Why Are There So Many Asian Lady Beetles in Southeast Minnesota This Fall?

Sunday's unseasonably warm weather here in southeast Minnesota was great-- until we noticed the invasion of the Asian lady beetles on our screen door. There were a ton of them! Have you noticed a large amount of the orange and red bugs at your place too?

Well, according to various sources, there's a bumper crop of them this year. And our warmer-than-usual fall has brought them out in full force, as they look for a cozy spot to spend the winter.

But what exactly are these orange and red bugs called? As a kid, we called them ladybugs. And while those insects are still around, they're likely not the ones we see swarming around on the outside of our houses. According to the University of Minnesota Extension, the bug we're seeing a lot of this fall is actually a cousin to our native ladybugs, usually referred to as the Asian lady beetle. (We've also had a lot of boxelder bugs at our place, but they're black in color with a red markings, and don't look like these beetles.)

"The multicolored Asian lady beetle,Harmonia axyridis (Pallas), has become very troublesome in Minnesota. Also known as the Asian lady beetle, Halloween lady beetle, and Japanese lady beetle, these insects cluster around buildings in large numbers during fall as they search for protected sites to overwinter," the site says.

So why were they out in such big numbers on Sunday? Last week's warm weather was a key.

"Large numbers of lady beetles generally begin to fly to buildings on the second day of temperatures above 65 o F that follow freezing or near freezing temperatures. Such conditions usually occur in Minnesota between late September and late October.

Once lady beetles reach buildings, they crawl into cracks and gaps around windows, doors, roof lines, and other openings. Some continue to move inside the structure until they reach the living areas of homes where they soon die. Others will find suitable overwintering inside wall voids, attics, and other areas, sometimes forming large living masses of insects," the site says.

And what should you do to keep them out of your house? The site says to make sure you've sealed areas around your windows and screen doors, and where cables and wires come into your house, as well as checking for gaps and spaces along your corners and walls.

If they do get into your house, the best way to get rid of them is to vacuum them up. "Keep in mind that lady beetles are not automatically killed when they are vacuumed. It is probably necessary to change the bag frequently to prevent lady beetles from escaping and to minimize their smell," the site says.