Brown Marmorated Stink Bug (Halyomorpha halys) — identification, habitat & look-alikes

Brown marmorated stink bugs are shield-shaped brown insects that gather on U.S. homes in fall and slip indoors to spend the winter. White bands on the antennae and alternating pale and dark patches along the abdomen help distinguish them from similar stink bugs.

Appearance

Appearance: Adults are mottled brown, shield-shaped, and about 0.55–0.67 in (14–17 mm) long. The antennae have broad pale bands, and the exposed edge of the abdomen alternates pale and dark.

Look-alikes

brown stink bugEuschistus servus

Brown stink bugs can have pale and dark marks along the abdomen, but they lack the two bold pale bands across the outer antenna segments. Check the antennae in a clear photo.

Why they get mixed upBoth are mottled brown, shield-shaped stink bugs found around U.S. crops.

Where it lives

Typical habitats: orchards
crop fields
gardens
buildings in fall
Range: Native to East Asia, this species is now established across much of the United States. It was first collected in Allentown, Pennsylvania, in 1998 after probably arriving several years earlier.
When it’s recorded: Recorded year-round, every year · most records in Sep–Oct
Active Apr–Oct
36,864 observations in the US · 10 years · for referenceChoose a state

Behavior

Diet: Adults and pierce plants and suck fluids from fruits, seeds, stems, and leaves. U.S. hosts include apples, peaches, beans, corn, tomatoes, soybeans, and many ornamental plants.
Activity: Adults emerge from winter shelters from late April into May in Pennsylvania. They begin seeking protected ing sites again in September and October.
Social life: Newly hatched nymphs remain clustered near their eggs for a short time. Adults can gather by the hundreds on buildings in fall.
Overwintering: Adults shelter in buildings, under bark, and in other protected crevices. They do not reproduce or damage structures while indoors.

Life cycle

Breeding season: In cooler U.S. regions, females lay eggs from May through August and usually produce one or two generations a year.
Clutch size: 20–30 eggs

Conservation

IUCN Red List: NENot EvaluatedNot yet assessed
Threats: Feeding can scar or distort fruit and injure seeds inside crop pods. The species is a serious agricultural pest, especially in parts of the mid-Atlantic.

Culture and stories

Culture and stories: The word marmorated means marbled and refers to the mottled brown pattern.
They do not bite people or pets and are not known to spread disease, but their defensive odor can be a nuisance.

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