Boxelder bugs, Boisea trivitta (Say), may be considered nuisance problems, especially when they invade the home, but they do not bite man, damage buildings, clothing, or food products. They do produce a foul odor when crushed and may cause spots on walls and curtains.
These bugs are most noticeable during the autumn months as they often enter homes to overwinter. On warm winter or spring days, these bugs become active inside the home and on the sunny side of white or lightly colored, painted buildings.
Appearance
This bug is about 1/2-inch long and 1/3 as wide. It is black with 3 red lines just behind the head and 4 red lines on the wings. The wings lie flat on the back when at rest. The young are wingless and red and gray.
Feeding Habits
Boxelder bugs rarely develop into numbers large enough to be a nuisance, unless they feed on female boxelder trees. Occasionally feeding occurs on ash, maple, and other trees with similar types of seed pods.
Life Cycle
The adult bugs lay eggs in the spring and the young emerge in a few days. The young are small and show more red than adults. These young develop into adults during the summer, then mate and lay eggs that hatch into the young of the second generation. Activity of nearly fully grown young is noticed in August and September, when they gather in large numbers on the trunks of boxelder trees. The migration of the adults begins at this time.
The adults' search for a place to winter, brings them where they hide in small cracks and crevices in walls, door, window casings, attics, and around foundations. During warm days in winter and early spring, they come out and scatter through the house. They are a nuisance as they crawl or fly about in the rooms. They do no damage by feeding, but their excrement spots on draperies cannot be removed.
