The brown marmorated stink bug (BMSB) is an invasive insect - so much so that one stowaway found its way into a laboratory at the Minnesota Department of Agriculture (MDA) in St. Paul, which, ironically, is an environmental protection agency for terrestrial plants in the state.
At first, MDA entomologist Bob Koch thought that one of the lab staff was playing a joke on him when the pest - which has been sighted on the east and west coast of the U.S., but never in Minnesota - was discovered on Nov. 18.
"We've found other new species of pests before in Minnesota, but never in our own home facility," Koch said. "Our best guess is that it showed up with some of our laboratory equipment that arrived from out East, where the insect has already invaded."
Other states have reported the appearance of the BMSB, so Koch was not entirely surprised by the invasion.
"The bug was found in Nebraska on lab equipment," he said. "It was also in a motor home in Arizona or New Mexico. They can be anywhere. They'll likely be showing up in other locations. We picked up on it, but others might not have."
Minnesota has other species of stink bugs, but the BMSB is the bothersome one. The half-inch long pest is marbled brown in color, shaped like a shield and can be distinguished by its alternating black and white pattern on its abdomen. It also has dark-colored antennae with light-colored bands and produces a pungent odor when disturbed.
"We identified it based on some literature that was sent from out east," Koch said. "We contacted some researchers and got ahold of some dead specimens, and then we compared it to the actual known insect. Now it's dead in the freezer and we'll add it to our entomology collection and will be a reference specimen for us."
Minnesota has seen its share of destructive insects in recent years - including the Japanese and Asian lady beetles, gypsy moth, soybean aphid and emerald ash borer - but had not had a confirmed sighting of the BMSB, which is native to China, Korea and Japan, and is known to feed on fruit, vegetables and crops.
The BMSB was first reported in the U.S. in 2001, in Allentown, Pa., but it appeared to take quite a few years for the pest to become troublesome to farmers and gardeners.
"When it first showed up, it didn't seem to cause much crop damage," Koch said. "But now they've become a significant problem for production in apple orchards and in vegetable production, including corn and soybeans as well."
Koch predicts that the BMSB will first become a nuisance pest, much like the Asian lady beetle or the boxelder bug.
"They're stinkier than the Asian beetles, but the preventative recommendation is similar," Koch said. "Using the hose of a vacuum, put a nylon stocking over it and loosely make a pouch so you don't stink up the bag or canister."
Sealing up cracks around windows can help. As a last resort, a pesticide could be used externally in the fall. According to the Department of Entomology at Penn State College of Agricultural Sciences, applications of a synthetic pyrethroid should be administered by a licensed pest control operator.
The MDA will likely assist the University of Minnesota in researching the new-found invader in order to protect the state's interests.
"It will probably be awhile before the population grows up," Koch said. "And, we don't know how they're going to respond. We have a different climate here, so it's a big mystery. A lot of insects can't tolerate the cold temperature and it can affect them differently."
In order to track invasions, the MDA is asking that people utilize the "Arrest the Pest" hotline (651-201-6684 metro, 888-545-6684 toll free or Arrest.the.Pest@state.mn.us) if they believe they have spotted a BMSB.
"We're asking people to keep their eyes open," Koch said. "In coming years, it could start coming into their homes like the Asian beetle. Who knows after that if it'll be a crop pest. We're not sure what the full scale of the problem will be."