The Brown Marmorated Stink Bug, Halymorpha, halys, first arrived in the United States around 1997 in shipments arriving from Asia in Allentown Pennsylvania. First Collected and identified there it has since multiplied by the square and made its presence made known in a big way. With no significant natural enemies on the North American continent and being an excellent hitch-hiker and a strong flier it has now spread to both coasts and has been sighted in 38 states (up from 33 in 2011) and the District of Columbia. In states where it is well established its numbers are in the millions and growing. The species has become well established in Northwestern Oregon and Southwest Washington where it has become a serious concern to orchardists and vintners. Just last month specimens were collected in the southern Oregon towns of Rogue River and Hood River. It has also been sighted in Southern California. At the current rates of migration and reproduction it could reach California’s Central Valley within a year or two. The economic impact could be enormous.
In autumn it invades homes and businesses by the dozens to thousands as it seeks shelter from the cold winter weather. If disturbed or crushed it emits a foul substance that smells like a cross between cilantro and dirty socks. But BMSB is more than a nuisance. The list of host species for the insect is long. It feeds on cultivated plants as well as weeds. It’s feeding causes significant damage to field and orchard crops, making the products unmarketable as fresh produce. Losses to home gardeners, farmers and orchardists in the Mid-Atlantic have been from 25 to 100 percent with revenue losses in the millions.
Currently the US Department of Agriculture is studying a tiny parasitic wasp from BMSB’s native range that may be an effective means of control. The adult female wasp lays her eggs in the eggs of the stink bug. The wasp larvae feed on the bug’s eggs killing them. The current USDA studies aimed at ensuring that the wasp doesn’t present a danger to native organisms should take about two years.
The adults are shield shaped, approximately 1.5cm long and the underside is white or pale tan, sometimes with gray or black markings. The legs and antennae are brown with faint white banding. The stink glands are located on the underside of the thorax, between the first and second pair of legs. If you believe you have seen a Brown Marmorated Stink Bug capture the specimen and submit it to your local county extension as soon as possible for identification.