John Orick, Purdue Master Gardener State Coordinator, Department of Horticulture and Landscape Architecture
The boxelder bug gets its name because this insect feeds and reproduces in boxelder trees during summer months. These “true bugs” can also be found on pear, apple, cherry, plum, ash, and other tree species in the landscape. Boxelder bugs have piercing-sucking mouthparts and suck plant juices from their host tree species. Home gardeners can often find these reddish-orange and black insects clustered in high numbers on trees and other garden plants growing in home landscapes. The first concern is that since these insects are found in such high numbers they might damage favorite garden and ornamental plants. But, damage from the feeding of boxelder bugs is minimal and rarely warrants an application of insecticide. Boxelder bugs can be a nuisance to homeowners when they invade homes and other structures in the fall to overwinter. These insect pests do not bite humans nor do they damage furniture or clothing. However, if crushed, they can omit a foul odor. In the spring, these invaders are discovered as they attempt to find their way outdoors to feed and reproduce. The boxelder bug develops by what is called “incomplete metamorphosis”. This means they mature in this sequence: egg – nymph – adult. The photo in this article shows boxelder bugs in the nymph stage of their life cycle.
So, how should homeowners handle this unwelcome visitor? Some suggest the applications of an insecticide around the perimeter of homes to prevent the invasion of the bug in the fall. Others recommend the use of chemical insecticides sprayed on clusters of boxelder bugs on host plants. And, insecticidal soaps are also mentioned as one possible non-chemical control. If these insects are a problem inside homes or buildings, then just vacuuming them and changing the vacuum bag after each cleaning may be the easiest option.