Date from: Top-down effects from parasitoids may mediate plant defense and plant fitness

Plants face many environmental stresses that can impact their survival, development, and fitness. Insects are the most diverse, abundant and threatening herbivores in nature. As a consequence, plants produce direct chemical and physical defenses to reduce herbivory. They also release volatiles to recruit natural enemies that indirectly protect them from herbivory. The recruitment of parasitic wasps can benefit plant fitness because they ultimately kill their insect hosts.
Recently, studies showed that parasitoids can indirectly mediate plant defenses by modulating herbivore oral secretions. In addition to the direct benefits of parasitoids in terms of reducing herbivore survival, we tested if the reduction in induced defenses by parasitized caterpillars compared to non-parasitized caterpillars may reduce the costs associated with defense expression.
We provide evidence that tomato plants treated with saliva from parasitized caterpillars have significantly higher fitness parameter...