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Nontarget effects on crepe myrtle by Galerucella pusilla and G. calmariensis (Chrysomelidae), used for biological control of purple loosestrife (Lythrum salicaria)

Published online by Cambridge University Press:  20 January 2017

Eric M. Coombs
Affiliation:
Plant Division, Oregon Department of Agriculture, Salem, OR 97310
Peter B. McEvoy
Affiliation:
Department of Entomology, Oregon State University, Corvallis, OR 97331

Abstract

Field experiments were used to assess how distance mediates the nontarget effect on crepe myrtle by two chrysomelid beetles that were introduced to the United States in 1992 for biological control of purple loosestrife. Previous laboratory tests in Germany and concurrent tests in Oregon showed that although the control organisms can feed on crepe myrtle, they cannot complete development. Therefore, we predicted that negative effects on crepe myrtle would decrease with distance from the purple loosestrife stand. To test this prediction, cohorts of both plant species were transplanted at increasing distances (0, 5, 15, 30, and 50 m) from the colonization source. We found that leaf damage inflicted by the beetles was negatively correlated with increasing distance. Damage was significantly lower at each distance for crepe myrtle plants than for purple loosestrife plants, with a mean difference of 22% and a 95% confidence interval ranging from 12 to 31%. Extensive defoliation of crepe myrtle was limited to within 30 m of the edge of the loosestrife stand. Plant yield was negatively correlated with damage: the closer plants were to the purple loosestrife stand, the greater the suppression of biomass in both plant species. However, loosestrife biomass decreased significantly more quickly than crepe myrtle biomass, with a mean difference in slopes of 0.035 and a 95% confidence interval ranging from 0.022 to 0.048. Our results suggest that release of the Galerucella beetles in North America poses little risk to crepe myrtle. Beetles can feed but cannot complete their life cycle on crepe myrtle, and damage to crepe myrtle approaches zero approximately 50 m from the beetle colonization source.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Anderson, M. G. 1995. Interactions between Lythrum salicaria and native organisms: a critical review. Environ. Manag. 19:225231.Google Scholar
Bailey, L. H. 1951. Manual of Cultivated Plants Most Commonly Grown in the Continental United States and Canada. New York: Macmillan. 720 p.Google Scholar
Balogh, G. R. and Bookhout, T. A. 1989. Purple loosestrife (Lythrum salicaria) in Ohio's Lake Erie marshes. Ohio J. Sci. 89:6264.Google Scholar
Blossey, B. 1995. Coexistence of two leaf beetles in the same fundamental niche. Distribution, adult phenology, and oviposition. Oikos. 74:225234.Google Scholar
Blossey, B. 1999. Before, during and after: the need for long-term monitoring in invasive plant species management. Biol. Invasions. 1:301311.Google Scholar
Blossey, B., Schroeder, D., Hight, S. D., and Malecki, R. A. 1994. Host specificity and environmental impact of two leaf beetles (Galerucella calmariensis and G. pusilla) for biological control of purple loosestrife (Lythrum salicaria). Weed Sci. 42:134140.Google Scholar
Blossey, B., Skinner, L. C., and Taylor, J. 2001. Impact and management of purple loosestrife (Lythrum salicaria) in North America. Biodivers. Conserv. 10:17871807.Google Scholar
Dunmire, J. R., ed. 1979. Sunset: New Western Garden Book. Menlo Park, CA: Lane. 479 p.Google Scholar
Grevstad, F. S. and Herzig, A. L. 1997. Quantifying the effects of distance and conspecifics on colonization: experiments and models using the loosestrife leaf beetle, Galerucella calmariensis . Oecologia. 110:6068.Google Scholar
Hager, H. A. and McCoy, K. D. 1998. The implications of accepting untested hypotheses: a review of the effects of purple loosestrife (Lythrum salicaria) in North America. Biodivers. Conserv. 7:10691079.Google Scholar
Harley, K.L.S. and Forno, I. W. 1992. Biological Control of Weeds: A Handbook for Practitioners and Students. Melbourne: Inkata Press. p. 28.Google Scholar
Hull, L. A. and Beers, E. H. 1990. Validation of injury thresholds for European red mite (Acari: Tetranychidae) on “Yorking” and “Delicious” apple. J. Econ. Entomol. 83:20262031.Google Scholar
Kok, L. T., McAvoy, T. J., Malecki, R. A., Hight, S. D., Drea, J. J. Jr., and Coulson, J. R. 1992. Host specificity tests of Galerucella calmariensis (L.) and G. pusilla (Duft.) (Coleoptera: Chrysomelidae), potential biological control agents of purple loosestrife, Lythrum salicaria L. (Lythraceae). Biol. Control. 2:282290.Google Scholar
Malecki, R. A., Blossey, B., Hight, S. D., Schroeder, D., Kok, L. T., and Coulson, J. R. 1993. Biological control of purple loosestrife. BioScience. 43:680686.Google Scholar
Martin, E. C. 1983. Landscape Plants In Design. Westport, CT: AVI. pp. 8889.Google Scholar
McEvoy, P. B. 1996. Host specificity and biological pest control. BioScience. 46:401405.Google Scholar
Pemberton, R. W. 2000. Predictable risk to native plants in weed biological control. Oecologia. 125:489494.Google Scholar
Radtke, H. and Davis, S. 2000. Economic Analysis of Containment Programs, Damages, and Production Losses from Noxious Weeds in Oregon. Oregon: Contract Rep. to Oregon Department of Agriculture. 40 p.Google Scholar
Schooler, S. S. 1998. Biological Control of Purple Loosestrife Lythrum salicaria by Two Chrysomelid Beetles Galerucella pusilla and G. calmariensis . . Oregon State University, Corvallis, OR.Google Scholar
Secord, D. and Kareiva, P. 1996. Perils and pitfalls in the host specificity paradigm. Bioscience. 46:448453.Google Scholar
Thompson, D. Q. 1991. History of purple loosestrife (Lythrum salicaria L.) biological control efforts. Nat. Areas J. 11:148150.Google Scholar
Thompson, D. Q., Stuckey, R. L., and Thompson, E. B. 1987. Spread, impact and control of purple loosestrife (Lythrum salicaria) in North American wetlands. U.S. Fish Wildl. Res. 55:155.Google Scholar
Visser, J. H. 1986. Host odor perception in phytophagous insects. Annu. Rev. Entomol. 31:121144.Google Scholar
Wilcox, D. A. 1989. Migration and control of purple loosestrife (Lythrum salicaria L.) along highway corridors. Environ. Manag. 13:365370.Google Scholar
Zwölfer, H. and Harris, P. 1971. Host specificity determination of insects for biological control of weeds. Annu. Rev. Entomol. 16:159178.Google Scholar