Education:
Ph.D. Entomology and Microbiology, Louisiana StateUniversity,
1980
M.S. Entomology and Microbiology, Louisiana State University,1977
B.S. Biology, Point Loma College, 1974
Research Interests:
Dr. David Ragsdale has been a professor in the Department of Entomology in the College of Agricultural, Food, and Environmental Sciences (CFANS) for 24 years. Dr. Ragsdale’s research interests are focused in two broad areas: 1) management of insect vectors of plant pathogens and 2) using arthropod herbivores to control invasive perennial plants.
Dr. Ragsdale leads an intensive multistate effort in the North Central US on the invasive aphid, Aphis glycines, or soybean aphid, whose native range is Asia. Dr. Ragsdale and colleagues have studied the overwintering biology of this aphid, evaluated the vector potential of this new exotic aphid, conducted foreign exploration for natural enemies of the soybean aphid in China, Japan and Korea for possible introduction into the U.S., and have developed management strategies to help soybean producers minimize losses caused by this invasive insect. In 2003, the Minnesota Soybean Research and Promotion Council recognized Dr. Ragsdale for his pioneering work on soybean aphid biology in North America.
Dr. Ragsdale is also a recognized authority in the area of potato pest management. Dr. Ragsdale has developed non-chemical control strategies that limit the spread of aphid-transmitted plant viruses in seed potato that have been adopted by virtually all seed growing regions in North America. His work includes molecular characterization of virus strains, identifying resistant genes in wild Solanum germplasm that might impart resistance to aphids and viruses in cultivated potato, and practical application of cultural practices that limit the spread of aphid transmitted viruses. In 2002, Dr. Ragsdale and his colleague Dr. Radcliffe, were jointly awarded the Meritorious Service Award by the National Potato Council for their work on aphid transmitted viruses in potatoes and a research article published in the American Journal of Potato Research was selected as the Outstanding Paper for 2004.
The use of insect herbivores to control invasive perennial weeds such as purple loosestrife, leafy spurge, garlic mustard and buckthorn represent the active projects Dr. Ragsdale is involved with along with colleagues at CABI, Delemont, Switzerland, Minnesota DNR and MDA and Agronomy and Plant Genetics (Weed Science). Projects range from discovery of agents overseas to developing methods of dispersing insects approved for release in North America. Dr. Ragsdale was honored by the Minnesota Vegetation Management Association of Minnesota for his work on biological control of purple loosestrife in Minnesota.
Dr. Ragsdale taught an undergraduate course, Economic Entomology for over 20 years, a graduate level course in Insects as Vectors of Plant Pathogens, and currently team-teaches an introductory course with faculty in weed science and plant pathology, Pests and Crop Protection. Dr. Ragsdale was elected as the Outstanding Teacher in the College of Agriculture by the student board in 1988 and was nominated by the College of Agriculture for the Horace T. Morse-Minnesota Alumni Association for outstanding contributions to undergraduate education in 1993. |
Recent Publications:
Davis, J. A., E. B. Radcliffe, and D. W. Ragsdale. 2006. Modeling effects of high and fluctuating temperatures on green peach aphid, Myzus persicae (Hemiptera: Aphididae). Environ. Entomol. (in press, accepted August 2006).
McCornack, B. P., R. L. Koch, and D. W. Ragsdale. 2006. A simple method for in-field sex determination of the multicolored Asian lady beetle (Coleoptera: Coccinellidae). J. Insect Science. (in press, accepted August 2006).
McCornack, B. D. and D. W. Ragsdale. 2006. Efficacy of thiamethoxam to suppress soybean aphid populations in Minnesota soybean. J. Crop Manag. (in press, accepted April 2006)
Zhu, M., E.B. Radcliffe, D.W. Ragsdale, I.V. MacRae and M.W. Seeley. 2006. Low-level jet streams associated with spring aphid migration and current season spread of potato viruses in the U.S. northern Great Plains. Agric. For. Meteorol. 138: 192-202. http://dx.doi.org/10.1016/j.agrformet.2006.05.001
Skinner, L.C., D.W. Ragsdale, R.W. Hansen, M.A. Chandler, and G. Spoden. 2006. Phenology of first and peak emergence of Aphthona lacertosa and A. nigriscutis introduced for biological control of leafy spurge, Euphorbia esula L. Biological Control. 37: 382-391. http://dx.doi.org/10.1016/j.biocontrol.2006.01.008
Carrillo, M.A., R.L. Koch, E.C. Burkness, K. Bennett, D.W. Ragsdale, and W.D. Hutchison. 2005. Overwintering of bean leaf beetle (Coleoptera: Chrysomelidae) in Minnesota: a revision of a predictive model for survival at low temperatures. Environ. Entomol. 34(6): 1395 – 1401. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/0046225x/v34n6s4.pdf
Hodgson, E. W., R. L. Koch, and D. W. Ragsdale. 2005. Pan trapping for soybean aphid (Homoptera: Aphididae) in Minnesota soybean. J. Entomol. Sci. 40: 409-419
Hodgson, E. W., R. C. Venette, M. Abrahamson, and D. W. Ragsdale. 2005. Alate production of soybean aphid (Homoptera: Aphididae) in Minnesota. Environ. Entomol. 34: 1456-1463. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/0046225x/v34n6s12.pdf
Davis, J. A., E. B. Radcliffe, D. W. Ragsdale. 2005. Soybean aphid, Aphis glycines Matsumura, a new vector of Potato Virus Y in potato. Amer. J. Potato Res. 81: 101-105.
