A Guest for the Winter – Asian Ladybug
Submitted by Brian Truskey, Communications Apprentice at Land Between
The Lakes
It’s that time of year again, when many of our homes play host to a
familiar visitor, the ladybug. Or more specifically, the Asian lady
beetle. Though most ladybugs make their homes outdoors, this often
uninvited guest will happily bunk with you over the winter.
What’s in a name?
Laybugs, also known as Ladybirds or Ladybird beetles, were named after
the Virgin Mary. “Beetle of our Lady,” the precursor to many of the
names we use today, was used as far back as 1699. Some sources claim
that the various names may have even older roots.
One story attributes the name Ladybug, or originally “Our Lady’s Bug” to
a miracle during the middle ages. As the story goes, small insects or
aphids were eating all of the crops. The people petitioned for
intervention, and were answered by a small swarm of spotted insects that
ate up the pests. Afterward, the helpful little bugs were given their
new name. More information on that particular story can be found here:
http://catholicism.org/our-ladys-bug.html
Telling the difference
With around 5,000 species of ladybug known through the world, and more
than 400 in North America, it might be difficult to tell the difference.
So, how can we tell them apart? There are several characteristics you
can look for when identifying ladybugs. The numbers of spots, for
example, can vary by species. Contrary to some beliefs, the number of
spots do not determine how old a ladybug is. Spots do, however, fade
with age.
The Asian ladybug, or Harmonia axyridis, is the variety you will most
likely find in your house in late fall, winter, and early spring. They
are oval, convex, about ¼ in long, with color varying from tan to orange
to red, and can have many or no spots. Females are more likely to have
more spots, while males tend to have few or no spots. Around16 spots is
fairly common. You can also look for a distinct “M” or “W” shape on the
white area by the base of their head.
Another non-indigenous European variety, the seven spotted ladybug, or
Coccinella septempunctata, will be found eating many of the same insect
pests and on the same plants that you find the Asian Ladybug on. They
can be differentiated from the Asian ladybug by their spots. They have
three spots on each elytra, or shell-like wing, with a seventh spot in
the middle, often near the head.
You can find several handy guides to identifying ladybugs on the
Internet, such as this one from the Natural History Museum.
www.nhm.org/site/activities-programs/citizen-science/lost-ladybug-projec
t/identifying-ladybugs
Where did they come from and why are they in my house?
The Asian lady beetle is not native to the United States. They were
imported to the United states in 1916. The first notable populations
weren’t reported until 1988 in Louisiana, however. Other accidental
introductions from them hitching rides on cargo vessels may also be a
contributing factor.
Sources conflict somewhat as to the reason Asian ladybugs are attracted
to our homes. Some say that they are attracted to light colors, while
others say they are attracted to contrasting light and dark colors, and
mistake such patterns for those of their natural wintering habitats.
These ladybugs also like to congregate on the sunny sides of buildings,
and may avoid homes that are shaded from the afternoon sun.
After they mistake your house for a good wintering spot, and enjoy a bit
of evening sunning, they crawl under the siding, or into the attic,
where they winter. Many times they crawl in deeper, or get lost. At
night when they see the light in your house they head toward it and
emerge into your home. Like many bugs and beetles, they are attracted to
light. This is especially common in late winter and early spring when
things begin to warm up and they are ready to head back out. If they get
turned around after their long sleep, they may just find their way into
your house rather than back outside.
The good, the bad, the buggy
Asian lady beetles are a mixed blessing. While they can bite if held,
and may leave stains if disturbed, they are also beneficial.
The good. Asian ladybugs eat a variety of aphids that feed on trees and
crops, especially soybeans. An adult ladybug can eat as many as 5,000
aphids in their lifetime. The work they do helps keep other plants
healthy, which in turn reduces the amount of pesticides that farmers and
gardeners have to use.
The bad. Their mouths have little pincers that they use to eat insects
such as aphids, and they can bite or pinch people when disturbed. Often
it is little more than a pin prick and not usually serious. Some
research also suggests that they may cause allergies or allergy like
symptoms in some people.
