Did you think doodlebugs were only make believe? Doodlebugs are real! Doodlebugs are the nickname given to certain types of nerve-winged insects. These critters can only walk backwards, and leave scribbled, cursive trails as they move along. Because it appears that they're doodling in the soil, people often call them doodlebugs.
Doodlebugs are the larvae of insects known as antlions, which belong to the family Myrmeleontidae (from the Greek myrmex, meaning ant, and leon, meaning lion). As you might suspect, these insects are predaceous, and are particularly fond of eating ants. If you're lucky, you might see an adult antlion flying weakly at night. You're much more likely to encounter the larvae than the adults, however.
Have you ever hiked a sandy path, and noticed clusters of perfectly conical pits about 1-2 inches in width along the ground? Those are antlion pits, built by the chubby doodlebug to trap ants and other prey. After constructing a new pitfall trap, the doodlebug lies in wait at the bottom of the pit, hidden beneath the sand.
Should an ant or other insect wander up to the pit's edge, the movement will start a cascade of sand sliding into the pit, often causing the ant to fall into the trap. When the doodlebug senses the disturbance, it will usually kick sand in the air to further confuse the poor ant and to accelerate its descent into the abyss. Although its head is tiny, the antlion bears disproportionately large, sickle-shaped mandibles, with which it quickly grabs the doomed ant.
If you want to see a doodlebug, you can try luring one out of its trap by lightly disturbing the sand with a pine needle or a piece of grass. If there's an antlion lying-in-wait, it may just grab hold. Or, you can use a spoon or your fingers to scoop up the sand at the bottom of the pit, and then sift it gently to unearth the hidden doodlebug.
Doodlebugs do fairly well in captivity, if you want to spend time watching them build their traps and capture prey. You can fill a shallow pan or a few plastic cups with sand, and add a doodlebug that you've captured. The antlion will walk backwards in circles, gradually forming the sand into the shape of a funnel, and then bury itself at the bottom. Catch a few ants and place them in the pan or cup, and watch what happens!
Not all members of the family Myrmeleontidae make pitfall traps. Some hide under vegetation, and others inhabit dry tree holes or even tortoise burrows. In North America, the seven species of doodlebugs that make sand traps belong to the genus Myrmeleon. Antlions can spend up to 3 years in the larval stage, and the doodlebug will overwinter buried in the sand. Eventually, the doodlebug will pupate within a silken cocoon, encased in sand at the bottom of a pit.
- Insects: Their Natural History and Diversity, by Stephen A. Marshall
- Kaufman Field Guide to Insects of North America, by Eric R. Eaton and Kenn Kaufman
- Antlions, by Wayne P. Armstrong, Palomar College, accessed December 11, 2012
- Family Myrmeleontidae - Antlions, Bugguide.net, accessed December 11, 2012
- Beneficial Insects: Lacewings and AntlionsUtah State University Cooperative Extension, July 2008. Accessed December 11, 2012