If you don’t follow myrmecologist Ajay Narendra’s flickr feed, you should. Ajay often turns up real treasures. He’s just returned from a research expedition to Poochera, South Australia, where he’s been working with the famous Nothomyrmecia macrops. Check out this shot of a worker ant, painted so that she’s easier to follow in the field:
Those of us in the Americas who think of predatory ant-killing ants usually imagine the specialized army ants. These nearly blind insects roam in stereotypically large columns across the landscape, attacking prey colonies with forces of thousands. Army ant raids can be spectacular, enough so to raise the question of just how such an unusual behavior could have arisen from more typical ant ancestors.
Army ants didn’t evolve their mass-raiding predation instantaneously (in spite of creationist assertions otherwise). Rather, they belong to a larger group of ants, the so-called “Doryline section”, whose members exhibit a great diversity of ant-killing strategies. We can see how intermediate army ant lifestyles work from example. Hundreds of present-day species, especially in Africa, Asia, and Australia, make a living at them. Many of these older lineages have decent eyesight, stationary colonies, and raid in rather civilized small parties. Apparently a taste for ants came first, accompanied by group foraging, while the massive raids and nomadic lifestyle followed in only a subset of more recent species.
Below is a short photographic essay covering a Cerapachys larvatus raid Mrs. Myrmecos & I happened across in the Australian Alps last year. We don’t have ants quite like these here in the United States, so our chance observation of an unfolding raid was a rare treat.
For those of you who dislike spiders, I’d like to introduce you to your new favorite friend:
The genus Pison refers to a small group of crabronid wasps containing about 200 species worldwide. These insects raise their young on a diet of living, but paralyzed, spiders. Paralyzed spiders don’t decay, staying fresh while the wasp grubs eat them alive. It’s a pretty gruesome death, being chewed up in the dark and unable to move. Not that spiders themselves kill humanely. What goes around comes around, I suppose.
While in Australia I photographed one female’s mud nest stuck to the side of a building. Knocking away drying mud walls reveals the efforts of what I timed to be half an hour’s worth of spider hunting:
After I disturbed the nest, the wasp rebuilt it and promptly filled the cell with new spiders.
Canon MP-E 65mm 1-5x macro lens on a Canon EOS 7D
ISO 200, f/13, 1/250 second
diffuse twin flash
Among the more conspicuous insects we encountered during our Australian travels were Paropsisterna eucalyptus leaf beetles. Most trees I looked at in southern Australia hosted clusters of pudgy yellow larvae hanging around in plain view, munching on the aromatic leaves in happy abandon.
The beetles have good reason to be seen: they are toxic. Unusually among insects, this beetle’s arsenal includes hydrogen cyanide. By advertising this fact to would-be predators, they avoid becoming a bird’s lunch.
While stalking ants in the southern Australian state of Victoria, I encountered one minuscule species over and over again. Another stone, another nest. It was a nearly translucent little dolichoderine:
I didn’t think much of it. The insects resembled- in appearance and odor- the ubiquitous Tapinoma that is so abundant elsewhere in the world. That I stopped to photograph it at all has more to do with, what- that I’d lined up the aesthetics of solid ant nest shots? I can’t even remember. It certainly wasn’t any realization that what I was shooting was perhaps interesting.
Yet looking at the photos yesterday evening, something didn’t quite add up for a Tapinoma. The petiolar node was scalar, and there weren’t many records for Tapinoma in that region.
Consulting Steve Shattuck’s excellent Australian Ants, I checked relevant characters for Doleromyrma. Clypeal setae curved: check. Petiole with scale: check. And so it was:
Doleromyrma, although frequently encountered, has received little attention in the published literature. They occur most commonly in dry forested areas, including coastal scrub or heath, where they nest in soil, under rocks or rotten logs…
A Google image search turned up a few images of preserved specimens, but not a single photograph of a living Doleromyrma. Am I really the first person to photograph this common ant in the field? Perhaps so. Or at least, I may be the first person to identify the live photos as such.
If so, it is my great pleasure to introduce the first living photograph of a Doleromyrma queen:
And, cropping in, the first living photograph of the queen’s mites:
So often it’s the little brown things, the ones I never think twice about, that end up being the interesting stories.
Several years ago Australian myrmecologist Alan Andersen proposed a set of categories for arranging ant species by “functional group“. These groups carried names like “cold-climate specialists,” and “subordinate camponotines,” and they were widely adopted by ecologists for their ease of use. The scheme also drew considerable ire from taxonomists, especially since the categories were somewhat arbitrary and many blended behavioral and taxonomic attributes.
Another issue was that these groups, crafted from Andersen’s knowledge of the Australian fauna, didn’t always make sense outside of Australia. Certainly the “Dominant Dolichoderines” were aptly described on the great southern continent. Any stray bit of picnic lunch in Australia is nearly instantly covered by ravenous and aggressive Iridomyrmex. But do the same functional categories apply to the more timid dolichoderines of Europe?
I’m not sure.
In any case, the Aussie genus Anonychomyrma fits the bill of a dominant dolichoderine. Here are couple recent photos of Anonychomyrma defending their title.
Here’s why I love the internet. Within 24 hours of tweeting a new photo of an odd Australian wasp, I received this tweet back from the fine folks at the NCSU insect museum:
I emailed chrysidid expert Lynn Kimsey, a friend from my grad school days back at U.C. Davis. I hadn’t recognized the wasp as a chrysidid- it’s that weird! Lynn replied almost immediately:
OMG!!! I’m currently revising this genus – Loboscelidia. I’ve never seen them alive. We have no idea how they make a living except for one obscure reference to rearing one from a walking stick egg. Do you have any other photos of it??? This is a male.
Awesome. Seriously, awesome.
Twitter got the wasp in front of the right set of eyeballs within a day after I posted the photo. Now we not only know what the insect is, but we know- after some additional sleuthing- these may be the only live photographs ever taken of this species, genus, and subfamily. A Myrmecos exclusive!
Here are a few more:
To make my life complete, now I just need instant image-processing and tweeting capabilities from remote tropical jungles. Had I known in the field that this bizarre animal was a rare and potentially valuable discovery, I would have devoted more than two minutes to it.