Stink Bug Exclusion in Upper Marlboro, MD

When do brown marmorated stink bugs move indoors?

MDA documents give the flights to overwintering sites as mid-September through October in one publication and October through November in another. The fall window therefore runs from mid-September into November, and the exclusion is best finished before it begins.

The insects gather on warm, sunny walls before they go inside. A cluster on a south or west wall is a sign that the openings nearby are about to be used, so the technician checks those walls first.

Once the insects are inside a wall or an attic, they stay there over the winter and may emerge on a warm day. That is why the indoor sightings in a room often come during the cold months and are not a sign of a new invasion.

Timing the work before the flights start is the difference between sealing a gap and cleaning up after it. The technician agrees the sealing date with the homeowner, and the indoor steps follow if insects are already inside.

Why do stink bugs gather where they do?

Stink bugs look for sheltered spots that are warm and out of the wind, such as the space under siding, behind shutters and in attics. Those are the places the exclusion work checks, because they give the insects a route in and a place to wait.

A gap under siding or a loose piece of trim gives an insect a route into the wall space. Once inside, the insect is out of the weather and can stay there for the winter, which is the reason for sealing the openings rather than only the visible cracks.

Shutters are a common resting spot. The space behind a shutter is sheltered and often unnoticed, so the technician checks shutters and their fixings during the outside walk.

Attic vents, dryer vents and pipe penetrations can also be used. The technician checks each one and fits a screen or a seal where it will not block the vent's purpose.

How do you remove stink bugs that are already inside?

Vacuum them up or release them outdoors, and avoid crushing them, since a crushed insect can leave a smell and stain. Seal the openings afterward so the next wave does not come in the same way.

A vacuum is the simplest tool for a few insects on a wall or a window. Empty the canister or seal the bag outside so the insects do not come back in, and wipe the spot with a damp cloth to remove any smell.

Releasing an insect outdoors is also an option. Take it away from the house and let it go, rather than letting it back in through the door. The technician explains the method on the visit.

Indoor clean-up does not stop the entry. The sealing work is what reduces the numbers the next year, so the indoor steps and the outdoor exclusion are planned together.

• Vacuum insects from walls and windows, then empty the canister outside
• Release insects outdoors rather than crushing them
• Wipe the spot with a damp cloth to remove smell
• Seal the openings after the clean-up