By Lena H. Sun
Washington Post Staff Writer
Friday, September 24, 2010; 11:59 PM
Shaped like shields and armed with an odor, dime-size brown bugs are crawling into area homes over windowsills, through door crevices and between attic vents in such numbers that homeowners talk about drowning them in jars of soapy water, suffocating them in plastic bags or even burning them with propane torches. In the process, some people are unwittingly creating another problem: When squashed or irritated, the bugs release the distinctive smell of sweaty feet.
Get used to it, experts say - the invasion is only going to get worse.
"This is the vanguard," said Mike Raupp, a University of Maryland entomologist and extension specialist. "I think this is going to be biblical this year," he said. "You're going to hear a collective wail in the Washington area, up through Frederick and Allegany counties, like you've never heard before. The [bug] populations are just through the ceiling."
The change in season, as days shorten and nighttime temperatures start to dip, is nature's call to the brown marmorated stink bug - pest extraordinaire - to leave its summer gorging grounds and seek refuge inside. What's happening now is a massive population shift from orchards, cornfields and gardens to suburban homes, office buildings and hotels - the urban U.S. equivalents of rocky outcroppings in the stink bug's native Asia.
Stink bugs are harmless to people and their possessions. They don't bite. They don't sting. They're not known to transmit disease. But their population has grown so tremendously that they are not only causing vexation to homeowners but also, for the first time, wreaking damage to peaches and apples, soybeans and corn, and even ornamental shrubs and trees.
There is no easy way to kill lots of the bugs at once. They have no natural predators in the United States. Pesticides don't work effectively. The insects travel easily - hitching rides on buses and construction material - and adapt to winter in homes. As a result, they have flourished, spreading to 29 states since they arrived in Allentown, Pa., in 2001, likely stowaways in a shipping container from Asia. They are native to Japan, Korea and China, where they are known as "stinky big sisters."
And now they are causing a stink in the mid-Atlantic region.
Experts say homeowners should prevent them from coming indoors by sealing cracks and openings around doors and windows. Once the bugs are inside, residents can vacuum them up, remove the bag and put it in the garbage outside. (Beware: The smell may linger in the vacuum cleaner.) Experts warn against using outdoor pesticides.It's true: 'They smell'
"I'm looking out my window here, and I bet I have 30 of them on the screen," said longtime Middleburg resident Margo Tate. "My husband smushes them and throws them in the trash. They're a mess. They smell when you squish them."
Lori Rice, 48, runs an organic farm in Middleton, in Frederick County. She finds them indoors and outside. Indoor bugs she traps in "death jars" - pint jars containing soapy water. The soap, she said, dissolves the exoskeleton. Twice a day, she flushes the bugs down the toilet.
On Rice's farm, Asian pears, raspberries and tomatoes have all suffered.
"If all our vegetables hadn't already [been] withered by the heat and drought this year, the bugs would likely have broken our hearts there as well," she wrote in an e-mail.
She is experimenting with spraying soapy water outside.
For people, stink bugs are nowhere near the menace of bedbugs, which feed on human blood. Their resurgence prompted the U.S. Centers for Disease Control and Prevention to issue an unusual statement last month about their public health impact.
Stink bugs, by contrast, are a mere nuisance for people, though they are causing farmers real distress.
Maryland's Agriculture Department last week warned that the bug is emerging as a devastating pest to orchard owners and potentially to soybean growers.
"In Maryland this year we have had the most extensive brown marmorated stink bug damage to both tree fruit and vegetables ever reported in the U.S.," said Jerry Brust, a University of Maryland pest expert.
Bob Black, whose 100-acre Catoctin Mountain Orchard in Thurmont, Md., includes peaches and apples, said he has lost about 20 percent of his crop. The bugs suck out juices, leaving pockmarks that make fruit and vegetables unmarketable.
Dairy farmers are worried that cows that feed on chopped-up field corn full of dead stink bugs might develop a bad smell in their milk.Federal intervention?
Rep. Roscoe Bartlett, a Republican who represents Maryland's rural 6th District, sent a letter Friday, signed by 15 members of Congress, asking U.S. Agriculture Secretary Tom Vilsack and Environmental Protection Agency Administrator Lisa P. Jackson to take immediate action to limit damage caused by Halyomorpha halys.
Because so little is known about the insect, researchers at the U.S. Department of Agriculture and state universities in Maryland, Pennsylvania, Delaware, Virginia and New Hampshire (the bug popped up there for the first time this year) have formed the Brown Marmorated Stink Bug Working Group. Among the priorities: study the bug's basic behavior and biology, identify natural ways to control it and develop public awareness.
Tracy Leskey, a USDA scientist and a leader of the group, made the first positive identification of a specimen in Maryland in 2003, at a gas station in Hagerstown. She tracks them from her research station in Kearneysville, W.Va. Outside Shepherdstown, where she lives, residents have reported having thousands massing on the sides of their homes. "I have never seen anything like this in my career," said Leskey, 42.
Researchers are racing against the clock to find ways to kill the stink bugs.
At a USDA lab in Newark, Del., scientists have quarantined tiny parasitic wasps - collected from China and Korea, where they are the bugs' natural predators - to determine whether the wasps can be used against the stink bugs without harming other species here. The wasps attack the eggs of the stink bugs. That research is likely to take two more years.
A more immediate solution may be ready for trapping them. At another USDA lab, in Beltsville, entomologist Jeff Aldrich and his colleagues found that stink bugs can be lured into traps with a chemical. The pheromone is released by a different species of stink bug native to Japan, a cousin of the dreaded bug now here.
One company is developing a trap, expected to be ready by next spring, that uses the pheromone as a lure.
Traps might be useful for homeowners but aren't likely to be effective in the orchards. For outdoors, Aldrich is working with another company to incorporate the compound in an existing attract-and-kill technology called Splat. It may be ready by next spring.
"It's some sort of goo, and the beauty is that you can mix in the pheromones and add in the insecticide and use regular farm equipment to spray it," Aldrich said.
In the meantime, homeowners are resorting to other methods. Silver Spring resident Parke Brewer used a plastic newspaper bag to trap 212 bugs one week this summer. Another Silver Spring resident, Muriel Cooper, said someone on her Stonegate neighborhood e-mail group list wrote of using a propane torch, damaging a screen door in the process.
Not everyone finds the bugs disgusting.
Lindsey Spindle's 2-year-old son is fascinated by them. They find three or four stink bugs in their Bethesda home a day. They are slow-moving and easy to catch. She uses them to explain how seasons change.