1. Organisms of the third trophic level can indirectly interact with plants. However, whether parasitoids of herbivores have a positive effect on plant fitness has been controversial. In addition to possible effects on plant fitness, parasitoid-mitigated herbivory can modify plant physiological responses and thereby alter the plant-mediated indirect interactions between different herbivore species. These types of indirect multitrophic interactions remain largely unexplored. Thus, to understand the full effect of the third trophic level on plants,...