These ladybugs also leave behind a yellow fluid with an unpleasant odor
when disturbed. This is known as “reflexive bleeding” and is a defense
mechanism that discourages birds and other predators from eating them.
The “blood” they leave behind has a strong odor and can stain certain
surfaces. If you get some of it on you, it’s probably best to wash it
off.
Ladybugs do not damage structures like some insect pests do, nor do they
bother clothing or food inside the home. They also will not breed
indoors, despite what may seem like growing numbers. It is more likely
the ones hibernating in the walls are simply waking up and heading
toward the light inside the house. Early in the season it could be that
more are making their way toward your home if they have mistaken the
outside coloration for a good wintering habitat.
How to best handle the problem
The best way to keep ladybugs from becoming a problem is prevention.
They like to hibernate inside the walls, and sometimes accidentally go
deeper inside your home when they are seeking a way out. Filling in the
cracks and holes they climb through eliminates the problem before it
begins. Caulk or other substances that fill in the gaps and crevices can
be used. This method doesn’t always work, especially in older homes with
lots of nooks and crannies, or may not be practical in some instances.
If you don’t have many of these visitors, it may be best to simply leave
them be. In the spring time they will leave on their own, and by not
disturbing them you can avoid the staining and the odor. If that’s not a
viable option for you, it may be time to get out the vacuum cleaner.
A vacuum or shop vac should work. Using a shop vac, or vacuum without
moving brushes that they have to pass through will minimize the harm to
the ladybugs if your goal is to remove them with minimal harm. Once
you’re done vacuuming them up, remember to empty the bag outside to
avoid releasing them into the house again.
There are also a variety of ladybug traps available that use lights or
black lights to attract and capture them. After they are captured in the
traps, simply release them outside.
Spraying is another option, although it may have limited success,
especially if they are already inside your home. Sprays can also be
washed away by rain, and some chemicals are neutralized by the sun. In
any case, check your local and state laws on which sprays and pesticides
can be used, and always follow safety instructions. Spraying may be most
effective when done early and often to keep them from entering your home
in the first place, especially if filling in the gaps is not an option.
Folklore
Variations of the children’s rhyme, “Ladybird, Ladybird, fly away home!
Your house is on fire, Your children do roam. Except little Ann, who
sits in a pan Weaving gold laces as fast as she can” have been
attributed as a warning to ladybugs. It is in reference to the burning
of hop plants, and warning the adult ladybugs to escape. The young grubs
still shedding their skin, or “little Ann” still in her “gold lace,”
were unable to flee from the fire. More on this story can be found at
http://campus.udayton.edu/mary/questions/ladybug.html
Some also believe that the ladybug is good luck. A few of the common
beliefs are that seeing a ladybug will bring good luck, good weather,
love, or that killing one will bring bad luck. The latter of which was
possibly propagated by farmers in an effort to help protect the little
bug that kept their crops safe from harmful insects such as aphids.
If you’d like to know more about ladybugs, visit the references below.
References
www2.ca.uky.edu/entomology/entfacts/ef416.asp
www2.ca.uky.edu/entomology/entfacts/ef105.asp
www.ars.usda.gov/is/br/lbeetle/
http://ento.psu.edu/extension/factsheets/multicolored-asian-lady-beetle
www.merriam-webster.com/dictionary/ladybug
http://images.nationalgeographic.com/wpf/sites/kids/NGS/wpf/printcreatur
e/ladybug.html
www.extension.umn.edu/garden/insects/find/multicolored-asian-lady-beetle
s/
http://entnemdept.ufl.edu/creatures/beneficial/multicolored_asian_lady_b
eetle.htm
www.nhm.org/site/activities-programs/citizen-science/lost-ladybug-projec
t/identifying-ladybugs
http://catholicism.org/our-ladys-bug.html
http://campus.udayton.edu/mary/questions/ladybug.html
http://animals.pawnation.com/ladybugs-considered-good-luck-5881.html
www.wisegeek.org/why-are-ladybugs-lucky.htm