Why do ladybugs enter my home?
By NELSON WYNN / Guest Columnist
The best guess is that you are having problems with Asian Ladybird Bug, which is notorious for coming into homes in fall and winter seasons, although the majority of them end up hibernating in warm harborages outside. Most of those that entered homes in fall will end up dead in spring, because they get active at warm room temperatures and use up reserves without food (aphids, scale insects, etc).
Those staying outside will emerge and get active every time when it gets warm in winter. They will try to enter homes when it gets cold, like the weather we are having recently.
Ladybugs only eat small “juicy” insects, so they do not cause damage to plants, paper, cloth or any other household items. They are merely nuisances. However, they release a yellowish and smelly liquid when they are disturbed, which can leave yellow markings on your wall and smell badly. There are some reports that they may bite and cause medical problems, but it is rare.
Even though they are beneficial insects, most people do not want them inside their homes. I do not suggest applying pesticide in homes. The most popular way to rid your home of ladybugs is vacuuming them up and releasing the unwelcome guests outside.
Are there other means to get rid of them? Yes. There is a product called a Ladybug Black Light Trap that attracts the bugs into it. I cannot comment on whether it really works since I never tested it and know no research data on it. Someone may recommend sticky traps but they have little effect on ladybugs. You may try insecticidal soap or diluted house-use ammonia liquid (window cleaner). They do kill ladybugs but have no residual effects.
Information based on research done by Dr. Xing Ping Hu.
Nelson Wynn is a regional extension agent for the Alabama Cooperative Extension System.