Western North Carolina is beginning to feel the effects of a new insect pest: the Brown Marmorated Stink Bug. The bug was accidentally introduced from Asia and was first spotted in Pennsylvania in 2001. Since then, the bugs have been slowly increasing their range outward from Pennsylvania and are beginning to make their first forays into North Carolina.
Researchers at North Carolina State University are concerned about the stink bug’s arrival because it could potentially have huge impacts on the state’s agricultural crops. In states where the insect has become established, such as northern Virginia, eastern West Virginia, Maryland, Delaware, New Jersey, and south central Pennsylvania, some farmers in 2010 lost more than half of their crops. Apples, peaches, tomatoes, peppers, sweet corn, berries and soybeans are all vulnerable. “These are all important crops in western NC, so the economic impact could be huge,” said Jim Walgenbach, a researcher at N.C. State University’s Mountain Horticultural Crops Research & Extension Center, in Mills River.
Unlike the several stink bug species that are native to our area, which are kept mostly in check by natural predators and parasites, the Brown Marmorated Stink Bug has no natural enemies here. It also prefers to spend the winter indoors, where it causes no harm to people or houses but can be a serious nuisance. “These insects look like our native stink bugs in that they are shaped kind of like a shield,” said Ginger Kowal, a technician working with Walgenbach on the project. “But they can be identified by white patches on their antennae and legs, and they have that unique habit of massing inside of houses and buildings.”
Walgenbach and his colleague Mark Abney, also of NCSU, are working on developing ways to hinder the spread of the insect, and will soon begin testing chemical sprays in the lab. They are also tracking the distribution and spread of the stink bug as it expands its range in North Carolina. So far, the Brown Marmorated Stink Bug has been found in Buncombe, Henderson, Madison and Haywood counties in Western North Carolina and several counties in the piedmont. They seem to exist mostly in isolated population patches centered around urban areas.
Walgenbach explains that he expects the stink bugs to continue their spread outward from those centers: “This distribution pattern is consistent with the early stages of infestation by an invasive insect,” he says. “Populations are likely to expand more quickly here than farther north, because of our warmer climate.”
At this time of year, the stink bugs are starting to make their way inside buildings and homes where they hope to spend the winter. Walgenbach and his colleagues have set up a website where anyone can go to see a map of confirmed sightings and report a sighting of the insect (www.tinyurl.com/NCStinkBug). Gardeners and homeowners who believe they have seen Brown Marmorated Stink Bugs on their property are strongly encouraged to report their findings. “This information from people out in the counties can really help us monitor the spread of the insect, and also target our research during next season,” said Walgenbach.