Just beneath the large overhang of my roof lies a no-mans land of earth so dry that no plant grows. This dusty desert is pockmarked with small craters about the size of half dollars. One of my favorite summer pastimes is to watch ants, beetles, and other small ground dwelling arthropods stumble into the craters and inevitably tumble to the base of the slope. At the base of this cone of death lies a ferocious predator – the antlion.
Conical pits characteristic of "doodlebugs".
The antlion larva, affectionately known as a doodlebug, constructs its funnel-shaped trap by backing into dry, sandy soil and carefully flicking soil particles with its mouthparts until a symmetrical pit forms. When a victim falls to the bottom of the pit and struggles to escape, powerful sickle-shaped jaws clamp on the unfortunate insect and drag it beneath the surface of the soil. The jaws of the antlion larva bear a groove used to channel blood from the living victim to the belly of the beast. After consuming the liquid portion of the prey, the antlion tosses the carcass from the pit with a snap of its head. Should the victim escape the initial strike and attempt a desperate scramble up the slope of the cone, the antlion larva flicks sand and dirt from the base of the cone towards its prey. The resulting avalanche causes the victim to slide back into the grasp of the lion where its fate is sealed.
Adult Antlion
The adult antlion is not frequently observed and is often mistaken for a damselfly or dragonfly. I happened to capture an image of one at dawn as it stretched it lacy, newly formed wings. Little is known about the feeding habits of adult antlions other than some are predators of soft-bodied insects and others are believed to feed on pollen. They are often attracted to outdoor lights at night. These beautiful insects lay eggs in sandy soil where they hatch into the voracious larvae. Upon completing their development, antlions spin silken cocoons in the soil where the transformation from larva-to-pupa-to-adult takes place. If you wander desert places and come across a conical pit, stay well back from the edge lest you tumble in. You never really know what might wait at the bottom.
References
For more information on antlions go to: