Minneapolis MN Box Elder Bug & Asian Beetles Pest Control
It’s the time of year when Box elder bugs and Asian lady beetles seem to come out of the woodwork. When the weather cools, our warm homes are just as enticing to pests as they are to us.
The Asian lady beetle, sometimes known as the Halloween lady beetle or the Japanese lady beetle, is a yellow-orange ladybug that is often seen in large congregations near the end of October. As many as several thousand adult beetles have been found congregating outside on windows, doors, porch decks, etc., often getting indoors as well and creating a nuisance.
Asian Beetles & Box Elder Bugs in Minnesota
As the weather cools, box elder bugs push into cracks and spaces around homes. In some cases they end up in the interior of buildings where they are often found around windows. They remain active until it becomes cold, which could continue into winter when the weather is mild. While you may see persistent numbers of these bugs, individuals are short-lived, only surviving for a few days up to a week. Other box elder bugs end up in sheltered areas in walls, attics and similar areas where they remain until it warms up.
Chances are box elder bugs are already creeping into a space near you this fall. Every year, right on time, they come out from their nests with a vengeance. Hundreds, thousands, swarms and swarms of beady, red little eyes and poking, prodding, peeking antennae, up over porches, plastering across the window panes, lining every door and crevice of every house across the entire state of Minnesota, they fly, perch, crawl, creep, zoom slowly and ominously around you as you try to make your way out of the house.
Their red and black wings spread straight out, their bodies vertical much like a lightning bug, and they hover and circle and dip and dive, and when they land they scuttle and scuttle and scuttle. They’re everywhere. You can’t escape them. The lawn is blanketed with their babies, little red dots with six, tiny legs. They like buildings to hibernate in, so they flock to the sides of them, and they wait for the opportune moment when an innocent human comes walking out of their door to then take flight and find their way into your home.
| Adult Asian lady beetle |
Cluster of Asian lady beetles |
During winter, box elder bugs and Asian beetles are generally inactive. However, during mild, sunny days, box elder bugs become mobile with the increased temperature. They enter a home’s interior from overwintering areas within the home, e.g in walls or attics. As they wake up, they follow the warmth into the home’s living quarters. Once there, they typically move towards windows and other sunny areas. However, the warmth does not reach the insects equally and they do not all become active at the same time.
Eventually by spring, all the surviving bugs that overwintered inside buildings become active. They try to move outdoors but many remain trapped inside. Despite the circumstantial evidence, they do not reproduce in homes — all the box elder bugs seen inside during winter and spring entered buildings the previous fall.
Prevention and Control
Preventing the lady beetles or box elder bugs from entering is the best approach to keeping them from becoming a household nuisance in fall and winter. Caulking exterior cracks and crevices–before the lady beetles seek overwintering sites– is the best way to keep them out.
Lady beetles that enter wall spaces in the fall may remain there, without entering living areas, until they depart in spring to search for food. But some may become active on warm days in late winter or early spring and move into living areas.
Sweeping and vacuuming are effective methods for removing these lady beetles from living areas. Using insecticides indoors for control of the lady beetles is not typically recommended unless the infestation is very heavy, and professional pest control advice should be sought.
Once Box elder bugs or Asian beetles have moved into the cavities of a home in the fall, there is little that can be done to eliminate them. Control or exclusion must be done in the summer and fall. Removing all box elder trees in an area will prevent breeding. Caulking windows and doors, and repairing window and door screens will prevent bugs from entering a home. If you decide you would like to spray for control, one home remedy is to use a 3-4% mix of water and soap (by volume) that can be sprayed directly on the insects. Remember however that soaps only kill on contact in extreme cases have a Minnesota pest control professional apply a residual insecticide to exterior walls in the fall where the bugs are congregating – this will tend to discourage them from landing. Insecticides are not very effective after the weather turns cold.
