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Doodlebugs - March 14, 2008


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I remember first time I ever saw a doodlebug.  A neighbor kid and I were playing out by my grandmother’s garage that had a sandy dirt floor.  The kid sticks his hand down and under a depression in the sand and brought his hand up, shaked the sand from his hand and there was the weirdest thing I think I had seen to that point in life - a larval doodlebug or antlion.  After that,  we’d scoop them out of their burrows and then watch them try to hide themselves in the sand grains trapped in our hand.  I don’t remember when I first heard the name doodlebug but it made sense.  If you looked anywhere around in loose dry sand, you might see tracks in the sand much like someone doodling on a piece of paper.  Doodlebugs or antlions would move around over the sand looking for a likely place to dig their pitfall.

The name antlion or doodlebug really applies only to the larval stage of an insect in the Order Neuroptera (literally - nerve wing) and the family Myrmeleontidae which translates from the Greek as myrmex or ant and leo or lion.  The name of the order comes from very nerve-like network of veins in the wings.  Like most winged insects, the adult antlion has two pairs of wings.  

Doodlebugs are great engineers.  They dig a pitfall by backing into the sand and then tossing out the sand particles to form an inverted cone shaped much like an upside down volcano.  The engineering comes in the angle of repose or the steepest angle at which the sand stays in place and doesn’t slide back down to fill the hole.  The larval doodlebug lies buried at the apex of the inverted cone and waits.  

Any insect that walks over the top of the cone begins a land slide and it falls into the waiting jaws of the doodlebug.  Even if it does escape the jaws and tries to crawl back out of the cone, the doodlebug will flick sand grains at it. If it hits anywhere close, the landslide begins again.  After killing the prey with its very large mandibles, it uses the hollow nature of the jaws to suck the jucies from the prey.  The dead carcass is then tossed out of the pitfall.

The larval stage is totally carnivorous while it is thought the winged adult feeds on nectar and pollen.  That makes the animal omnivorous over its life cycle.  Due to the infrequency of the chance encounter with meals, the larval-pupal stage may last as long as 3 years (Wikipedia).  

The larvae pupate in the ground by forming a cocoon of sand grains.  The adult emerges, climbs out and then dries its wings before taking off to look for a mate.  The female lays her eggs in the sand and the eggs hatch to larvae that begin to look for a dry, well drained, sandy site.

The winged adult is a terrible flyer, or at least it seems so.  They aren’t very good in maneuvering and seem to barely stay in the air.  You most often see the adults in the late afternoon or early evening.  They are sometimes conused with the damselfly but they can be separated from them by their wing type and their antennae.  Antlion adults have knobby atennae.

So, the next time you see a conical impression in the sand, scoop up under it, shake the sand out and you should have a close encounter with a doodlebug.  Just remember, once you study it a little while, put it back in the sand so we can keep the cycle going.

© Fred Searcy 2017