Is It a True Bug? How to Tell True bugs From Look-Alikes
True bugs: 6 marks to check, what they are often confused with, whether they bite or sting, and where they turn up, quoted from university entomology and IPM sources.
At a glance
- Group: Hemiptera
- Body plan: Sucking mouthparts point downward, perpendicular to the body; forewings are thickened at the base with membranous tips, and when folded overlap to form a triangle or X-shape on the back.
- Size: Common stink bugs are roughly 1/2 to 5/8 inch long, varying by species.
- Bites or stings: Boxelder bugs do not bite people. Kissing/conenose bugs, blood-feeding relatives in the same true-bug group as assassin bugs, do bite (often around the face) and can transmit Chagas disease.
- Where you find them: Many true bugs (e.g. leaffooted bugs) overwinter as adults in protected sites like woodpiles, buildings, and tree bark, and feed outdoors on host plants otherwise.
How to tell it is one of the true bugs
- Stink bugs are shield-shaped with a large triangular scutellum covering the base of the abdomen.
- Boxelder bugs are dark grey/black with red eyes and orange-red stripes on the thorax and wings; smaller than eastern conenose (kissing) bugs.
- Assassin bugs have an elongate head and body with long legs, unlike the compact shield shape of stink bugs.
- Folded wings form a visible triangle or X-shape on the back, a general hallmark of true bugs.
- Brown marmorated stink bug has alternating light/dark banding on its antennae, a key feature separating it from similar bugs.
- Stink bugs release a foul-smelling defensive fluid when disturbed, the origin of their common name - a behavioral tell not shared by boxelder bugs.
Often confused with
People most often mix true bugs up with:
Open the other page and compare its list against the marks above; the differences are usually in the antennae, wings or the way the body is divided.
Bites and stings
Boxelder bugs do not bite people. Kissing/conenose bugs, blood-feeding relatives in the same true-bug group as assassin bugs, do bite (often around the face) and can transmit Chagas disease. Seek medical care promptly for severe symptoms or any allergic reaction.
Pest or beneficial?
Assassin bugs are general predators but are not considered reliable biological control agents because they also feed on beneficial insects.
Where they turn up
Many true bugs (e.g. leaffooted bugs) overwinter as adults in protected sites like woodpiles, buildings, and tree bark, and feed outdoors on host plants otherwise.
How to photograph it for identification
Get as close as your camera will focus, from directly above, in daylight or a bright lamp. Include the whole body with the legs and antennae in frame; a second shot from the side shows wings and body segments. Put a coin or ruler next to it for scale. For a bite or a bug found on skin or bedding, photograph the bug itself, not the mark. The app names the likely group; use the list above to confirm.
FAQ
Do true bugs bite or sting?
Boxelder bugs do not bite people. Kissing/conenose bugs, blood-feeding relatives in the same true-bug group as assassin bugs, do bite (often around the face) and can transmit Chagas disease. Seek medical care promptly for severe symptoms or any sign of an allergic reaction.
What is the quickest way to recognize true bugs?
Stink bugs are shield-shaped with a large triangular scutellum covering the base of the abdomen.
Are true bugs a pest?
Assassin bugs are general predators but are not considered reliable biological control agents because they also feed on beneficial insects.
How do I tell true bugs from beetles?
Assassin bugs have an elongate head and body with long legs, unlike the compact shield shape of stink bugs. The Beetles page lists its own marks.
Related
See what's really crawling, flying, and buzzing past.
Start with a single photo.
Sources
- https://ipm.ucanr.edu/natural-enemies/assassin-bugs/
- http://ipm.ucanr.edu/PMG/GARDEN/PLANTS/INVERT/truebugs.html
- https://ipm.ucanr.edu/PMG/GARDEN/VEGES/PESTS/stinkbug.html
- https://extension.psu.edu/kissing-bugs
- https://ipm.ucanr.edu/home-and-landscape/leaffooted-bug/
Updated 2026-09-11.