Ongoing Coevolution of and a Widespread Invasive Ant, .

While are commonly found among arthropods, intraspecific infection rates can vary substantially across the geographic populations. Here we report nearly 100% prevalence of in the global populations of the yellow crazy ant, . To understand coevolutionary history between and , we identified single nucleotide polymorphisms (SNPs) in from the ant across 12 geographical regions and compared the phylogeny of SNP-based to patterns of the ant's mitochondrial DNA (mtDNA) variation. Our results revealed a strong concordance between phylogenies of and host mtDNA, providing immediate evidence of co-divergence. Among eight identified SNP loci separating the genetic clusters of , seven loci are located in potential protein-coding genes, three of which being non-synonymous SNPs that may influence gene functions. We found a hypothetical protein gene with signature of positive selection. These findings jointly allow us to characterize -ant coevolution and also raise a question about mechanism(s) underlying maintenance of high prevalence of during the colonization of this invasive ant.