Boxelder Bug
Boisea trivittata
📖 Description
Boxelder bugs are primarily a nuisance pest rather than a serious plant pest. They feed on the seeds, leaves, and tender twigs of female boxelder trees and other maples, but the damage they cause to trees is typically minor and rarely requires treatment. Their real impact comes in fall when they congregate by the hundreds or thousands on sunny exterior walls and then push into homes through tiny cracks to overwinter. Once inside, they become a persistent nuisance, appearing on windows, walls, and ceilings throughout the winter and spring. While they do not reproduce indoors, bite, or cause structural damage, their sheer numbers and the stains they leave when crushed make them one of the most annoying fall home invaders.
⚠️ Symptoms to watch for
- Large red and black bugs clustered on tree trunks and sunny walls,Red discoloration and spots on fruit from feeding,Slight leaf curling and yellowing on host trees,Seed pods with feeding damage and deformities,Nuisance presence in and around homes in fall,Minor leaf distortion on maples and boxelders
🩹 Treatment
- Spray congregating bugs with soapy water to kill them (organic),Use a shop vacuum to collect bugs from walls and windowsills (organic),Apply diatomaceous earth around entry points (organic),Spray with insecticidal soap where bugs congregate (organic),Apply permethrin spray to exterior walls and entry points (chemical),Use bifenthrin perimeter treatment around the home (chemical)
🌿 Organic treatments
- Spray congregating bugs with soapy water to kill them,Use a shop vacuum to collect bugs from walls and windowsills,Apply diatomaceous earth around entry points,Spray with insecticidal soap where bugs congregate
🧪 Chemical treatments
- Apply permethrin spray to exterior walls and entry points,Use bifenthrin perimeter treatment around the home
🛡️ Prevention
- Seal cracks and gaps around windows, doors, and siding,Replace damaged window screens and door sweeps,Remove female boxelder trees if practical (they produce the seeds bugs feed on),Rake and remove boxelder seeds that accumulate on the ground,Use weather-stripping on doors and windows,Clear leaf litter and debris from around the foundation in fall
🪴 Affected plants
- Boxelder Trees,Maple Trees,Ash Trees,Apple Trees,Grapevines,Strawberries
🦋 Natural predators
- Birds,Spiders,Predatory Stink Bugs
🌱 Host plants
- Acer negundo,Acer spp.
🔄 Lifecycle
- Adults emerge from overwintering sites in spring and feed on boxelder seeds and developing leaves.
- Females lay clusters of 10-15 red eggs on bark, leaves, and seeds.
- Eggs hatch in 10-14 days.
- Nymphs feed through 5 instar stages over 6-8 weeks.
- New adults appear by mid-summer and feed through fall.
- One generation per year.
- In fall, adults seek overwintering shelter in buildings, under bark, and in debris.
- They often congregate in massive numbers on warm south-facing walls before moving indoors.
📅 Season
- Spring to Fall (active outdoors); Fall to Spring (overwintering in buildings)
🔎 Appearance
- Distinctive black insects with three red or orange stripes on the thorax and red veins on the wings.
- The abdomen beneath the wings is bright red.
- Nymphs are smaller and bright red with black wing pads developing in later instars.
- They congregate in large numbers on sunny walls, tree trunks, and the ground beneath boxelder trees.
💥 Damage level
- Low
🔁 Reproduction rate
- Slow
🗺️ Geographic regions
- North America
Have an Insect to Identify?
Upload or take a photo of an insect on your plant and our AI will identify it and recommend treatments.
📷 Diagnose from Image