The quickest way to tell a ladybug from an Asian lady beetle is to look just behind the head. Asian lady beetles have a white patch there with a dark marking shaped like an “M” or a “W,” and they tend to run a little bigger, with colors anywhere from yellowish orange to red. The other big giveaway is how they act. If you’re finding dozens of them clumped together on a sunny wall or around your windows in Asheville, you’re almost certainly looking at Asian lady beetles, not the ladybugs from your garden.
Is this a ladybug or something else on my windowsill?
You find one sitting on the windowsill in the kitchen, or crawling up the window trim in the back bedroom, and your first thought is probably a good one. Ladybugs are the helpful ones, right? Then you notice three more by the curtain rod, and a couple more in the light fixture, and you start to wonder if this is the same bug at all.
A quick note on names before we get into it. In our guide to why stink bugs and ladybugs come inside in fall, we used “ladybugs” loosely for the bugs swarming Asheville homes, since that’s what most people call them. From here on, we’ll use “ladybug” for the native kind you see in the garden and “Asian lady beetle” for the lookalike that ends up in your house.
Not sure what’s on your windowsill? A photo and a question are a good place to start with the Pisgah Pest Control team.
How can you tell a ladybug from an Asian lady beetle?
Start with the area right behind the head, the part that looks like a little collar before the wing covers begin. On an Asian lady beetle, that area is mostly white with a dark marking in the middle. Depending on which way you’re looking at it, the marking reads as an “M” or a “W,” which is why you’ll hear people describe it both ways. It’s the same marking, just viewed from a different angle.
That marking is the best single way to tell them apart, but it isn’t always easy to see. On some beetles it’s faint or partly filled in, and on a bug that’s tucked into a window corner, you may not get a good look. If you can, gently tip it onto a piece of paper and check it in good light. A phone camera zoomed in works well too.
Are Asian lady beetles bigger than ladybugs?
Asian lady beetles are generally a bit larger than native ladybugs, at about ¼ inch long. Their color is the other clue. Instead of one consistent shade, they range from a pale yellowish orange through deeper orange to red, and some are darker still. If you’ve got a windowsill full of beetles in a handful of different shades, that mix is a strong hint you’re dealing with Asian lady beetles.
Fun fact: Counting spots won’t tell you much. Asian lady beetles can have anywhere from no spots at all to nearly twenty, so two beetles that look completely different on the back can be the exact same kind.
What else gives an Asian lady beetle away besides its looks?
Sometimes the easiest clue isn’t on the bug at all. Asian lady beetles gather in big groups. A few here and there is one thing, but dozens clumped together on the outside of the house, around a window frame, or along the trim is a pattern native ladybugs just don’t follow. Once they find a way into older homes around West Asheville, Fairview, or Black Mountain, they tend to settle into attics and wall voids and stay out of sight for a while. Then a warm winter day comes along and a few wake up and turn up on a sunny window, which can feel like they’ve appeared out of nowhere. We cover the why and when of all that in our guide to why they’re getting into Asheville homes.
The other giveaway is small yellow spots on your walls or windowsills. When an Asian lady beetle is disturbed, it releases a yellowish fluid with a musty, unpleasant smell. If you’ve been brushing them off the trim and noticed little stains or a lingering odor afterward, that’s a pretty good sign of what you’ve got.
How do you tell a stink bug from other bugs?
The stink bug that shows up in Asheville homes this time of year is the brown marmorated stink bug, and once you know what to look for, it’s hard to mistake. It’s shaped like a shield, wide at the shoulders and narrowing toward the back, and it’s about two thirds of an inch long, so noticeably bigger than an Asian lady beetle. The body is a mottled brown, a bit like weathered wood. The easiest detail to check is the antennae, which have lighter bands on them that stand out against the brown.
Then there’s the smell. Crush one, or even handle it roughly, and it lets off an odor that’s hard to forget. If your nose is telling you something’s off after dealing with a brown bug, you’ve likely got your answer.
The brown marmorated stink bug is well established across the mountains, so if you’re seeing a brown, shield shaped bug around your windows in North Asheville or Weaverville this fall, there’s a good chance this is the one.
What happens if you squash a stink bug or an Asian lady beetle?
Squash an Asian lady beetle and you’ll likely end up with a yellow stain on your wall. Squash a stink bug and you’ll get the smell. So the simple rule is not to squash either one. Our guide to what to do about stink bugs and ladybugs in your home walks through better ways to handle them.
Beyond that, neither one is going to hurt your home. Asian lady beetles will occasionally give a small pinch of a bite that’s more surprising than painful, and stink bugs are mostly just unpleasant to have around if you handle them the wrong way.
Knowing which bug you’ve got takes the guesswork out of what comes next. A white marking behind the head, a mix of colors, and a crowd of them on the trim points to Asian lady beetles. A brown, shield shaped bug with banded antennae and a smell to match points to stink bugs.
If you’re still not sure, or you’re finding more of them than you’d like, you can send our team a message with a photo. You can also read more about our stink bug and ladybug service or see what we offer for pest control in Asheville.
Frequently Asked Questions
Yes. Asian lady beetles have a dark marking on the white area just behind the head that looks like an “M” from one angle and a “W” from the other. It’s the most reliable way to identify them, though on some beetles it’s faint.
Not quite. They’re closely related and look a lot alike, but Asian lady beetles are a different kind. They’re the ones that gather in large numbers on and inside homes, while native ladybugs generally don’t.
It’s a brown, shield shaped bug about two thirds of an inch long, with a mottled pattern on its back and lighter bands on its antennae.
When Asian lady beetles are disturbed or crushed, they release a yellowish fluid with a strong, musty odor. That fluid is also what leaves small yellow stains on walls and windowsills.
Often, but color alone isn’t enough to go on. Asian lady beetles range from yellowish orange to red, so the better check is the white area with the dark “M” or “W” marking behind the head.