Brown marmorated stink bug
Halyomorpha halys
- Identification
- Shield-shaped, mottled brown, about ⅝ inch, with white bands on the antennae. Releases an odor when disturbed.
- Lifecycle & behavior
- An invasive that feeds on plants in summer and seeks structures to overwinter in fall, clustering in walls and attics.
- When it's active in Central NY
- Massing on warm CNY walls each fall and emerging indoors on warm days through winter and spring. Numbers have grown across the region.
- Risk & damage
- A nuisance indoors (no biting or breeding) but an agricultural pest outdoors; the odor when crushed is the main household complaint.
- Why DIY falls short
- Vacuuming helps with the few inside, but crushing spreads odor; interior sprays don't reach wall populations.
- How we treat it
- Timed exterior barrier and sealing in late summer, ideally bundled with cluster fly service.
Brown marmorated stink bug or a native stink bug?
Check the antennae and the shoulders. The brown marmorated stink bug has two distinct white or pale bands on each antenna and smooth, rounded shoulder edges. Native brown stink bugs lack the clean antennal banding and often have toothed or jagged shoulders. Both are shield-shaped and mottled brown, which is why the antennae are the practical check.
It is also worth separating from the western conifer seed bug, which is longer, narrower, and has distinctly flared, leaf-like flattened hind legs that the stink bug does not.
Brown marmorated stink bugs in Central New York
An invasive species, now well established across the region, and one of the main components of the fall invasion. They gather on sunny south and west walls in September and October and work into wall voids, attics, window frames, and behind siding to overwinter, reappearing indoors on warm days through the winter and again in spring.
Do not crush them indoors — the defensive odor is genuinely persistent, and vacuuming them into a bag that can be removed immediately is the better indoor response. As with cluster flies, real control is exterior and timed for late summer, before they gather.
Dealing with brown marmorated stink bug?
Our overwintering pest control handles it — guaranteed, family-owned, and local.
Brown marmorated stink bug — common questions
Should I squash stink bugs I find indoors?
Better not to. The defensive compound they release is persistent and unpleasant, and crushing them on a windowsill or carpet leaves it there. Vacuum them into a bag you can take straight outside instead.
How do I keep them out next fall?
Exterior treatment on the sunny south and west elevations in late summer, before they gather, combined with sealing around window frames, siding gaps, soffits, and utility penetrations. Once they are inside the wall voids there is no practical way to reach them.