Asian Lady Beetles

The Asian lady beetle is common throughout most of the United States and parts of Canada. The scientific name is Harmonia axyridis (Pallas). This is one of a very large family of beetles known as Coccinellidae.  Many people call these beetles “ladybugs”.

Lady beetles are easy to recognize. They are small, round-to-oval insects. Their size ranges from 1/32” to 3/8”. They are usually red or orange, but can be yellow, brown, or black. Some species have spots.

There are 475 species of Coccinellidae in the U.S. and Canada. All but a few species are beneficial insects. Plant specialists imported several species of lady beetles into the United States to control crop pests. The adults and larvae of most lady beetles are predators of aphids, mealybugs, and scale insects.

In the fall lady beetles gather in large numbers on the outside of light-colored houses. As they gather on the house, some find cracks or holes.  They use these holes to get inside. Some lady beetles enter quiet places like the attic. They hibernate through the winter and become active again in spring. Other lady beetles get into the living space of the home.  These usually become nuisances.

The vacuum cleaner is the simplest way to remove the lady beetles that get into the home. They do not bite or sting. They do not reproduce inside the home.

During the summer, homeowners can prevent many lady beetle problems. Inspect the outside of the house carefully. Caulk cracks around windows and doors.  Check the attic, roof, and overhang vents.  Repair any damaged screens. Check the weather-strip on all exterior doors.  Repair any damaged window screens. Inside the home, patch any holes that lead into the attic.

Insecticide application on the outside of the home will act as a barrier. It will repel many of the pests that gather on the home and keep them from entering. The application should begin in the late summer. Because of temperature and other factors, the barrier will need to be re-applied periodically. The pest control professional has the equipment to make this treatment.