Mycorrhizal fungal-plant-insect interactions: the importance of a community approach.

Mycorrhizal fungi and insects are important components of most ecosystems that are likely to interact with one another indirectly through a common host plant. In this paper, we review the literature examining the effects of insects on mycorrhizal fungi and the effects of mycorrhizal fungi on insects and show that both groups of organisms can indirectly and, occasionally directly, influence each other. We explore the mechanisms for these interactions and test a recently proposed model predicting mycorrhizal fungal community responses to herbivory. We emphasize the results of several recent studies that showed that experiments conducted in isolation are unlikely to predict the outcome of interactions between insects, plants, and mycorrhizal fungi, and we highlight the need for a community approach to the study of mycorrhizal fungal-plant-insect interactions.