Why do we keep seeing beetles and bugs in our home throughout the winter?
In Wisconsin, we experience several overwintering pests that want to enter our homes and business, the most common being the Boxelder bug and multi colored Asian lady beetle. These insects seek out structures to get out of the cold harsh elements and find shelter inside of your house or business. We seem to find most of them behind or in insulation or insulated areas such as your walls or attic.
The Boxelder bug (Boisea trivittatus) can be identified as a black bug, long and slender with red “X” marking on the wing covers and 3 red lines on the pronotum, the part of the insect right behind the head. This insect cannot bite but will fly and crawl around and become a nuisance. In 2014 we had a mild population of boxelder bugs which is usually associated with a fair amounts of rain fall throughout the summer months. In 2014 parts of Wisconsin experienced an increase in the Multi Colored Asian Lady Beetle (Harmonia axyridis) populations. As you probably already know, these small beetles are usually orange with black spots and white markings behind the head. These are not the metallic green Japanese beetle (Popillia japonica) that are often confused with or misnamed. We are not sure why there was an increase of Asian lady beetles in 2014 but some experts say that there were more soybean aphids that this beetle feeds on which may have contributed to the large numbers. These beetles usually do not bother us in the summer, but later in the season, when the nights get cooler and especially after the first freeze, we see these beetles head for shelter. Unfortunately, our homes may be the shelter that they are seeking to overwinter.
Is there anything we can do now or is it too late?
It is true that the best prevention from these bugs and beetles is to have your home treated by a professional in the Fall (preferably September). This will create a barrier on the structure to help repel and reduce insects from entering your home or business. If you are seeing them in the winter, they are already in your home or building and you will probably see them crawling on your walls and windows or flying around your lights throughout the winter months, especially on warmer and sunny days, until spring, when they when they will start to exit back into the environment. In the Fall, sealing gaps in the foundation, fixing door seals or pipe entries will help, but these critters still seem to find their way in. As a home owner, you can vacuum the pests up and remove them as they appear. With the Asian lady beetle, make sure you use the hose end or shut the beater off on the bottom. The beater on the vacuum will agitate the beetles and they can release an unpleasant order. In addition, they have been known to stain a variety of surfaces due to “reflex bleeding”. If you find that you simply do not want to deal with them or vacuuming is not helping, please call a professional. They will strategically apply localized crack and crevice treatments that can provide you some relief from these pesky critters.
Jim Gilbert-Associate Certified Entomologist
Terminator Pest Control