red beetle with black spots and a white and black head

Multicolored Asian Lady Beetle

Allies outdoors, pests indoors.

Multi colored Asian lady beetle

Harmonia axyridis

Beneficial Role: Biocontrol predators (insect eaters)  
Problems caused: Can be a nuisance when they move indoors 

red beetle with black spots and a white and black head

Adult multicolored Asian lady beetle

orange beetle with a white and black spotted head

Adult Asian lady beetle

red and black alligator shaped insect

Lady beetle larva are very effective beneficial insects.

What do they look like? 

  • ‘Typical’ ladybeetle appearance, but more oval than round
  • Length up to 3/8" (9.5mm)
  • Colors and spots vary—can be yellow to red, with spots or without, spots are not always black
  • The best indicator is a W or M shape on the thorax

Should I Worry About Multicolored Asian Lady Beetles?

While the occasional indoor visitor is not a problem, large numbers of lady beetles inside a structure can cause allergy problems in sensitive individuals, and although they have a small mouth, they can bite. They do not carry diseases or harm building materials, but can stain upholstery, including curtains. Act to isolate or prevent access inside building by sealing cracks and gaps. Outdoors, consider them effective at managing other pests.

If you have never seen a lady beetle larva they look rather intimidating. Some people think they look like tiny alligators. They are a very effective beneficial insect so beware if you are an aphid or other small insect. 

Biocontrol Predators
an alligator shaped beetle eating an aphid among aphids
Image credit: Ken Wise

Why Do I Have Multicolored Asian Lady Beetles?

Multicolored Asian ladybeetles gather in large groups in the fall, and tend to invade buildings for overwintering where they find gaps and holes in structure, around eaves, windows and foundations. Warm winter days prompt activity, and by spring, overwintering adult females emerge from hibernation to lay orange colored eggs in clusters of about a dozen on plants with pest activity (most often aphids). Hatched larvae have four instars (molts) and pupate without a cocoon under leaves. Both the larvae and adults of this insect are predators of garden pests including aphids, scales, mites and fly larvae.

How Do I Manage Multicolored Asian Lady Beetles?

Exclusion

Avoid problems with lady beetles indoors by preventing them from entering in the first place. Pest exclusion is the safest, most effective way to reduce or prevent invasion. Use a sealant around window frames, outdoor faucets, vents. Fill holes with mesh and sealant, add rubber or brush sweeps to the bottom of doors (including roll down doors) and keep window screens in good repair.

Physical Removal

Vacuum: If you find clusters of lady beetles indoors, vacuum with shop-vacs (they may leave an odor in the vacuum hose).

Collect and release in spring: You can collect live beetles and keep in a cool area with water drops added once a week until spring. When insect activity has begun outside (daytime temps averaging near 55 degrees)—release them as beneficial insects.