The Truth About Stink Bugs
Dr. Michael J Raupp - College of Agriculture and Natural Resources, University of Maryland
Wednesday, October 3, 2012
the arrival of autumn comes the annual invasion of brown marmorated stink
bugs (BMSB) as they seek winter refuge inside homes and
businesses. A native of Asia, BMSB first appeared in the United
States in the middle 1990’s near Allentown, PA and are now found in
38 states ranging from coast to coast, border to border, with the
epicenter in the middle Atlantic region.
How has this pest spread so
Due to its penchant for hiding in sheltered
locations to pass the winter, this pest often invades recreational
vehicles and campers. One vacationer reported driving hundreds of
miles away from a home in Pennsylvania, opening the camper, and
unwittingly releasing BMSB in a new location.
What kind of damage do stink bugs cause?
While noted as an occasional pest of crops in
Asia, in 2009 we heard dire reports from growers in the middle
Atlantic region who sustained significant losses to peaches, pears
and apples to stink bugs. The next year was even worse, with
regional losses to apples alone exceeding $37 million. This
development was particularly disagreeable from a pest management
Much to our dismay, it has become abundantly
clear that BMSB are more than just a pest of fruits. Over the past
few years damaging numbers of stink bugs have been seen in soybean
fields across the region. This rascal has spread to more than 20
counties in Virginia, leaving a broad swath of damage to soybean
along the way. In 2010, we witnessed record numbers of stink
bugs in fields of sweet corn. By plunging their sturdy beaks
through the corn husk, they remove the nutritious contents of
developing kernels. In some cases, so many kernels were damaged
that the ear of corn failed to fill out.
Stink bugs are not just problems for
conventional vegetable growers. With fewer options for insecticidal
control, organic vegetable growers in the region have been
overwhelmed where stink bugs are common. Community gardeners and
homeowners have been vexed when hordes of stink bugs lined ripening
tomatoes, poking holes in the skin and draining the juicy tissues
below leaving speckled, puckered, and pockmarked fruit. Similar
injury has been reported on peppers and many other vegetables.
Although populations of BMSB cropped up in new
states in 2011, in general, stink bug populations were lower
throughout our region and this trend continued through the spring
and summer of 2012. The reasons for the decline have been
attributed to weather, better management by growers and greater
activity of natural enemies of stink bugs, but the exact cause or
causes remain a mystery.
For many urbanites, stink bugs in apple orchards
or corn fields probably seem like a remote problem. However, the
nuisance potential of BMSB is almost without equal. In 2011, a
homeowner in western Maryland captured more than 26,000 BMSB from
January through June as they moved about his home seeking egress
from their overwintering refuge. That’s a lot of nuisance!
Why do stink bugs enter homes and
man-made structures in the first place?
Many folks incorrectly believe they enter to be
warm for the winter. Bear in mind that millions of years ago when
BMSB evolved, there were no mansions or man-made structures to
invade. In chilly locations where winter halts the growth of
deciduous trees and shrubs and withers herbaceous plants, food for
the plant-eating stink bug all but disappears.
Cold brings movement and development of BMSB to
a standstill. During this inimical season, BMSBs seek refuges to
chill-out, protected from the harsh weather and dangerous
predators. Until recently, these natural winter redoubts were
thought to be rocky crags and piles of leaf litter. However, a new
study revealed that the loose bark of large, freshly deceased but
still standing trees may be a prime winter hideout for BMSB.
However, for a BMSB leaving a senescing field of soybeans, the
siding on a home might look like a mighty fine place to spend the
What does the autumn of 2012 hold for
Unlike the cooler, wetter summer of 2011, 2012
has been a year of record warmth and BMSB completed a full second
generation in grand style. On a recent safari to a western
Maryland, I collected almost a thousand BMSB in a couple hours of
easy picking in soybeans and trees. Some scientists fear that we
may be seeing a renaissance of
stink bugs in the autumn of 2012 that could translate into a
stink bug ridden 2013 similar to the watershed year of 2010. Only
time holds the answer to this one. One thing is for certain, as
BMSB continues to spread across our nation and as populations rise
on regional and local levels, many more folks will learn the true
implications of a bug that really stinks.
I thank Doo-Hyung Lee, Doug Inkley, Tracy Leskey, Galen
Dively, and other members of the BMSB Working Group for providing
information and inspiration for this article. To learn more about
the biology, ecology, and current research on BMSB, please visit
the following websites.
Watch this video to learn how to keep BMSB out
and what to do when they get in.
Photo Credit: Mike RauppView Comments
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