Stink Bug Control in Media and Delaware County, PA

The Brown Marmorated Stink Bug, a Pennsylvania Story

The brown marmorated stink bug is an Asian species whose first U.S. record came from near Allentown, Pennsylvania, in the late 1990s. It is shield-shaped, roughly 5/8 inch long and mottled brown, with pale bands on the antennae and along the edge of the abdomen. All summer it feeds on fruit, vegetables and ornamental trees, then spends the winter sheltered, ideally inside a heated building.

Stink bugs do not bite, sting, breed indoors or damage wood. The trouble is volume and odor: hundreds can gather on a single wall, and crushing or startling them releases the smell that gives them their name.

Stink Bug Control Timing: When Do They Come Inside?

Shortening days and cooler afternoons set the timing. Once highs start slipping into the 60s, stink bugs leave crops, fruit trees and ornamentals to look for a winter site, and they pick the warmest surface they can find: light siding, brick and stone that soak up the afternoon sun. A run of warm days right after the first cold snap often brings the biggest wave of the year.

The local landscape shifts the pressure. Houses at the edge of fields, orchards and wooded tree lines in western Delaware County see the heaviest arrivals, while rowhome blocks in the east usually see smaller numbers because there is less summer food nearby. Upper-floor windows and attic gable vents on the sunny side are where most of them find a way in.

In Delaware County the move indoors usually begins in mid-to-late September as nights cool, and it follows a predictable calendar:

Signs Stink Bugs Are Overwintering in Your Walls

Numbers give it away: dozens on the siding on a warm October afternoon, or clusters along window frames, attic vents and soffits. Indoors, they buzz around lamps and windows on mild winter days and crawl out of outlets, ceiling fixtures and window casings.

Homes facing open fields, orchards or woods get hit hardest. Large-lot houses in Thornbury, subdivisions in Concord and Bethel built on former farmland, and the split-levels along Aston's Chester Creek valley all sit right where stink bugs feed through the summer.

Fall Stink Bug Treatment and Sealing: What Works and What Doesn't

Here is how the common approaches hold up:

• Exterior residual treatment (works): applied in late summer to the sunny walls, window and door frames, soffits, eaves and vents where stink bugs land. It reduces how many get in; sun and rain break it down, so timing matters.
• Sealing entry points (works, takes effort): caulking trim and siding seams, screening attic and soffit vents, replacing worn door sweeps. The longest-lasting step, though every gap counts.
• Treating inside wall voids (usually a bad idea): killing stink bugs inside walls leaves dead insects that attract carpet beetles and other scavengers, so we rarely recommend it.
• Indoor sprays and foggers (do not help): they kill a few visible bugs and do nothing about the ones already tucked into the walls.
• Vacuuming (works for strays): a shop vac or a bagged vacuum removes indoor bugs without crushing them; empty it outdoors right away.

Our Stink Bug Visit, Step by Step

Most stink bug work happens outside, on the walls the bugs actually use.

1. 1

   Exterior walk-around

   We check the south and west sides first, where afternoon sun draws stink bugs, then rooflines, vents and window frames.

2. 2

   Entry point mapping

   We note gaps in trim, siding seams, utility lines and attic vents, plus missing or torn screens.

3. 3

   Written quote

   The treatment and any sealing recommendations are written out before work begins.

4. 4

   Exterior application

   A residual treatment goes on the walls, frames, eaves and vents where stink bugs land and enter, not inside living areas.

5. 5

   Sealing plan

   We tell you which gaps to caulk or screen first and which repairs belong with a contractor.

6. 6

   Winter guidance

   You get a simple routine for the strays that show up on warm days so none get crushed indoors.

What Does Stink Bug Control Cost?

Height is the biggest variable around Delaware County. A three-story Victorian in Lansdowne or Ridley Park has tall gables, dormers and soffits that take ladder work, while a ranch in Brookhaven can be treated largely from the ground. Siding matters as well: old wood clapboard and cedar shakes have far more gaps than vinyl or brick, and a stone house's mortar joints and deep window returns need closer attention.

Setting plays a part too. A house backing onto fields or a tree line may get a heavier first wave and do better with a second fall application, while a twin with one exposed side wall often needs less product and time than a detached house with four.

The written quote follows the free inspection. These factors change it:

• Size and height of the house and how many sun-facing walls need treatment
• Number of windows, vents and soffits on the treated sides
• Whether the property borders fields, orchards or woods
• Timing: a late-summer treatment versus a visit after the bugs are already in the walls
• Whether a second fall application is needed
• Whether boxelder bugs or lady beetles are using the same walls

Wall Treatments, PDA Rules and the Lanternfly Quarantine

Stink bugs are not a regulated pest in Pennsylvania, but the products sprayed on your walls are. Exterior work done for hire falls under the Pesticide Control Act of 1973, administered by the Pennsylvania Department of Agriculture (PDA), which licenses pest control companies and certifies their applicators; ask any provider for its PDA license number. Product labels also set how close a wall treatment may come to vegetable gardens, fruit trees and downspouts that drain to a storm sewer.

A second invasive does carry rules. PDA's spotted lanternfly quarantine covers Delaware, Chester, Montgomery, Bucks and Philadelphia counties, and lanternflies gather on the same sunny walls and decks in late summer. Businesses moving goods out of the zone need a PDA permit, and residents are asked to check vehicles and outdoor items before traveling. Our spotted lanternfly control page explains that side.

Stink Bug Prevention in Pennsylvania: A Homeowner Checklist

Keeping stink bugs out is a summer project; work through this list before Labor Day, sunniest walls first. If the same walls attract other fall swarms, see boxelder bug and lady beetle control.

Gaps that admit stink bugs also let in other insects. Silverfish often settle into the same damp siding seams and attic insulation, which our silverfish control page covers, and when squirrels or raccoons tear through vent screens, fleas can follow them inside; see flea control.

• Caulk gaps around window and door trim, especially on south and west walls
• Replace torn window screens and add fine mesh behind attic and soffit vents
• Seal around air conditioner lines, dryer vents, cables and outdoor faucets
• Install or replace door sweeps and garage door seals
• Remove window air conditioners by early September, or seal tightly around them
• Keep a bagged vacuum handy for the few that still find a way in