Tracy Leskey spends part of
her day getting in and out of her Jeep at the United States Department of
Agriculture Appalachian Fruit Research Station in Jefferson County. She’s
collecting Stink Bugs from traps.
“I’ve never seen anything
like this,” Leskey said. “This is unprecedented.”
This is the second year Leskey
has conducted research on how to control the insects.
“We’ve seen incredible
population growth over the last few years and so in tree fruit orchards,
particularly in apple and peach, we’ve seen the adults entering the orchard
early, beginning to feed, causing severe injury,” Leskey said. “The nymphs also
feed on the fruit.”
“This year we have seen
growers who have had a total loss of their crop from this insect,” Leskey
added.
Leskey said stink bugs have
what’s described as a piercing, sucking mouth part, which is essentially a
straw. The bug inserts its mouth part into the flesh of the fruit and it
injects pre-salivary enzymes. Leskey said these are enzymes that break down the
fruit tissue allowing the insect to suck up the contents.
Leskey said the pre-salivary
enzymes cause brown, corky spots in the flesh of the fruit. Leskey said the
damaged fruit is still edible, but farmers are usually unable to sell it for
consumption.
“For a consumer generally
they are not happy if they slice open a peach and they see these large brown
areas in the fruit, they wonder what that is, is it insect injury, is it rot,
who knows?” Leskey said. “We as American consumers expect perfection in our
fruit and this stink bug is definitely destroying the ability for a grower to
produce clean fruit.”
Lesky said stink bug damage
forces growers to sell their crop for fruit juice instead of for consumption,
so they make less money on it.
The damage is found
throughout West Virginia and in the surrounding states and the bugs aren’t just
a threat to fruit.
“They’re damaging corn,
sweet peppers, tomatoes, beans, so yes they are more than just a nuisance they
are a serious crop pest as well,” Leskey said.
A series of traps are
located next to the peach, apple and pear orchards at the Appalachian Fruit
Research Station. The bases of the
traps, which stand about three feet tall, are shaped like a pyramid and are
painted different colors. Leskey is trying to figure out what attracts the
stink bugs.
“These bases represent
different visual stimuli,” Leskey said. “When you see yellow or green those
would sort of be indicative foliar stimuli so it’s basically the color of
vegetation according to how insects see.”
Leskey said black traps
represent something like a tree trunk, or a structure.
“And so the bugs climb up
these traps and are funneled into the collection devices at the top,” Leskey
said.
She then collects the bugs
and freezes them.
Leskey is also putting
scented lures on some traps to try to determine what attracts the bugs.
“The lure itself does
attract and aggregate them around this trap,” Leskey said. “Down the line we
may be able to use this behavior as a control strategy, as an attract and kill
type strategy where we can aggregate them into a particular area and only have
to treat that particular area with an insecticide to knock them down rather
than treating an entire orchard.”
Brown Marmorated Stink Bugs
are natives of Asia. According to the
Penn State College of Agriculture web site, the bugs were first detected in
this region in Allentown Pennsylvania in 1998.
They’ve been found in at least 26 states.
As their population grows
and spreads, Leskey hopes the research she’s doing will help prevent them from
becoming an even bigger threat to U.S. agriculture.