Ithaca, New York
May 1, 2009
Cornell
University researchers are spending time in the fields this
spring collecting 20,000 alfalfa snout beetles. They need them
to test ways to biologically control the pests, which devour
alfalfa and other crops.
Two very different beetle controls are under investigation. One
is to grow tiny worms called nematodes that naturally attack the
beetle.
The other is to develop alfalfa varieties that are resistant to
the beetle.
The invasive insect, which infests about 13 percent of New
York's agricultural land, including all of northern New York's
six counties, causes substantial damage to alfalfa forage crops,
lowering the production and profitability of dairy and livestock
farms, say two Cornell professors, entomologist Elson Shields
and plant breeder Donald R. Viands, who are leading the
investigations.
So far, tests with the nematodes are proving highly successful,
says Shields. "The field results produced on northern New York
farms showed the nematodes were able to maintain themselves in
the field while reducing the larval populations of the alfalfa
snout beetle and reducing or eliminating feeding injury to the
alfalfa crops," says Shields, who is developing a cost-effective
method for farmers to "grow" and apply their own nematodes to
control the beetles. "We think the protocol for using nematodes
will require only one inoculation per field with farm-grown
persistent nematode strains to reduce the snout beetle
population on a farm," he says.
Meanwhile, Viands, who is also associate dean of the College of
Agriculture and Life Sciences, has been selectively breeding
snout beetle-resistant varieties of alfalfa. After a decade of
breeding, some varieties will be entering their sixth and
seventh generations of selections this year. The beetles
collected by the researchers this spring will be used to stress
alfalfa growing in the Cornell plant breeding lab.
Field testing already is under way on several northern New York
farms. "We have seen promising trends of less and less root
damage on the greenhouse-grown alfalfa and are eager to see how
well the experimental plant populations showing the greatest
potential for resistance perform on the farms in northern New
York," says Viands.
"The nematodes in combination with planting snout
beetle-resistant alfalfa varieties may just be the long-term
biological solution the region's agricultural industry needs,"
Shields observes.
The alfalfa snout beetle is about as long as a human thumbnail
with a tough gray shell. The insect is wingless and migrates by
walking, often causing large, dark moving masses along rural
roadsides. It also spreads by traveling on trucks and farm
equipment. The beetle is believed to have first arrived in the
United States in the ballast of sailing ships, ultimately
arriving in Oswego, N.Y., in the 1800s.
The research is funded by the Northern New York Agricultural
Development Program, Cornell University Agricultural Experiment
Station and New York Farm Viability Institute.
By Kara Lynn Dunn, freelance
writer
Photo credit: Cornell University |
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