Insects from AbroadMissy Henriksen
Wednesday, October 3, 2012
Invasive pest species that every American should know
foreign origin, commonly called
invasive species, are a major concern in the United States.
Often, invasive pests do not have natural predators in the U.S. so
their populations can grow quickly. Many invasive pests, including
some beetles and moth species, pose a major threat to the U.S.
agricultural industry as they destroy crops. In fact, the
Associated Press, citing a 2004 Cornell University study, put the
total annual cost of all invasive species in the country at
$120 billion. According to the AP, “much of that burden is borne by
consumers in the form of higher food costs and by taxpayers who pay
for government eradication programs.”
But some invasive species can also pose threats to American
homeowners and families. Formosan
termites are one such example. Originally from China, Formosan
termites were brought into the U.S. through military cargo
shipments after World War II. This termite species is one of the
most destructive of the more than 2,000 termite species known to
They pose a greater threat than their native counterparts
because they form larger colonies and tend to be more aggressive,
thus consuming more wood at a much faster rate. Formosan termites
are heavy contributors to the $5 billion in annual U.S. property
damage caused by all species of termites.
Another problematic invasive pest is the red imported fire
ant (RIFA). This ant, native to Brazil, was first introduced to
the U.S. in 1933. Today, they can be found throughout the South and
in parts of California and other western states.
RIFAs get their common name from their ability to inflict
painful bites and stings, which form into raised welts that become
white pustules. RIFAs will attack humans who disturb or threaten
their nests, and often a person stung by a RIFA receives multiple
painful stings from more than one of the ants. Those allergic to
insect stings will react more severely. Red imported fire ants and
their telltale mound nests should be carefully avoided.
Since arriving from Asia in 1996, brown marmorated
stink bugs have also become an increasing nuisance for
homeowners in the Eastern U.S. Named for the odor they emit as a
defense against predators, stink bugs are especially unpleasant to
Stink bugs have the potential to spread throughout the country,
which could be harmful to the agricultural industry. Although these
smelly pests do not pose serious property or health threats to
homeowners, their tendency to invade homes in high numbers can be a
nuisance. Adult stink bugs enter homes and other structures in the
late fall to seek shelter from the winter weather. They reemerge
from overwintering sites in early spring and try to exit, but
sometimes enter living spaces instead. Like other overwintering
insects, they often congregate on the sides of buildings.
The good news is that, like indigenous species, invasive
pest infestations can be curtailed or prevented altogether with
some pest proofing know-how. Homeowners should inspect the outside
of their home and identify potential pest entry points. Any cracks
or crevices on the outside of the home – including around windows,
doors and utility pipes – should be sealed with a silicone caulk.
Torn or damaged window screen should be repaired, and screens
should be installed on attic and crawl space vents.
In addition, homeowners should take steps to reduce moisture in
and around their homes, which attracts many pest species. Divert
water away from the home’s foundation with properly functioning
downspouts, gutters and splash blocks. Reduce humidity in crawl
spaces, attics and basements with proper ventilation.
To prevent Formosan termites, store firewood at least 20 feet
away from the house and 5 inches off the ground. Maintain a
one-inch gap between soil and wood portions of your home, and
routinely inspect the foundation of a home for signs of mud
tubes, cracked or bubbling paint and wood that sounds hollow
Anyone suspecting an invasive pest infestation should contact a
pest professional right away. A trained professional will be able
to identify the species and recommend a course of treatment to
control the infestation before it becomes a major problem. Remember
that some invasive pest species, especially Formosan termites,
should always be left to the professionals to handle.