As we switch out our tee shirts for sweaters and our iced tea for pumpkin lattes, we are not the only creatures preparing for the coming of cooler weather. The cooler days, especially mornings, signals to begin searching for a place to over winter. Squirrels are scavenging for food to bury and building nests. Small mammals are building dens and birds are flying south. And many insects will be drawn from the plants on which they feed to a place where they can shelter over the cold season. You may see them gathering on sunny sides of trees, fences and buildings. They are looking for warmer places where they can over winter, including your house! The colder weather can cause many bugs that are normally good or neutral to go bad when they get into your house.
The boxelder bug is a large, native bug that feeds on boxelder, maple and ash trees. Hot dry summers like we had this year produce a large population of boxelder bugs, so you may have noticed a great number of them on your house this fall as they try to find a warm space to overwinter. Boxelder bugs are mostly an annoyance. They don’t damage plants, bite people or spread disease. At worst they have a bad smell when crushed.
The Multicolored Asian Lady Beetle is not a native insect; it is about 1/3 inches long, and ranges in color from yellow to red. It looks very much like a common lady bug, but it usually has 19 black spots on its back and a clear black “M” shaped marking behind its head. During the summer the Multicolored Asian Lady Beetle is a big ally to soy bean farmers. 7.5 million acres of cropland in Minnesota is devoted to soybeans and the main pest threatening the soybean crop is the soybean aphid. An adult Multicolored Asian Lady Beetle can eat up to 65 aphids a day. They also eat aphids in our gardens. The Multicolored Asian Lady Beetle goes bad when it can no longer find food or moisture; biting people when they are in search of it. They can smell bad when they emit a strong yellowish liquid from their leg joints. They do not spread disease but can produce an allergic reaction in some people. In China they will over-winter in sun facing caves but in Minnesota they will try to enter homes for shelter.
Probing Pirate bugs are another insect that may try invading your house this fall. You may not notice them because they are minute (0.2 inches), oval in shape with black and white coloration. They hunt other insects like aphids and mites, which love the hot, dry weather that we had this summer. In fall they probe with their mouths to find food and moisture and may bite people in the process. They don’t feed on blood, inject saliva or spread disease so the bite is mostly an annoyance; but like other bugs they don’t like the cold so they may try to enter your home for the winter.
So what is the best way to deal with these home invaders? The best way is to prevent them from entering in the first place. Check around the outside of your house for places where they can get in. Remember most of them are not very big so they can get in very small places. Seal around your windows and screens, check for gaps around you doors, including garage doors and check that your door sweeps are tight. Seal around all cords, cables, pipes and vents that are going into your house. Look for cracks in the foundation and fill them in. A bonus for making sure that you seal all of these places is you are also sealing out the cold weather and possibly other critters, (mice only need a ¼ inch space, about the size of a dime to get in).
If you are not successful in keeping them out the best way to deal with them is to vacuum them up. Vacuuming them won’t kill them however – so be sure to empty your vacuum cleaner bag outside after you vacuum them up. I would avoid pesticide use in your home. The bugs may be unappealing but they won’t make you sick as a pesticide might. If you do choose to go the pesticide route, be sure to follow the directions on the label. Pesticide use is regulated by the Federal Government and the label is the law! And is there for your safety.
Good luck preparing your home for a pest free winter.