As warmer weather is heating up the frozen winter ground, brown marmorated stink bugs are beginning to emerge.
Susan Hyland, Master Gardener coordinator with the Penn State Cooperative Extension of Schuylkill County, said Wednesday that they can be pests but are not harmful and might be found in your home during the winter when they hibernate.
"The stink bugs have started moving because of their life cycle, which means that they're resting right now in some sheltered place, usually in the walls of your house and if it gets warm enough, then they wake up and they go out and start looking around, finding places outdoors," Hyland said. "They are not eating, nesting, laying eggs or having babies in your house. They are a nuisance in the house, but they are not ruining anything."
In nature, all the stink bugs are under leaves, bark, rocks and any snow that's left, she said.
As more emerge, usually in late April to mid-May, they will be attempting to find leaves on which to lay their eggs.
Hyland said the stink bugs can also be seen flying around and there have been increasing numbers year after year.
For people troubled by the pests, there is really nothing that can be done.
"Pheromone traps aren't very successful, so don't bother spending money on them," she said. "Insecticides don't work. If you've got a huge infestation, that would be very costly, but you won't see much of a decline in the numbers."
Hyland said that people should beware of traps advertised for stink bugs since they are more a marketing gimmick as the bugs just wander around aimlessly and "don't seem to be attracted to it."
"I think they (scientists) are working on some sort of trap that would keep them from getting out," she said.
While essentially nothing can be done about them, Hyland said scientists are attempting to determine what kind of predators prey on their eggs and if they're successful, they will be trying to encourage those native predators to eat the stink bug eggs so many don't hatch.
"In China and Asia, where they come from, there are numbers of native predators that don't live here," she said.
If any brown marmorated stink bugs are getting into homes, the best thing to do would be to "gently sweep them out" since "they do make a terrible smell if you smoosh them."
"If you vacuum them up, that can jostle them and your vacuum will stink," Hyland said. "You should be certain all your cracks are sealed so it's not so accessible and shade your house. They want that hot bright cliff to hide in or cracks between siding."
According to the Penn State Cooperative Extension, the brown marmorated stink bug was first found near Allentown in the late 1990s, but has now spread across much of the U.S. and its heaviest populations are found in the mid-Atlantic region, centering on southern Pennsylvania, New Jersey, Maryland, Delaware, Virginia and West Virginia.
Penn State said that in this region, it first gained attention as a nuisance pest due to its tendency to overwinter in homes, but soon became a severe pest of fruits, vegetables and ornamental plants.
"Everybody who has got them has gotten a lot of them, and now they're eating commercial crops such as soft-skinned fruits, peaches, pears, even apples and have been seen in corn," Hyland said. "It leaves brown splotches on apples and, of course, it won't hurt you to eat it, but it's no good for commercial growers."
Beginning in 2009 and 2010, populations really started building in corn and soybean fields and growers experienced yield losses.
Hyland said that the extension in Schuylkill County collected population data about the bugs until about 2002 or 2003, when they began to get out of hand and could be found everywhere.
"If you look at a map at where they are, they're mostly moving with humans," she said. "They are human trafficked. They're up under your car, in the cracks of your camper."
The brown marmorated stink bug has been found as far away as Missouri.
While Hyland said there are two generations in areas such as Virginia and West Virginia, Schuylkill County is fortunate to only have one per year.