We have a lot of antlions at work. The sand under our outdoor classroom building is very fine and has a lot of ants moving about, so there are hoards of antlions hanging out down there. Hoards!! If you aren’t familiar with antlion pits, they look like the Sarlacc in Star Wars. Or, if you’re not a sci-fi lover like me, they look like this:
At the base of each one of those little craters is a monster:
Well, they’re monsters if you’re an ant! Antlions, you see, are predators and they wait for their unsuspecting victims to slip into the cone-shaped pits they construct and tumble down to the bottom. The pits are lined with fine, loose sand, so the ants have a hard time getting back out and they’ll slide back down to the bottom every time they try. Sliding down to the bottom is bad if you’re an ant as that antlion is lying in wait for you, jaws poised to snap shut around you, just below the surface where they’re hidden from sight. Once an antlion gets you, your life as an ant is probably over.
A lot of people haven’t played with antlions much, so I wanted to share a series of photos I took recently of that antlion above re-burying itself after I dug it up to take some photos. These larvae crawl around backwards and they enter the dirt the same way, butt first. The bewildered antlion sat on top of the sand for a moment before it realized it was back in its usual home. Then it started digging. The butt disappeared first:
Then most of the abdomen disappeared:
It was quickly up to its thorax in sand:
Then the head and thorax started to disappear:
All you could see was the mouthparts for a moment…:
… then the whole larva was swallowed by the sand! This process took just a few seconds from start to finish, so it’s fast. Over the next hour or so, it built itself a new cone-shaped pit by throwing sand all over the place, then it waited, lurking at the bottom of the pit for a hapless ant – or other insect – to become its next meal.
Antlions are crazy cool insects as larvae, then (at least in this species) they roll themselves up in a ball of dirt to pupate before turning into a damselfly-like adult:
Check out the long, hooked antennae! That’s the easiest way to tell these are not damselflies. I know I’ve preached about this before, but it’s my very biggest insect misidentification pet peeve so I feel it bears repeating.
So there you have it! An antlion larva burying itself in sand. Next time you see a pit, think about what lurks beneath the surface. It’s the stuff of ant nightmares…
11 thoughts on “Going, Going, Gone! (Friday 5 – on Saturday)”
Great photos of an awesome insect, sadly only found in literally 1 or 2 localities in the UK, had to go to Southern Europe to see my first one. Still with global warming they may spread further in the UK, which will be an upside I guess!
There aren’t many upsides of global warming, but the movement of interesting species into places that are convenient to see them is one of the only ones I can think of. Sorry you don’t have many in your country! That’s too bad. They’re absolutely fascinating insects!
Oh, Chris, as much as I find Asian giant hornets, African type killer bees and fire ants interesting (’cause they actually are!), I’d never think of them invading new territory as an upside. More like horrors.
But I know that’s not what you meant at all. Years ago, no one would’ve heard the coos of an Eurasian Collared Dove but the last few years they’ve moved up here. I considered their calls a delight. I only wish mourning doves that I used to hear on the Prairies were here too. We’ve got the lovely great blue heron around here. I’d love to see the green heron and equally lovely white egret here too but I’ve no idea if they’d be considered invasive and unfairly compete with our heron.
Perhaps with warming, I’ll get to see antlions yet too!
Oh, I’m not talking about invasive species as an “upside” as that is almost never an upside. I’m thinking of animals (or plants or fungi or…) that move on their own as a response to climate change. Things that have been moved by people, like fire ants, are a whole different matter, but things that get to a new place on their own… It’s still a sad story and it’s unfortunate that they’re there as it points to a whole enormous problem that is going to be very hard to solve, but perhaps you can enjoy the fact that they’re there just a little? Of course the ideal situation would be for things to stay happy where they are so they don’t HAVE to move in the first place, but that’s going to be reality for a while I think…
Hmmm, never actually realised they lived so closely together: very illuminating.
Apparently they can! There are probably thousands of them in the area where I took this shot. Maybe if they have enough space and enough food, a whole bunch of them can pack into a small space? Now what I want to know is this: if you’re an antlion and you have a pit near the center of a big field of pits like we see in the photo, do they get as much to eat as the antlions near the perimeter? And if not, do these little guys jockey for position in the field, claiming good feeding areas and excluding weaker individuals? I don’t know a whole lot about this group – this may have already been worked out for antlions – but they’re the sorts of things I think about when I see so many packed into a small space like this.
Thoroughly LOVED this post with all your photos and commentary! I enjoy commentary as much as I do photos as I live to learn. As much as I’ve dug up ant nests as a child and studied ants as an adult whenever I saw them moving about, I’ve never come across antlions even though I knew what they were. So to read your post is a real treat! And I have to admit, this is the first time I’ve seen a photo of an adult. I had no idea that the fierce larvae turned into such delicate beauties. Thank you, Chris!!
I’m so glad! I had a lot of fun writing this one. Always nice when you can laugh at your own jokes. :)
I was thinking of you today as I saw two big swarms of dragonflies hunt like silent whirlwinds through the garden. But I have no idea what they were. big though. Exciting to see. And then when I drove to the other barn to feed the calves there was another lot over there too. I have never seen them do this here before.. farmland, 100 miles south of chicago, Illinois.. i hope you are having a lovely day.
We have antlions with this sort of density, but I thought there were an Australia-only beast. Thanks for posting. :-)
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