Asian Ladybird Beetles are Invading Homes

By John Wilson, Extension Educator

If you aren’t already, you should be on high alert. I’ve received numerous calls about home invasions around the county, many in broad daylight while the residents were in their homes. I have to confess that we didn’t take all the necessary precautions and our home also fell victim to these invaders.

So who is responsible? The perpetrators are Multicolored Asian Ladybird Beetles (MALBs), a common species of ladybug that congregates on the south and west sides of homes as temperatures drop and harvest forces them from their summer home in fields.

This odd trait goes back to Asia, the original home for this species of ladybug. They would migrate to overwinter in the cracks and crevices of cliffs in their native habitat. Since cliffs are few and far between in eastern Nebraska, the next best thing they can find are the vertical walls of buildings, your home and mine!

Outside, this ladybug doesn’t really cause problems other than large masses of the beetles will emit an odor. However, when these home invaders look for sheltered places to overwinter and find their way inside your home, it may be difficult to remember they are a beneficial insect that voraciously feeds on aphids. Once inside, they present several problems for homeowners:

• They secrete a foul-tasting chemical, which makes them unpalatable to their enemies. This secretion can stain fabric and wallpaper.
• Large infestations have a distinct unpleasant odor.
• They have been reported to be an asthma trigger in sensitive individuals.
• They will bite. It isn’t particularly painful, but it is annoying.

My wife identified two other problems with the MALBs I hadn’t considered:

• MALBs are annoying as they walk across the television screen in the evening when other lights are off and they are drawn to the light of the TV.
• One MALB proved to be particularly annoying when it landed in her cup of coffee when she wasn’t looking. There is no way to describe what happened next other than, “That wasn’t pretty!” The biggest challenge has been getting the coffee stains out of our carpet!

The best method to control MALBs inside your home is to keep them outside your home! Locate entry points and use caulking to seal cracks and crevices. Use weather stripping to insure a tight seal around your doors and windows, and make sure your screens are in good repair. Spraying MALBs with an insecticide where they congregate on the south and west sides of your home will have limited effect because others will migrate in, replacing the ones you might have killed.

Here are my suggestions to callers once these beetles have found their way inside:

• Do not swat or smash these ladybugs. Their body fluids will stain your draperies and wall coverings.
• Do not use insecticides to kill them inside your home. Insecticides will not prevent other beetles from coming inside and will have limited effectiveness unless sprayed directly on the MALBs.
• Do vacuum up MALBs. This is the recommended strategy because it is safer and more effective than an insecticide application in your home.

If large numbers of ladybugs are sucked into the canister of the vacuum cleaner, their secretions will cause the vacuum cleaner to smell like ladybugs every time it is used. To prevent this, insert a knee-high nylon stocking into the hose wand to capture the beetles before they are sucked into the vacuum cleaner body.

Insert the knee-high stocking into a connection joint in the wand so it forms a bag inside the hose. A portion of the stocking is folded over the outside of the wand to secure it in place when the wand is put back together. After sucking up the beetles, remove the stocking and dispose of the beetles.

For more information on controlling ladybugs, contact your local Nebraska Extension office.

John Wilson