DOODLEBUGS IN THE DUST

The Ant Named After the King of Beasts Lies in Wait to Ambush Its Lunch

Suddenly one of the tiny holes erupts like a volcano, sending a shower of sand grains flying up from the bottom. For a moment or two, fine debris rains on the sides of the pit, and then the encircling ground becomes still again.Three dozen minicraters pockmark the powdery soil kept dry beneath a sheltering rock overhang. The symmetrical depressions in the sand range from a couple of inches across to a half inch, with corresponding differences in their depths. In the flat space between the conical sand pits, thin lines wander haphazardly in loops and arcs.

Using a pocketknife from my pack, I slip it under the bottom of the crater, lifting the dry sand, tweaking and tossing until there, I have it. Oops, it slips off the knife blade and disappears into the sand like a stone dropped into water.

I try again. There, ah, good. On the blade of the knife sits a pale flat-bodied insect that looks vaguely like a hairy louse of some sort, except that its head is endowed with reddish hooked pincers that seem far too big for the rest of its body. I manage to keep the creaturein view briefly before it scuttles off the knife blade and back into the protective sand of its now damaged home.

My momentary captive was a juvenile ant lion, or doodlebug. This insect is dusty and grubby but beautifully designed to make a living in the dirt. The key to survival for ant lions is the ability to build those neat symmetrical pits in the sand where they bide their time hoping that dinner will arrive.An ant lion in search of a construction site wanders around, just under the surface of the ground, moving backward, while tossing the sand about with rapid flicks of its head. These maneuvers create the small lines in the soil that zig, zag, and loop erratically before the doodlebug settles on a spot where it moves about in a tight circle, using its head to hurl upward and outward sand and pebbles weighing as much as 10 times its body weight.To put this achievement in human terms, imagine a 150pound man lying face down on the ground with a halfton stone on his head and neck; then imagine the man catapulting the stone far into the air with a convulsive backward jerk of his head.

The extraordinary head flips of an ant lion gradually produce the pit where the insect waits and waits some more. The patient and lucky ant lion may eventually be rewarded when a foraging ant or other walking insect steps too close to the pit and slips in.

The pit is constructed in a way that produces as steep a downhill slope as possible, one of about 40 degrees. Thus the slightest disturbance sends the sand avalanching downward, carrying the prey into the trap toward the waiting ant lion, which responds with a flurry of head flicks. Sand grains hail down on the now thoroughly alarmed prey, helping prevent its escape from the slippery pit.

Should the prey tumble to the very bottom of the sand trap, the toothed pincers of the ant lion snap shut around its leg or body in a pit-bull clamp. The captive strains mightily to break free but as it pulls forward, hairs on the ant lion's body flare outward, anchoring it all the more firmly in the soil. Soon the stabbed prey sinks beneath the sand.

Each piercing mandible of the ant lion contains a groove holding a thin tube that siphons off fluids from the body of the captured ant. When the prey is drained, the ant lion The juvenile ant lion (below, left) will lie in wait for its hapless ant victim at the bottom of an inverted conical trap. Dozens of ant lions (left) wait in ambush in such traps. (RIGHT) A metamorphosed adult ant lion shows the amazing transformation from its subterranean juvenile form.

pushes it to the surface and positions the empty husk on its head to toss it away. Thanks to their predatory prowess, many small ant lions grow larger, molting from time to time to accommodate an expanding body.

For the final molt, the now relatively large ant lion spins a silken cocoon about itself. Inside the buried cocoon, the immature insect undergoes a Cinderella-like transformation into a flying adult with a long thin abdomen and lacy wings, the very antithesis of the working-class juvenile form.

The ethereal adult crawls out of the pit to spend its remaining days far from the grit and grime of its youth, flying here and there on missions of reproduction. After mating, females lay their eggs on thin stalks attached to leaves above dusty places. The tiny hatchling larvae fall from grace into the dirt. There they begin to doodle and dig, hiding themselves at the bottom of their traps, where they wait, jaws wide open, with the patience of their parents when they were young.