Symbiont-Mediated Digestion of Plant Biomass in Fungus-Farming Insects.

Feeding on living or dead plant material is widespread in insects. Seminal work on termites and aphids has provided profound insights into the critical nutritional role that microbes play in plant-feeding insects. Some ants, beetles, and termites, among others, have evolved the ability to use microbes to gain indirect access to plant substrate through the farming of a fungus on which they feed. Recent genomic studies, including studies of insect hosts and fungal and bacterial symbionts, as well as metagenomics and proteomics, have provided important insights into plant biomass digestion across insect-fungal mutualisms. Advances in understanding of the divergent and complementary functions of complex symbionts not only reveal the mechanism of how these herbivorous insects catabolize plant biomass, but also represent a promising reservoir for carbohydrate-active enzyme discovery, which is of considerable biotechnological interest. Expected final online publication date for the Annual Review of Entomology, Volume 66 is January 11, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.