In order to control a ladybug infestation, you must first repair any damaged or ill-fitting window or door screens to limit access to the home. Next, seal all entry points around doors, windows, siding, and vents with weather-stripping or expandable foam insulation. Then spread a layer of diatomaceous earth around the home’s exterior foundation. These steps should be followed by an application of pesticide containing pyrethrin or pyrethroid to all exterior surfaces. All interior insects should be removed with a vacuum cleaner and properly disposed of.
A ladybug infestation typically begins when the insects make their way into a home through torn or poorly fitted screens. These screens can often become ripped or misshapen during use or removal. Controlling ladybugs usually requires a thorough inspection of window and door screens. Make certain that the all screens fit properly in their openings and repair any tears or holes in the fabric. Do-it-yourself repair materials are available at most hardware stores and home improvement centers.
These insects may also enter a home through access points around doors, windows, siding, and vents. Inspect all doors and windows for damaged or missing weatherstripping and make any necessary repairs. Inspect the exterior siding and roof vents for possible entry points as well. Any openings should be repaired with caulking, weatherstripping, or expandable foam insulation. Remember to also check for openings around plumbing pipes and utility wiring.
Another way to control a ladybug infestation is to significantly reduce the outdoor population. Many professional exterminators recommend spreading a layer of diatomaceous powder around the home’s exterior foundation to stop the insects from migrating indoors. This natural material is composed of razor-edged, fossilized algae that damage the insect’s outer shell. Ladybugs typically die from dehydration after crawling through diatomaceous earth. This method of controlling a ladybug infestation only affects insects on the ground.
Outdoor pesticide treatments are often the best way to prevent a ladybug infestation from occurring indoors. Exterior surfaces should be treated with a pesticide containing pyrethrin or pyrethroid to kill flying ladybugs. The pesticide also contains an adhesive substance that prevents it from washing away during rain showers. Apply the pesticide to all exterior siding, attic vents, eaves, and overhangs. Foundation vents, doors, and windows should also be treated.
Ladybugs living in the interior of the home should be removed using a vacuum cleaner with a hose attachment. After vacuuming, change the bag or empty the dust cup into a disposable container to prevent the insects from escaping. This vacuuming procedure must be very thorough to prevent further reproduction by leftover ladybugs. Remember to look for ladybugs in secluded locations such as closets, pantries, cabinets, drawers, and basements.