Karban 9701109 Induced resistance following herbivory has been broadly documented across many taxa of plants. The investigators examine two aspects of induction 1) whether induced responses increase plant fitness, and 2) why plants employ induced responses over constitutive strategies. Field-grown annual plants will be experimentally induced in an environment with herbivores and male and female fitness components will be compared to uninduced control plants. In addition, three non-exclusive hypotheses for the benefits of induced responses over constitutive strategies will be tested: Do plants that employ induced responses benefit from 1) saving allocation costs when not induced, 2) not being apparent to specialist herbivores when not induced, and 3) having slower adapting herbivores than plants that are constitutively (continuously) defended? Costs of induced plant responses have rarely been found and the benefits have been largely ignored. This proposal attempts to fill these gaps. Additionally, understanding the ecological benefits of induced defenses will be potentially useful in the protection of crop plants from yield-reducing herbivores.