Boxelder bugs are pests of the boxelder tree, a species of maple native to the Midwest. As the boxelder tree was introduced to other areas of the United States and Canada, boxelder bugs followed. The western boxelder bug is present from New Mexico, Utah and Idaho westward to the Pacific coast and up into British Columbia. The boxelder bug is present east of this region in Canada and the United States with some overlap between the two regions. These two boxelder bugs look similar except the western boxelder bug has more red veins on the upper membranous half of its forewings.