Who's that odd ant out?

While in sunny Florida last summer (ah, sunshine! I vaguely remember what that looks like), I spent an hour peering into a nest of little Dorymyrmex elegans. These slender, graceful ants are among Florida’s more charming insects.

Every few minutes, though, the flow of elegant orange insects out of the nest was interrupted by a darker, more robust ant: Dorymyrmex reginicula. Who was this interloper?

Dorymyrmex reginicula is a temporary social parasite. Mature colonies behave pretty much like normal ants. Workers guard the nest, forage for food, and tend the larvae. The queen lays the eggs. Nothing unusual there.

But new colonies are a different matter. Instead of starting with a young mated queen, cloistered in a chamber and patiently rearing a crop of workers on her own, D. reginicula skips those difficult early steps. She invades an existing ant colony. If she’s successful in usurping the position of the resident queen, the colony will slowly metamorphose from the host species to her own, with an intermediate period when older workers of the attacked nest coexist with the newly emerged workers of the parasite.

I’ve normally seen D. reginicula infiltrating nests of the common D. bureni. But this nest was of the rarer D. elegans, and the transition didn’t appear smooth. The host ants were putting up belated resistance, occasionally attacking the D. reginicula workers. It’s a futile fight as their own queen must already have succumbed, but it did provide great drama for a photo shoot.

A tangle at the nest entrance.

Grabbing the problem by the jaws...

...or the legs.

A Dorymyrmex reginicula worker, free of her tormentors.