Creature Feature

Meet the largest moth in North America 

In the late spring and early summer, a giant reddish-orange moth can be found fluttering around the bright lights of buildings. They emerge after a two-year rest underground and have only a few weeks of life. The royal moth (aka the regal moth) is the largest moth you can find in Maryland.  

With a wingspan up to six inches and a body as big as my little finger, this moth has several unusual characteristics. When they emerge from the ground, they do not feed or drink. They have lost the ability to swallow. Their only objective is to reproduce. The female moth attracts males with pheromones and males will follow from up to miles away.  

After the female lays her eggs, she dies. The eggs are usually laid on the leaves of hickory or walnut trees and the caterpillars that emerge are incredibly horrible looking, earning them the nickname Hickory Horned Devils.  

Over a summer the devils go through four molts with each variation making them look more hideous and dangerous. At their fourth and final molt, they are four inches long and have several sword-like projections from just behind their head and long soft spines at the end of their body. They are green with little green triangular patterns on their sides.  

Before returning to the ground, they will turn a blue-green color and burrow six inches into the earth. There they form a resting chamber and spend two years pupating into the moth. 

As forests are lost to development and insecticide use increases, the royal moth becomes collateral damage. The May issue of National Geographic magazine describes the tremendous decline in the insect biomass since 1970. In Germany, the loss is 70 percent. It is easy then to know why the insectivores, like birds, have also begun to disappear by the same amount.  

I have said it before, but it’s vital to plant native plants as much as possible and use little or no insecticide or herbicide. Leave a section of your yard or park on the wilder side, a spot that doesn’t need to be mowed or trimmed or sprayed.