Making a Big Stink: Invader from Asia Turning up on Doorsteps

The brown marmorated stink bug. Credit: Yerpo via Wikimedia Commons
The brown marmorated stink bug. Credit: Yerpo via Wikimedia Commons

By Stephen J. Kotz

Gypsy moths, deer ticks, termites. Is it time to add stink bugs to the list of pests, whose presence causes near panic among East End residents? Probably not, although some posters on Facebook have made it sound like this year’s bumper crop of stink bugs is the worst plague since God rained locusts on the Egyptians.

That said, the brown marmorated stink bug, an invasive species from Asia that gets its name from the foul odor it emits if threatened or crushed, is, in fact, enjoying a spike in population this year that has made them a fairly common sight lurking on window screens and around doorways here on the East End.

First things, first: If you happen to find a brown bug that looks like a miniature shield about a half-inch in diameter loitering on your front porch, don’t panic and do anything stupid like stepping on it. They have a well-deserved reputation for stinking up the joint — their odor has been described as similar to crushed onions or pungent Coriander.

Despite a smelly self-defense mechanism that makes them unsavory to potential predators, stink bugs are harmless to humans and their homes, according to Dan Gilrein, an entomologist with Cornell Cooperative Extension in Riverhead.

“It doesn’t bite, damage the structure or reproduce indoors,” Mr. Gilrein said this week. “It’s just looking for a place to overwinter.” Starting in early September, adult stink bugs look for protected places — from a cozy opening under tree bark to a corner in your closet — to spend the cold months. “They seem to be attracted to white or other color lights, including white or light-colored houses or trim,” he added.

While stink bugs are harmless to humans, they can cause serious damage to fruit crops, like apples and peaches and vegetables, including beans and sweet corn, if left unchecked. They are also known to feed on ornamental landscaping plants, though the damage to them is generally minor, according to Mr. Gilrein.

“I’ve noticed somewhat higher numbers this year than in previous years,” he said, while adding that far more serious outbreaks occurred in some mid-Atlantic states, including Delaware, New Jersey and Maryland, several years ago, resulting in widespread damage to orchards and vegetable crops. “I recall a photograph in The New York Times of homeowners shoveling them of their home porch,” Mr. Gilrein said.

Stink bugs were first reported in the United States in Allentown, Pennsylvania, in 1996. They have been on Long Island since 2010.

Even though he is in the pest control business, Brian Kelly, the owner of Twin Forks Pest Control in Southampton, said he did not recommend trying to control the insects with chemical insecticides.

“The best thing to do about stink bugs is not let them into the house to begin with,” he said this week. Mr. Kelly said homeowners should seal cracks and seams around windows, doors, vents and other openings to prevent the insects from entering. “But if you find them in the house, you can just vacuum them up, although you want to be careful because they will make your vacuum stink,” he added.

Mr. Kelly said he would not necessarily liken the bugs’ odor to a spice, “but it is strong and pungent.”

Some sources suggest do-it-yourself traps: Take a large aluminum foil pan and fill it with soapy water and leave it in a dark area with a light above it. The light attracts the bugs, which then drown in the water.

Stink bugs are not known to have any natural enemies because their odor tends to make them unsavory to birds or other predators, said Mr. Gilrein. But the recent arrival in the United States of the tiny samurai wasp, also from Asia, might help. The wasp, which doesn’t sting, is a parasite that lays its own eggs in stink bug eggs. The wasp larvae hatch first and devour the stink bugs before they can hatch themselves. The only problem is the wasp is an invasive species itself, raising questions about its long-term impacts on ecosystems to which it is introduced.