D3155: Exploring species boundaries in a widespread army ant genus using DNA barcodes

The army ant genus Labidus (Hymenoptera: Formicidae) is one of the most wide-ranging of the American dorylines and has high ecological importance due to local abundance and a broad dietary niche. Although the genus has been solidly placed as a sister clade to Eciton and Nomamyrmex, Labidus taxonomy at the species level is in need of revision. There are seven valid species based on the morphology of workers and/or males, but little information on cryptic species within them or phylogenetic relationships among them. Here, we attempt to define species boundaries within the genus by reconstructing a phylogeny using 2,513 available CO1 barcodes from BOLD, from Labidus coecus, L. praedator, L. spininodis, and nine morphospecies. Maximum Likelihood and Bayesian Inference analyses were used to reconstruct phylogenies, and a species delimitation analysis was obtained through a Bayesian implementation of the PTP model (bPTP). Our analyses show that while most morphospecies were recovered as clusters with morphologically similar, currently recognized species, Labidus sp. JTL001 was placed in a separate cluster distinct from the morphologically similar Labidus praedator. With the addition of morphological and genomic data, this most likely indicates an undescribed stock of species within Labidus.