Asian lady beetles are originally from Asia, but have since become established through much of the U.S. and Canada. While gardeners appreciate the Asian beetles' ability to control plant pests such as aphids, the beetles can also be undesirable. Large populations of Asian lady beetles can disrupt the natural ecology of an area, especially when they compete with native insects for food. They can also become a pest when congregating inside a home. Asian beetles can be killed quickly and safely, however.
Use an insecticide or pesticide containing permethrin, a chemical that's toxic for Asian lady beetles. Spray any area in which the beetles congregate. Permethrin kills Asian beetles upon contact and also acts as a repellent to deter future infestations of beetles. Check the ingredients list of your favorite insecticide to see if it contains the compound. Example products include Sara Lee's Ridsect Flying Insect Killer and some Raid sprays such as Raid House & Garden Insect Killer and Raid Extra Flying Insect Killer.
Dust plants and surfaces in your home with diatomaceous earth. The all-natural powder cuts through the beetles' exoskeleton and kills them over time. Homeowners who find lady beetles crawling into their home under doors or through windows may wish to apply a thin layer of diatomaceous earth around the foundation of their home and on exterior sills.
Apply a residual insecticide such as Coopex Residual Insecticide, Doktor Doom, Demon WP or Demand CS around your home and outdoor buildings at the end of summer. Asian beetles begin hibernating and preparing for the next year during this time. Break their life cycle by killing them and deterring them during the hibernation stage. A residual insecticide will stick to your buildings' surfaces and continue to kill the beetles as they look for a hibernation spot.
Set out sticky bug traps such as sticky fly paper. Place the traps near windows, doors and other areas in which you notice large amounts of beetles. Once the trap is filled with stuck bugs, discard and replace with a new trap.
Inspect your home to prevent new Asian beetles from entering your home. Use caulk and seal window frames and any open gaps around exterior pipes or wiring. Also check that your window screens and screen doors are sealed and do not have any holes through which the beetles can crawl.