Asian Lady Beetle

Harmonia axyridis

Asian Lady Beetle

Harmonia axyridis

Take care

Handle with care

This one does bite. It is a small nip rather than anything medical — brief, and it breaks skin only occasionally — but it is a real difference from a native ladybug, which does not.

We identify, we don't diagnose. If you've been bitten or stung and symptoms develop, or you're worried, seek medical attention.

Size5–8 mm

MarkingsA white M or W shape on the black-and-white plate behind the head · Colour ranges from pale orange to deep red, with anywhere from zero to nineteen spots

WhereOutdoors on crops and trees in summer; indoors in wall voids, lofts and window frames through the winter.

SeasonSwarms on buildings in autumn, then reappears indoors on warm days

How to tell it apart

A white M or W shape on the black-and-white plate behind the head
Colour ranges from pale orange to deep red, with anywhere from zero to nineteen spots
Larger and more domed than most native ladybugs, around 7 mm
Gathers in large numbers on sunny walls in autumn
Leaves a yellow, strong-smelling fluid when disturbed

Where you’ll find it

Across most of the United States. It was introduced repeatedly as an aphid control and is now one of the most abundant lady beetles in the country, in many places outnumbering the natives.

Outdoors on crops and trees in summer; indoors in wall voids, lofts and window frames through the winter.

Swarms on buildings in autumn, then reappears indoors on warm days.

How it behaves

In autumn it looks for a cliff face to overwinter in, and a pale sunlit wall is a good enough substitute. That is why hundreds arrive at once on the south side of a house, then turn up indoors in ones and twos all winter whenever the heating brings them out of a wall void. When handled or crushed it releases haemolymph from its leg joints — the yellow fluid that smells and stains.

You’ve found one indoors

Vacuum rather than squash, and empty the vacuum outside — crushing them is what causes the stains and the smell. Sealing gaps around window frames, fascias and vents before autumn does far more than any spray, because once they are inside a wall void there is nothing useful to spray. They do not breed indoors, eat anything in the house, or damage the building.

Common questions

Do Asian lady beetles bite?

Yes, unlike native ladybugs. It is a brief nip that occasionally breaks the skin and needs nothing beyond washing it. They are looking for moisture rather than feeding on you.

How do I tell it from a real ladybug?

Look at the plate behind the head. This species carries a white M or W marking there; native ladybugs do not. Spot count is useless — this one ranges from none to nineteen.

What is the yellow stuff, and will it stain?

It is the beetle's own blood, released from the leg joints as a defence. It smells strongly and does stain light paintwork and fabric, which is the main argument for vacuuming rather than squashing.

Why are there suddenly hundreds on my wall?

They overwinter communally and are drawn to warm, pale, sunlit surfaces in autumn. The gathering is temporary; the problem is that some of them find a way inside while it is happening.

Commonly confused with

Ladybug Harmless
Carpet Beetle Take care

Side-by-side comparisons

Ladybug vs Asian Lady Beetle

Keep identifying

Identify another animal from a photo or return to the Beetles guide.

Previous: Carpet Beetle · Next: Ladybug

Where this was checked

iNaturalist — Harmonia axyridis checked 2026-07-30
NC State Extension — Multicolored Asian Lady Beetle in the Landscape checked 2026-07-30

Last reviewed 2026-07-30. We identify, we don’t diagnose — what we can and can’t tell you.