| MadSci Network: Zoology |
Dear Brenda,
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
can’t 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 won’t happen. Unfortunately, the
repellent isn’t 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 don’t 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 don’t 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 University’s department
of entomology has more information on the USDA’s 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.
John Carlson,
MAD Entomologist