Boxelder bugs are commonly found trying to enter
houses, especially if there’s a boxelder tree nearby. These insects
are about one-half inch long and black with orange or red markings.
During the spring and summer, the adults will feed on leaves and
seeds of boxelder trees (and occasionally maple and ash trees). When
temperatures begin to cool in the fall, they will begin to seek out
warmer areas.
“They are most often attracted to buildings with large southern or
western exposures, because they are warmer than the surrounding
area,” Johnson says. As they aggregate on a building, they will find
cracks and other spaces to squeeze into, occasionally making their
way indoors and ending up in walls and attics until warm weather
returns.
Multicolored Asian lady beetles are also commonly found attempting
to make their way into homes. According to Johnson, these lady
beetles were introduced into the United States to control aphids on
pecan trees. Since their introduction, they have spread throughout
the country. The beetles vary in color from yellow to reddish-orange
and have anywhere from zero to 19 spots. They can often be
distinguished from other lady beetles by the presence of an ‘M’
pattern near their head. In their native China, they will overwinter
on tall cliffs. “Since we lack these in most parts of Illinois, they
will instead use buildings to overwinter,” Johnson says.
The brown marmorated stink bug (BSMB), on the rise in Illinois, is
the final home invader. This stink bug is native to Asia and was
first discovered in the U.S. in the late 1990s in Pennsylvania.
Since then, Johnson says, it has quickly spread throughout the
country. Like the others, BMSBs will also congregate on buildings
looking for somewhere to overwinter. [to top of second
column] |
But unlike boxelder bugs and multicolored Asian lady
beetle, these insects are more than a nuisance. According to
Johnson, “They will feed on a wide variety of tree fruits,
vegetables, agricultural crops, and ornamentals and can cause a
significant amount of damage.”
They have the typical ‘shield’ shape of stink bugs.
And, as their name implies, BSMBs are brown and marmorated
(mottled). There are a few characteristics that can be used to
differentiate them from our native stink bugs: the antenna are
striped with white bands, they have smooth “shoulders,” and they
have black and white triangular patterns on their abdomens. Several
other insects are commonly confused with BMSBs. Johnson recommends
contacting your local Extension office if you are unsure.
For all of these insects, the best management strategy for keeping
them out of your home is exclusion. Johnson says, “Make sure windows
and doors fit tight and window screens are free from holes. Seal any
openings, cracks, and crevices around the foundation, pipes, wires,
and chimneys. Finally, make sure siding, eaves, and soffits are in
good condition.”
Insecticides can be applied to the perimeter of buildings, but since
these insects are rather mobile, it can be difficult to get good
control of them. Once they enter your home, they can be vacuumed up
and placed in soapy water and disposed of. Using insecticides to
control these insects indoors is generally not recommended.
[Ken Johnson, Horticulutre Educator,
University of Illinois] |