Each year about this time and earlier, I get calls about lady bugs in houses, sheds, vehicles and other areas. Honestly, they should have been there for a while, long before earlier freezing temperatures.
Lady bugs are also referred to as “lady beetles” or “lady bird beetles.”
Lady beetles are considered one of our most beloved insect. While there is a native lady beetle, you are probably seeing the multi-colored Asian lady beetle which is native to Asia but has a long history of being released throughout the United States. This beneficial insect was released in the United States a century ago, as early as 1916! More lady bugs were released in the late 1970’s and early 1980’s. It has taken years for the populations to spread, but now large populations are found in many areas of the south, northeast, Midwest, and as far north as Oregon and Washington.
The Asian multi-colored lady beetles were imported and released to help control tree-feeding aphids. The reasoning behind this was native lady beetles were not as effective in controlling tree-feeding aphids because so many of our ornamental and fruit trees were from other areas of the world. Now the Asian lady beetle thrives in many parts of North America. During spring and summer, each Asian multi-colored lady beetle will consume over 300 aphids per day of more than 50 species of aphids.
Lady beetles are insects that are considered beneficial and are not invading your home to cause problems, only to stay warm. You should know the lady beetle are not interested in eating your walls, furniture, carpet, or human food, and they do not lay eggs in homes.
While they cause no harm, their overwintering inside people’s homes causes them to be somewhat of a nuisance. At night, like most insects, they are attracted to light. They may cluster against a structure and find a nook or cranny to enter wall spaces. Many scientists believe they can become disoriented; the beetles believing spring has arrived during warm days of late winter can invade a living space as they are looking for an outlet. This phenomenon could also be due to the warm interior temperatures or lighting.
The lady beetle also has a defense mechanism. If agitated or disturbed, the beetle’s reaction is to “reflex” bleed in which a yellow fluid with an unpleasant odor is released from the leg joints. This reaction helps prevent predators, such as birds, from eating the lady beetle.
This fluid can sometimes stain walls and fabrics.
The lady beetle is attracted to lighter colors such as whites, grays, and yellows. They enter homes through cracks and crevices. During warm winter days and early spring, the lady beetle may become more active searching for an exit.
No “control” of these beneficial insects is warranted. The lady beetle is an effective and natural control for harmful plant pests such as aphids, scale, and other soft-bodied arthropods. One adult lady beetle may eat over 5,000 aphids during its lifetime.
Prevent them from entering the home by caulking exterior cracks and crevices. Sweeping and vacuuming are effective means of removing these insects from living areas.
