Ant Lions
Every morning when I bicycle to work, I go past “Houghton Medical Arts”, a private clinic. For a long time, their sign out in front has said “Try Acupuncture for Pain”, and whenever I saw this, i would think of a scenario kind of like this:
Acupuncturist: Now hold still . . . [Jab]
Patient: Ow! Hey, that hurt!
A: Well, what did you expect? Didn’t you read the sign? [Jab]
P: Ow!
[and so on]
But now, as of Wednesday, the sign has been changed to read “My New Acupuncture Stops Pain Now”. I guess that whoever does the acupuncture got tired of the jokes. Although, now I get the impression that he is saying that the acupuncture is finally working, after a long period of miserable failure. It doesn’t strike me as being as funny as the previous image, but I have to get my amusement where I find it.
Speaking of poking things, this picture is the closest ants get to come to acupuncture[1]
For a lot of ants, this is the last thing they see before it clamps on and starts sucking out vital fluids.
This is an antlion larva (genus Myrmeleon[2]) that lives in the bottom of a little conical pit in a sandy patch in our backyard, under the cedar tree[3]. They are in the same order as lacewings, and the adults look a bit like small dragonflies. The larvae all look fairly similar and species identification is difficult, but the Myrmeleon genus are the only North American antlions that dig pits. If I kept it as a pet until the adult emerged, I might be able to identify the species based on things like patterns on the wings.
When an ant (or other small creature) slides into the pit that an antlion digs, those jaws snatch hold of it and suck the juices out. When it is done, the antlion flicks its head to toss the withered husk out of the pit, then waits for its next victim. The color isn’t really the color of the antlion, its body is covered with these short hairs that trap sand on its back, so it is camoflaged by the very sand that it is buried in. This is very effective. When I dug it up, the only way I could tell that it wasn’t just a clump of sand was by noting that clumps of sand usually don’t have mandibles like that.
Looking at the underside, we can get a better idea of what its native coloration would be without the sand on the back. The first pair of legs are a bit small, with the second pair quite a bit longer (you can see them in the previous picture, sticking out to the sides like oars). When the antlion moves, it strokes those long legs against the ground and moves backwards. If one is put on a sandy patch of ground, it will twitch the end of the abdomen to burrow into the sand, then push itself backwards with those long legs, shoving itself under the sand. It took less than a minute to rebury itself. The motions of this one were always convulsive. When I had it on its back, it stayed perfectly still for about a minute, then suddenly twitched and flipped over in an eyeblink. Then it sat stationary, with occasional twitches that would drive it backwards. I guess its normal lifestyle involves long periods of zero activity, with occasional very fast movements to snatch prey, and so its entire metabolism is geared towards that sort of motions.
Looking at the underside of the jaws, there is what looks like a tube embedded in the bottom. I think this is the tube that it uses to suck juices from its prey. You know, overall an ant lion really doesn’t hunt very much like a lion does. Unless there are lions that dig pits in the desert, hide under the sand, then grab on to gnus that fall into them and suck their blood. The name is really singularly inappropriate.
Finding these is really quite easy. Just look in dry, sandy soil for perfectly cone-shaped pits about 3 cm in diameter and maybe 1 cm deep. If you aren’t sure, drop an ant into it and see if it gets grabbed. I dug this one up by sliding my pocketknife blade about an inch under the bottom of the hole, prying to fluff up the sand, then looking for suspicious-looking lumps. I’m told you can also just stick your finger in the hole, and then when it grabs on just pull out your finger with the antlion hanging on to it. I’m not sure if they can break the skin or not, if they can, I think the finger method might be a bit painful.
[1] Yes, I know I’m straining the transition here, but it was worth a try.
[2] I’m pretty sure that “Myrmeleon” is just a latinized translation of “Ant lion”. This is one of the few cases I’ve seen where the scientific name of an insect has exactly the same meaning as the common name.
[3] This was far from the only one. Later in the year, there was a new brood of them and we must have had at least 20 just in that approximately 3-foot diameter circle, and they were showing up pretty much everywhere that there was loose sand. They were more plentiful this year than I have ever seen them before.
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