Wasmannia auropunctata – little fire ants
Buenos Aires, Argentina
One of the world’s worst invaders, the little fire ants have spread from the new world tropics to warmer regions around the globe, becoming especially problematic on oceanic islands. The ants above, though, are from an innocuous native population in northern Argentina. They arrived at a cookie bait at the Costanera Sur reserve, barely noticeable specks of orange just over a millimeter long.
Wasmannia has a painful sting for such a small insect, and the ants do this annoying thing where they’ll wander around on your body for an hour or two before deciding to stick it to you. So there you’ll be, relaxing at the bar long after getting in from the field, and ZAM! Right between the shoulder blades.
Photo details: Canon mp-e 65mm 1-5x macro lens on a Canon EOS 20D
ISO 100, f13, 1/250 sec, diffused flash
Myrmecos Blog 
They’re a scourge in the Galapagos, where their depredations destroy the eggs of the unique tortoises on several islands.
Great picture. Is auropunctata the only Wasmannia species, incidentally? It’s the only one I hear about, anyway.
Thanks, Jason. Good question. W. auropunctata is really the only common species, but there are several others, most rather similar in appearance and all Neotropical. See here:
Wasmannia at Antweb
So do they all have the same potential to be invasive, then?
That’s one of those unanswered questions. Nobody knows anything about the other species- they might become invasive but have so far lacked the opportunity to be spread by commerce, or they might just not have the traits (e.g. polygyny, tolerance of disturbance) that make some ants good invaders.
I’d recommend it as a research project, but the other species can be so difficult to locate that you won’t necessarily be guaranteed any results.
Are these the same as regular fire ants? I really do not like fire ants!