What These Insects Do—And Don't Do
Lady beetles are not structure-damaging pests, unlike insects such as termites and carpenter ants. Lady beetles do not chew or bore holes in walls or eat carpet or furniture. They do not lay their eggs in homes.
Multicolored Asian lady beetles are attracted to lighter colors: whites, grays, yellows. So, light-colored houses, especially on hillsides in forested areas, might serve as “homing beacons.”
Once the lady beetles enter the walls of a building through cracks and crevices, they may or may not proceed to the interior of the building. Most stay in the wall spaces.
During warm days of late winter and early spring, overwintering beetles in a wall space may become active. In their search for an exit, they may enter the home's living areas and become a nuisance. Warmer temperatures or lighting in the living areas may attract these active beetles as they search for an exit.
Prevention and Control
Preventing the lady beetles from entering is the best approach to keeping them from becoming a household nuisance in fall and winter. Caulking exterior cracks and crevices--before the lady beetles seek overwintering sites-- is the best way to keep them out. This will also keep out other unwanted insects such as wasps, and will save homeowners money on energy costs.
Lady beetles that enter wall spaces in the fall may remain there, without entering living areas, until they depart in spring to search for food. But some may become active on warm days in late winter or early spring and move into living areas.
Sweeping and vacuuming are effective methods for removing these lady beetles from living areas.
Blacklight traps work well for catching beetles in some situations and this may be particularly critical for commercial facilities, such as hospitals and some manufacturing plants, where biocontamination is a critical issue. These facilities often use the more expensive industrial style light traps (not the traditional "bug zapper" type of trap). USDA scientists in Georgia developed a trap that uses no insecticide and it catches the beetles alive for future release or disposal. The trap is about 12" x 24" and reportedly can be easily assembled or disassembled in as little as two minutes. CLICK HERE to access the details for building your own blacklight trap. Or shop for a commercial one HERE.
For more information see: http://www.ces.ncsu.edu/depts/ent/notes/Other/goodpest/note107.html