| Scientific name | Boisea trivittata |
|---|---|
| Group | True Bugs |
| Size | 11–14 mm (up to about 0.55 in) |
| Colors | Black, Red and Orange |
| Legs | 6 legs |
| Wings | Yes |
| Where found | Indoors, anywhere and Trees or shrubs |
| Most active | Fall and Winter |
| Bites | No |
| Stings | No |
| Risk level | Nuisance |
How to identify it
The boxelder bug is a small 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:
- Black body with three red lines on the thorax
- Red edges along the wings
- Bright red nymphs clustered on tree trunks
About this bug
A black bug with red-orange lines on its back that feeds on the seeds of boxelder and maple trees. Large groups sun themselves on warm walls in fall before crawling inside.
You'll usually find boxelder bugs indoors and on trees and shrubs. They are most active in fall and winter.
Is it dangerous?
Boxelder bugs rarely bite and are harmless, but their droppings can stain curtains.
Our rating: Nuisance, meaning it is a nuisance pest but not a health threat to most people.
When you'll see boxelder bugs
Boxelder 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 trees or shrubs.
About true bugs
The boxelder 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
- Seal gaps on the sunny side of the house
- Spray clusters on outside walls with soapy water
- Vacuum bugs that make it indoors
Read the full guide: how to get rid of boxelder bugs.
Bugs that look similar
Size: Large Milkweed Bugs are larger, reaching 18 mm, while boxelder bugs top out around 14 mm.
Size: Kissing Bugs are larger, reaching 25 mm, while boxelder bugs top out around 14 mm.
Frequently asked questions
What does a boxelder bug look like?
Black body with three red lines on the thorax. Adults measure 11–14 mm (up to about 0.55 in).
Does the boxelder bug bite or sting?
It does not bite. It does not sting. Boxelder bugs rarely bite and are harmless, but their droppings can stain curtains.
Where do boxelder bugs live?
Boxelder Bugs live indoors and on trees and shrubs.
When are boxelder bugs most active?
Mostly in fall and winter.