Interesting Animals: Antlion

 

An antlion larvae. There are numerous species, all in the Family Myrmeleontidae which literally means "ant lion"

Have you ever wondered what those little pits in the ground ringed by mounds of soil are? Well, wonder no more. They are made by what is known as an antlion; the larvae to be specific. They are also sometimes called "doodlebugs" because of the patterns they can leave in the sand. The patterns are actually created when the insect is searching for the ideal place to build it's tiny ant deathtrap.

Adult antlion

They're very odd looking as larvae, with those large jaws and fat bodies, but as adults they look a bit like a dragonfly. They adults aren't very good at flying. There are about 2,000 different species in the antlion family, and they are found all over the world.

The reason they are called "antlions" is because of the fact that as larvae, they specialize in eating ants. Those mounds are used to trap the ants and the shape of that mound and the antlion's behavior is such that once an ant falls in, it's almost impossible for the ant to get out. Once captured, the antlion paralyzes and then sucks the juices out of its prey. It will then discard the dried out husk with a flick of its head.  Also, apparently, the larger the mound, the hungrier the antlion. There are some very interesting videos of the entire process to be found on the internet.

An antlion mound I found today

Many list antlions as quite benificial insects mostly because of the fact that they prey on ants, a commonly cited pest. The relation to ants has always been recognized. They were even once classified as species of ants, but that classification was long ago disproved.

The Biology department at the college where I earned my Bachelors degree did some interesting experiments on antlions, including such things as if they have a preferred species of ant prey and how large does a stone have to be before the antlion can no longer fling it out of the way. During the experiment, the professors found Cyphomyrmex rimosus ants, which proved to have interesting behavior that helped prevent the antlions from eating them. One of the researcher's interest in the little fungus-growers eventually led to me working with them.

Here's a video about these odd insects from National Geographic:

Source is the Antlion Pit: A Doodlebug Anthology. First two images are from Wikimedia Commons under a creative commons license or the copyright holder allows any use: one, two