The boxelder bug is a small, seed-eating insect native to North America, named for its primary host, the boxelder tree. They are known for seeking shelter in homes during colder months, often becoming a nuisance despite being harmless to humans and pets.
Key Features of Boxelder Bug
Physical Characteristics:
- Size: About 1/2 inch (12-14 mm) in length.
- Color: Primarily black with distinct red or orange markings.
- Red lines along the thorax.
- Red veins on the wings.
- The abdomen is also red beneath the wings.
- Shape: Elongated, flat-bodied with six legs and two antennae.
Life Cycle:
- Eggs:
- Laid on leaves, bark, or in crevices.
- Typically reddish in color.
- Hatch in 4-5 days during warm weather.
- Nymphs:
- Bright red when young.
- Gradually develop black markings as they mature.
- Adults:
- Emerge by mid-summer and can live for several months.
- Adults overwinter in protected spaces, including homes and buildings.
Habitat:
- Host Plants: Primarily boxelder trees (Acer negundo), but also feed on other maples and ash trees.
- Feeding Habits: Boxelder bugs feed by sucking the juices from seeds, leaves, and twigs. They prefer:
- Boxelder tree seeds, particularly the female trees.
- Sap from fruits like apples or plums, but rarely cause significant damage.
Behavior:
- Seasonal Activity:
- Active in spring and summer.
- Seek warmth during fall and invade homes to overwinter in walls, attics, and cracks.
- Aggregation: Boxelder bugs often cluster together in large groups, especially on warm, sunlit walls, which can be alarming.
- Invasiveness: Although they enter homes in large numbers, they do not bite, damage property, or breed indoors.
Control and Prevention:
- Prevention:
- Seal cracks and openings around windows, doors, and siding to prevent entry.
- Remove boxelder trees or limit planting of female trees.
- Rake up fallen seeds and leaves to reduce food sources.
- Removal:
- Vacuuming is an effective method for removing them from homes.
- Insecticides are generally not needed, as they are not harmful.
- Soapy water sprays can kill the bugs on contact outside.
Common Issues:
- Nuisance: While harmless, large infestations can be bothersome.
- Staining: They can stain walls and surfaces with excrement.
- Odor: When crushed, they release a pungent smell.
The boxelder bug is a classic fall invader and, while it doesn’t cause harm, its tendency to overwinter in homes makes it a significant annoyance.