Bug Identifier

True Bugs

Brown Marmorated Stink Bug

Halyomorpha halys

048121620
Body length in millimeters. Shaded bar shows the typical adult range.
Scientific nameHalyomorpha halys
GroupTrue Bugs
Size12–17 mm (up to about 0.67 in)
Colors Brown and Gray
Legs6 legs
WingsYes
Where foundIndoors, anywhere and Garden or plants
Most activeFall and Winter
BitesNo
StingsNo
Risk levelNuisance

How to identify it

The brown marmorated stink bug is a medium-sized member of the true bugs group. Piercing, straw-like beaks and wings that overlap in an X on the back. Check for these three features:

  1. Shield-shaped, marbled brown body
  2. White bands on the antennae and legs
  3. Alternating light and dark bands along the edge of the abdomen

About this bug

A shield-shaped, mottled brown bug that invades homes in fall to overwinter and feeds on fruit and vegetables in summer. It releases a sharp odor when disturbed or crushed.

You'll usually find brown marmorated stink bugs indoors and in gardens and on plants. They are most active in fall and winter.

Is it dangerous?

Stink bugs don't bite or sting people; they are a household and crop nuisance.

Our rating: Nuisance, meaning it is a nuisance pest but not a health threat to most people.

When you'll see brown marmorated stink bugs

Brown Marmorated Stink Bugs are most active in fall and winter. In fall, many bugs look for shelter, and some move toward or into buildings. In winter, activity continues mainly indoors in heated spaces.

Typical places to check: indoors, anywhere and garden or plants.

About true bugs

The brown marmorated stink bug is one of the true bugs. True bugs have piercing, straw-like mouthparts used to suck plant sap or, in a few species, blood. They develop through gradual metamorphosis: nymphs look like small, wingless adults and molt several times as they grow. Many release strong odors from scent glands when threatened.

Because nymphs look like adults, you'll often see mixed sizes of the same bug together, which is a good sign that a population is breeding nearby.

What to do about it

  1. Seal cracks around windows, siding and vents before fall
  2. Knock indoor bugs into a jar of soapy water
  3. Use a vacuum with a disposable bag for large groups

Read the full guide: how to get rid of brown marmorated stink bugs.

Bugs that look similar

Western Conifer Seed BugLeptoglossus occidentalis16–20 mmNuisance

Size: Western Conifer Seed Bugs are larger, reaching 20 mm, while brown marmorated stink bugs top out around 17 mm.

Wheel BugArilus cristatus25–38 mmCan bite or sting

Size: Wheel Bugs are larger, reaching 38 mm, while brown marmorated stink bugs top out around 17 mm.

Squash BugAnasa tristis14–16 mmNuisance

Where found: look for brown marmorated stink bugs indoors and in gardens and on plants; squash bugs turn up in gardens and on plants.

Frequently asked questions

What does a brown marmorated stink bug look like?

Shield-shaped, marbled brown body. Adults measure 12–17 mm (up to about 0.67 in).

Does the brown marmorated stink bug bite or sting?

It does not bite. It does not sting. Stink bugs don't bite or sting people; they are a household and crop nuisance.

Where do brown marmorated stink bugs live?

Brown Marmorated Stink Bugs live indoors and in gardens and on plants.

When are brown marmorated stink bugs most active?

Mostly in fall and winter.