Asian Lady Beetle

Category:

Actual Size: 6 to 10 mm

Characteristics: Mustard-yellow to a dark reddish-orange. Spots on the wing covers, but in some species, the spots are absent.

Habits:

  • Slightly larger than typical ladybugs.
  • Dark “M” shaped marking on pronotum, behind head.
  • As a defense mechanism, will release yellow, foul-smelling substance from joints.

Overview

The multicolored Asian lady beetle was introduced into the United States from Asia to control aphids, scale and other crop pests from 1978 to 1981. It is now widely distributed from Mississippi to the Midwest, Southwest, and Pacific Northwest. Asian lady beetles may enter homes in large numbers and have become consistent overwintering pests in buildings and homes.

Asian Lady Beetle Habitats

This species is a voracious predator of crop pests and produces several generations per year. Their tendency to aggregate and ability to enter structures often causes this insect to become a significant structural pest. Hundreds and even thousands of these beetles have been found in and on homes. Asian lady beetles can be found in attics, wall voids, on siding, inside closets and may be attracted to light.

Asian Lady Beetle Behaviors, Threats or Dangers

Although Asian lady beetles may bite, their bite does not seriously injure humans or spread diseases. If handled or crushed, the beetles will emit a foul odor and leave a stain. In fall, beetles seek out crevices and protected areas around homes to spend the winter, congregating in attics, wall cavities, cracks around door frames, and within soffits and wall voids. If a large number of beetles gain access inside of homes, they can stain drapery and clothing. Asian lady beetles cannot survive sub-freezing temperatures, although they can survive within homes and buildings that provide adequate warmth and humidity.

Asian Lady Beetle Prevention

To avoid an Asian lady beetle infestation in your home, the best prevention is to seal cracks and crevices around windows, doors, utility pipes, soffits and wiring with a silicone based caulk. Asian lady beetles and other insects can gain entry through cracks ⅛” or less. Seal gaps around exterior doors and under sliding glass doors with foam weather stripping. Any beetles that you see indoors can be removed with a vacuum cleaner. Remember to dispose the vacuum bag, or place a rag between the hose and dust collection bag to trap them and release them outside.