Synonyms and other taxonomic changes
Numbers
The largest ant subfamily, containing the most genera and the most species, both in the Nearctic and world-wide. Some of the genera are very diverse on a worldwide scale, including Pheidole, Crematogaster, Solenopsis, Pyramica & Monomorium, the first three well represented in our fauna. Indeed, worldwide Pheidole contains over 1000 described species, with perhaps that many or more remaining to be sorted out, and may be the largest ant genus of all time (the formicine genus Camponotus may rival it).
Size
In the Nearctic, workers usually barely over 1 to ~6 mm (a few to 14 mm)
Identification
An important metric character of this group is their two-segmented abdominal waist (pedicel) composed of petiole and postpetiole. Outside the myrmicines, the distinctive Pseudomyrmex and Ecitoninae share this trait.
Key to Genera in the southeastern United States (the most comprehensive online identification resource for this subfamily in North America)
this
key to genera works well for northern states
Range
Equatorial to boreal - One extending to within the Arctic Circle.
Habitat
Grassland to forests, a few in wetlands. Nesting is various, but great majority live in soil, leaf litter or rotting wood on the ground. Many Crematogaster & Temnothorax are arboreal, while many northern and alpine species nest under heat-gathering rocks.
Food
Generalist foragers (most), seed harvesters (Pogonomyrmex, Messor, many Pheidole) and fungus cultivators (Attini) are all found in this group.
