During their yearlong residency in my house, I've become rather intimate with these small, airborne beasts. I know them: We've shared meals and watched each other grow, and they've even accompanied me in the shower, though typically to their own watery demise. I have seen these moths through all phases of their lives, through multiple generations. I know how they are born and what makes them thrive, but most importantly, I know what kills them.
I knew it was over between us when I caught my moths writhing around in my jasmine rice, their squirming, pale-yellow larval bodies cocooned in silk threads, their dark, miniscule eyes and mandibles just large enough to identify with the naked eye. It was disgusting. There had been signs of course. We'd seen the fully formed adult moths fluttering around the kitchen and observed the webbing in the pantries, and we had even found one particularly pioneering larva in the bristles of my partner's toothbrush. But this rice infestation? This was enough.
As a science and environmental reporter, keen to the toxicity and environmental havoc of traditional extermination practices, I hired Danny through one of New York City's many eco-friendly pest-extermination companies -- one that promises to kill the designated pests in your abode without killing the environment (or your wallet). "Pantry moths," explains Danny, stretching a pair of pale-blue surgical gloves over his hands, "are hard to get rid of."
As Danny sprays, I tell him that I'm working on a story about the ethics of extermination and the various species we encounter and kill within our homes. Danny isn't exactly allowed to speak on the record on behalf of his company ("Danny" is not his real name). The word "silica" however, does pique his interest.
As it turns out, that mineral compound is one of nature's most effective natural insect killers. If you've ever had a bedbug problem, you will probably have seen silica in the form of diatomaceous earth -- a white, chalklike powder made up of a fossilized algae. "The bedbugs will crawl all over it, and it dries them up!" explained Jared, an exterminator for Ecology Exterminating, another New York-based, eco-friendly extermination company whose staff preferred not to be fully identified. He continued to describe how as insects traverse DE's chalky plains, the compound sticks to their waxy exoskeletons. The silica, bearing a particular knack for absorbing moisture, then leeches all the lipids from the insect's exoskeleton, causing them to dehydrate and die. As Jared reiterated, "It gets into their skin and it sucks 'em dry."
While diatomaceous earth is not used to address moths, there is still silica present in the cedar oil that Danny has been administering in my kitchen. As he sprays every nook and cranny, he tells me this liquid form of the mineral works to dehydrate the moths while the cedar-oil fumes suffocate them. For my moths and most other insects, the scent of cedar oil forms a noxious, dizzying fog that inhibits their respiratory functions. It also leaves them too disoriented to mate -- something I ruminate over while I watch one affected moth begin to descend into confused swallow loops before it lands clumsily onto the kitchen counter. That moth is in no condition to fly, let alone consent to intercourse.
Heeding the common adage, I've made it a point to keep these enemy moths very close. In my dogged quest to gain a deeper understanding of my cohabitant species, I also consulted entomologist Lou Sorkin of the New York Entomological Society about my pantry-moth problem. "Oh!" he exclaimed. "Is it plodia? Indian meal moths? That's a common one."
The "plodia" he is referring to is plodia interpunctella, the taxonomic term for pantry moth. These insects also go by the colloquial "Indian meal moth," a colonial relic born of a time when European settlers in the Americas referred to Native Americans as "Indians" and cornmeal (a favored food source of the plodia) as "Indian meal."
Just as their name is the product of colonial expansion, so too is their origin as an American pest. "Pantry moths are not native to [this area]," Sorkin informed me. "They're an invasive species originally from Asia. They wound up here through international trade routes, when we started importing and exporting food around the world." Even today, pantry moths are typically introduced into households by hitching a ride in a grain source, from cereals to flours, or in my case, a bag of Kokuho brand jasmine rice. Today, plodia interpunctella can be found in a kitchen pantry on every continent on earth, with the sole exception of Antarctica.
On the northeastern coast of the continental United States, under the dark gray roof of my house in the suburbs, these moths have found a particularly happy home. "They like to mate at around 4 to 5 PM," said Sorkin. "Female moths will release pheromones to attract males." The results of these late-afternoon copulations are microscopic eggs. An individual female moth can lay up to 400 of these in her short lifetime as a winged, adult moth. I quickly estimated that there were at least thirty moths floating around my house at any given time. Assuming half of them were females laying their 400-egg capacity, I deduced that within three days, up to about 6,000 infantile moths could have been planted inside my house. That's way too many eggs and way too many moths.
When I asked Jared, my second extermination expert, what inspired his 11-year career in pest extermination, he replied with a simple truth: "Things change, technology changes, but one thing that's not gonna change is that there's always gonna be mice and rats and roaches. They'll be around forever." My moths, I thought, had better not be around forever. Still, Jared is absolutely right. Since the dawn of agriculture, humanity has been trying to eradicate species we deem pests from our areas of dominion in all manner of ways.