Radio Iowa, IA
09-23-06
Iowa farmers seeing new pest in fields
by Matt Kelley
A corn-gobbling pest is appearing in Iowa fields for the first time this fall, leaving
some farmers stumped as to how to fight it.
Dr. Matt O'Neal, an entomologist at Iowa State University, says the western
bean cutworm may have "bean" in its name, but the insects thrive on munching
corn by the ear. For corn growers in Iowa, O'Neal says the western bean
cutworm has replaced the European corn borer as the number-one pest. "The
moths fly into the state and lay their eggs. The caterpillars, the immature stages,
feed on the ears and do extensive damage, damaging the ears and reducing
yield," O'Neil says.
He says the cutworms have been found before as far east as Illinois, Indiana and
Wisconsin, but now "heavy flights" of the moths are being reported over Iowa and
Nebraska. Farmers who find a few of the worms this year may be faced with a
much larger problem next year. "Our website has recommendations for growers
as to what level of abundance is high enough to merit the use of some kind of
management program," O'Neil says.
In fields with non-BT corn hybrids, researchers are seeing as much as 70 to 90percent ear infestation, with an average of two-to-three-percent yield loss in
those fields. He says if you already have bean cutworms in your crops this year,
there's no defense. The best bet, according to O'Neil, is to plan ahead for next
year.
O'Neal says two varieties of genetically-modified corn are out there from
competing companies, one of them protects against the western beat cutworms,
the other does not. He says farmers that are seeing infestations may want to
keep that in mind when buying their seed for next year's planting. The university's
website has pictures of the worms and more information about the pests -"www.ent.iastate.edu/trap/westernbeancutworm".