Recent advances in elucidating mechanisms of symbiont transmission and developmental integration in cicadas

All insects that feed exclusively on plant sap, whether xylem or phloem, have established long-term partnerships with microbial symbionts. These symbionts provide essential nutrients to their hosts via solo de novo synthesis and, typically, also, for a handful of metabolites, de novo synthesis in collaboration with their host and/or co-symbionts. Such long-term partnerships persist because they have evolved stable mechanisms of transmission. Here, we review recent advances in elucidating the mechanisms of symbiont transmission and developmental integration in cicadas.