Field Notes––

Life As A Luna Moth: Hanging Out By Day, Mating By Moonlight

By Dottie Evans

You could live your whole life and never see a luna moth. Or you might be one of the lucky few who can count the number of encounters on one hand.

It’s not that Actias luna is all that hard to spot. It’s as big as your fist and its wingspan is a full four inches across. Its color is an eye-catching luminescent yellowy green, the hind-wings have eyespots, and the under-wings sport long feathery tails.

This spectacular insect looks like a butterfly but you know it’s a moth because the antennae are hairy, even feathery. Once you’ve spotted it you’ll have plenty of time to get a closer look due to its daytime habit of resting quietly. The luna moth relaxes by hanging from a vertical surface such as a tree trunk or a vertical wall.

The problem is finding one in the first place.

The luna moth was nearly eradicated from Connecticut by aerial spraying that began in the 1950s to control its undesirable cousin, the gypsy moth. Thanks to more recent awareness of the negative environmental effect of broadcast spraying, luna moths are making a slow comeback in Fairfield County. Though the Department of Environmental Protections (DEP) lists it as endangered in several states, Connecticut is not on that list.

From egg to caterpillar to pupa to adult, the luna moth’s life cycle illustrates the miracle of metamorphosis. For five to six weeks in early spring, the caterpillar gorges itself on foliage from a variety of sources including sweetgum, American beech, red maple, hickories, white oak, black cherry, willows, smooth sumac, and American chestnut. (The latter might be missing from the menu since 1904, when the chestnut blight first hit New York City.)

After bulking up and shedding its skin several times, the full-grown caterpillar falls to the ground and begins to pupate. It draws a leaf around itself and spins a papery silk cocoon, making a cozy retreat where it undergoes a final transformation. Within three weeks, the adult luna moth emerges triumphant –– looking nothing at all like the bristly, three-inch-long green caterpillar that ate everything in sight.

Now, the luna moth is done eating –– in fact, eating would be impossible since it does not possess a mouth. It will live only one week longer, and its sole mission is finding a mate.

Despite this urgent imperative, luna moths make the most of their brief courtship period. No wonder they are named after the Roman goddess of the moon since they fly only on clear nights and mate only after midnight. They manage to find each other by scent, since the females exude chemicals known as pheromones that attract the males.

After mating, it’s mostly all down hill. The male luna moth dies, and so does the female –– but not before she has laid her 200 or so eggs on the undersides of black walnut leaves.

I have seen luna moths only twice, and it’s not enough.

My first encounter was June 15, 2002, in Pittsfield, Mass., when I was visiting friends for the wedding of their daughter. The moth was hanging from the brick wall of the greenhouse at Miss Hall’s boarding school where we had gone to arrange the wedding flowers. Perhaps it drew inspiration from the upcoming nuptials.

My second encounter was two weeks ago on Monday, June 13, outside the law office of Lux & Timmel at 45 South Main Street. Attorney Bill Timmel had called The Bee saying he’d seen the moth when coming into work that morning. He noticed it hanging on the yellow, shingled wall by the back door, and he guessed it might have flown out of the lush meadows in Amaral’s field behind the office.

Judging by the timing of these two sightings, we might all see luna moths if we simply dedicated the middle week of June to looking for them. Taking care not to bump into each other, we should walk slowly past buildings, telephone poles, and tall trees with our eyes cast modestly down to luna moth lounging level, which is two feet off the ground.

To witness their miraculous, mating flight we’d grab our flashlights and head for the nearest meadow at midnight. Once a year every June, hang out with luna moths.