|MadSci Network: Zoology|
I believe that you are being pestered by the Multicolored Asian Lady Beetle (Harmonia axyridis). Large numbers of this ladybug were released by the US Department of Agriculture (USDA) in order to fight off other insect pests (such as aphids) which destroy many different kinds of plants. The ladybugs have been doing their job well, eating aphids, mealybugs, and scale insects in ways that pesticides canít work. As they eat up the pest insects during the spring and summer, the numbers of Multicolored Asian Lady Beetles skyrockets.
As temperatures get colder with winter, these large numbers of ladybugs search for warm places to hide. If they find their way into your house, the ladybugs call their friends with pheromones they release into the air. Within a day, some homeowners are swamped with these colorful beetles all over their houses. This can be quite upsetting, of course. The USDA is working to develop a ladybug repellent so that this wonít happen. Unfortunately, the repellent isnít made yet.
So what can you do to get rid of ladybugs swarming into your house? First of all, you need to seal up your house so that more donít get in. Use a caulk gun to seal up the cracks in walls, floors, and ceilings, especially around pipes that enter your house. Repair holes in your window screens and use weather-stripping around windows and doors that donít have a nice seal. (Sealing up your house in this way will also keep out other pests such as cockroaches!) To get rid of the ladybugs already in your home, use a vacuum cleaner or gently sweep them into a dustpan and drop them outside. Some of the insects will continue to hide in your house, and you may be discovering them for months to come. Using pesticides on ladybugs is generally not recommended, even if they do work.
Ladybugs are wonderful animals that really help people. In this case, it is unfortunate that they are also a pest to many people in their homes. However, if you can seal up your house with caulk and weather-stripping, you may be able to appreciate their benefits without suffering from their swarms in the years to come.
Cornell Universityís department of entomology has more information on the USDAís project, the usefulness of ladybugs, and even information on how to get rid of ladybugs in your house. While I'd recommend this site to anyone, I recommend it to you in particular to learn just how benificial these ladybugs can be!
Other MAD Scientists have answered some interesting questions about ladybugs, which I also recommend reading. Why are ladybugs called ladybugs? by David Richmand is an interesting essay about various names that ladybugs have around the world. How can you tell if a ladybug is a girl or a boy? by Justin Remais has big pictures that apply to many different kinds of insects. Wha t should I feed all the ladybugs coming out of hibernation? by Justin Roux also has basic information on the life of ladybugs.
Of the many elementary school children I have polled, Ladybugs are the second most loved insect (just after butterflies). I hope you can find it in your heart to forgive their intrusion in your home! If you have any more questions about insects, or how to keep them out of your house, please feel free to write us another question.