Otherwise known as maple bugs, boxelder bugs do not bite or cause structural damage to homes. Instead, they are considered nuisances when they move inside during the colder months of the year. The pests congregate in large numbers, making their presence that much more overwhelming. Their primary host is the aptly named boxelder tree, though the pests only infest female, seed-producing trees; they also infested other plants. As a result, homeowners with boxelder trees in their yards may find themselves dealing with unpleasant infestations.
Appearance / Identification
Growing up to 14 mm long, boxelder bugs are black in colour with three distinctive, reddish-orange stripes on their thoraxes. When their wings lie flat, these stripes overlap to form what looks like a letter ‘X.’ The colour red carries through to the edges of their wings and appears in their eyes, as well. Immature boxelder bugs, called nymphs, are bright red with black wing buds.
These seasonal pests are found primarily on boxelder trees as well as other maples and ashes. However, they are also known to gather on home exteriors on sunny days and overwinter indoors.
Boxelder bugs feed on the seed pods of their host trees and other similar species by sucking the sap out of them. From time to time, these pests will also feed on fruit trees, including cherry, plum, peach, and apple.
Life Cycle / Reproduction
Overwintering adult boxelder bugs emerge in the spring and deposit red, oval-shaped eggs on the leaves and bark of host trees. These hatch into nymphs that immediately start feeding on seeds, foliage, twigs, and fruit. Nymphs develop through a series of molts before reaching adulthood and begin reproducing immediately. It is the second generation of adults that will overwinter and emerge the next season.
Problems Caused by Boxelder Bugs
Host trees may experience some cosmetic damage, including speckled leaves and scarred fruit, depending on the size of the infestation. The mere presence of boxelder bugs causes the majority of homeowners’ issues with these pests. Due to the insects’ propensity to gather in large numbers, homes and other structures can be overrun quickly in the late fall and early winter. Crushed boxelder bugs emit a foul odour and the orange colour from the body can stain structures, while their excrement can stain draperies, furniture, and other linens.
Detection / Signs of Infestation
Adults prefer to overwinter in dry, sheltered areas such as woodpiles, inside barns and sheds, or around window casements. Brightly coloured and easy to see, boxelder bugs infest homes in large numbers when searching for refuge from cold winters.
Gaps around foundations, open vents, and unscreened windows and doors can provide easy access into homes for these pests. Seal these and other entry points to make it more difficult for boxelder bugs to get indoors. Removing any female boxelder trees from the property or choosing male trees when landscaping and planting may help homeowners avoid future problems.
Control / Removal
Homeowners can remove boxelder bugs with vacuums. Nevertheless, as infestations generally occur in overwhelming numbers, contacting a trained pest removal specialist is usually the best method to keep these pests away. Proper treatment is important as for overwintering boxelder bugs because any dead bugs can become source of attraction and food for other insects, such as carpet beetles. Indoor influxes can often be prevented by application of exterior perimeter treatments by a professional; however timing of this application is crucial for it to be effective. Boxelder bugs already inside can be removed by use of vacuuming.