LA CROSSE, Wisconsin (WXOW) - Populations of Asian Lady Beetles and Box Elder Bugs usually spike at this time of year, becoming a pest around the home. They haven't arrived yet, but this doesn't mean there won't be any.
Populations of Asian Lady Beetles and Box Elder Bugs often spike at this time of year.
Asian Lady Beetles, see this spike when their preferred food source, the soybean aphid, increases in number at the end of the summer.
Box Elder Bugs, on the other hand, hatch twice a year, with the second generation normally popping up in the fall.
Most years, these insects stay out of sight until cool temperatures attract them to our warm houses. In all likelihood, the only reason we haven't seen these insects yet is because it's been so warm.
"They won't like the cooler temperatures, and similar to the Asian Lady Beetles, they're going to move toward the home, or find those warm locations to over winter in," said Steve Huntzicker, La Crosse County UW Extension Agriculture Agent. "[They are] more of a nuisance than anything else for coming inside our home. They don't breed inside our homes so they're actually going to move back out once the winter is done."
Soybean aphids have been down this year, so it's possible that Asian Lady Beetle populations will be down this fall as well. And since Box Elder Bugs favor dry weather, their populations may be unaffected by the weather. But it's hard to know for sure.
With the unusual weather we've seen this year, the exact behavior and number of Asian Lady Beetles and Box Elder Bugs is unknown.
"We're probably seeing them a lot on, maybe, some of our tree species or out in the landscape right now," Huntzicker said. "They haven't probably made the migration yet, but they will be soon, towards some of our homes and buildings if they haven't already started to come there. They're probably around, it's just where they're going to show up and how many are going to come in, exactly."
If these insects do find their way into your home, you can eliminate Box Elder Bugs by spraying them with a soap-water solution.
Asian Lady Beetles can leave stains if smashed, so a vacuuming them up is a good choice.
More information on these insects and other common pests in Wisconsin can be found on the La Crosse County UW Extension website at http://lacrosse.uwex.edu/insects/.
