Imperial moths make quite majestic critters

On a recent family outing, my dad reached down and picked up a fat, green caterpillar and set it on a picnic table. It was a very strange-looking creature. I put my cell phone camera near its face and snapped a close-up. The image was both spectacular and a little spooky. 

 

My first thoughts were of the “sandworms” from the 1984 movie “Dune,” but this caterpillar was far more colorful and would be less likely to try eating a human being. Its face would have made a great Halloween mask. An online caterpillar search began, and we soon decided that we had found our specimen’s identity. This colorful critter was the fifth instar, or molt, of what would soon be Eacles imperialis imperialis, or an imperial moth.

 

Welcome to the fascinating and esoteric field of entomology, the study of insects. Very few of us, myself included, are overly familiar with the circuitous path caterpillars take to become the beautiful butterflies and moths we so admire. We see birds hatch from their shells, grow feathers and learn to fly. We watch mammals give birth and care for their young as they grow. What we don’t often see are the many stages of life of caterpillars. 

 

In this particular case, eight stages take the imperial moth from an egg, through five different caterpillar molts, to a pupa or chrysalis which buries itself alive, and finally to the finished product. Several larval stages bear little resemblance to the molt before, and the final transformation from pupa to moth takes place underground.

What a crazy way to earn a pair of wings!

 

Imperial moths are large, with wingspans of up to six or seven inches, and are considered to be one of our prettiest moths. They can be identified by brown and yellow or brown and green wings, which help them blend in well with autumn leaves. In North America, they are generally found in the eastern half of the United States.

Imperials are unlike other silkworm moths in that the pupae dig into the soil rather than spinning cocoons. In southern climates like ours, most adults emerge in late summer. They mate almost immediately and the females lay their eggs, which will hatch in 10 to 14 days. That is also how long the adult moths will live. Adult imperial

moths are designed for one purpose and that’s to reproduce. To ensure they can’t outstay their welcome, mother nature gave them no way of taking in food. Imperial moths have no working mouths and cannot eat.

 

So, our caterpillar had completed six stages of life and had two stages left to go. Yet it had only lived a few weeks and would be dead in a couple more. Its magical metamorphosis — from egg, through five stages of larvae, to pupa, and finally to moth — served only to create another moth to start the whole complex cycle all over again.