Ottumwa Courier, IA
09-07-06
Iowa sees increase in corn pests
By SCOTT NILES Courier staff writer
OTTUMWA — Another pesky crop insect is causing problems for area farmers,
depleting some Iowa fields of more than 40 percent yield losses.
The western bean cutworm, which was introduced in Iowa near the Sioux City
area almost a decade ago, has been inching its way to more crops across the
state.
“It’s predominantly in the western part of the state,” said Rich Pope, extension
program specialist for Iowa State University. “But, it is moving eastward. It
has went as far as Ohio so far.”
He said there have been multiple sightings of cutworm across Iowa.
The western bean cutworm is a moth. Pope said the insects arise from the
ground around early to mid July, mate and then the females lay their eggs on the
corn crops. It was originally introduced as a soybean insect, but has expanded to
include corn crops, which Pope said, is more of an issue for Iowa.
Once the eggs hatch, the larvae start feeding on the ears of corn. Each “moth”
can lay up to 200 eggs and have a significant impact on lost crops.
“They are univolting; that means they can only have one generation each year,”
Pope said. “Once the season is over the larvae boar into the ground and
hibernate until the next year [starting the process over again].”
Since the introduction of the insects to Iowa, Pope said ISU, along with Pioneer
Hybrid Company, have set up pheromone traps to try and get a count of the
insects.
“In one trap, there has been as many as 1,800 moths,” he said.
The amount of crop loss has varied from area to area, he said, but the cutworms
are defiantly an issue to farmers if they have not been aware of them.
There have not been many sightings in southeast Iowa, Pope said, but the
insects have moved farther south and east each year.
“They go wherever they can get established. We don’t know why they are in
Iowa. It could be the weather, but that is what we are trying to find out,” he said.
Scott Niles can be reached at (641) 683-5360 or via e-mail at
sjniles@mchsi.com.