While in Austin at the Entomological Society of America meetings, I had the chance to tour The University of Texas at Austin’s Brackenridge Field Laboratory. Located on 82 acres of land bordering the Colorado River, the station supports studies in biodiversity, ecosystem change and natural history. A major focus of research at the station involves efforts to establish biological control agents for control of imported fire ant (Solenopsis invicta) using entomopathogens and parasitoids (e.g. phorid flies in the genus Pseudacteon). This research relies on maintaining cultures of fire ants to support rearing of the phorid fly. While time was limited and I did not have much opportunity to photograph either the ant or the fly, I did manage to quickly sneak in a shot or two of some winged reproductives that were removed from the teaming formicid mass in a rearing tray and placed on a table top for all to see (and when I say “a shot or two” I mean it. I had the chance only for one shot of the female and two of the male as they crawled crazily about and the tour leader quickly tried to move us on). I’m sure Alex Wild has all stages/forms of this species covered in spades, but the sexually dimorphic winged reproductives were new for me, and perhaps some readers of this blog as well.
Solenopsis invicta winged reproductives: male (top), female (bottom).
Copyright © Ted C. MacRae 2013
Beetles In The Bush 
Male Solenopsis invicta (and other saevissima group species) are pretty darn awesome. Giant, weird-looking, and of course, neglected. Thanks for the ant reproductive shots! 😀
I never realized the males had such tiny heads and that their antennae were not elbowed..
Yeah, it’s a pattern that crops up occasionally, where we have pin-headed males with massive bodies. Some other cool examples include Pheidole (a hyperdiverse genus for which we know nothing whatsoever about what the males are doing), Trachymyrmex (a graded genus basal to the leaf-cutting ants), and Linepithema humile, the infamous Argentine Ant. I think the argie males are particularly cool because this is a case where we have massive pin-head males are clearly derived from within a clade with males which are almost all “female proportioned.” I’d be a happy camper if someone figured out what drives the evolution of these “steroidal” male ants.
Oops—I got totally side-tracked too. About the elbowed antennae: Only a few lineages of ants have males with long antennal scapes! The pleisiomorphic state for males (and for whoever the deep stem ant was) is having very short scapes. I can count on my left hand the number of times long scapes have evolved in male ants (at least for the New World).
This sexual dimorphism is fairly typical for ants, though there are a few oddballs (e.g., Hypoponera opacior) that have wingless, worker-like males.
See this http://alexwild.smugmug.com/Ants/Natural-History/Male-Ants
I swear the males of some of those species look more like braconids or something.
Cool transluscent heads on those Hypoponera opacior males.
They are commonly intitially misplaced in Braconidae or as “wasp” at bugguide.net.
Ahahaha, don’t those look familiar. 🙂
The way I was taught, male ants generally have “big shoulders, tiny brains.”
It’s neat how you can really see how they hang onto normal-sized eyes, though. I’ve never noticed that before.
Hah – good point. I think about it occasionally (occasionally): From the myrmecological perspective, it’s the male ants which have weird, massive eyes. Really, from the non-Formicidae hymenopteran perspective it’s the females who have the derived, miniscule eyes. For queens (and to a greater extent, the workers) there is likely an energetic trade-off between production of eyes suitable for flight and eyes which are “good enough” to see when walking (or nestled in the nest).
Funny – I happen to be watching football as I read this 🙂