Ant Usurpers - Harpegnathos saltator

Hey guys. I've been an ATS member for a few months now and have finally decided to make my first thread. To lighten up the atmosphere I've decided to do a write-up of my favorite creatures - ants! This particularly species is very interesting and I hope to not only lighten up the mood, but provide some information on creatures many of you have probably overlooked. If it goes well, I might do a weekly or monthly thread on an interesting species. For now, Harpegnathos saltator!

This brightly colored ant is indigenous to India. They are in the Ponerinae subfamily which is widely believed to contain the most primitive of ants. They're tendancy to hop (which is an unusual mode of transportation for ants) has earned them the common name "Jerdon's jumping ant".

As evidence of their age, they exhibit no polymorphism (workers, soliders, etc.) and the workers look almost identical to the queen. With big compound eyes and long, sharp mandibles they look downright mean.



Besides the interesting look, they also have some interesting physiology and behavior. In "Journey to the Ants" by Holldobbler and Wilson, the two myrmecologists explain that these colonies undergo normal reproduction in that new queens found colonies, raise workers, and do little else, but otherwise have no typical behavior.

After a certain point, workers will assassinate their queen. In the picture linked above, that is exactly what is happening. Note the slightly larger thorax of the top ant? That's the queen's and she once had wings, hence the larger thorax. Why do they do this? Who will lay the eggs? Well, these workers are in fact termed gamergates. This basically means they have the ability to mate and lay eggs continuing the colony. They will produce new queens who will fly off, begin a new colony, and continue the cycle.




Not all of the workers get to mate and lay eggs, though. These ants have another peculiar behavior - social hierarchy. They can effectively be divided into three classes: the top class that mates, lays, and otherwise does no work. The middle class that was essentially demoted from the top class; these ladies are mated, but aren't allowed to lay eggs and instead perform normal nest duties. And finally, the lower class that is unmated and performs typical nest duties including foraging.

How do they determine this hierarchy? Why, they duel, of course! In "Journey to the Ants" these fights are illustrated with a few diagrams and an explanation of the process. I wish I could find the pictures for you, but I don't own a copy of the book; I took it out of the library. Essentially a worker will challenge another with a particular body language. The two ants then square off and take turns whipping each others heads with their antennae. They go back and forth up to, I think, 21 times. Neither ant is apparently injured and it is unclear how a victor is determined, but alas, the winner goes on to mate and the loser goes on to dig. A current top-class gamergate can be challenged, lose, and relegated to the middle class where she has to tend brood and expand the nest. From rags to riches... The ant way!




Unfortunately asian ants aren't particularly well studied and most of the information on ants isn't readily available via the internet. Typically if you want references, you find a book. If you have an interest in ants, though, I recommend finding a copy of both Journey to the Ants and The Ants. Both are, at least in part, by E. O. Wilson.

Maybe next time: Dracula Ants. How about it?

Hey, thanks. I really enjoyed that!

I'm looking forward to Dracula ants. Excellent....