At the University of Maryland’s Home and Garden Information Center, a team of horticulture specialists fields calls on all manner of plants and pests.
But for the past few weeks, one topic has dominated the call center: stink bugs.
“By and large, that’s all everybody wants to talk about,” said Christine McComas, a certified professional horticulturist who estimated that 90 percent of calls to the center’s hotline in recent weeks are for stink bug queries.
Callers want to know what they are, where they came from and, most of all, how to get rid of them.
McComas has answers. They just might not be the answers callers want.
They are winged brown marmorated stink bugs from Asia (Halyomorpha halys) ... and there’s no foolproof way to control them at this time, McComas said.
In recent weeks, homeowners throughout the region have been brushing them, carrying them, vacuuming them and squishing them — though that particular remedy carries a high price. Namely, the bugs stink.
It could be worse, according to Jane Wolfson, director of the Environmental Science and Studies Program at Towson University.
“They can’t hurt you. Be glad they’re not mosquitoes,” said Wolfson, a resident of Jacksonville. “They do smell, there’s no question about it. But the smell’s not permanent.
“They’re looking for a place to hang out for the winter,” she said. “If you shoo them outside, they’ll just try to come inside again.
“It’s not personal,” Wolfson said. “They’re just trying to do what they do.”
Oh, you little stinker
The bugs, which are roughly the size of a pumpkin seed and are a mottled brown color with a shield-like back, made their first confirmed appearance in Allentown, Pa., in 2001. They arrived in western Maryland by 2003, and began heading east.
The bugs are native to areas of China, Japan, Korea and Taiwan, and were unintentionally transported to the U.S. in shipping containers.
The bugs have spread to more than 20 states, although the epicenter of the infestation is the mid-Atlantic, according to Michael Raupp, professor of entomology at the University of Maryland.
Raupp calls the exotic bug a “wild card in the ecosystem.”
Residents have seen an insurgence of the insects in recent weeks, as the air cools and they seek indoor places to “overwinter.”
They mate and lay eggs outdoors in the spring and summer and spend their winters in a somewhat dormant state in sheltered areas.
Then they come back in the spring.
“It’s arrived, but I don’t think it’s over,” he said. “We’re just on the front edge of the infestation,” he said.
The odor emitted by stink bugs serves as the insect’s defense when it feels threatened.
Olfactory reports from area residents vary, likening the smell to everything from musk, pine and detergent to rotten fruit and skunk.
According to Raupp, the stink bug’s odor has two aromatic chemicals: trans-2-decenal and trans-2-octenal, the former of which is also found in cilantro.
“I don’t find that smell to be particularly offensive. I kind of like it,” said Raupp, who first noticed the bugs near his home in Columbia in 2006. “Maybe we’ve got a new dip coming up here.”
Still, Raupp said he understands the fear many feel toward these new critters.
“We shouldn’t discount a general fear people have of insects,” he said. “I don’t think it’s trivial that people are afraid of insects and spiders. It might be irrational, but it shouldn’t be minimized.
“I’m trying to tell people not to freak out about these things,” he said. “This is something everyone is dealing with.”
The U.S. has native brown and green stink bugs, McComas said, although those aren’t the ones now driving homeowners and farmers crazy. McComas said stink bugs are not known to carry diseases and are not harmful to humans or pets. (The Asian stink bugs can be distinguished from native stink bugs by the alternating dark and light bands on their antennae.)
The best line of defense, experts say, is to try to prevent the bugs from entering one’s house by sealing and caulking windows, foundation cracks and other points of entry and to be sure that window screens are in good condition.
The bugs typically are more attracted to light-colored houses and the south side of buildings, she added.
“These are nuisance pests, but they’re not going to bite you,” McComas said.
Raupp and McComas both said chemical pesticides are not the answer, as they aren’t particularly effective in controlling stink bugs but can kill plants and pose serious hazards to humans and animals that inhale them.
McComas recommends residents vacuum the bugs.
Wolfson has her own home remedy: partially fill an old liter soda bottle with soapy water and use a funnel to direct bugs into the bottle.
Although they may let off their defensive odor, “the bottle should be easy enough to cap off quickly with little of the odor escaping,” she said.
What a pest
The first telephone calls about strange flying insects came into Atlantic Pest Control, in Baltimore City, about three years ago, Charlie Libby remembers.
“People didn’t know what they were,” he said.
Now they know. The stink bug phenomenon in Maryland has the region buzzing — and from a business standpoint, Libby couldn’t be happier.
In the past week, Libby said, Atlantic Pest Control has received about 200 calls to exterminate the smelly, buzzy bugs.
“This year, it just literally exploded,” he said.
Exterminators are seeing the effect of the stink bug boom.
“Last week, every day we had at least five to six calls,” said Abderrahim Elhani, owner of All Star Pest Management in Catonsville.
Elhani has been fighting the good fight against the bugs, but recalled one memorable infestation.
“Basically, two sides of the house were 80 percent covered with the stink bugs,” he said. “They were flying all around me. I was there an hour, and when I left I could still smell the odor.”
If it’s any consolation, the stink bugs know no geographic boundaries. Catonsville resident Lisa Dickey makes two rounds with her vacuum cleaner each day to sweep up stink bugs that have found their way into her home near Oella.
“I dump the vacuum bag immediately so it doesn’t stink too bad,” she said.
“They do frighten me. I don’t like bugs, especially when they flutter around and get in your face. One was on my shirt the other day and I nearly peed my pants,” she said with a laugh.
As a real estate agent, the bugs present a professional challenge for Dickey as well, she said.
“When a home is on the market, they’re trying to keep it looking as nice as possible. No one wants to walk into a home and find bugs,” she said. “It’s frustrating to say the least.”
At Towson University, Wolfson said there’s still much to learn about the Asian stink bug.
Based on her understanding of insect behavior and life cycles, Wolfson said a lack of predators, plentiful food sources and weather conditions likely contributed to the insurgence of the bugs this year.
“As long as there aren’t predators or pathogens or parasites that are affecting these organisms, their survival rate is very high,” she said.
“This year we had very unusual weather. It was warm early. There were very many very hot days.
“We might have been very uncomfortable,” she said, “but it might have been stink bug heaven.”