Brown Marmorated Stink Bug Adult.  Photo courtesy of Wikimedia Commons

Most likely transported to America in shipping crates and first collected in September of 1998 in Allentown, PA, the Brown Marmorated Stink Bug is a strong flier that has shown a remarkable ability to rapidly expand its territory.  According to the Penn State College of Agricultural Sciences Halyomorpha halys this foreign insect has now been collected in 37 counties of the state and may exist in all of its counties.  It has also spread to Connecticut, Delaware, Indiana, Illinois, Iowa, Maine, Maryland, Minnesota, Mississippi, Missouri, New Jersey, New York, North Carolina, Ohio, South Dakota, Tennessee, Virginia, West Virginia, Wisconsin and Wyoming.  It has even reached the western states of California, Nevada, Oregon, Washington, Utah and Idaho.  The species may have invaded other states as well.

The adult of the species is approximately 17 mm in length, generally brown in color with white segments on segments of their antennae and alternating white and dark bands on the membranous, overlapping part at the rear of the wings.  There are areas of copper or blue, metallic punctures on the head and pronotum.  The scent glands are located on the dorsal surface of the abdomen and the underside of the thorax.  These glands are what secrete the substance that gives them their nasty odor.

The immature form hatches from clusters of 20 to 30 green, elliptical, 1.6 x 1.3 mm eggs, deposited on the undersides of leaves.  They develop from newly hatched to adult, through 5 stages or instars.  The first instar has a yellowish-red abdomen and dark, red eyes.  As they progress through the next 4 instars their abdomens gradually turn to off-white, with reddish spots.

Although not yet considered an important pest in the United States by the USDA, simply because it has not reached sufficient numbers to warrant the attention, it may become one in the future.  In its native Asian habitat it is a serious pest of fruit crops.  The necrosis and deforming damage caused by its feeding makes the fruit unmarketable.  There are currently no known predator species in the new world that would offer any natural control of the pest so it may continue to spread unchecked, at least in the near future.

Even though its status as an agricultural pest is not established here, this true bug, in the insect family Pentatomidae, has definitely caught the attention of homeowners.  According to Rutgers NJAES Cooperative Extension, in the Fall, when temperatures begin to cool, rather than overwintering in leaf litter, as most stink bug species do, adult Brown Marmorated Stink Bugs seek out protected shelters and Homes make perfect overwintering sites.  Prior to entering structures they will typically congregate in large numbers on the exterior walls, much like the Asian Ladybird Beetle and the Boxelder Bug, creating concern among homeowners.  From there they move inside, sometimes en-masse.  Once inside, these little invaders pose quite a nuisance.  They get into every room in the house, seeking places to hibernate.  They will squeeze into closets dresser drawers and other locations.  If sat upon, captured squeezed or disturbed they will emit a foul odor from two glands located on either side of the body.  The odor can persist for up to 3 days or until the area is thoroughly aired out.  They are incapable of biting.

Control of the BRSB can be accomplished by exclusion, physical removal or treatment with a pesticide.  The first line of defense is exclusion.  Caulk and seal all cracks, crevices and holes around the exterior of your home.  Ensure that all screens fit tightly.  Check all attic and crawl space vent screens to make sure they are tightly in place and intact.  Also check seals around the large doors and make sure there is a tight-fitting sweep at the bottom of the man door.  If the bugs make it past your exclusion efforts you can try physical removal.  If you pick them up try using rubber gloves so your hands don't pick up their odor.  You may vacuum them up then empty the vacuum contents into a plastic bag and tie it shut prior to disposal so no bugs escape.  Bear in mind that your vacuum may smell like these insects for a period of time.  The third option is treatment with a pesticide.  For this I recommend calling in a professional.  If you decide to do it yourself Rutgers, The State University of New Jersey has screened numerous insecticides against the adult BMSM's.  Their screening suggests that products containing the following materials may be of help.  Bear in mind that they have only been tested in the laboratory and not in the field:

B-cyfluthrin, Bifenthrin, Cyfluthrin, Deltamethrin, Dinotefuran, Fenpropathrin, A-cyhalothrin.

Some of these products may not be registered for interior use.

Some or all of these materials may be available to and only legally for use by professionals.  This will depend on federal, state or local government regulations.  Check the regulations for your area.  As with all pest control materials, be sure to read and follow all label directions, to the letter.  The label is the law.  To use a pesticide in a manner inconsistent with its labeling may be unsafe and is a violation of federal law.  Be sure to wear appropriate personal protective equipment.