Comparing Host Plant Resistance, Engineered Resistance, and Insecticide Treatment for Control of Colorado Potato Beetle and Potato Leafhopper in Potatoes
The Colorado potato beetle, Leptinotarsa decemlineata (Say) Order Coleoptera and the potato leafhopper, Empoasca fabae (Harris) Order Homoptera, are the major insect pests of potato in eastern North America. In two years of field trials, we compared the effectiveness of three pest management options for the control of Colorado potato beetle and potato leafhopper: natural host plant resistance (glandular trichomes), engineered resistance (Bacillus thuringiensis [Bt] Berliner cry3A gene) and a susceptible potato cultivar (Superior) with an at-planting application of the insecticide thiamethoxam. Similar and acceptable control of the Colorado potato beetle larvae was obtained with the Bt-cry3A lines and the thiamethoxam treated “Superior” variety. The glandular trichome cultivar had significantly less Colorado potato beetle damage than did the untreated “Superior” in 2004, although damage was significantly greater than in the Bt-cry3A lines and the insecticide-treated potatoes for both years, and was the only treatment that consistently had very little potato leafhopper damage. These data demonstrate that although each type of host plant resistance mechanism (Bt-cry3A or glandular trichomes) was as effective as the chemical control against one of the insects, neither provides adequate resistance to both Colorado potato beetle and potato leaf hopper. 1. Introduction The Colorado potato beetle, Leptinotarsa decemlineata (Say) Order Coleoptera, is considered the most important pest of potatoes throughout the northeastern and mid-Atlantic regions of the United States [1]. Growers rely on pesticides to control Colorado potato beetle in the field but it has developed field resistance to nearly every insecticide used against it and is now resistant to more than 40 chemical insecticides [2]. Another important insect pest of potatoes, the potato leafhopper (Empoasca fabae (Harris) Order Homoptera), is a sap-feeding insect pest that causes damage known as “hopper burn” [1, 3]. Even low numbers of leafhoppers can cause significant yield losses [4]. In addition, this insect in organic potato fields can cause significant yield losses as there are few control options that are approved for organic production systems [5]. Currently, growers throughout the potato-producing regions of the USA use an at-plant insecticide such as thiamethoxam to control both Colorado potato beetle and potato leafhopper. Although thiamethoxam is systemic, the length of effective protection can vary and additional foliar insecticide sprays may be needed to control midsummer populations of
References
[1]
J.L. Capinera, Handbook of Vegetable Pests, Academic Press, New York, NY, USA, 2001.
[2]
M. E. Whalon, D. Mota-Sanchez, and P. Bills, The database of arthropods resistant to pesticides, 2005, http://www.pesticideresistance.org/DB/index.html.
[3]
E. B. Radcliffe, “Insect pests of potato,” Annual Review of Entomology, vol. 27, pp. 173–204, 1982.
[4]
A. G. Peterson and A. A. Granovsky, “Relation of Empoasca fabae to hopperburn and yields of potatoes,” Journal of Economic Entomology, vol. 43, pp. 484–487, 1950.
[5]
A. Seaman, W. M. Tingey, and A. G. Power, “Potato Varietal Mixtures for Potato Leafhopper Management on Organic Farms,” New York State Vegetable IPM Project Reports, NYS IPM Publication, 2006.
[6]
R. J. Wright, M. B. Dimock, W. M. Tingey, and R. L. Plaisted, “Colorado potato beetle (Coleoptera: Chrysomelidae): expression of resistance in Solanum berthaultii and interspecific potato hybrids,” Journal of Economic Entomology, vol. 78, pp. 576–582, 1985.
[7]
R. A. Casagrande, “Colorado potato beetle resistance in a wild potato, Solanum berthaultii,” Journal of Economic Entomology, vol. 75, pp. 368–372, 1982.
[8]
W. M. Tingey and J. E. Laubengayer, “Defense against the green peach aphid and potato leafhoppers by glandular trichomes of Solanum berthaultii,” American Journal of Potato Research, vol. 74, pp. 721–725, 1981.
[9]
R. L. Plaisted, W. M. Tingey, and J. C. Steffens, “The germplasm release of NYL235-4, a line with resistance to the Colorado potato beetle,” American Journal of Potato Research, vol. 69, pp. 843–846, 1992.
[10]
G. W. Zehnder and W. D. Gelernter, “Activity of the M-ONE formulation of a new strain of Bacillus thuringiensis against the Colorado potato beetle (Coleoptera: Chrysomelidae): relationship between susceptibility and insect life stage,” Journal of Economic Entomology, vol. 82, pp. 756–761, 1989.
[11]
J. J. Coombs, D. S. Douches, W. Li, E. J. Grafius, and W. L. Pett, “Combining engineered (Bt-cry3A) and natural resistance mechanisms in potato for control of Colorado potato beetle,” Journal of the American Society for Horticultural Science, vol. 127, no. 1, pp. 62–68, 2002.
[12]
M. J. Adang, M. S. Brody, G. Cardineau et al., “The reconstruction and expression of a Bacillus thuringiensis cryIIIA gene in protoplasts and potato plants,” Plant Molecular Biology, vol. 21, no. 6, pp. 1131–1145, 1993.
[13]
D. S. Douches, T. J. Kisha, W. Li, W. L. Pett, and E. J. Grafius, “Effectiveness of natural and engineered host plant resistance in potato to the Colorado potato beetle (Leptinotarsa decemlineata (Say)),” HortScience, vol. 36, pp. 967–970, 2001.
[14]
Anonymous, “Commercial vegetable production recommendations for New Jersey,” in Rutgers NJAES Cooperative Extension, S. A. Garrison, Ed., p. 135, Rutgers, The State University of New Jersey, Rutgers School of Environmental and Biological, New Brunswick, NJ, USA, 2003.
[15]
SAS Institute, SAS/STAT User’s Guide, Version 8, SAS Institute, Cary, NC, USA, 4th edition, 1990.
[16]
L. L. Sanford and R. E. Webb, “Loss of yield in potato selections infested with potato leafhoppers,” American Potato Journal, vol. 54, no. 12, pp. 581–586, 1977.
