DOVER — Something wicked this way comes. A mysterious gnat infestation making its way through Windham County recently landed in the East Dover and Williamsville post offices. The little flies are cropping up across the region, for reasons unknown.
They’re fungus gnats, specifically. Their scientific name is Bradysia sp., and they’re tiny flying things that are attracted to light. They’re identifiable by a Y-shaped vein in their wings, and they travel in numbers — big numbers. According to postmaster Marshall Stevens, the East Dover and Williamsville post offices were sweeping up 20,000 to 30,000 of the mini pests each morning until a few days ago, when the infestation suddenly dried up.
Dr. Margaret Skinner, a research professor at the University of Vermont whose areas of expertise include pest management and biological control, says she’s received numerous calls about fungus gnats as of late from Brattleboro, Townshend, and heading west toward Bennington County. Stevens reports hearing of them in Jacksonville. “It’s a wide area, but it’s all in the same region,” says Skinner. “And just why this is happening in your area is a bit of a mystery. I had never heard of this happening with fungus gnats in the years I’ve been doing this, which is since 1984.”
Skinner says she was able to find one other incidence of a similar influx of fungus gnats in Indiana in 2008 following some major flooding. One theory for what’s happening here this year is that the area has been experiencing a hot and wet summer. “But it’s not like this is the first wet summer we’ve ever had,” she says. “Really, it’s probably a whole bunch of different factors that are all coalescing and causing it to happen. And it would be lovely to know, but that’s the mystery of life.”
Whatever the reason, it’s not fun for those it’s happening to. Fungus gnats by the tens of thousands are zooming around in residences and businesses and then, like in the post office, are dying on surfaces. But although they’re no fun, Skinner says they’re not cause for alarm in terms of health. “They don’t bite and they don’t sting,” says Skinner, “and I’ve never heard of them causing an allergic reaction.”
In other words, as far as infestations go, fungus gnats are not the worst thing that could happen. “They are certainly a nuisance,” says Skinner. “But they too will pass.” The average life span of an adult fungus gnat is five to seven days, and although Stevens thought the post offices’ problem disappearing may have had something to do with a sudden lack of wet weather, Skinner’s theory is that time was simply up for the population of fungus gnats that was plaguing the buildings, and so they went the way of all things, with the final groups dying out earlier in the week.
Skinner says to her knowledge, pesticides or sprays are not effective means of controlling fungus gnats. “All you’re really doing with that is exposing yourself to pesticides,” says Skinner. “I really believe there is nothing to do except keep them out of the house.”
She says although many people initially think their house is sealed, when they take a closer look, they find tiny spaces the fungus gnats may be able to pass through, such as a vent in a bathroom or a larger-than-average hole in a screen. “For example, I’ve got a screen door and the screen has no big holes, but it’s not that tight a door,” says Skinner. “I know there are gaps around that door. And what’s the big deal in the summertime? Well, if you have millions of fungus gnats coming in, it is a bigger deal.”
Skinner says keeping porch lights off and keeping curtains closed to block indoor lights may also help, since fungus gnats are attracted to light. “Or if I had a barn that was a fair distance from the house and I didn’t care if there were fungus gnats in there, I might put a light on over there and let them go over there instead,” says Skinner. Skinner, like Stevens, hypothesizes that the fungus gnats may have been attracted to the post offices because their lights are on through the night.
Skinner says it’s possible that given the recent onslaught of adult fungus gnats in our air, we may soon see incidences of fungus gnat larvae on the ground. Fungus gnat larvae are teeny tiny, white, wormy organisms that tend to travel in packs and sometimes form long (as in several feet long) lines of squirmy matter. Sometimes they even form a giant circle.
“It’s safety in numbers,” says Skinner. “If you’re going in a large group like that the chances of your survival are better. If we have some wet periods in the coming little while, it wouldn’t surprise me if we started seeing this and getting reports of these kind of things.”
“Don’t be alarmed if you see these formations,” says Skinner. Like the fungus gnats themselves, the larvae aren’t dangerous, even if they are gathering in numbers, forming shapes, and moving about as one creepy-crawly unit.