Watch out for the pesky “Brown Marmorated Stink Bug (BMSB)” that sneaks into the homes at this time of the year. In the last few years, the population of BMSB increased in southeast Wisconsin and in several other regions in the state. BMSB is native to Asia and was first detected in Wisconsin in 2010.
Like other fall invading ladybugs and boxelder bugs, BMSB spend their winter indoors and leave in spring. But BMSB can become more than just a nuisance. Under high populations, these bugs can release a stinking odor and can make indoor settings inhospitable. They can also cause allergic reactions to sensitive individuals. The bug’s frass can stain walls and curtains. If these bugs are squeezed or vacuumed, they emit a stinking vapor that makes it challenging to handle this bug.
The appearance of BMSB is very similar to native stink bug with a shield-shaped body (1/2 to 5/8” long) with a blotchy brown to grayish color. But BMSB has a few key differentiating characteristics: 1) alternating white to brown spots on the outer edge of the abdomen beneath the wings, 2) alternating bands of light and dark brown color near the tips of the antennae, and 3) dark red eyes.
Besides being an indoor nuisance bug, BMSB can affect a wide range of outdoor landscape and garden plants, so be on the lookout. Common entry points for BMSB into our homes include the cracks and crevices of walls, doors, windowsills, attics, and basement floors.
- Check entry doors for any gaps and prevent the entry of the bugs by using door sweeps at the base.
- Plug the utility openings that enter from outdoors and fix any damaged or large holes in door screens.
- Sweep the bugs into a bucket filled with soapy water, causing them to drown.
- Use of insecticides inside the house is not recommended. Exterior application of insecticides provides temporary relief and should be applied prior to swarming of the bugs.
- Vacuum cleaners can be used to remove the BMSB, but they need to be emptied and tossed outside immediately. But beware that the vacuum cleaner may retain the stinking odor for a period.
– Vijai Pandian, Horticulture Educator for Extension Racine and Kenosha Counties
