Stink Bugs & the Mid-Atlantic Fall Invasion
Every autumn the DMV's overwintering pests pour indoors. Here is who they are and how to stop them.
The Mid-Atlantic's fall ritual
If you live in Silver Spring, you know the drill: the first cool nights of September arrive, and suddenly the sunny side of the house is covered in shield-shaped bugs looking for a way in. This is the fall invasion, a Mid-Atlantic phenomenon driven by insects that survive winter by overwintering inside structures. The star is the brown marmorated stink bug, an invasive pest that first took hold in the Mid-Atlantic and now defines autumn here, but it travels with a whole cast of fellow invaders.
Meet the invaders
The brown marmorated stink bug is the headliner, harmless to people but relentless, releasing its namesake odor when disturbed and gathering by the hundreds in attics and wall voids. The Asian lady beetle, an orange look-alike of the native ladybug, does the same and can stain surfaces and even nip. The spotted lanternfly, a striking invasive planthopper now spreading across Maryland under a state quarantine, swarms trees and structures in late summer. And as it cools, house mice and camel crickets push into basements and crawlspaces for warmth and moisture. All of them are chasing the same thing: a warm, sheltered place to wait out the Mid-Atlantic winter.
Why they get in
These pests do not breed indoors or damage the house, they simply move in to survive winter, and a typical Silver Spring home offers countless entry points. Gaps around windows and doors, cracks where siding meets trim, unscreened attic and soffit vents, utility and cable penetrations, and worn weatherstripping all become doorways when the temperature drops. Older colonials and Cape Cods with decades of settling have the most gaps. Once the insects are inside the wall voids and attic, they are extremely hard to treat, which shapes the whole strategy.
How to keep them out
Because you cannot effectively spray them out of the walls once they are in, the fall invasion is a sealing problem, not a spraying one. The winning move is exclusion done before the invasion: sealing the gaps around windows, siding, utility lines, vents and the roofline, repairing screens and weatherstripping, and treating the exterior in late summer so the insects that land on the walls do not find easy entry. A local exterminator focuses on the building envelope ahead of the September-to-November window. Inside, a vacuum (not a squash, given the odor) handles the stragglers.
When to call
A few stink bugs at the window are a nuisance you can manage. Hundreds pouring in each fall, or lady beetles and cluster flies filling an attic, mean the house has open invasion routes that are worth sealing professionally, ideally in late summer before the rush. A local exterminator can inspect the envelope, treat the exterior, and seal the gaps, turning a yearly invasion into a manageable one. See the stink bug control page and the general pest control page for how treatment is structured.
Sources and further reading: mda.maryland.gov, extension.umd.edu.
Call (240) 368-1945 for pest control across Silver Spring and Montgomery County.
Ready to get the pests out?
One call gets you a clear plan and a real answer on timing and price. No obligation, day or night.
Call (240) 368-1945