Symbiont-assisted herbivory in beetles

Abstract

A specialized herbivorous lifestyle is one of the key factors contributing to the enormous diversity of several beetle families. To cope with the challenges associated with a strictly plant-based diet, many beetle species engage in symbioses with microorganisms that they harbor in the gut or in specialized organs. These microbial symbionts support their hosts’ nutrition by supplementing limiting nutrients, specifically essential amino acids or vitamins, by providing enzymes for the digestion of plant cell wall components, or by detoxifying plant secondary metabolites. As such, the symbionts can enable their insect hosts to utilize novel food plants and improve their resistance towards abiotic stressors. Considering the current decline in insect populations and their central importance for most terrestrial ecosystems, a detailed understanding of their interactions with microorganisms is not only of fundamental interest but also of utmost relevance for nature conservation.