Brown Marmorated Stink Bug
Scientific Name: Halyomorpha halys
Pest Type: Invasive • Fall Invaders • Indoor Nuisance • Agricultural Pest
Brown Marmorated Stink Bugs (BMSB) were detected in the US in 1998 and are now a widespread, successful outdoor pest of many crops and ornamental plants. They also like to overwinter indoors.
What Do Brown Marmorated Stink Bugs Look Like?
Adult BMSBs are shield-shaped, 1/2–5/8 inch long (12-15mm), marbled browns in color, with light banding on antennae, abdomen, and legs.
Nymphs are 1/8–1/2 inch (3-12mm) long with red eyes, orange and black bodies in early instars; later instars are predominantly black.
Later instar nymph
Should I Worry About Brown Marmorated Stink Bugs?
Finding a few indoors suggests a need to check for entryways and to improve exclusion. A large number of BMSBs might be gathering in crawl spaces, wall voids, and above false ceilings, especially near the building’s sunny side.
Indoors: BMSBs indoors are mostly an annoyance but handling crushed stink bugs can cause contact dermatitis.
Outdoors: These stink bugs damage a wide range of plants, including ornamental and fruit plants.
Why Do I Have Brown Marmorated Stink Bugs?
Fall: In the fall, brown marmorated stink bugs gather to find protective winter habitat and find their way into wall voids around windows, doors, outlets, light fixtures, and air conditioners unless they are prevented from getting into gaps with exclusion.
Spring: Overwintered adults generally become active in April when they leave structures to mate. They lay clusters of 20–30 eggs on the undersides of leaves from May through August. Eggs hatch in 4–5 days after deposit. Nymphs go through 5 instars.
How Do I Manage Brown Marmorated Stink Bugs in the Home?
Exclusion: Pest exclusion is the key to preventing problems with brown marmorated stink bugs. BMSBs are attracted to vertical structures in their search for protected areas such as under loose bark, or gaps in siding. The problem won’t go away unless gaps are sealed
Vacuuming: Vacuuming live or dead bugs is a solution to removal but has a risk of contaminating the vacuum hose with a strong odor.
Professional pesticide applications: When very large numbers of brown marmorated stink bugs are gathered in the surrounding landscape, treatment options may include professional pesticide applications around the perimeter, particularly eaves, soffits, roof vents, flashing, chimneys, and around doors and windows. However, this is an extreme measure and must be made with much detail to safety and concern for air quality and exposure risk. .
Traps: In some cases, the use of a trap light employing a glue board will reduce numbers indoors. Heat from the light unit may increase the odor when these insects release scent under stress.
The best treatment is prevention. Screens and good seals around doors and windows can help keep BMSBs out. Prepare for possible problems before the fall.