Author
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Heagle, Allen |
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Submitted to: Journal of Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/15/2003 Publication Date: 6/1/2003 Citation: Heagle, A.S. Influence of elevated carbon dioxide on interactions between frankliniella occidentalis and trifolium repens. Journal of Environmental Entomology. 2003. v. 32.p.421-424. Interpretive Summary: Elevated concentrations of carbon dioxide (CO2) expected in the 21st century can increase plant growth and change plant nutritive value for insects. Several reports indicate that some insects consume more foliage of plants grown at elevated CO2 than of plants grown at ambient CO2. Research with additional plant-pest systems is needed to determine how widespread this phenomenon is and if increased insect feeding might significantly affect plant productivity. Western flower thrips are tiny winged insects that infests numerous plant species. It is one of the most difficult plant pest to control and spreads the tomato spotted wilt virus. Effects of CO2 enrichment on foliar consumption and population size of Western flower thrips on white clover were measured. White clover infested with flower thrips was exposed to ambient and double-ambient CO2 concentrations. At double-ambient CO2, clover stem and leaf weight were approximately 50% greater than at ambient CO2, and leaf area was approximately 20% greater. Thrips population size was not significantly affected, but leaf area eaten by thrips was approximately 90% greater at elevated than at ambient CO2. In spite of increased thrips feeding, undamaged leaf area was approximately 15% greater at elevated than at ambient CO2 suggesting that elevated CO2 will be a net benefit for white clover. Because Western flower thrips and tomato spotted wilt virus both enjoy and extremely wide host range increased thrips feeding caused by elevated CO2 might results in increased prevalence of disease caused by the tomato spotted wilt virus. Technical Abstract: Elevated CO2 concentrations can increase plant growth and change plant nutritive value for herbivores. Several reports indicate that leaf- chewing insects consume more foliage of plants grown at elevated CO2 concentrations than of plants grown at ambient CO2. Research with additional plant-pest systems is needed to determine if this phenomenon is widespread and if increased insect feeding might significantly affect plan productivity. Effects of CO2 enrichment on foliar consumption and population size of Western flower thrips (Frankliniella occidentalis) on white clover (Trifolium repens) were measured. White clover infested with thrips was exposed for 24h d-1 to approximately 396 (ambient) or 745 uLL- 1 (elevated) CO2 for up to 35 days in 10 greenhouse exposure chambers. At elevated CO2, clover shoot weight and laminae weight were approximately 50% greater, and laminar area was approximately 20% greater than at ambient CO2. Thrips population size was not significantly affecte by CO2, but laminar area scarred by thrips feeding was approximately 90% greater at elevated than at ambient CO2. Because of increased growth however, undamaged leaf area was approximately15% greater at elevated than at ambient CO2. The results suggest that double ambient CO2 concentrations will be a net benefit for white clover under field condition where thrips populations are usually lower than occurred in the present experiment. |
