Polyergus breviceps
Polyergus breviceps is an obligate social parasite on Formica ants. Polyergus queens force their way into a host nest, kill the host queens, then have the newly enslaved Formica workers raise the Polyergus queen's brood. When these brood mature, the Polyergus workers begin slave raids on more Formica nests, stealing Formica pupae and larvae for food and as future slaves.

The Polyergus workers do very, very little to maintain the nest - their Formica slaves gather food, maintain the nest on their own. If the ants relocate the nest, the Polyergus workers don't even move themselves to the new nest - the Formica workers carry them!

These photos were taken in Arizona's Chiricahua Mountains, near the Southwest Research Station.


Click on the images below to see a larger version

Polyergus breviceps worker returning to the nest with a pupa raided from a Formica nest.
Polyergus breviceps worker returning to the nest with a pupa raided from a Formica nest.
Polyergus breviceps biting photographer
Polyergus breviceps biting photographer
Polyergus breviceps nest site, in and around a tree stump
Polyergus breviceps nest site, in and around a tree stump
Polyergus breviceps worker, side view.
Polyergus breviceps worker, side view.
Polyergus breviceps worker - you can clearly see the sickle-shaped mandibles.
Polyergus breviceps worker - you can clearly see the sickle-shaped mandibles.
Polyergus breviceps worker returning to her nest, carrying a newly eclosed Formica worker from the victim nest. The worker will probably be eaten at the Polyergus nest.
Polyergus breviceps worker returning to her nest, carrying a newly eclosed Formica worker from the victim nest. The worker will probably be eaten at the Polyergus nest.