Authors: Megan DuVal, John Longino, Rodolfo da Silva Probst
Mentors: John Longino
Insitution: University of Utah
Army ants (Formicidae: Dorylinae) are top predators throughout most tropical and subtropical regions of the world. Their nomadic colonies and cooperative social hunting make them behaviorally and ecologically unique keystone species that are of conservation concern. Their status as nomadic top predators makes army ants vulnerable in areas affected by habitat fragmentation. An obstacle to conservation efforts is the outdated army ant species-level taxonomy, which hasn’t been updated since the 1950s for many genera. For Labidus, a widespread and ecologically important army ant genus in the Americas, there are currently seven valid species recognized solely based on morphology of workers and/or males. Three species are only based on males, which need to be associated with their respective workers, and within the four primarily worker-based species, there are likely cryptic species. To address these issues, we applied cutting-edge phylogenetics and phylogenomics to update the species-level taxonomy. To construct our phylogenetic tree, we used ultraconserved elements (UCEs, which use thousands of regions across the genome and can accurately infer evolutionary relationships across broad timescales) from 17 specimens, 66 COI barcodes from the Barcode of Life Database (BOLD), and 35 new COI barcodes obtained through in-house Nanopore sequencing. Through our analyses, we found that the genus Labidus contains at least 11 species and that all of the previously recognized wide-ranging species are made up of multiple cryptic species with more restricted ranges. We were able to associate all three previously identified male-based species with their respective workers. We have also found patterns of parallel and overlapping biogeography across multiple Labidus clades. Our UCE+Nanopore approach allows for an updated taxonomy of Labidus, leading to a better understanding of its evolutionary history and a better ability to promote its conservation.