Pest control companies in Knox County have seen a spike in seasonal business due to an invasion of smelly uninvited house guests.
"They really become a problem in the middle of October," said Adam Weckesser, a technician with Dayton's Pest Control. "We have had at least 200 more calls for them this year compared to last year. They multiply by the thousands."
'They' are Brown Marmorated Stink Bugs. The creatures are originally from Asia and were first spotted in Pennsylvania in the late 1990s. The pests have spread throughout the mid-Atlantic in enormous numbers. The smelly insects first showed up in Tennessee in 2008.
"The first place they were documented in Tennessee is Knox County. It has only been around three years and it is amazing how fast they have built up," said Karen Vail, an entomologist and professor at the University of Tennessee. "The brown marmorated stink bug is an agricultural pest during the spring and summer. It is a sucking insect that does a lot of damage to fruits and pods."
Vail said some states in the mid-Atlantic lost more than 25 percent of their apple crops due to the invasive stink bugs. The odorous creatures seasonally become a problem for homeowners.
"It is a pest to our crops and to us. This time of year as things cool off, they're going to seek shelter. They've decided your home is the place to spend the winter," said Vail.
The moniker "stink bug" is an accurate description. The small insects defend themselves by packing a powerful pungent punch.
"When you crush them they smell really bad," said Weckesser. "When they get defensive they secrete an odor that just stinks like rotten trash."
"I've heard some people describe the odor as rotten cilantro," said Vail. "They have a gland that produces the odor as a defense against predators."
A quick web search for ways to kill a stink bug in your home without producing a foul odor will recommend using a vacuum cleaner. While that may sound like a good idea, in truth the method does not pass the smell test.
"I would tell you not to vacuum them. They will release that odor and then the vacuum exhaust will blow the odor all over the room," said Weckesser.
"After you vacuum you're going to take the bag, stick in a ziplock, and throw it away," laughed Vail.
"The best way I've found to kill the stray stink bug is to get a piece of toilet paper, grab them without crushing them, and flush them down the toilet," said Weckesser. "You can also use a mixture of water and dish soap. It will kill them eventually, but mostly if there is a bug on the ceiling that you can't reach, hit it with something like Dawn and that will slow them down long enough for you to grab them and flush them."
Both Vail and Weckesser said the best method to avoid the bugs' defensive stench is to prevent them from invading your home in the first place.
"We spray the exterior of homes with a pesticide that will get into the cracks and seams of the house to kill the stink bugs," said Weckesser. "They can get through almost any small crack. They can flatten themselves almost as thin as a couple of sheets of paper."
"If you don't have them inside your home yet, it is time to go on a walkabout around the outside of your house. Pretend you're the bug trying to make its way in. Look where you have any small gaps," said Vail. "Pesticides are short-term solutions because they break down in sunlight and wash away in the rain. Caulking and screening tends to be a more permanent solution."
Vail recommends caulking any cracks around windows, ensure you have proper weather-stripping, and look for seams around doors.
"A good way to check is to turn on the lights inside at night and go outside. Anywhere you can see light coming through needs to be sealed. Check around windows and doors. Look to see if you need a door sweep for the bottom of the door," said Vail. "If you already have them in your house, there are some light traps you can put in the attic that will attract the stink bugs. It won't get all of them, but it will reduce their numbers."
Aside from the fact that you don't want encounters with a smelly bug or a home filled with insects, the brown marmorated stink bugs does not pose any direct health threat.
"They're not going to hurt you. They're not going to reproduce in your home. They just came for a vacation to spend the winter with you," said Vail. "In the spring they will leave to go eat vegetation and reproduce. Then they'll try to get back inside your home again when the weather becomes cool."
Stink Bug spotting
As of now, the confirmed distribution of stink bugs in Tennessee is limited to six counties. All are along Interstates 81 and 40.
"Hamblen, Knox, Loudon, Sullivan, Hamilton, and Davidson Counties were confirmed last December," said Vail. "I would not be surprised if they are all along the interstate areas, but we need people to help us track and confirm their distribution."
Vail said anyone who lives outside the aforementioned counties should contact their county extension office to report any stink bug sightings.
"We definitely want people to call. The bugs have really boomed along the mid-Atlantic, but we are just on the edge of the invasion right now. The numbers are going to get a lot worse," said Vail. "People should catch the bug. They can go to the UT extension website to contact their county extension agent. Then the agent can confirm it is actually a brown marmorated stink bug and not another type of stink bug. The main thing to look for is the brown marmorated stink bug has stripes on its antennae."