Brown marmorated stink bug (BMSB) adults are flat insects (approx. 5/8 by 3/8 inches) with drab coloration, although nymphs are brightly colored.
Key characters for identifying adult BMSB (see photo) and distinguishing them from similar species, are 1) the distinct light bands on the dark antennae, 2) smooth "shoulders", and 3) abdominal margins have a distinct banding pattern.
If all three characteristics are present on your Oregon specimen it is BMSB. The common name, marmorated, refers to the color pattern of the insect, which vaguely resembles marble. Like other stink bugs, a foul odor may be produced by BMSB when they are disturbed.
The brown marmorated stink bug spends the winter in a protected area (such as inside the warmth of your home) and then emerges and becomes active in early spring. Mating follows and eggs are laid on the underside of host plants through early fall. Over the summer months, nymphs and adults feed on plants in the garden causing damage to a variety of fruit, vegetables and flowering plants.
Stink bugs feed on peaches, apples and soybeans as well as grapes, raspberries, snap beans, hazelnuts, cherries, peppers, tomatoes and many ornamental flowers. Additionally, black cherry, maples, Juneberry, hollies and crabapples are some of the host plants growing in natural areas. It is believed that stink bugs will thrive, not just survive, on many native plants as well.
Stink bug damage in many cases can be hard to see. For example, stink bugs have been observed feeding heavily on snapdragon plants, seeming to prefer the seed pods with no damage to the flower itself. Feeding on tomato and pepper stems, fruit and flowers caused stippling of foliage and spotting of fruit. In essence, the quality of fresh market fruits, vegetables and nursery stock can be reduced due to the feeding habits of stink bugs, but more university research is planned to further evaluate the effects of this comparatively new pest.
BMSB damage is subtle and not always easy to spot. However the insects themselves are, and if you see them in your home or garden you can bet there is damage being done!
If they do enter your home or garden, figure out how severe the infestation is to determine your best course of action and when to use it.
Stink bugs will begin their search for warmer homes as cool, fall weather approaches. The best way to combat the invasion of stink bugs into YOUR home is to seal cracks around windows, doors, siding, utility pipes, behind chimneys and so forth with a good-quality silicone or silicone-latex caulk.
Repair or replace damaged screens on doors and windows. Eliminate the possibility of these bugs gaining entrance into your home in the first place.
The course of action will be determined based upon the threshold set. It's always a good idea to move from least invasive method upward. Early onset can be treated fairly simply by hand picking (mechanical). While wearing gloves, pick off the adults and nymphs from your plants and drop them into a bucket of soapy water. Also be sure to destroy clusters of light green, barrel-shaped eggs found on the underside of leaves. Introducing predators like ladybugs and green lacewings can also help to control the population (biological). Commercially available stink bug traps are good for removing bugs from the area and to monitor concentrations.
Best to put these out in early spring, around April 1. Another option is to grow early crops of “sacrificial plants” of stink bug favorites such as sweet corn, amaranth and okra. Plant near your vegetable garden and when the “trap” crops become infested with stink bugs, destroy them and the plants. Regardless of method/product used ALWAYS read and follow package instructions, and NEVER use insecticides when beneficial insects are present.
Should those pesky bugs make their way into your home, not all hope is lost. Try to locate the opening where they are gaining access. Typically, they will emerge from cracks around baseboards, around window and door trim and around exhaust fans or lights in the ceilings. Seal openings with caulk. Both live and dead bugs can be removed with the use of a vacuum cleaner.
The Best Practices approach, sometimes called Integrated Pest Management (IPM) is an environmentally sensitive approach to dealing with garden pests. Printable pdfs can be found on each page.