Multi-Locus Molecular Phylogeny of Solenopsis (Hymenoptera: Formicidae)

The myrmicine ant genus Solenopsis is species-rich, globally distributed, and is often a common and ecologically important faunal element of the leaf litter. The genus is also well-known for containing several widely distributed tramp species and some of the worst invasive species in the World (the Red Imported Fire Ant, S. invicta, and the Tropical Fire Ant, S. geminata). Although not hyper-diverse and despite its ecological and economic importance, Solenopsis has long frustrated systematists due its lack of reliable diagnostic characters and no phylogenetic hypothesis exists to date. We present a preliminary multi-locus molecular phylogenetic analysis of Solenopsis to address this knowledge gap. Our analyses recover mostly well-supported phylogenetic hypothesis, which suggests Solenopsis arose in the Neotropics and spread to all other continents (except Antarctica). Importantly, it demonstrates problems with current systematic understanding of the genus, but provides an evolutionary framework upon which to build future research.