Refining the process of agent selection through understanding plant demography and plant response to herbivory

Authors

  • S Raghu,

    1. Cooperative Research Centre for Australian Weed Management, Alan Fletcher Research Station, Queensland Department of Natural Resources and Mines, PO Box 36, Sherwood, Qld 4075, Australia.
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    • *

      Present address: Centre for Ecological Entomology, Illinois Natural History Survey & University of Illinois, 1816, S. Oak St., Champaign, IL 61820, USA (email: raghu@uiuc.edu).

  • John R Wilson,

    1. Centre for Invasion Biology, University of Stellenbosch, Private Bag X1, Matieland 7600, South Africa.
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  • K Dhileepan

    1. Cooperative Research Centre for Australian Weed Management, Alan Fletcher Research Station, Queensland Department of Natural Resources and Mines, PO Box 36, Sherwood, Qld 4075, Australia.
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Abstract

Abstract  Understanding plant demography and plant response to herbivory is critical to the selection of effective weed biological control agents. We adopt the metaphor of ‘filters’ to suggest how agent prioritisation may be improved to narrow our choices down to those likely to be most effective in achieving the desired weed management outcome. Models can serve to capture our level of knowledge (or ignorance) about our study system and we illustrate how one type of modelling approach (matrix models) may be useful in identifying the weak link in a plant life cycle by using a hypothetical and an actual weed example (Parkinsonia aculeata). Once the vulnerable stage has been identified we propose that studying plant response to herbivory (simulated and/or actual) can help identify the guilds of herbivores to which a plant is most likely to succumb. Taking only potentially effective agents through the filter of host specificity may improve the chances of releasing safe and effective agents. The methods we outline may not always lead us definitively to the successful agent(s), but such an empirical, data-driven approach will make the basis for agent selection explicit and serve as testable hypotheses once agents are released.

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