McCornack, B. P., M. A. Carrillo, R. C. Venette, and D.W. Ragsdale. 2005. Physiological constraints to the overwintering distribution of the soybean aphid (Homoptera: Aphididae). Environ. Entomol. 34: 235-240. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/0046225x/v34n6s12.pdf
Hodgson, E. W., E. C. Burkness, W. D. Hutchison, and D. W. Ragsdale. 2004. Enumerative and Binomial Sequential Sampling Plans for Soybean Aphid (Homoptera: Aphididae) in Soybean. J. Econ. Entomol. 97(6): 2127-2136. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/00220493/v97n6s48.pdf
McCornack, B., D. W. Ragsdale, and R. C. Venette. 2004. Demography of Soybean Aphid (Homoptera: Aphididae) at Summer Temperatures. J. Econ. Entomol. 97(3): 854-861. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/00220493/v97n3s22.pdf
Skinner, L. C., D. W. Ragsdale, R.W. Hansen, M.A. Chandler and R.D. Moon. 2004. Temperature-dependent development of overwintering Aphthona lacertosa and A. nigriscutis (Coleoptera: Chrysomelidae), two flea beetles introduced for the biological control of leafy spurge, Euphorbia esula. Environ. Entomol. 33: 147-154. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/0046225x/v34n6s12.pdf
Ragsdale, D. W., D. V. Voegtlin and R. J. O’Neil. 2004. Soybean Aphid Biology in North America. Annals Entomol. Soc. Amer. 97: 204-208. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/00138746/v97n2s2.pdf
Heimpel G. E., D. W. Ragsdale, R. C. Venette, K. Hopper, R. J. O’Neil, C. Rutledge, and Z. Wu. 2004. Prospects for importation biological control of the soybean aphid: anticipating potential costs and benefits, Ann. Entomol. Soc. Amer. 97: 249-258. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/00138746/v97n2s9.pdf
Wu, Z., D. Schenk-Hamlin, W. Zhan, D. W. Ragsdale and G. E. Heimpel. 2004. The soybean aphid in China – an historical review. Ann. Entomol. Soc. Amer. 97: 209-218. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/00138746/v97n2s3.pdf
Venette, R. C and D. W. Ragsdale. 2004. Assessing the invasion by soybean aphid (Homoptera: Aphididae): where will it end? Ann. Entomol. Soc. Amer. 97: 219-226. http://docserver.esa.catchword.org/deliver/cw/pdf/esa/freepdfs/00138746/v97n2s4.pdf
Legg, D. E., S. M. Van Vleet, D. W. Ragsdale, R. W. Hansen,
B., L. Skinner, T. R. Collier, and J. E. Lloyd. 2003. Roles
of bootstrap resampling, measure of central tendency, and method
for calculating thermal units when developing phenology models
for pest management. International J. of Pest Management. 49:
319-325.
Book Chapters
Radcliffe, E. B., D. W. Ragsdale and R. A. Suranyi. 2006. IPM
case studies — seed potato, In. Aphids as Crop Pests,
H. F. van Emden and R. Harrington [eds.]. CABI Publishing, Wallingford,
U.K. (accepted for publication, in press)
Ruano-Rossil, J.M., E.B. Radcliffe and D.W. Ragsdale. 2004.
Disruption of entomopathogenic fungi of green peach aphid, Myzus
persicae (Sulzer), by fungicides used to control potato
late blight, In: Simon J.C., Dedryver C.A., Rispe C.
and Hullé M. (eds), Aphids in a New Millennium, INRA,
Versailles, pp. 365-370.
Ragsdale, D. W., E. B. Radcliffe, and C. D. DiFonzo. 2001.
Epidemiology and field control of PVY and PLRV, pp.237-270.
In G. Loebenstein and P. Berger,A. A. Brunt and R. Lawson
[eds.] Virus and virus-like diseases of potatoes and production
of seed-potatoes, Kluwer Academic Publishers, The Netherlands,
460pp.
Andow, D. A., D. W. Ragsdale, R. F. Nyvall. 1997. Biological
control in cool temperate regions, pp. 1-28. In D. Andow,
D. Ragsdale, & B. Nyvall, [eds.], Ecological Interactions
and Biological Control, Westview Press, Boulder. |
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