what is a boxelder bug
A boxelder bug is a small, plant-feeding insect that mostly lives on boxelder trees and sometimes invades houses in big groups, becoming more of a nuisance than a true pest.
What Is a Boxelder Bug?
Boxelder bugs are sap-sucking insects in the genus Boisea , commonly found across much of North America.
They are strongly associated with boxelder trees (a type of maple), especially the female, seed-bearing trees.
How they look
- About 0.5 inch (1–1.5 cm) long as adults.
- Mostly dark gray to black with narrow red or orange lines along the thorax and wings.
- The abdomen is red, and young nymphs are bright red, turning darker with black markings as they mature.
Where They Live and What They Eat
- Spend spring and summer on female boxelder trees, feeding on leaves, twigs, and developing seeds.
- Can also feed on maple and ash, and sometimes on fruits like apple, cherry, peach, pear, plum, grapes, raspberries, and strawberries, usually causing only minor deformities or discoloration.
- Often seen sunning themselves on warm, south- or west-facing walls in late summer and fall.
Are Boxelder Bugs Harmful?
From a gardening and health standpoint, they’re mostly just annoying.
- They rarely cause serious plant damage; injuries are usually cosmetic (slight fruit deformities, yellowing leaves).
- They do not sting and are not known to spread disease.
- Bites are very rare and usually only defensive if handled.
- Their droppings can stain light-colored walls, curtains, or furniture, and crushing them can release a bad odor.
Why They Come Into Houses
As temperatures drop in fall, adults gather in large numbers on buildings and try to move inside to overwinter.
- They cluster on sunny exterior walls, around windows, doors, and rooflines.
- They slip into cracks, vents, and gaps and hide in wall voids, attics, and other protected spots until warmer weather returns.
- Indoors they are mainly a nuisance—walking or flying around, especially near windows—rather than causing structural damage.
Simple Control & Prevention
Outside the home
- Seal entry points
- Caulk gaps around windows, doors, siding, and utility lines before fall.
* Repair screens, door sweeps, and vents.
- Reduce hiding spots
- Clear piles of firewood, rocks, boards, leaves, or other debris near the house foundation.
- Tree choices
- Limiting female (seed-bearing) boxelder trees near the house can reduce large populations, though full removal is a bigger landscaping decision.
Inside the home
- Vacuum or sweep bugs up and dispose of the bag or release them outdoors.
- Avoid crushing them on walls or fabrics to prevent stains and odor.
- If infestations are heavy, local extension offices or pest professionals can advise on targeted treatments.
Quick HTML Fact Table
| Feature | Details |
|---|---|
| Common name | Boxelder bug |
| Scientific names | Boisea trivittata (boxelder bug), Boisea rubrolineata (western boxelder bug) | [5][1]
| Size | About 0.5 inch (1–1.5 cm) long as adults | [5]
| Color | Black or dark gray with red or orange lines on thorax and wings; red abdomen | [5]
| Favored host | Female (seed-bearing) boxelder trees | [7][1][3][5]
| Other hosts | Maple, ash, and some fruit trees (apple, cherry, peach, pear, plum, grapes, berries) | [9][1][3][5]
| Damage level | Mostly cosmetic; rarely serious to plants | [9][1][3][5]
| Human health risk | No known disease transmission; defensive bites are rare | [3]
| Main issue | Nuisance pest when gathering on buildings and entering homes to overwinter | [8][4][3][5]
| Key prevention | Seal cracks, maintain screens and door sweeps, reduce debris and host trees near buildings | [4][1][3][5]
Information gathered from public forums or data available on the internet and portrayed here.