Myrmicinae

Myrmicinae is a large and diverse subfamily of ants within the family Formicidae. It comprises hundreds to thousands of described species across many genera and has a cosmopolitan distribution, inhabiting forests, grasslands, deserts, and urban areas around the world.

A hallmark of Myrmicinae is the presence of a two-segmented petiole, consisting of a petiole and a postpetiole, between the thorax and abdomen. Members typically have elbowed antennae and, in many species, a functional sting. The worker caste shows substantial size variation, and several genera exhibit pronounced polymorphism, with major and minor workers in groups such as Pheidole.

Ecology and behavior in Myrmicinae are highly varied. Foraging strategies range from generalist predation to specialized seed collection and scavenging. A notable lineage within the subfamily is the Attini, the fungus-growing ants, which cultivate fungal gardens for food in their nests; this group includes the genera Atta and Acromyrmex. Myrmicine ants also include social parasites, predators, and numerous other ecological roles that influence soil structure, plant communities, and insect networks.

Notable genera within Myrmicinae include Solenopsis (fire and thief ants), Tetramorium (pavement ants), Crematogaster (acrobat ants), Myrmica, Aphaenogaster, Pogonomyrmex (harvester ants), and Messor. The subfamily also encompasses diverse tribes and many other genera, reflecting its extensive evolutionary diversification.

Economic and ecological significance is broad. Myrmicine ants affect soil turnover, seed dispersal, and predator–prey dynamics. Some species, such as Solenopsis invicta, are invasive and can pose medical and agricultural challenges due to aggressive behavior and stinging. Research on Myrmicinae informs understanding of social organization, division of labor, and chemical communication in eusocial insects.