Wisconsin, known for its vibrant fall season, is currently seeing an uptick in insect activity across the state. As cooler weather approaches, various insects, from common fall invaders like the Asian lady beetle to newly emerging pests, are actively seeking winter shelter. State entomologist PJ Liesch says that this is a typical phenomenon but requires awareness and prevention efforts by both homeowners and farmers.
“In just the last week and a half, reports of several common fall pests have surged,” Liesch stated. “The multicolored Asian lady beetle, boxelder bugs, and brown marmorated stink bugs are particularly active.” These insects, often nuisances when they enter homes, seek sheltered areas to survive the winter. While they typically pose no major threats indoors, they can certainly be a frustration for residents.
Liesch mentioned that physical exclusion is one of the best strategies to prevent pests from entering. “If you want to keep them out, it starts with sealing entry points like gaps around windows and doors,” he explained. “Using materials such as insulation foam, caulk, or weather stripping can be incredibly effective.”
In addition to common household pests, Liesch also warns about tick activity, which continues through the fall. “Deer ticks, whose life cycle takes about two years, emerge as adults in early fall,” he shared. “Anyone hiking, hunting, or enjoying the outdoors should take extra precautions to avoid ticks.” Regular tick checks and insect repellent are highly recommended.
For Wisconsin farmers, this increase in insect activity can have mixed effects. “Farmers growing crops like corn and soybeans may benefit from Asian lady beetles, which help control aphid populations,” Liesch explained. “However, invasive insects like the brown marmorated stink bug can be damaging to crops, feeding on plant kernels and pods.”
New and potentially harmful pests, such as the spotted lanternfly and box tree moth, are also on Liesch’s radar. “These insects haven’t been detected in Wisconsin yet, but they’re moving closer,” he stated. “They could have significant impacts on trees, crops, and ornamental plants if introduced here.” As a result, Wisconsin residents and farmers alike should stay informed and report any sightings of unfamiliar insects.
For persistent issues with indoor pests, Liesch recommends using a vacuum rather than pesticides indoors. “Once inside, insects deplete their stored energy and often die. A vacuum is a simple solution,” he added. As an added measure, repellent insecticides around outdoor entry points can also help reduce indoor invasions.
