Wild About Texas: Antlion 11-05-14
Published 4:45 am, Tuesday, November 4, 2014
We as Americans have a tendency to overlook the smallest of things due to the busy-ness of our schedules. One small predatory insect that can be found in our own backyards is one such example of how amazing the natural world can be.
Antlions (Scotoleon sp.) are an abundant insect throughout most of the deserts of the southwestern United States, including right here in West Texas. It requires sandy soils, and it prefers shaded areas provided by brush, grasses, and commonly, carports and farm stables. Their presence can be detected by the conical pits resembling funnels in the soil. It is in these pits that the larvae stage of this insect resides.
The larvae stage of the antlion is rather small, only achieving a length of approximately one-quarter inch. The miniscule size is not the story on this tiny insect however, as it looks like a character straight out of the Star Wars saga. As with other insects, it has three pairs of legs, as well as three body parts (head, thorax and abdomen). Each one of the legs ends in a sharp spike, and the hairy abdomen actually encroaches onto and even over the thorax. Attached to the front of the head is two large, sickle-shaped mandibles that have several jagged edges that aid it in holding onto its prey. It is these mandibles that give this animal a truly terrifying appearance.
The adult phase of this insect are rather drab in appearance, so much so that they are seen by many but recognized by very few. The overall body coloration is typically a dull gray, and the wings are delicately clear. The abdomen is elongated and thin. They have large bulbous eyes and stubby antennae. In short, they look like dull colored dragonflies.
After hatching, the larvae will dig its first aforementioned pit into the loose soil. It is in this funnelized pit that the antlion receives its food like manna from heaven. As unsuspecting ants (its favorite dietary item) fall into the funnel, the antlion snaps its massive jaws shut on its prey. If this predatory response somehow miscues, then a truly ferocious attack will ensue. As the ant attempts to climb out of the pit, the antlion will use its spiked legs to flick loose soil upward, causing the prey item to come tumbling toward it massive mandibles again. This sequence happens time and time again until the antlion achieves its goal of obtaining food. The larvae antlion will remain in this pit for up to three years until it spins a cocoon, transforms and emerges as an adult.
Adult antlions are also insectivorious predators, although not nearly as brutal as when they are in the larval stage. In fact, some species of antlion adults do not even feed once before they mate and subsequently die.
The larvae stage of this amazing creature is very unique, not only in appearance, but in its behavior as well. If you are lucky enough to come across one of the conical pits in the ground, take the time to disturb it gently and watch as the larval antlion hurriedly repairs its “death-trap.” Its body shape is designed in such a way that it can only walk backwards and it uses its oversized abdomen as a spade to dig down in a circle to fix its home.
Michael S. Price is executive director of the I-20 Wildlife Preserve and Jenna Welch Nature Study Center in Midland.