Key to Forelius species in or possible in the Southeast (adapted from Cuezzo 2000, Ward 2005, and pers. comm. Stefan Cover, Harvard, MA; Mark Deyrup, Archbold Biological Station; and Lloyd Davis, Gainesville, FL)

The genus Forelius has been a source of confusion for many years now, at least in the United States. Most references mention both F. analis and F. mccooki as being western species, and F. pruinosus as being a more widespread species. However, both F. pruinosus and F. analis have been recorded from the Southeast. At one time in the not so distant past, F. analis was considered a subspecies of F. pruinosus, but was later lumped with F. pruinosus (Bolton 1995). Cuezzo (2000) later elevated F. analis to species status, but separation of species based on information in that paper made little practical sense, and it became impossible to separate species in this country. Recently, in a paper on California ants by Ward (2005), F. analis was sunk and is again considered a synonym of F. pruinosus. According to Ward's paper, only two described species are present in the US: F. mccooki and F. pruinosus. Cool! It should now be easy to identify Forelius in the US! But, it does not appear to be so simple. Here in the Southeast, we appear to have at least three distinct species: F. mccooki (or an undescribed eastern species similar to F. mccooki), F. pruinosus, and and undescribed species that has been collected in sand dune habitats in FL, GA, and SC. Our eastern "mccooki" has been identified historically as F. analis and often F. pruinosus. These two species have been confused in the literature and often misidentified historically. Our eastern "mccooki" ranges in color from yellowish brown to darker brown and has few to numerous erect setae on the mesosoma and scapes (but not nearly as hairy as western "mccooki"). This species is widespread in the Southeast in open areas, although not so much in sand dunes habitats. It is quite possible, if not likely, that this species represents a distinct undescribed southeastern species. Conversely, F. pruinosus is dark colored with few erect setae on the mesosoma and none on the scape, and is only found in sand dune habitats.

1   

Scapes lacking erect setae; 2-6 erect hairs on mesosoma dorsum (color uniform grayish brown and gaster with iridescent reflections on dorsum; this species is apparently strictly a sand inhabiting species)

 

Few to very numerous erect setae present on scapes, numerous erect setae on mesosoma dorsum (usually more than 10)

...2
2(1)  Entire body including head, mesosoma, gaster, scapes, and legs covered with numerous erect hairs giving an overall "hairy" appearance; color grayish brown (this species is apparently strictly a sand inhabiting species)
  Erect hairs present on head, mesosoma, gaster, and sometimes scapes, but never enough to give a hairy appearance; color yellow orangish to dark brown