Those Nasty Asian Lady Beetles!
What can I do about the hundreds of Asian lady beetles that invaded my home last fall? This is a question many Minnesotans have posed and the answer is remove them with a vacuum cleaner. Unfortunately, as they are being sucked up and crushed, they emit an unpleasant odor that may linger inside the vacuum. To prevent this odor problem place a cup-shaped gauze or nylon trap near the end of the vacuum hose, then clean out the gauze traps and dispose of the trapped beetles. Composting is a good idea.
Asian lady beetle populations are increasing in Minnesota because this species presently has no known natural enemies to control its numbers. The worst news is that they are replacing other species of lady beetles that are native to Minnesota.
Will these beetles invade my house next fall? The answer is possibly. To reduce the possibility of another invasion this fall, seal cracks and openings around windows, doors, siding and utility pipes with caulk. Install door sweeps on thresholds at the base of entry doors and repair damaged window and door screens. Installing a screen behind the attic vent will keep the bats out, too.