We moved into our home in the Driftless area of Wisconsin in the middle of September 2020. There were several initial challenges but none was as unexpected as when the Asian lady beetles starting trying to overwinter a month later.

What’s an Asian lady beetle? It looks similar to a regular ladybug:

The easiest way to recognize one is by the M-shaped mark on the head.

Asian lady beetles are an introduced species. They love to eat aphids and were introduced for pest control. I will say, I am not sure I’ve seen an aphid in the six years I’ve been living here. We’re surrounded by farmers. There’s a lot of corn and other crops and I imagine the farmers love having something that eats aphids.

If you look up Asian lady beetles online, instantly you’ll find comparison charts to native ladybugs, painting one as an evil, invasive bug and the other a harmless garden helper good for the environment. In the minority, you can find posts like this one arguing that the asian lady beetle is a tool, neither good or bad.

I can only speak to my experience. I don’t see the asian lady beetles most of the year. Come mid-October though, they start looking for a warm place to overwinter. They start landing on our sun-facing house surfaces in droves. At their height, they are an unavoidable swarm.

Our first fall, we were trying to get a coat of stain on the front of the house. As soon as the afternoon sun warmed the house surfaces, the Asian lady beetles descended. They do bite, not hard but it’s really annoying when you’re trying to accomplish a task in peace. They land on you, especially if you are wearing something dark and warm. If you swat them, they let loose a yellow “I’m in distress” goop that is sticky. It’s a hot mess. And, worst of all, they want to overwinter INSIDE.

We went into chemical warfare mode that first year and sprayed every seam we could find that they might get into along the porch, doors, windows, etc. It’s no exaggeration that in 24 hours we killed thousands of them. We went out and bought a leaf blower for the first time in our marriage, not to blow leaves but to blow corpses off the porch that runs the length of our house. If you try to sweep them away, that sticky yellow goop makes them stick to the broom. The leaf blower is the only way to be efficient and clean about it.

On Day 2, the next wave was about 50% of Day 1. More “leaf” blowing. Day 3, 50% reduction again. After a week, we had it under control.

We’re on a exterior bug spraying plan now and the population is much more manageable. I can’t blame the Asian lady beetle for doing what they do, but I draw the line at letting them in my house.