Insight into the Microbiome of the Subterranean Aphid Anoecia corni

Aphids are valuable models for studying the functional diversity of endosymbiotic bacteria in insects. However, studies of microbial diversity associated with aphids remain based on a limited number of species. In this study, we analyzed the symbiotic diversity associated with the dogwood-grass aphid Anoecia corni, an aphid species that spends much of its life cycle in a subterranean environment. Little is known about the symbiotic diversity associated with aphids displaying such a lifestyle, and one hypothesis is that close contact with the vast microbial flora of the rhizosphere could promote the acquisition of a rich bacterial diversity. Using 16S rRNA amplicon Illumina sequencing on specimens collected on wheat roots in Morocco, we identified 10 bacterial operational taxonomic units (OTUs) corresponding to five bacterial genera. In addition to hosting the obligate symbiont Buchnera, we identified the facultative symbionts S. symbiotica and Wolbachia in certain aphid colonies. The detection of Wolbachia is unexpected since it is considered rare in aphids and its biological significance remains unknown in these insects. We also detected Arsenophonus and Dactylopiibacterium carminicum. Our results highlight the bacterial partners associated with a little studied subterranean aphid living on plant roots.