IPM Checklist
Brown Marmorated Stink Bug in the Garden and Home
The short answer
The brown marmorated stink bug (BMSB) is an invasive shield-shaped bug that feeds on developing fruit and vegetables, causing distortion, speckling and spongy damaged areas, and then aggregates on warm house walls in fall seeking a place to overwinter.
In the garden, protect fruiting crops and remove bugs by hand; there is no need to spray your whole vegetable garden.
To keep them out of the house, seal cracks and gaps before they get in during late September and October, because mechanical exclusion is the most reliable method.
Do not spray insecticides inside wall voids and do not crush or vacuum large numbers indoors, since dead bugs can attract carpet beetles and crushing releases their odor.
What BMSB damage looks like on crops
BMSB feeds with piercing-sucking mouthparts on many garden crops including apples, peaches, tomatoes, peppers, beans and okra.
Penn State Extension notes that feeding on tree fruits such as apples produces a characteristic distortion called cat-facing, while feeding on tomatoes and peppers can produce spongy areas and internal tissue damage, and feeding in beans and okra can cause scarred, sunken areas and deformed pods.
Iowa State adds that overall damage can appear as deformation, distortion, speckling and stunting, ranging from mild to severe.
Why they show up on your house in fall
As temperatures drop, adults are attracted to the outside of houses on warm fall days while searching for protected overwintering sites, and they can arrive in large numbers.
Iowa State points out that every stink bug found indoors walked or crawled in through cracks and gaps, usually from late September through October, so once cold weather sets in the ones inside are the ones that already got in.
Keep them out: exclusion first
Mechanical exclusion is the best method to keep stink bugs from entering.
Penn State recommends sealing cracks around windows, doors, siding, utility pipes, behind chimneys and under the wood fascia and other openings, and Iowa State stresses doing this before the bugs get in.
⚠ Indoor insecticide sprays and 'bug bombs' are not recommended and do not prevent entry. Penn State advises against spraying inside wall voids or attics because dead bugs attract carpet beetles that then attack woolens and stored goods.
Don't squash them indoors
If many BMSB are crushed or sucked into a vacuum cleaner, their smell can become quite apparent.
For the few that get inside, remove them gently by hand or with a vacuum reserved for the purpose rather than smashing them on walls or fabrics.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- Penn State Extension — Brown Marmorated Stink Bug — Verifies cat-facing on apples, spongy/internal damage on tomatoes and peppers, scarred deformed pods on beans and okra, fall attraction to houses seeking overwintering sites, mechanical exclusion as best method, that indoor spraying in wall voids is not advisable because dead bugs attract carpet beetles, and that crushing or vacuuming many bugs makes their smell apparent.
- Iowa State University Extension — Brown Marmorated Stink Bug — Verifies damage appears as deformation, distortion, speckling and stunting; that bugs enter in fall seeking overwintering shelter; that every indoor bug crawled in through cracks and gaps in late September to October; that the first step is sealing cracks and gaps before entry; and that indoor insecticide sprays and bug bombs are not recommended and do not prevent entry.