03/10/2026
THAT'S NOT A LADYBUG.
The swarm covering your window frame right now is the Asian Lady Beetle — Harmonia axyridis. It was imported in the 1960s and 70s for agricultural pest control. It worked. Then it spread. Now it's the dominant species in most of North America, and it's actively displacing native ladybugs.
Here's how to tell them apart.
The Asian Lady Beetle has a black M-shaped marking on the white area behind its head. Native ladybugs don't. That's the fastest identification — flip it over in your mind next time you see one. White area behind the head. M or W shape. Asian.
The swarming itself is the giveaway. Native ladybugs don't cluster on buildings in spring. They overwinter under bark, in leaf litter, in natural cavities. The Asian Lady Beetle seeks heated structures — your house, specifically the south and west walls.
When disturbed, it secretes a yellow-orange fluid from its leg joints. The fluid stains fabric, stains paint, and smells acrid. It can also bite — not dangerously, but enough to startle you. Native ladybugs do none of this.
Meanwhile, your actual native ladybug — the Convergent Lady Beetle, the Seven-spotted, the Nine-spotted — is outside in your garden right now. Each one will eat 5,000 aphids this season. The Nine-spotted Ladybug hasn't been reliably documented in the northeast since the 1990s. The Asian import helped push it there.
The one on your wall is the invasive. The one you want is already in the garden.
They're not the same animal. Look for the M.