Boxelder bugs, scientifically known as Boisea trivittata, are a common insect species found across North America. These insects are often recognized by their distinctive black bodies marked with red or orange stripes. They are primarily plant-feeding insects, and their presence is frequently associated with certain types of trees. Understanding their dietary habits provides insight into their behavior and why they often appear in residential areas.
Main Dietary Preferences
Boxelder bugs derive their common name from their preference for boxelder trees (Acer negundo). They primarily feed on the seeds of these trees, a significant nutrient source for their development. They also consume sap from the leaves and tender shoots of boxelder trees. This feeding activity is noticeable during spring and summer when trees produce new growth and seeds.
While boxelder trees are their preferred host, these insects also feed on other species within the maple family (Acer spp.), such as silver maples and red maples. Ash trees (Fraxinus spp.) can also serve as a food source for boxelder bugs. They extract fluids from the leaves, seeds, and sap of these alternative hosts. However, populations are most abundant where female, seed-bearing boxelder trees are present.
Alternative Food Sources
When their primary food sources are scarce or unavailable, boxelder bugs can adapt their diet. They may feed on the seeds of other tree species, as well as fallen fruits. This allows them to sustain themselves where preferred hosts are less common. Fruits such as apples, cherries, plums, peaches, grapes, and strawberries may occasionally be targeted.
While they may feed on these alternative plant materials, they are not predatory insects. Their diet remains strictly plant-based, relying on the extraction of fluids from plant tissues. This occasional consumption is not their primary diet, occurring more out of necessity than preference.
How They Feed and Its Effects
Boxelder bugs possess specialized piercing-sucking mouthparts, used to extract sap and plant fluids. They insert these needle-like mouthparts into plant tissues, such as seeds, leaves, and tender shoots, to draw out the nutrient-rich liquids. This allows them to access internal fluids without consuming solid plant material.
Their feeding activity can result in visible signs on affected plants. Discolored spots, such as yellowish or reddish marks on leaves, indicate their presence. New shoots may exhibit distorted or stunted growth if heavily fed upon. Damage to seeds can cause them to appear shriveled or discolored, potentially reducing their viability. While large congregations of boxelder bugs can cause aesthetic damage to plants, significant harm to mature, healthy trees is uncommon.