By Don Robinson
Along the Cacapon every summer, we always manage to see some giant moths flitting about lights, or flying into our headlight beams. It is always a time of excitement, and everyone drops what they are doing to go and look at these natural wonders. The family name of the giant silk moths is 'Saturniid' which I suppose in Latin must mean 'awfully big moths'. The order of these insects is Lepidoptera and includes all butterflies and moths.
The adult stage of these moths, of which there about fifteen varieties in West Virginia, only live for about a week, and that is usually in the early summer. There aren't many of them, and their numbers have been in decline at least in part due to the introduction of artificial night lighting. The female emits a pheremone, and the male, which 'smells' her with his chemo-sensitive 'antennae' can be drawn from miles away. They mate for a day, then the female lays about 100 eggs and dies, while the male may attempt to meet another female, but will die shortly. Many bird species feed on the young caterpillars, so few make it to adulthood. They mostly eat foliage of trees and shrubs. Generally, the caterpillars are colored in greens and browns making them hard to see. If not, then they may have fierce looking fake eyespots to scare off predators. Their cocoon is a silken pouch that is big and strong enough so that Native Americans, Mexicans, and African tribes used them for durable containers.
Here are a few paragraphs that may help you identify silk moths you might see.
A giant brownish-winged moth with a reddish body and whitish crescent shaped marks on the wings is likely to be a Cecropia moth (Hyalophora cecropia). The Cecropia is the largest of the moths in North America. A promethea moth (Callosamia promethea) is also brown, with noticable eyespots on the wingtips and waterstain type wing markings. A tuliptree moth (Callosamia angulifera) is missing the crescents and the body and wings are brown. The polyphemus moth (Antheraea polyphemus) is also brown, and has four large eyespots, the two on the hindwings being surrounded by a dark region.
The green Luna moth (Actias luna) is likely the most commonly seen, with it's long 'tails' and pale green color. The Io moth (Automeris io) has two huge dark spots on its hindwings. The male is yellowish in color with a purple-brown area near the body. The female has the same eyespots, but is more purple to brown in tint. The Royal Walnut Moth (Citheronia regalis), also called the Emperor moth and the Regal moth, has reddish brown wings with yellow spots on them. I once saw a dead one float by my dock. The Imperial moth (Eacles imperialis) is large and yellow with purplish brown markings. My wife once had one fly into our van, and wrapped it in her shirt to show me when she pulled into the cabin. It was unhurt, as she had come to a near stop when it flew in. It hung around for a while the next morning, but was gone when I looked for it in the afternoon. The Eastern Buckmoth (Hemileuca maia) is greyish with a few white markings.
The Oakworm moths (three different species: Anisota stigma,Anisota senatoria,Anisota virginiensis ) are reddish-brown to orange and pink with a light colored spot on each wing. I saw a couple of these mating, and a huge number of Saturniids (13 as I recall) on my neighbor Joe Michael's porch this summer. They must have been attracted by some chemical odor, perhaps from a dryer? I know it wasn't me. Another Saturniid on Joe's porch was the distinctive yellow and pink Rosy Maple moth Dryocampa rubicunda.
The Pine-devil moth Citheronia sepulcralis and the Bi-colored Honey Locust moth Sphingicampa bicolor are similar in their color, grey with pink markings on the hindwings.
There are 1500 known species of the giant silk moths, Saturniids, on Earth, mostly in the tropical zone. Enjoy seeing some in West Virginia!