A few weeks ago I mentioned my discovery, just down the road from my house, of a Formica field ant species I’d never seen before: Formica vinculans. This active little ant is a prairie specialist, and I was surprised to find a healthy population in downtown Urbana. We’ve lived in our present house for several years, and these had somehow escaped my notice the whole time.
I should have suspected these little ants would host parasitic ants I’d also never seen. And so they do!
Last week I chanced across a raid by the social parasite Formica gynocrates, spilling across the sidewalk with their mandibles full of F. vinculans pupae. Formica gynocrates are one of many so-called “slave-raiding” ants that benefit from the labor of ants taken as immatures from the nests of other species. I didn’t have my camera with me for the raid, but I returned later to capture a few photographs at the parasites’ nest.
A remarkable aspect of ant taxonomy, even in well-studied faunas like our midwestern one, is that many species are still essentially unknown. Formica gynocrates was not formally described until 1985.
Canon MP-E 65mm 1-5x macro lens on a Canon EOS 7D
ISO 250, f/13, 1/250 sec
diffused MT-24EX twin flash
thanks to James Trager for helping confirm the ID