PITTSBURGH - A new stink bug with attitude is heading toward Pennsylvania.
As if farmers and homeowners haven't been bothered enough by the brown marmorated stink bug that landed in Pennsylvania in the late 1990s, a smaller but equally pesky bug is making its march toward the state's border, experts say.
The Megacopta cribraria, known as the kudzu bug, has an armor-like shell and a beak for ripping into plants and feeding on legumes, particularly soybeans.
They can swarm but not feed on other plants such as grapes, wheat and corn, according to researchers at North Carolina State University's College of Agriculture and Life Science.
The kudzu bug, which has been detected in large numbers in the South, secretes a distinctive odor and can bite humans, causing a minor skin irritation or even a small welt, researchers said.
"They're in three counties in Kentucky ... and will hitchhike in (to Pennsylvania)," said Wayne Allan Gardner, a professor of entomology at the University of Georgia. "They are right on your border."
"They get in your hair. . They cover the cars," said Erin Cook, 39, of Barnesville, Ga., about 30 minutes northwest of Macon. "If you smush them, they smell horrible."
Cook said her baby shower last year had to be moved inside because the swarming bugs "covered all the decorations." Her back porch "had little trails of brown stuff all over the siding."
"If you were outside, you couldn't get away from them," she said.
Like the marmorated stink bug, scientists believe the kudzu, which comes from Japan and the Korean peninsula, probably entered the United States near Atlanta in an international shipping container.
The oblong-shaped bugs, about a quarter-inch long with olive-green coloring and brown speckles, have been spotted as far north as Sussex County, Del., and four counties in Maryland.
John Tooker, a professor of entomology at Penn State University, has alerted Pennsylvania farmers to the threat.
"There are no reports (of kudzu bugs) in Pennsylvania yet," he said. "But ... everyone expects them to be here."
The bugs, which are strong fliers, travel in large numbers and began tearing through Georgia four years ago, working their way to Florida, the Carolinas and into Maryland and Virginia.
They live off the kudzu plant, an invasive vine that grows unimpeded across the Southeast, as well as soybean plants.
Similar to the brown marmorated stink bug discovered in Allentown in 1998 and believed to be in all 67 of Pennsylvania's counties, swarms of kudzu bugs look for warm places to hunker down in the fall and winter. They're attracted to light-colored surfaces and seek out cracks and crevices in homes, lawn furniture and cars.
"They can pretty much cover the side of your home," Gardner said.
For farmers growing soybeans, the damage can be high. Field tests in Georgia showed 10 percent to 80 percent crop losses.
The bug was first discovered on the outside of homes in nine northeast Georgia counties in October 2009, according to the Megacopta Working Group, comprising researchers at Clemson University, North Carolina State, the University of Georgia, Emory University and Dow AgroSciences.
A year later, they had spread to more than 60 north and central Georgia counties and were heading into the Carolinas.
The bug emits a distinctive odor.
A woman in Georgia called 911 because she smelled what she thought was a gas leak in her home, Gardner said. No leak was found, and rescue crews determined the smell was coming from a layer of kudzu bugs covering the screens in her windows and doors.
Researchers at the Department of Agriculture are trying to identify natural predators of the kudzu bugs to help reduce their numbers. Some scientists have isolated a gnat-sized wasp that they believe could be introduced into areas to combat the bugs.
Farmers in the South have had some success with insecticides, Gardner said. It's been tougher going for homeowners.
"A lot of the insecticides for home use have a short window of activity," he said. "You may kill the ones you have today, and tomorrow there will be hundreds more."