The Hours of the Moth

A common white sheet, an uncommon lamp, some patience, and then: amazement.

By Yankee Magazine

Jun 28 2022


Luna Moth

Photo Credit : Photo by Samuel Jaffe/The Caterpillar Lab

By Loree Griffin Burns

When was the last time you were astonished by a creature you’ve never seen before? I’m talking unable to speak or even to breathe as something unexpected swoops from the deep dark of your own not-knowing and alights, glowing, on your extended finger. My feeling is that it’s been too long. My feeling is that you may need a mercury vapor lamp.

A mercury vapor lamp is a device that pushes electricity through vaporized mercury in order to produce light. In simpler terms: It’s a fancy light bulb. More than how it works, I want to tell you what this fancy light bulb does. A mercury vapor bulb burns hot, for one thing. When placed inside a glass tank, it creates the kind of heat in which snakes and turtles and iguanas can thrive; that’s why you’ll find mercury vapor lamps in your local pet store’s cold-blooded animals aisle. Mine cost 40 bucks.

Mercury vapor lamps also emit lots of wavelengths of light, many more than the bulbs we usually shine in our bedrooms and hallways and on our front porches. This is important because there are, right now, outside the place where you’re reading these words—no matter if it’s a house or an inn or an apartment or a school or a bus or a tree fort—insects who can see these wavelengths of light. Who are, in fact and for reasons that aren’t completely clear even to scientists who study insects, attracted to them. Which means that if you were to purchase a mercury vapor lamp and bring it home and shine it on a white surface—the back of the garage or, if the back of your garage is gray, like mine, a white sheet tacked to the gray garage—well, these insects would come. And of the insects who come, the majority will be moths.

A mercury vapor lamp will call to the same small, drab moths you sometimes see around your regular porch light. But also, because of those extra wavelengths of light, it will pull in other species, moths that are bigger, and more brightly colored, and possibly completely unknown to you. These moths are your neighbors. You haven’t seen them before because, well, you haven’t been looking. Plus, unless they’re drawn in by a fancy light bulb, they will mostly stay in the shadows, invisible. But a mercury vapor lamp will call to them. It will call even to moths in shadows that are miles from your light. Such is its power.

How do I know all this? Someone who bought a lamp and met the moths told me, just as I’m telling you. And though I could barely believe it to be true, I was curious. I went to the pet store and soon I set up a mercury vapor lamp behind my garage in central Massachusetts, and shone it on a tacked sheet. And when the first few moths showed up—several of the same kind, about an inch and a half long, sporting tented wings checkered with two distinct tones of ivory and each carrying two bright turquoise stripes down the very center of its hairy back—I was surprised. I stayed up half the night to see who else might show up.

This is how I met my first rosy maple moth (Dryocampa rubicunda), my first agreeable tiger moth (Spilosoma congrua), my first Virginia creeper sphinx (Darapsa myron). How I met the remarkable promethea moth (Callosamia promethea), and the wee micromoths that defy all my attempts at identification. Exquisite, each and all. But the moth that changed me, that turned me from a fancy light bulb owner to a bona fide watcher of moths and recruiter of other moth watchers? That was Actias luna, the luna moth.

Luna Moth
Photo Credit : Photo by Samuel Jaffe/The Caterpillar Lab

The luna is a giant and a showboat. Including antennae, it can stretch seven inches, stem to stern, and up to four inches port side to starboard. This moth is so big that if one were to get itself trapped behind the white sheet you tacked to the back of the garage, a sheet at which you’d been shining your mercury vapor lamp for hours and to which you’d come, just now, late at night, well, that moth might sound, flapping around behind the sheet as you stood in front of it, transfixed, it might sound like something larger and more leathery. It might make you think of bats.

What on God’s green earth? I asked the dog when this happened to me. His eyes were also trained on that place where the sheet rippled from behind, and he was whining. But I was half moth woman by now, to be honest, and I couldn’t rest until I’d seen what was behind that sheet.

I approached from the side.

I pulled the sheet away from the barn.

And I spied behind it two flying boats, shocking in their ghostly pale greenness, with four staring brown eye spots between them. I saw their girth and speed and—I swear it!—their tails. As I gaped, edge of the sheet in my hand, the two charted a dizzy path straight by my head, synchronized though completely haphazard, and landed in the light on the front side of the sheet.

I released the sheet, resting it against the barn again. I stretched the pointer finger of my right hand toward the closest moth, as slowly as I could. It took a year or more for my fingertip to touch the sheet, and another for that fingertip to slide down to the place on the sheet where a sprawling moth foreleg rested. And when I was nearly there, so close I wondered if we’d already touched, the sprawling foreleg moved. It lifted, swooped in from the deep dark of my own not-knowing and then landed, glowing, on the tip of my very own finger.

This gift from a pet store, from a fancy light bulb. Nights will never be the same.