New species discovery is not so simple as finding a critter in the woods and declaring “Eureka!” A background knowledge of related species is essential for recognizing something novel. Trachymyrmex has been an especially challenging group of ants in this regard, as the published taxonomy of the group is limited and many of the species are confusingly similar. In the absence of a taxonomic synthesis, one is reduced to using isolated taxonomic papers written decades ago on individual species and going through endless drawers of museum specimens. Fortunately, Rabeling et al. do exactly that for the North American Trachymyrmex, and on top of it they throw in DNA sequence data from two loci sampled across multiple populations per species. Once the dust settled, they inferred the existence of nine species but had only eight valid, pre-existing names to apply to them. The extra species became the new T. pomonae.
Students of the biannual Ant Course in Arizona might recognize T. pomonae. It is not an uncommon ant around the Southwestern Research Station in Portal where the course is taught. If you’re an Arizona Ant Course alumnus, check your collection!