The Multicolored Asian Lady Beetle was introduced from Asia and is now found throughout the United States from coast to coast. It was first released as a biological control for mites, aphids and other pests during the nineteen hundreds. By the mid 1990s it was well on its way to becoming a beneficial insect and a pest at the same time.
It's well known that Lady beetles (ladybugs) and their larvae consume aphids, scales insects, moth & butterfly eggs, etc., that infest many of our shrubs and trees. This is what they do for most of the year. While feeding on all these pests, they're also increasing in numbers. It's when the weather begins to cool these very beneficial insects become a nuisance.
Many of our native ladybugs will gather in large numbers to wait out the winter season. However, unlike our native species, Multicolored Asian Lady Beetles will use light colored structures (including our homes) to overwinter in.
They will enter homes through cracks and crevices around doors, windows and attic vents, sometimes in large numbers; 15,000 or more is not uncommon. With numbers this large, some say they can actually hear these insects moving as they look for a suitable spot to enter dormancy. Because Lady beetles are in constant search of a suitable area, they sometimes enter the interior of the structure. This is where the trouble begins.
Once inside where it's warm, they fly around and land on furniture, walls, drapery, etc., becoming quite an annoyance. When people try to remove them by sweeping or using a vacuum cleaner, this beneficial beetle secretes a foul smelling, yellow staining defense compound. Right away, you can see the problem here!
The Multicolored Asian Lady Beetle is a very beneficial natural predator of many insects and should be tolerated if possible. However, if they've become an extreme nuisance in your home, give us a call. We may be able to help.