A stink bug hijacked a recent meeting of plant pest regulatory officials. Brown marmorated stink bug (BMSB, Halyomorpha halys) wasn’t even on the agenda, but once it came up everyone wanted to talk about it. The stories from mid-Atlantic states were disturbing. This could be a very bad pest for Oregon. Our best hope for avoiding problems may be a tiny Chinese wasp.
BMSB, an Asian pest, gets its name from its marbled (aka marmoreal) appearance. It was first detected in Allentown, Pennsylvania in 1996, thought it was well established by then, so it was certainly introduced years earlier. In the time since, it has spread to 29 states, including Oregon. Our first BMSB was found in 2004 in SE Portland. The entire north and central Willamette Valley is now infested. A single specimen was collected recently in Sunriver, and there is an unconfirmed report from Ashland. It is an excellent hitchhiker, so if it is not in your part of the state yet, it will be soon.
How serious a pest will it be? That is a multi-million dollar question. It could fade into the obscurity, or it could be the worst pest of fruits, vegetables, and houses that Oregon has ever faced. A 2005 ODA risk assessment rated BMSB a moderate risk. Given the extensive crop damage in 2010 to corn, apples, grapes, hazelnuts, etc. seen in Maryland, New Jersey, and neighboring states, that rating should be increased to high. The scariest thing I heard at the meeting was that farmers were forced to throw out their integrated pest management (IPM) programs, return to regular insecticide sprays, and still some lost their crops. Here is a link to a good video on BMSB from the Smithsonian Institute: http://www.webtvhub.com/watch-brown-marmorated-stink-bug-info-video-how-to-get-rid-of-new-pest/.
The first problem people notice is stink bugs in houses in the winter. Like boxelder bugs, they search out shelter when the weather gets cold. Easterners report they are annoying when they crawl across TV screens and fly around indoors, and as their name suggests, they have an odor. Farmers and gardeners will be the next to notice problems. Stink bugs have straw-like mouthparts. Every time they stick their proboscis into developing fruits/vegetables, it creates a wound that makes the fruit/vegetable unappetizing and unfit for sale.
Can we head off BMSB and keep them for becoming a nightmare? We’ve got to try. ODA is teaming up with OSU scientists and other experts to develop a coordinated response. The first order of business is to track BMSB spread and get the word out to farmers and gardeners so they aren’t blindsided. If you find one outside the current known distribution, please report it to ODA via our invasive species hotline (1-866-INVADER) or online at: oregoninvasiveshotline.org.
We’re also developing contacts with USDA scientists that are exploring the potential of biological control. Three parasitic wasps have been identified as potential biological control agents. One of them, an egg parasite, shows promise in early tests. It could be three years before testing determines if these parasites are safe to release. That process is important, no one wants to release another non-native species and have it cause more harm than good. You don’t have to look far for examples of poorly chosen biological control agents. Asian lady beetle, another home-invader, comes to mind.
We’ve offered to help with the testing, and USDA has responded with interest. Maybe we can speed things up. Cross your fingers that little wasps will prove to be a match for big bad brown marmorated stink bug. Otherwise our toolbox is pretty empty. Let’s hope we can borrow a Chinese tool that works.
Dan Hilburn
