Back to Pest LibrarySeasonal Invaders

Asian Beetles & Stink Bugs

Every fall, Asian lady beetles and stink bugs look for a warm place to spend the winter—and your home's sunny exterior walls are exactly what they are looking for.

Fall AlertLate September through November is peak season for both pests across our service area. Treating exterior entry points before the first cold snap makes the biggest difference in keeping them out of your home.

Signs to look for

Large swarms or clusters gathered on sun-facing exterior siding, window frames, and porch columns in early fall.
Live beetles or stink bugs crawling indoors near windows, skylights, ceiling corners, and attics.
A distinct musty, unpleasant odor released if stink bugs are crushed or disturbed.
Yellowish defensive fluid stains left on light-colored walls, curtains, or window trim by Asian lady beetles.

Why do I have an Asian beetle or stink bug problem?

Both of these pests are overwintering insects. During spring and summer, they live outdoors in crop fields, gardens, and trees. As temperatures drop in late September and October, sunlight heating the southern and western sides of your home attracts them in search of sheltered crevices to hibernate through winter.

Where will I find them?

Both pests turn up in predictable places, inside and out.

Outdoors: Clustered around sunny siding, brickwork, door frames, soffits, and window screens.
Indoors: Hiding inside wall voids, attics, drop ceilings, window sills, and quiet rooms on upper levels where warmth draws them out of hibernation on warm winter days.

Insect Identification

Knowing which one you have helps us tailor the treatment.

Asian Lady Beetles: Oval, dome-shaped beetles ranging from orange to deep red with variable black spots; distinguished by a black "M" or "W" shaped marking behind their head.
Brown Marmorated Stink Bugs: Shield-shaped, mottled brown insects (about 5/8" long) with banded antennae and a signature defense mechanism that emits a strong odor when threatened.

Why crushing or vacuuming requires caution

Crushing stink bugs releases a pungent odor that can linger indoors, while squishing Asian lady beetles causes them to discharge an oily yellow fluid that stains walls, upholstery, and carpets. Vacuuming them into standard bagless vacuums can also leave your vacuum smelling bad.

Are they dangerous?

Neither pest bites, stings, or causes structural wood damage. However, they are significant nuisance pests. In large indoor numbers, their staining secretions and persistent stink bug odors can ruin indoor air quality and damage interior finishes.

How we treat it

We apply a targeted, long-lasting residual barrier treatment around key entry points—including window frames, door surrounds, soffits, eaves, fascia, and utility penetrations—before the fall migration rush, following up as needed through the season.

Prevention Tips for Homeowners

1Seal gaps and cracks around window frames, exterior doors, and siding trim with exterior-grade caulk.
2Inspect and repair torn mesh screens on windows, patio doors, foundation vents, and attic gables.
3Install tight-fitting door sweeps under all exterior entry doors.
4Seal utility pipe penetrations and electrical conduit entries along exterior walls.