EN11075.
Dalton D.T., Walton V.M., Shearer, P.W., Walsh, D.B., Caprile J. and R. Isaacs. 2011. Laboratory survival of Drosophila suzukii under simulated winter conditions of the Pacific Northwest and seasonal field trapping in five primary regions of small and stone fruit production in the United States. Pest Manag Sci 67(11): 1368-1374.
Gadino A. N., Walton V. M. and A.J. Dreves. 2011. Laboratory bioassays to determine impact of six pesticides on the beneficial arthropod, Typhlodromus pyri (Scheuten) (Acari: Phytoseiidae). Econom Entomol 104(3): 970-977.
Walsh D.B., M.P. Bolda, R. E. Goodhue, A. J. Dreves, J. Lee, D. J. Bruck, V. M. Walton, S. D. O’Neal and F. G. Zalom. 2011. Drosophila suzukii (Diptera: Drosophilidae): Invasive Pest of Ripening Soft Fruit Expanding Its Geographic Range and Damage Potential. J Integ Pest Mngmt 2(1): 1-7.
Walton V. M., Dreves A. J., Coop L., Jones G. and Skinkis P. 2010. Degree-Day model for Calepitrimerus vitis (Nalepa 1905) (Acari: Eriophyidae) and susceptibility feeding damage in Wine Producing areas of Western Oregon. Environ Entomol 39(6): 2006-2016.
Chambers U., Bruck D., Olsen, J., and V. M. Walton. 2010. Behavior of Over-wintering Filbertworm (Cydia latiferreana) (Lepidoptera: Tortricidae) Larvae and Their Control with Steinernema carpocapsae. Econom Entomol 103(2): 416-422.
Walton V.M., Krüger K., Saccaggi D.L., Millar I.M. 2009. A survey of scale insects (Sternorryncha: Coccoidea) occurring on table grapes in South Africa. J Insect Sci 9: 47.
Wang X. G., Nadel, H., Johnson, M. W., Daane, K. M., Hoelmer, K., Walton, V. M., Pickett, C. H., and Sime, K. R. 2009. Crop domestication relaxes both top-down and bottom-up effects on a specialist herbivore. Basic Appl Ecol 10(3): 216-227.
Gent D.H., D.G. James, L.C. Wright, J.D. Barbour, A.J. Dreves, G.C. Fisher, and V.M. Walton 2009. Effects of powdery mildew fungicide programs on twospotted spider mite (Acari: Tetranychidae), hop aphid (Homoptera: Aphididae), and their natural enemies in hop yards. J Econ Entomol 102(1): 274-286.
Daane K.M., Sime K. R., Wang, X., Nadel, H., Johnson M.W., Walton, V.M., Kirk A. and C.H. Pickett. 2008. Psyttalia lounsburyi (Hymenoptera: Braconidae), promising biological control agent for the olive fruit fly in California. Biol Contr 44:79-89.
Gutierrez A. P., Daane, K. M., Ponti, L., Walton, V. M. and C. K. Ellis. 2008. Prospective evaluation of the biological control of vine mealybug: refuge effects and climate. J Appl Ecol 45: 524-536.
Bruck, D. J., & Walton, V. M., 2007. Susceptibility of the Filbertworm (Cydia latiferreana,Lepidoptera: Tortricidae) and Filbert Weevil (Curculio occidentalis, Coleoptera: Curculionidae) to Entomopathogenic Nematodes. Journal of Invertebrate Pathology.
Gutierrez, A. P., Daane, K. M., Walton, V. M., Ponit, L., and Ellis, C. K., 2007. Prospective evaluation of the biological control of the vine mealybug: Refuge effects. Journal of Animal Ecology. (Accepted).
Walton, V. M., Daane, K. M., Bentley, W. J., Millar, J. G., Larsen, T. E., Malakar-Kuenin, R., 2006. Pheromone-based Mating Disruption of Planococcus ficus (Hemiptera: Pseudococcidae) in California Vineyards. Journal of Economic Entomology Vol.99, No.4, 1280-1290. (pdf)
Daane, K. M., Bentley, W. J., Walton, V. M., Malakar-Kuenin, R., Millar, J. G., Weber, E. A., Gispert, C., 2006. New controls investigated for vine mealybug. California Agriculture, January-March 2006, Vol. 60, No.1, pp.31-38. (pdf)
Walton, V.M. & Pringle, K.L., 2005. Developmental biology of vine mealybug, Planococcus ficus (Signoret) (Homoptera: Pseudococcidae), and its parasitoid Coccidoxenoides perminutus (Timberlake) (Hymenoptera: Encyrtidae). African Entomology 13(1):143-147. (pdf)
Daane, K.M., Bentley, W.J., Walton, V.M., Malakar-Kuenen, R., Yokota, G.Y., Millar, J.G., Ingels, C.A., Weber, E.A., Gispert, C., 2005. New controls investigated for vine mealybug. California Agriculture, Volume 60 Number 1, 31-38. (pdf)
Walton, V.M., Daane, K.M. & Pringle, K.L., 2004. Monitoring Planococcus ficus in South African vineyards with sex pheromone-baited traps. Crop Protection 23, 1089-1096.(pdf)
Walton, V.M. & Pringle, K.L., 2004. Vine Mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), a key pest in South African vineyards: A Review. South African Journal of Enology and Viticulture 25(2), 54-62. (pdf)
Daane, K.M., Malakar-Kuenen, R., & Walton, V.M., 2004. Temperature-dependent development of Anagyrus pseudococci (Hymenoptera: Encyrtidae) as a parasitoid of the vine mealybug, Planococcus ficus (Homoptera: Pseudococcidae). Biological Control 31, 123-132.(pdf)
Walton, V.M. & Pringle, K.L., 2004. A Survey of Mealybugs and Associated Natural enemies in Vineyards in the Western Cape Province, South Africa. South African Journal of Enology and Viticulture 25(1), 23-25. (pdf)