Robert T. Rhode

Robert T. Rhode
Robert T. Rhode

Saturday, March 25, 2017

Majestic Moths 6 (Last Installment in This Series)

I thought I might end this series of blogs about moths in the Saturniidae family by turning to royalty. Two moths come to mind: the regal moth and the imperial moth. Citheronia regalis, commonly called the regal moth (a.k.a. the royal walnut moth), boasts a deeply vibrant orange and steel gray wings with lemon yellow spots. Eacles imperialis, commonly called the imperial moth, is costumed in purple (the color of royalty) and yellow. The wingspan of the regal moth can exceed six inches and that of the imperial can reach nearly seven inches! In A Girl of the Limberlost, author Gene Stratton–Porter named the imperial moth “Yellow Emperor,” and it performs a critical function in the plot, which I will not give away for those who have not yet had the pleasure of reading the novel. To lure readers to the book, I will share this link:

Regal Moth, Photographed by Scott D. Werner

There is great variation in the coloring of the imperial moth. The males often have larger areas of purple while the females have more yellow, making the females appear more speckled. The purple sections of the males’ wings can veer into pink or tilt into tan.

Imperial Moth, Photographed by Joel Mills

Who can deny that these are magnificent moths?

Hickory Horned Devil, Photographed by Bob Warrick

The larva of the regal moth is the so-called “hickory horned devil.” I admit that it looks fierce, but I imagine it would resent being called diabolical. When ready to pupate, the larvae make their way down the trunks of the host trees and burrow into the ground to a depth of some six inches. There, they hollow out an oval chamber wherein they transition from the larval stage to the pupal stage. Stratton–Porter believed that the pupae work their way up through the soil—point first—before the emergence of the adult moths.

My 1970s Watercolor Painting of a Regal Moth

I have never found an underground pupa, nor have I seen many of the adults. Most of those that I have witnessed have flown to the bright lights of fairgrounds.

My 1970s Watercolor Painting of a Cecropia Moth

Both enjoy feasting on the leaves of a wide variety of trees, although the list differs from one to the other. The regal prefers persimmon, ash, walnut, sweetgum and many more. The imperial selects sweetgum, oak, maple, and sassafras, as well as several others.

My 1970s Watercolor Painting of a Female Io Moth

My 1970s Watercolor Painting of a Male Io Moth

My 1970s Watercolor Painting of a Luna Moth

My 1970s Watercolor Painting of a Polyphemus Moth

My 1970s Watercolor Painting of a Female Promethea Moth

My 1970s Watercolor Painting of a Male Promethea Moth

Sunday, March 19, 2017

Majestic Moths 5

I once raised promethea moths. Here is my story.

I was disking a field on what my father called the “farm south of town” The land in Indiana was so near what had been the prairie that it was flat and had almost no trees. There was a tiny tree, a wild cherry, in the northern fencerow. When my tractor pulled alongside it, I could not believe my eyes. Could they really be cocoons? I hopped down from the tractor and strode over to the tree for a closer look. Sure enough! There were seven promethea cocoons tied lightly to the branches with silk. Each cocoon had adhered to a waxy amber leaf in such a way that predators would see leaves, not cocoons. How had the mother moth found the wild cherry so far from any other trees? … and how had so many larvae lived to the pupal stage of their metamorphosis?

Female Promethea Moth
Photographed by Tom Peterson, Fermilab
With Marking Like a Human Profile on Underside of Wing

I collected them all and took them home. Within a few days of one another, all seven cocoons “hatched,” if you will. The adult moths mated, and I provided branches from another wild cherry tree for one of the females to lay her eggs on leaves. (The others were released.) I never dreamed what a job I had just given myself! When the eggs hatched, I had to supply fresh leaves of the wild cherry on which the larvae dined. I had some ninety larvae, and, as they grew larger and entered into successive instars, or periods of development culminating in the shedding of their larval exoskeletons, they required more and more leaves. The box in which I kept them also had to be replaced by ever larger boxes. Toward the end, I was harvesting armloads of wild cherry leaves twice a day! Many of the larvae failed to survive—most of them perishing during an instar transition that did not go well. Eventually, I had thirty-three new cocoons. I vowed I would not repeat the experiment of raising promethea moths, and I kept my vow. When the second brood of adults emerged from the cocoons, I released all of them.

Promethea Moth Pair
Photographed by Tim Dyson
For the Peterborough Examiner

The scientific name of the moth is Callosamia promethea. Like all the moths I have described in these blogs thus far, the promethea is a silk moth in the family Saturniidae. It shares dimorphism with the io moth: the wings of the males are a velvety purplish brown with pale yellow edges while the wings of the females are reminiscent of the cecropia—only more tan than gray. Measured in inches, the wingspan can reach three and three-quarters. Beneath the wings of both females and males are markings that I see as profiles of human faces!

The moth is named for Prometheus, the well-known Titan in Greek myth who, as the creator of human beings and as an advocate for his creations, stole fire from the gods on Mount Olympus. In the strange ways that the Saturniidae moths become the topics of spiritual musings, I might ask if, quite by accident, the moth might have been named for a long-forgotten goddess named Promethea.    

Sunday, March 12, 2017

Majestic Moths 4

This moth’s scientific name is Hyalophora cecropia, a.k.a. Samia cecropia. Like the polyphemus, the io, and the luna, the cecropia moth is a member of the family Saturniidae. Hoosier author Gene Stratton–Porter and others of her time period were fond of calling it the “robin moth” because its colors are similar to those of the bird called “the robin.” The cecropia bears the distinction of being North America’s largest moth. Wingspans of six inches are fairly common and some greatly exceed that measurement!

My Photograph of a Cecropia Moth in June of 2002

The cecropia is named for a mythical king of Athens, Greece. It is said that King Cecrops ruled for over half a century. He was a sort of “mer-king”: that is, his upper half was that of a human, but his lower half was the tail of a fish. He taught his people to read and write. He encouraged them to practice meaningful rituals such as marriage and funerals. Cecrops was the first to distinguish Zeus as the head god, and Cecrops taught the people how to worship Zeus. In honor of Cecrops, the Acropolis (the rocky citadel crowned with many famous buildings) was designated “Cecropia.”

Cecropia Moth in Montana’s Bowdoin National Wildlife Refuge
Photo by the Mountain–Prairie Region of the U.S. Fish and Wildlife Service

The cecropia moth makes a pursy cocoon usually well attached along a lengthy twig. Over the years, I have found several of the cocoons, but rarely have I happened across the moth itself. When I have discovered the moth, I have stood in awe of its colors. Having earned three degrees from Indiana University in Bloomington, Indiana, I would like to say that the moth wears the cream and crimson, but I will admit it is more accurate to state that the moth is adorned with the scarlet and gray of The Ohio State University of Columbus, Ohio. The scarlet can vary from moth to moth, with some moths wearing the wedding red of India.

When I was living in Cincinnati, I found a cecropia with a wingspan of six and a half inches clinging to the concrete block wall behind my neighbor’s house. What maple or cherry tree had fed what must have been a gigantic larva, and what birds considered themselves fools for having overlooked such a prize? Where was the cocoon, and how many squirrels had scampered past it without realizing what a tasty morsel it contained? The moth had survived to adulthood—in the midst of a city—and I hoped its line would carry on. The next morning, the cecropia was nowhere to be seen, and I trusted that, in the night, it had found a mate.