A stink bug is a shield-shaped insect about 1/2 to 3/4 inch long, as wide as it is tall, with a triangle-shaped plate in the middle of its back. The one most people find indoors, the brown marmorated stink bug, is mottled brown with light bands on its antennae and alternating light and dark bands along the edges of its body. Other common stink bugs are bright green, and a few are black, red or patterned. All release a pungent smell when crushed or disturbed.
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How to Identify a Stink Bug
- Shape: a broad shield or pentagon, which is why they’re also called shield bugs.
- Back: a large triangle (scutellum) between the wings, reaching about halfway down the body.
- Size: most species about 1/2 to 3/4 inch; the brown marmorated stink bug is about 17 mm (2/3 inch).
- Antennae: five segments. The brown marmorated stink bug has pale bands on the last two segments.
- Edges: alternating light and dark bands along the abdomen edge, visible from above.
- Smell: a sharp odor often compared to cilantro or dirty socks. See what stink bugs smell like.
Stink Bug Pictures by Type
| Stink bug | Color and markings | Where you’ll see it |
|---|---|---|
| Brown marmorated | Mottled brown, pale bands on antennae, banded edges, coppery or bluish specks on head | Invading homes in fall; gardens and orchards |
| Green stink bug | Bright green, narrow yellow or orange edge | Gardens, soybeans, fruit trees |
| Southern green | Plain green, row of small pale dots across the back | Southern US vegetable gardens |
| Brown stink bug | Plain tan or brown; no banded antennae | Fields and gardens; rarely indoors |
| Harlequin bug | Black with bright red, orange or yellow pattern | Cabbage, kale and other brassicas |
| Rough stink bug | Gray-brown, rough bark-like texture | Tree trunks; a beneficial predator |
Baby Stink Bugs and Eggs
Baby stink bugs (nymphs) are round rather than shield-shaped and have no wings. Brown marmorated nymphs go through five stages from 2.4 mm to 12 mm, with deep red eyes, black heads and a yellowish-red to off-white abdomen with red spots. Eggs are barrel-shaped, about 1.5 mm, and laid in neat clusters of 20 to 30 on the undersides of leaves. See the stink bug life cycle.
Stink Bug Signs: Poop and Clusters
Stink bugs don’t build nests. In fall they gather in groups on sunny walls, window frames and siding, then squeeze into wall voids, attics and behind trim to spend the winter. They don’t breed or damage anything indoors, but small brown or yellowish spots of excrement can stain curtains and walls.
Bugs That Look Like Stink Bugs
| Look-alike | How to tell it apart |
|---|---|
| Squash bug | Longer and narrower, dark gray-brown, found on squash and pumpkins |
| Leaf-footed bug / western conifer seed bug | Longer, slimmer body with flat, leaf-like flaps on the hind legs |
| Boxelder bug | Narrow, black with red or orange lines; gathers on sunny walls in fall |
| Spined soldier bug | Similar shape but with sharp spines on the “shoulders”; a beneficial predator |
| Kudzu bug | Small, olive-green and square-ended; found near kudzu and soybeans |
Are Stink Bugs Harmful?
Stink bugs don’t sting, rarely bite and don’t spread disease. They are a nuisance indoors and a crop pest outdoors. See do stink bugs bite, what stink bugs eat and how to get rid of stink bugs.
Keep stink bugs out
- Indoor stink bug light traps for attics and rooms
- Window screen repair kit to close gaps
- Exterior caulk for gaps around windows and siding
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FAQs
A stink bug is shield-shaped, about 1/2 to 3/4 inch long, with a triangle-shaped plate on its back. The brown marmorated stink bug is mottled brown with pale bands on its antennae and banded body edges.
Most stink bugs are brown or green. Some species are black with red, orange or yellow markings, like the harlequin bug.
Baby stink bugs are round, wingless and colorful, often black, red and yellow-white with red eyes. They get larger and more shield-shaped with each molt.
Squash bugs, leaf-footed bugs, western conifer seed bugs, boxelder bugs, spined soldier bugs and kudzu bugs are often mistaken for stink bugs.
No. Stink bugs don’t sting, rarely bite and don’t spread disease. They are a nuisance indoors and a pest of fruit and vegetables.
Sources
Facts in this guide are checked against the sources above and reviewed when they change. See how we research in our editorial policy.
Thank you for showing the look-alikes! I saw a leaffooted bug and thought it was a giant stink bug. Appreciate your help identifying!