Moscow, Idaho
June 18, 2008
A new aphid monitoring network
operated by University of Idaho
entomologists will help Idaho and eastern Washington pea and
lentil producers gauge when to fight back against the insect
pests.
Each spring waves of aphids take shape in the southwestern
reaches of the Columbia River Basin, then take flight to the
northeast and threaten crops with viruses the sap-sucking
insects can carry.
University of Idaho entomologist Sanford Eigenbrode
(EYE-gen-brod) pioneered the aphid detection network in 2006
with the help of growers and scientific colleagues at Idaho and
Washington State University. The Moscow-based USA Dry Pea and
Lentil Council provided early financial backing and strong
support for the project.
The project will expand into a detailed landscape ecology study
of aphid infestations during the next three years with $1.25
million in US Department of Agriculture funding.
Eigenbrode experimented with a range of traps, from those that
relied on vacuum suction to yellow plastic picnic plates armed
with a small amount of antifreeze.
The plates proved the most reliable, efficient and cost
effective tool for aphid monitoring. The point, Eigenbrode said,
is to help growers monitor both the number of aphids throughout
the season and evaluate the likelihood of outbreaks of three
major viruses, pea enation mosaic virus, bean leaf roll virus,
pea streak virus that could cut crop yields.
Once collected, the aphids are returned to the laboratory where
DNA testing through a collaboration with University of Idaho
virologist Alexander Karasev determines whether the insects
carry a virus.
Most of the traps will be located by pea fields and a few will
be located by lentil fields. The funding for this season’s work
comes from a U.S. Department of Agriculture Cool Season Food
Legume Program grant.
Eigenbrode said the project will also receive a larger USDA Risk
Assessment Mitigation Program grant of $1.25 million. It will
allow expansion of the monitoring network to 60 trapping
locations within the Palouse and extend it the study to four
years.
In addition, the larger study will emphasize a landscape ecology
approach that may help solve a fundamental aphid mystery: where
the aphids originate each year. To do this sampling will take
place from Pendleton, Ore., to Washington’s Tri-Cities and
eastward to Idaho.
The evidence so far suggests the aphids that will launch each
season’s wave of invaders survive the winter in the Columbia
Basin’s warmest areas. As spring begins, the tiny green insects
multiply rapidly, then hitch a ride on prevailing winds that
carry them into the legume crops of the Palouse region.
“Our data suggests there are as yet undiscovered sources of
aphids that primarily fuel the population immigration,”
Eigenbrode said. The regional trapping and wider survey work
will help located these sources of the aphids, so their threat
can anticipated or even reduced through interventions once their
winter refuge is discovered.
“We still don’t have enough data to be able to predict virus
risk, but patterns are emerging. For now, we will provide what
we have and allow producers to weigh all of this information and
make their own decisions. We think that after five summers of
data collection we’ll be able to establish levels virus risk
early in each season,” Eigenbrode said.
The impact of viruses on crop production varies widely each
year, Eigenbrode said, depending how early in the season
infected aphids appear and when they begin feeding on pea and
lentil plants.
The appearance of viruses in early June may pose enough threat
to plants that growers will invest in pesticides to stop crop
losses. The arrival of virus-laden aphids in late June may
threaten only minor cuts in yields because the plants are
already past peak production.
The newly funded project will determine these critical dates for
each of the viruses that affect peas and lentils on the Palouse.
The project will refine recommendations for when aphid numbers
in the crop merit spraying with insecticides, depending on the
level of virus risk. University of Idaho entomologist Ed
Bechinski will contribute to this part of the work.
Beginning this year, the traps will be checked twice a week.
Eigenbrode said growers will have timely access to data
throughout the season through the Internet at
http://www.ag.uidaho.edu/aphidtracker/
University of Idaho Extension educator Larry Smith in Lewiston
and Washington State University Extension’s Diana Roberts at
Spokane will help coordinate other communication with producers.
Other components of the RAMP project will include improving the
methods for incorporating virus resistance into new pea and
lentil varieties. This work will be accomplished by
co-investigators on the project at the USDA Agricultural
Research Service in Pullman and Prosser, Washington.
Founded in 1889, the University of Idaho is the state's
flagship higher-education institution and its principal graduate
education and research university, bringing insight and
innovation to the state, the nation and the world. University
researchers attract nearly $100 million in research grants and
contracts each year; the University of Idaho is the only
institution in the state to earn the prestigious Carnegie
Foundation ranking for high research activity. The university's
student population includes first-generation college students
and ethnically diverse scholars. Offering more than 150 degree
options in 10 colleges, the university combines the strengths of
a large university with the intimacy of small learning
communities. For information, visit
www.uidaho.edu. |
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