Montana Public Radio

Bug Bytes: Antlions

Feb 5, 2019

If you’re a Star Wars fan, they may remind you of the Sarlacc and its deadly sand pit in the "Return of the Jedi."

In their adult life stage, antlions are pretty innocent. With long, slender abdomens and two pairs of translucent wings, they resemble dragonflies or damselflies and mostly feed on nectar and pollen.

Their larval stage is an entirely different story, and where they get the name “antlion."

Antlion larvae have large, square, flattened heads which bear an enormous pair of sickle-like jaws.

Unlike insect predators that actively hunt, antlion larvae are sit-and-wait predators. But they have a unique way of hunting.

They are found in dry, sandy places where the larva digs a conical pit by flinging sand out of their construction zone with a quick jerk of their head. As the pit becomes deeper and deeper, it eventually reaches the “angle of repose” or the steepest angle the larva can dig without the sand sliding down.

With the trap set, the antlion buries itself at the bottom of the pit, waiting with wide-open jaws.

When an ant or other hapless insect wanders into the pit, the ensuing landslide will bring the prey to the waiting lion. If its potential meal manages to crawl away, the larva will throw a shower of sand into the air, undermining the pit, causing it to collapse and delivering the meal.

With its prey secured, the antlion will suck the fluids out of its victim, tossing the dry carcass out of the pit when done.

After some quick repairs to the pit, it’s once again time to sit and wait for the next victim.

BugBytes is made possible by the Missoula Butterfly House and Insectarium, and Montana Public Radio. This show is also supported by funding from the Greater Montana Foundation: Encouraging communication on issues, trends and values of importance to Montanans.