It's That Time of Year Again!
Every Spring and Fall we see these black bugs with red markings - the Box Elder Bug - everywhere. But how much do you know about these seasonal guests?
Everything you wanted to know about box elder bugs but were afraid to ask
Or maybe you just didn't care enough? Nevertheless, we see them in great hordes. Some quick facts:
Box elder bugs (Boisea trivittatus) are a nuisance because they enter homes and other buildings, often in large numbers. You might not notice them during summer, but they can become an issue when they try to move into homes during fall to find a warm place to hide for winter.
The adult bug is:
Box elder bugs are "true bugs" and belong to the same family as stink bugs, cicadas and other insects with piercing and sucking mouthparts. They release a bad odor when crushed. You can see bugs at all stages of development at any given time during the summer.
Boxelder bugs are not a serious problem every year. They are most abundant during hot, dry summers when followed by warm springs.
Box elder bugs emerge during spring as the weather starts to warm up. Adults feed on plants and seeds on the ground during spring and early summer. They begin mating a couple of weeks after they start feeding. Starting in mid‑July, they move to female seed-bearing box elder trees where they lay eggs on trunks, branches and leaves. They are rarely found on male boxelder trees. Box elder bugs may also feed on maple or ash trees. There is no noticeable feeding injury to these trees. During years of high populations, you may find nymphs on the ground or in gardens feeding throughout the summer.
Box elder bugs start to leave the trees where they were feeding to find protected areas for the winter. Adult box elder bugs can fly several blocks, and may travel as far as two miles. Although nymphs may be present in the fall, only fully grown adults survive the winter. Box elder bugs like warm areas and are attracted to buildings with a large southern or western exposure. Buildings standing taller than surrounding structures or standing alone on flat ground can also attract large numbers of box elder bugs. The color of the building doesn't matter.
As the weather cools, box elder bugs push into cracks and spaces around homes. They are often found inside around windows and will be active until it becomes cold.
Some box elder bugs end up in sheltered areas in walls, attics and other places inside where they stay until it warms up.
- Box elder bugs like warm areas and are attracted to buildings with a lot of southern or western exposure.
- The best time to control them is in the fall and is most effective by sealing openings and the timely use of insecticides
- They normally do not cause property damage but they can potentially stain surfaces.
- Once they are indoors, the only practical control is physical removal.
- They are not a serious problem every year.
Box elder bugs (Boisea trivittatus) are a nuisance because they enter homes and other buildings, often in large numbers. You might not notice them during summer, but they can become an issue when they try to move into homes during fall to find a warm place to hide for winter.
The adult bug is:
- About 1/2-inch long
- Black with orange or red markings, including three stripes on the area right behind the head (prothorax)
- Wings lay flat over their bodies, overlapping each other to form an ‘X’
- 1/16th-inch long
- Bright red when they first hatch, they change to red and black as they get larger
Box elder bugs are "true bugs" and belong to the same family as stink bugs, cicadas and other insects with piercing and sucking mouthparts. They release a bad odor when crushed. You can see bugs at all stages of development at any given time during the summer.
Boxelder bugs are not a serious problem every year. They are most abundant during hot, dry summers when followed by warm springs.
Box elder bugs emerge during spring as the weather starts to warm up. Adults feed on plants and seeds on the ground during spring and early summer. They begin mating a couple of weeks after they start feeding. Starting in mid‑July, they move to female seed-bearing box elder trees where they lay eggs on trunks, branches and leaves. They are rarely found on male boxelder trees. Box elder bugs may also feed on maple or ash trees. There is no noticeable feeding injury to these trees. During years of high populations, you may find nymphs on the ground or in gardens feeding throughout the summer.
Box elder bugs start to leave the trees where they were feeding to find protected areas for the winter. Adult box elder bugs can fly several blocks, and may travel as far as two miles. Although nymphs may be present in the fall, only fully grown adults survive the winter. Box elder bugs like warm areas and are attracted to buildings with a large southern or western exposure. Buildings standing taller than surrounding structures or standing alone on flat ground can also attract large numbers of box elder bugs. The color of the building doesn't matter.
As the weather cools, box elder bugs push into cracks and spaces around homes. They are often found inside around windows and will be active until it becomes cold.
Some box elder bugs end up in sheltered areas in walls, attics and other places inside where they stay until it warms up.
what to do about the invasion
The best way to manage box elder bugs is prevention—keep them from entering your home from the start. This is done by sealing possible entry points around the home so they are unable to enter. Make repairs to openings they can get into before the end of August.
Once box elder bugs are found inside the best option is to remove them with a vacuum or a broom and dust pan (they can stain items if crushed). It is not practical to try to treat wall voids and other hiding places to prevent them from emerging. Since they don't live for very long, insecticides are not recommended once they have emerged into the inside of a home.
Spraying with insecticides or removing box elder trees in your yard is not a good way to manage box elder bugs. Adult box elder bugs can fly up to a couple miles from their source of food so they don’t need to be near the trees in order to infest your house.
Once box elder bugs are found inside the best option is to remove them with a vacuum or a broom and dust pan (they can stain items if crushed). It is not practical to try to treat wall voids and other hiding places to prevent them from emerging. Since they don't live for very long, insecticides are not recommended once they have emerged into the inside of a home.
Spraying with insecticides or removing box elder trees in your yard is not a good way to manage box elder bugs. Adult box elder bugs can fly up to a couple miles from their source of food so they don’t need to be near the trees in order to infest your house.