Stink Bug Invasion in Westchester & Rockland: How to Keep Them Out This Fall

The Stink Bug Problem Nobody Warned You About

Every September, as temperatures dip, a parade of shield-shaped, mottled brown insects materializes on sun-warmed siding, screens, and window frames across Westchester County. By October, dozens — sometimes hundreds — are congregating on south and west-facing walls, searching for a way inside.

The brown marmorated stink bug (*Halyomorpha halys*) arrived from Asia in the 1990s and has established itself as one of the most frustrating fall pests across the Hudson Valley region. From Ossining to Suffern to Riverdale, stink bugs are an annual autumn reality.

Why Westchester and Rockland Homes Are Hit Hard

Older housing stock: Pre-war Colonials, Victorians, and Cape Cods throughout Westchester have more gaps, cracks, and structural voids than newer construction. Stink bugs are expert at finding the smallest opening in a window frame, a gap around a utility penetration, or a loose piece of siding.

Proximity to orchards: The Hudson Valley's apple orchards support enormous summer stink bug populations that migrate toward residential structures in fall. Homes in Pearl River and New City are at the suburban-rural transition zone where this migration is most intense.

Forest edge habitat: Stink bugs feed on oak, maple, and black walnut — all abundant in Westchester's tree canopy.

Understanding Stink Bug Behavior

Fall aggregation: As day length shortens and temperatures drop below 54°F, stink bugs stop feeding and begin searching for overwintering sites. They're attracted to heat signatures — warm, sun-exposed walls on the south and west sides of buildings. Once one bug releases an aggregation pheromone, others are attracted to the same site.

Overwintering indoors: Once inside, stink bugs enter a dormant state in attics, wall voids, and crawl spaces. They don't reproduce indoors, don't damage structures, and don't eat — they just sit there until late winter when warming temperatures cause them to emerge.

The stink: The famous odor — often compared to cilantro or something chemical — is a defense mechanism. Crush a stink bug and the smell is memorable. Use a vacuum instead.

Step-by-Step: How to Keep Stink Bugs Out

Seal every gap you can find:

- Caulk around window and door frames, especially where they meet siding

- Install door sweeps on all exterior doors

- Caulk around all utility penetrations

- Seal around attic vents with fine mesh screening

Reduce attractiveness of your exterior:

- Turn off exterior lights during peak aggregation weeks (late September through October) or switch to yellow/sodium vapor bulbs

- Vacuum visible stink bugs off exterior surfaces before they find entry points

Interior management:

- Vacuum stink bugs you find indoors — never crush them

- Sticky traps near windows and light sources can catch individuals that emerge in winter

Professional Treatment for Heavy Infestations

For homes in Mamaroneck or Tuckahoe seeing hundreds of stink bugs annually, a professional pest control fall perimeter treatment can dramatically reduce entry. Applied to the exterior foundation, siding, window and door frames, and soffits in late September, a residual insecticide treatment creates a barrier that kills stink bugs as they crawl toward entry points.

Timing is critical — treatment must happen before the major aggregation begins.

BluesWay Pest Control serves Westchester County, Rockland County, and the Bronx with fall perimeter treatments timed to your specific pest pressure. Call (914) 968-8404) to schedule a consultation.