16S rRNA sequencing reveals the bacterial communities of Pogonomyrmex harvester ants

Many insects, including several ant species, host communities of symbiotic bacteria; many of these host insect species rely on bacterial symbionts for dietary processing. Granivory (seed-feeding) is a well-known diet among insect species, but the symbiotic bacterial communities of granivorous insect taxa, including granivorous ant species, are still poorly known. In this study, we examine the host-associated bacterial communities of the granivorous ant genus Pogonomyrmex using 16S rRNA amplicon sequencing and bioinformatic analyses. We identify 2,926 unique bacterial ASVs within the whole Pogonomyrmex bacterial community that represent 20 bacterial phyla and 559 bacterial genera, some of which are known insect- or seed-associated bacterial symbionts. Further, in the Pogonomyrmex core bacterial community (ASVs with >50% abundance in all samples) we identify 28 ASVs that represent 21 bacterial genera. Additionally, tests of beta diversity indicate a marginally significant bacterial community dissimilarity based on average annual precipitation, which may reveal an influence of extreme aridity on bacterial communities of Pogonomyrmex. Overall, our results demonstrate that the bacterial community of Pogonomyrmex, and particularly the core bacterial community, is consistent among species, even when geographically separated.