The brown marmorated stink bug has become one of the most recognizable fall pest invaders in the Midwest. Since spreading from its native range in Asia — arriving in the U.S. in the mid-1990s — it has established itself across Iowa, Nebraska, Kansas, and Missouri, showing up on exterior walls and inside homes every September and October. It earns its name honestly: when disturbed or crushed, it releases a cilantro-like chemical smell that most people find deeply unpleasant.

Identification

Adult brown marmorated stink bugs are about 5/8 inch long with a broad, shield-shaped body — the classic “stink bug” silhouette. The back is mottled brown and gray (marmorated means marbled), and the shield shape is distinctive. Two key diagnostic features: alternating light and dark banding on the antennae, and alternating dark and light banding on the exposed edges of the abdomen. These characteristics distinguish it from native stink bug species.

Why They Enter Homes in Fall

Like several other overwintering pests, brown marmorated stink bugs enter a state of dormancy in winter (diapause) and spend the cold months sheltered in protected locations. In the wild, that means under bark and rock crevices. In suburban and urban environments, it means inside homes — in wall voids, attics, and other thermally stable spaces. They aggregate on warm, sun-facing exterior surfaces in fall, probing for entry points. Once inside, they’re dormant until spring warmth revives them.

Agricultural and Garden Damage

Beyond being a home nuisance, brown marmorated stink bugs are serious agricultural pests. They damage apples, peaches, soybeans, tomatoes, sweet corn, and many other crops by piercing fruit and plant tissue to feed. In gardens, they cause pitting and scarring of fruits and vegetables. They’ve caused significant losses to commercial orchards in the eastern U.S.

Signs of an Indoor Infestation

  • Shield-shaped insects on exterior walls in September–October
  • Stink bugs crawling on interior walls or window frames in fall or spring
  • Distinctive cilantro-like smell when insects are disturbed
  • Insects found in attic spaces or inside light fixtures

Prevention Tips

  • Seal all exterior gaps before fall — around windows, doors, soffits, utility penetrations, and exhaust vents
  • Apply a perimeter insecticide to exterior walls in September before bugs begin aggregating
  • Install or repair window and door screens
  • Use a vacuum to remove stink bugs indoors — don’t crush them
  • Dispose of vacuum contents outside immediately to avoid odor inside the vacuum

Professional Fall Treatments

Perimeter insecticide applications in September are the most effective tool against stink bug invasion. The timing matters — applications need to go on before the insects begin clustering in large numbers. Miller Pest Solutions provides fall perimeter treatments throughout the Des Moines, Omaha, and Kansas City areas. Don’t wait until they’re already inside your walls to address them. Call for a free phone bid: Omaha (402) 769-0997 | Des Moines (515) 329-8801 | Kansas City (816) 815-0498