Elevated atmospheric carbon dioxide impairs the performance of root-feeding vine weevils by modifying root growth and secondary metabolites

Johnson, S. N., Barton, A. T., Clark, K. E., Gregory, P. J. ORCID: https://orcid.org/0000-0002-4118-4833, McMenemy, L. S. and Hancock, R. D. (2011) Elevated atmospheric carbon dioxide impairs the performance of root-feeding vine weevils by modifying root growth and secondary metabolites. Global Change Biology, 17 (2). pp. 688-695. ISSN 1365-2486 doi: 10.1111/j.1365-2486.2010.02264.x

Abstract/Summary

Predicting how insect crop pests will respond to global climate change is an important part of increasing crop production for future food security, and will increasingly rely on empirically based evidence. The effects of atmospheric composition, especially elevated carbon dioxide (eCO(2)), on insect herbivores have been well studied, but this research has focussed almost exclusively on aboveground insects. However, responses of root-feeding insects to eCO(2) are unlikely to mirror these trends because of fundamental differences between aboveground and belowground habitats. Moreover, changes in secondary metabolites and defensive responses to insect attack under eCO(2) conditions are largely unexplored for root herbivore interactions. This study investigated how eCO(2) (700 mu mol mol-1) affected a root-feeding herbivore via changes to plant growth and concentrations of carbon (C), nitrogen (N) and phenolics. This study used the root-feeding vine weevil, Otiorhynchus sulcatus and the perennial crop, Ribes nigrum. Weevil populations decreased by 33% and body mass decreased by 23% (from 7.2 to 5.4 mg) in eCO(2). Root biomass decreased by 16% in eCO(2), which was strongly correlated with weevil performance. While root N concentrations fell by 8%, there were no significant effects of eCO(2) on root C and N concentrations. Weevils caused a sink in plants, resulting in 8-12% decreases in leaf C concentration following herbivory. There was an interactive effect of CO(2) and root herbivory on root phenolic concentrations, whereby weevils induced an increase at ambient CO(2), suggestive of defensive response, but caused a decrease under eCO(2). Contrary to predictions, there was a positive relationship between root phenolics and weevil performance. We conclude that impaired root-growth underpinned the negative effects of eCO(2) on vine weevils and speculate that the plant's failure to mount a defensive response at eCO(2) may have intensified these negative effects.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/28482
Item Type	Article
Refereed	Yes
Divisions	Interdisciplinary Research Centres (IDRCs) > Walker Institute Interdisciplinary centres and themes > Centre for Food Security Life Sciences > School of Agriculture, Policy and Development > Department of Crop Science Interdisciplinary centres and themes > Soil Research Centre
Uncontrolled Keywords	black vine weevil; carbon dioxide; induced responses; phenolics; roots; secondary metabolites; soils;Otiorhynchus-sulcatus Coleoptera; below ground herbivory; plant-growth; phytophagous insect; C02 enrichment; responses; temperature; nitrogen; soil; curculionidae
Publisher	Wiley-Blackwell
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