What’s that Munching Sound?

Spring on that Bend in the Bayou

April 28, 2024

(Updated May 1, 2024. Errors identifying caterpillars are solely the fault of the editor.)

We were standing on that high bank in the woods of Memorial Park looking up and down at Buffalo Bayou flowing round the bend, preparing to take our spring photo for our years-long series documenting the same bend in the bayou through the seasons. The muddy river was rolling slowly at about 200 cubic feet per second, slightly above its very low normal flow of about 150 cfs.

The woods seemed a little thin still for springtime. Skeletal branches stuck their dark, woody fingers in front of us, likely victims of the severe drought last summer and fall followed by the hard winter freeze.

Down by the sweet, winding creek that empties into the bayou slightly downstream, a tall sweetgum had fallen across the stream, still festooned with ropes for swinging and climbing.

But what was that munching sound? We looked around, looked closely. We were surrounded by an army of hairy white caterpillars, gnawing their way through the leaves of just about everything, young box elder and ash. On the sandy trail a fuzzy black one inched along, testing, tasting anything In its path.

Some of them appeared to be fall webworm caterpillars, according to bug and butterfly expert Nancy Greig, founding director of the Cockrell Butterfly Center at the Houston Museum of Natural Science. Others were salt marsh caterpillars. They would soon wrap themselves in a cocoon, spend a week or more metamorphosing, and emerge as moths, pale white or yellow, wet in the wings. After drying out for a few hours, if they survive the birds and other predators waiting for them, they might live for a few months, until they lay eggs, starting the cycle all over again, and die.

Kinda confusing. What’s the point? Other than providing sustenance to other creatures.

But then, what’s the point of us?

Greig wasn’t sure why this spring seemed to be “completely crazy” with caterpillars. But she was sure they were eating up her backyard cabbages, artichoke, mullein, and Dutchman’s pipevine.

SC