Skip to main content Skip to navigation

Identifying BMSB

BMSB adults are one of the larger stink bugs encountered in WA (12-17 mm).  Adults have several key characteristics that distinguish it (apart from their large size):  the alternating white bands on the antennae, and the smooth margin on the front edge of the prothorax.  They also have alternating light and dark bands around margins of the abdomen; however, this feature is not unique to brown marmorated stink bug.

Brown marmorated stink bug is most likely to be confused with the other brown stink bugs, namely the consperse stink bug (Euchistus conspersus) and predatory (beneficial) stink bugs in the genus Brochymena (rough stink bugs).  The rough stink bug has a coarsely toothed margin on the prothorax, with solid colored antennae.  The consperse stink bug is much smaller, has a finely toothed margin on the prothorax, and lacks white banding on the antennae. Stink bugs in the genus Chlorochroa are also brown, but have smooth white margin on the prothorax and abdomen, and a white dot at the tip of the prothorax, where the forewings meet.

For more information, including photos of BMSB and local lookalikes, see Extension Bulletin FS079E – BMSB PestWatch.

1st instar BMSB on eggs
Early instar BMSB
3rd instar BMSB
5th instar BMSB
bmsb on a leaf
Adult BMSB
NOT BMSB (Bronchymena)
NOT BMSB (Consperse stink bug)
NOT BMSB (green soldier bug)

Report BMSB

If you see a BMSB, please send a photo, general location (inside or outside of house or car, backyard, park, etc.)  and the address it was found to:

How to search for BMSB