Thursday, July 17, 2014

The Personal Moth

(Reclaimed from Bubblews, now with a Morguefile photo by Mary B. Thornton, "Puravida," showing a pair of giant silk moths that might be Eacles imperialis, or they might be something else; without size and location information I'm not positive.)

Long ago, a nickname for a person who kept following someone else around, in the absence of any encouragement, was "personal moth." Many moths are attracted to light (some scientists think they're trying to navigate by moonlight and other lights confuse them), and your personal moth is attracted to you in a dizzy, confused, sometimes self-destructive way.

During the past week I had a personal moth that really was a moth. I'm not sure of its species identity--something in the very large Geometrid family, all of which, except the Tulip Tree Beauty, I have to look up to identify. It flew into my bedroom one night while the light was on. It stayed while the light was off. It didn't do much flying at all, but when it did it always seemed to want to fly right at me--as if to tag me in a game--just once every evening.

I had some idea why the moth wanted to make itself a nuisance in that way. It, probably she, had found a territory in which its subtle scent could be detected by other moths. (Most animals other than moths don't notice moths' scent, but moths use scent to find each other.) It was trying to attract a mate. Possibly it even had an instinctive urge to "tag" anything in its territory that moved about--tree branches, large animals, whatever--in order to broadcast its scent further and attract a moth of the opposite sex to its territory.

One year, long ago, this strategy almost worked for a rare and showy moth, Eacles imperialis, and a couple of Eacles became my personal moths.

This started when I was at the home of friends on the far side of Kingsport, Tennessee, almost twenty miles from my home. Someone went to the door and screamed. "Eww, what is this thing on the screen door! Is that some kind of butterfly, or is it...a...bat?" She was obviously afraid of bats.

I recognized it at once as the female Imperial Walnut Moth, the second or third largest moth found in Virginia and Tennessee. At the time I had a copy of Paul Villard's book, Moths and How to Rear Them," which described the habits of Eacles imperialis. So I knew that, although the moths are enormous and have proportionately large and hungry caterpillars, their population is very well controlled and they don't become pests. In fact, in most of their range, they're seldom seen; even the adults in that house hadn't actually seen one flying about.

Populations of Eacles imperialis are controlled by the same things that control populations of most of the big silk moths. The moths don't eat, and have less than a week to live on their body fat. Flying about in search of mates shortens their life expectancy, since it takes considerable energy to carry their relatively heavy bodies. Most individuals never find mates. When they do, Villard reported, Eacles like to enjoy their day or so together in privacy, and may snuggle all day.

"Well, take it away! It's so big and ugly!" the teenager screamed. So I released Ms. Eacles, not at the Cat Sanctuary, but into some pine trees outside my geriatric patient's catless home. The caterpillars of this species eat pine needles, although this web site lists a variety of other things on which they may be able to survive:

About a week later, I found a male Eacles imperialis clinging to the door of the Cat Sanctuary. He didn't move when I approached, nor did he protest when he was scooped up in a box and taken to the pine trees. Anyone would have thought he knew where he was being moved to, and why. Quite possibly he did.

And for the rest of his short life, Mr. Eacles remained a personal moth. He spent nights in the pine trees. As the sun rose, he would come to the door or window and wait to be let in. He spent most of the day sleeping in an empty vase in a closet. Around sunset, he would fly up out of the vase, circle the room once or twice, find the window, and flap against the pane until he was let out for the night.

He was no trouble at all, but he aged visibly every day and lived with humans for only five nights.

Nice clear pictures of the male and female Eacles, showing how easy it is to tell the sexes apart, are found at the Wikipedia page:

...but those pictures don't necessarily prepare people who see these moths for the sight of a native North American moth whose wings spread out more than wide enough to cover most women's hands. This moth is completely harmless to humans at all stages of its's only surprising.