During the warm days of fall, many bugs may become a nuisance. This is because insects are looking for a warm dry place to spend the winter.

The boxelder bug is one insect that does just that, but instead of seeking outdoor sites, it prefers your home.

The adult boxelder bug is brownish-black in color with a bright red body and red stripes on the thorax (area between head and abdomen) and wing margins. During the autumn months, adult and large nymph boxelder bugs congregate in large numbers primarily on the bark of boxelder trees and then begin migrating to a place to live over winter. Only full-grown adults over winter, and they may crawl from a nearby tree or fly about two miles to find shelter.

Over wintering sites include cracks and crevices in walls, in door and window casings, around foundations, in stone piles, in tree holes and in other protected places. On warm days during winter and early spring, they sometimes reappear on light-painted surfaces outdoors on the south and west sides of the house, resting in the sun.

When the weather warms up in the spring, the insects leave their places of hibernation to fly to boxelder trees where they lay their eggs.

The eggs are a rusty red color and are usually hard to see because the insect deposits them in small crevices found in the bark. Eggs tend to hatch in 11 to 14 days and the nymphs (immature stage) feed throughout the summer on the boxelder plant juices by inserting their beaks into leaves, fruits or soft seeds.

Occasionally, they have been observed feeding on ash, maple, plum, cherry, apple, peach, grape and strawberries, causing some scarring or dimpling of fruits.

However, boxelder bugs seldom develop in large enough numbers to become a nuisance, unless they feed on seed-bearing boxelder trees.

The good news is these insects do not bite or cause damage (outside of the female boxelder trees). Yet, if they are a great nuisance to you, then you may want to look into management options.

Since boxelder bugs feed and reproduce primarily on pistillate (female) boxelder trees, removal of these trees, especially around the house, would most likely eliminate nuisance populations.

Also, eliminate potential hiding places such as piles of boards, rocks, leaves, grass and other debris (leaves, cut grass etc.) close to the house.

Be sure to caulk and close openings where bugs can enter such as around light fixtures, doors and windows, unscreened vents, holes in walls around utility pipes or conduits, air conditioners, heat pump lines and through the foundation.

For more information, please contact Cornell Cooperative Extension of Cayuga County at 255-1183.

Resources for this article include: Cornell University boxelder bug fact sheet and the Ohio State University boxelder bug fact sheet.

Renee Jensen is a community educator of environmental issues for Cornell Cooperative Extension of Cayuga County.