Evol Ecol Res 4: 1131-1151 (2002)     Full PDF if your library subscribes.

Induced plant defence and the evolution of counter-defences in herbivores

Shea N. Gardner1 and Anurag A. Agrawal2*

1Biology and Biotechnology Research Program, Lawrence Livermore National Laboratory, PO Box 808, L-448, Livermore, CA 94551, USA and 2Department of Botany, University of Toronto, 25 Willcocks Street, Toronto, Ontario M5S 3B2, Canada

Author to whom all correspondence should be addressed.
e-mail: agrawal@botany.utoronto.ca


We examine how induced plant defences affect the evolution of resistance in herbivores (i.e. the ability to overcome plant defences) compared with constitutive defence strategies. Since resistance of herbivores may evolve as a result of major monogenic and/or quantitative (polygenic or gene amplification) genetic sources, and the selective pressure imposed by plant defences affects the rate of evolution of each genetic source of resistance, we incorporate both into a model of herbivore evolution. We combine Mendelian single-locus and quantitative genetic models with a logistic population growth model based on an empirical plant–herbivore system. Induced defences may delay the evolution of both quantitative and major gene resistance and thus depress herbivore population size for more than 50 herbivore generations longer than constitutive defences. This increased longevity in the effectiveness of plant defence is associated with the production of substantially less plant defence over the long term, hence maximizing the benefit to cost ratio from the plant’s perspective.

Keywords: evolution of resistance, induced versus constitutive defence, major gene resistance, phenotypic plasticity, plant–insect interactions, quantitative characters.

IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.


        © 2002 Anurag A. Agrawal. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.