Management

Although a number of cultural measures, including crop rotation, isolation from previous potato crops, planting of nonpreferred and early maturing potato varieties, and use of trap crops, were recommended measures for potato beetle control, hand removal of adults, eggs, and larvae from infested plants was the primary means of control prior to the introduction of the insecticide Paris Green (copper acetoarsenite) in the late 1800s. Arsenic-based insecticides remained the primary means of control until DDT replaced them in the late 1940s. Resistance of the Colorado potato beetle to DDT was first reported in New York in the early 1950s. Resistance to other chlorinated hydrocarbon insecticides soon followed throughout much of the potato-growing region of the eastern United States. A series of insecticides was used to control the beetle during the succeeding decades and the potato beetle developed resistance to each. By the early 1980s, insecticide resistance had reached a crisis level. In many locations, potato beetle populations could not be controlled using insecticides. This stimulated a burst of research activity, which resulted in the development of more holistic pest management approaches. These involved foliar applications of the bacterial pathogen Bacillus thuringiensis tenebrionis, crop rotation, naturally occurring biological control, scouting and the use of economic thresholds, and the use of narrow-spectrum insecticides. By the late 1990s, several new, highly effective, narrow-spectrum insecticides had become available to control resistant potato beetle populations. Currently, potato beetle management relies on these new insecticides but heavily emphasizes their use within a pest management context, which is designed to minimize selection for insecticide resistance and negative environmental impacts.

During the mid-1990s, transgenic potato varieties were commercialized that expressed a protein from B. thuringiensis tenebrionis, which is highly toxic to the Colorado potato beetle. These varieties produce high-quality potatoes and are highly effective in controlling the potato beetle. Nonetheless, they have received only limited use because of their inability to compete with insecticides that controlled other insect pests (aphids and leafhoppers) in addition to the Colorado potato beetle and because of concern that consumers would not buy potato products made from transgenic potatoes. It is not clear at this time whether transgenic potato varieties will play a significant role in the future management of the Colorado potato beetle.

See Also the Following Articles

Agricultural Entomology • Coleoptera • Insecticide and Acaricide Resistance • Integrated Pest Management • Plant—Insect Interactions

Further Reading

Bishop, B. A., and Grafius, E. J. (1996). Insecticide resistance in the Colorado potato beetle. In "The Classification, Phylogeny and Genetics" (P. H. A. Jolivet and M. L. Cox, eds.), Vol. 1 of "Chrysomelidae Biology." SPB Academic Pub., Amsterdam. Casagrande, R. A. (1987). The Colorado potato beetle: 125 years of mismanagement. Bull. Entomol. Soc. Am. 33, 142—150. Ferro, D. N. (2000). Success and failure of Bt products: Colorado potato beetle—A case history. In "Emerging Technologies for Integrated Pest Management: Concepts, Research, and Implementation" (G. G. Kennedy and T. B. Sutton, eds.). APS Press, St. Paul. Hare, J. D. (1990). Ecology and management of the Colorado potato beetle.

Annu. Rev. Entomol. 35, 81—100. Lashomb, J. H., and Casagrande, R. (eds.) (1981). "Advances in Potato Pest

Management." Hutchinson Ross Pub., Stroudsburg, PA. Zehnder, G. W., Powelson, M. L., Jansson, R. K., and Raman, K. V. (eds.) (1994). "Advances in Potato Pest Biology and Management." APS Press, St. Paul.

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