From the second article we discover that an alien species of stink
bug has been running amok and damaging crops way more than expected.
It gives us an opportunity to catch up on the biology of a pest any
farmer knows and generally ignores. This option has presently
disappeared although it likely succumbs well enough to early timed
pesticide applications. The organic farmer will not be so lucky.
It is also good to know that a wasp solution is available for the
alien and plausibly through future work this method can be expanded.
In fact, it is almost time to use genetic engineering to produce
wasps able to target a selected class of pests as a general control
system. After all it flies out and finds the pest and deals with it.
Normally the stink bug does not produce infestation and damage is
generally slight at worst. An occasional apple is tossed. Now the
alien is producing serious infestation likely able to wipe out a
crop. This is not a good plan. Thus we have to pay attention and
likely get in the habit of even looking for them and collecting them
in our gardens.
This reminds me a little of potato bug control.
Biology and
Management of the Green Stink Bug
by Staff Writers
Lanham, MD (SPX) Sep 27, 2012
The
green stink bug is one of the most damaging native
stink bug species in the United States. Stink bugs feeding on cotton,
soybeans, tomatoes, peaches, and other crops can result in cosmetic
damage as well as reduced quality and yield.
A
new article in the Journal of Integrated Pest Management, "Biology
and Management of the Green Stink Bug," offers farmers and
growers advice on how to deal with this insect pest.
According to the
authors, stink bugs have become a major challenge to integrated pest
management systems because control options are basically limited to
the application of broad-spectrum insecticides such as
organophosphates, carbamates, and pyrethroids. However,
neonicotinoids are generally effective for control of this stink bug
and may be less disruptive to its natural enemies.
Further options for
stink bug management that are being explored include the use of trap
crops and enhancing beneficial parasitoid populations. Cultural
options, including trap cropping and the planting of resistant
varieties, have been documented as decreasing crop injury by stink
bugs. In addition, there are multiple natural enemies that reduce
population numbers.
The
authors go on to describe the green stink bug's life cycle, seasonal
biology, host plants, and management options such as
pheromone trapping, chemical control, cultural control, and
biological control.
Just Ask: Stink Bug
Invasion; Is a Wasp the Solution to Save Valued Crops?
BY: JENNY MARDER
When it comes to fruit
and vegetables, brown marmorated stink bugs don't discriminate. They
feast on peaches, plums, apples, and grapes, along with corn,
tomatoes, peppers and soybeans. They extract fluid from the apples,
turning them dry and corky, and then leave them to rot.
And when threatened,
as their name suggests, the stink bugs release a pungent odor that
smells like cilantro.
Farmers have been hard
hit by stink bug damage since the brown marmorated species was first
spotted in Pennsylvania in 2001, but the numbers have exploded in
recent years.
Mark Seetin, director
of regulatory and industry affairs for the U.S. Apple Association
says that in the 40 years that he's been in the industry, he's never
seen one insect pose such a big threat.
"Unlike a typical
insect which focuses on a crop or a narrow range of crops, this bug
eats virtually anything," Seetin said. "The most unique and
dangerous thing about this bug is its scope ... I'm waiting to hear
that it feasts on plastic plants in the hotel lobby."
Scientists believe
that the bug hitchhiked to the United States on a shipment of goods
from Asia in the late nineties. It has since spread to 33 states,
extending from the east coast all the way to California, Oregon and
Washington, wreaking havoc on mid-Atlantic crops. The industry began
noticing damaged crops in 2008, but it only recently expanded from a
late-season problem to a season-long pest.
In 2010, mid-Atlantic
apple growers lost 18 percent of their apple crop to the bugs,
resulting in a $37 million loss, Seetin said. And our native
predators and pesticides have little success at combating them.
"It is typical of
an invasive species that it doesn't have the natural enemies that it
evolved with," said Tracy Leskey, an entomologist at the U.S.
Department of Agriculture's Appalachian Fruit Research Station in
Kearneysville, W. Va. "And a lot of the insecticides labeled as
excellent against native stink bugs didn't work as well as we'd hoped
against the brown marmorated."
"The most unique
and dangerous thing about this bug is its scope... I'm waiting to
hear that it feasts on plastic plants in the hotel lobby."
MARK SEETIN, U.S. APPLE ASSOCIATION
Many are hanging their
hopes on a wasp -- from the trissolcus genus -- that is an effective
predator against brown marmorated stink bugs in China, Japan and
Korea.
Kim Hoelmer, a
research entomologist with the USDA Agricultural Research Service,
began studying brown marmorated stink bugs in 2005. His team quickly
determined that predators of other North American stink bugs were not
switching over to include this new species in their diet. But they
identified the parasitic trissolcus wasps in Asia, which eat nothing
but these bugs.
"It's all they
can recognize as food," Hoelmer said. "If they can't find
brown marmorated stink bug eggs, they die."
These non-stinging
wasps hold high promise for controlling stink bugs in the U.S., said
Michael Glenn, director of the USDA's Appalachian Fruit Research
Station. "But much testing must occur before it could even be
considered for release."
The wasps attack like
creatures from the movie, "Alien," Hoelmer said. They lay
their eggs inside clusters of stink bug eggs. When the wasp eggs
hatch, the larva consumes the stink bug egg from the inside out.
"By the time the
young wasp is mature and ready to come out, it's eaten everything
inside the brown marmorated egg except for the shell, "Hoelmer
said. "Then it chews a hole in the shell and pops out."
Both are tiny. A mass
of stink bug eggs would fit on an adult's pinky fingernail. The wasps
are barely bigger than a pencil tip when they emerge.
Hoelmer is studying
four different species of these wasps in a quarantined lab in
Delaware. Under current guidelines for introducing an invasive insect
into the wild, they won't consider releasing the wasp unless they
know it will only attack the brown marmorated stink bug and not other
stink bug species. There are more than 200 species of stink bugs in
North America; some are important predators of other insect pests.
But back home, they've
proven to be effective killers. "In Asia, two-thirds of egg
masses have been found and killed by these parasitic wasps,"
Hoelmer said. "So they really do have the potential to have a
real impact on stink bug populations."
Hoelmer thinks his
team is about two years from knowing whether the parasitic wasps can
be safely introduced into farms.
Brown marmorated stink
bugs are named for the grey and brown marble patterns on their back.
They feed by inserting a straw-like mouth part called a stylet, into
the fruit. The stylet pierces and sucks sap from the plants, while
they inject their own salivary juices.
At the Appalachian
Fruit Research Station, entomologists study behavior, olfactory cues
and pheromones of the bugs, as well as the wavelengths and intensity
of light that attract them. They are also researching a computer
based vision system that would use near infrared reflectants to
assess early damage to fruit.
But those in the field
fear that any real solution is still years away. And in the meantime,
it is doing a "breathtaking" amount of damage, Seetin said.
"Comparing this
thing to the regular stink bugs we have is like comparing a guppy to
a great white shark," he said. "The only thing they have in
common is that they're fish."
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