|Monsanto Corn May Be Failing to Kill Bugs in 4 States, EPA Says|
Bloomberg, December 2 2011
Monsanto Co. corn that's genetically engineered to kill insects may be losing
its effectiveness against rootworms in four states, the U.S. Environmental
Protection Agency said.
Rootworms in Iowa, Illinois, Minnesota and Nebraska are suspected of developing
tolerance to the plants' insecticide, based on documented cases of severe crop
damage and reports from entomologists, the EPA said in a memo dated Nov. 22 and
posted Nov. 30 on a government website. Monsanto's program for monitoring
suspected cases of resistance is "inadequate," the EPA said.
"Resistance is suspected in at least some portions of four states in which
'unexpected damage' reports originated," the EPA said in the memo, which
reviewed damage reports.
The insects, which begin life as root-chewing grubs before developing into adult
beetles, are among the most destructive corn pests, costing U.S. farmers about
$1 billion a year in damages and chemical pesticides, according to the U.S.
Department of Agriculture.
Monsanto, the world's largest seed company, introduced its rootworm-killing corn
technology 2003. The modified corn was planted on more than 37 million acres
this year, Lee Quarles, a spokesman for St. Louis-based Monsanto, said
yesterday. Corn is Monsanto's largest business, accounting for 41 percent of its
$11.8 billion of sales during the fiscal year ended Aug. 31.
An Iowa State University study said in July that some rootworms have evolved
resistance to an insect-killing protein derived from Bacillus thuringiensis, or
Bt, a natural insecticide engineered into Monsanto corn. Entomologists in
Illinois and other Midwestern states are studying possible resistance where the
insects devour roots of Monsanto's Bt corn.
Monsanto continues to believe there's no scientific confirmation of resistance
to its Bt corn, Quarles said by telephone. Still, Monsanto takes the EPA report
"seriously" and is increasing efforts to teach farmers how to respond to
unexpected damage in their fields, he said.
Less than 0.2 percent of the acres planted with Monsanto's Bt corn were affected
by unexpected rootworm damage this year, Quarles said. Farmers with root damage
in their fields should consider changing practices to "stay ahead of this
insect," Monsanto said in a statement. That could include rotating corn with
soybeans or using a product such as Monsanto's SmartStax corn, which kills
rootworms with two types of Bt, the company said.
The agency said in the memo that using SmartStax in fields where the bugs have
developed resistance to Bt corn could hasten resistance to SmartStax because
SmartStax's effectiveness is predicated on both types of Bt working as designed.
SmartStax corn produces the second type of Bt with a gene licensed from Dow
Chemical Co. (DOW)
The EPA tries to deter resistance to Bt corn by requiring farmers to plant corn
that doesn't produce the pesticide alongside the modified crop. This creates a
so-called refuge of unexposed bugs that can mate with insects developing
resistance, creating a second generation of bugs that's susceptible to the
The EPA's requirement of a refuge equal to at least 5 percent of a SmartStax
crop, compared with 20 percent for Bt corn, "will be substantially less durable
and could ultimately compromise the second unrelated toxin used to control the
pest" if insects are already resistant to Monsanto's Bt, the agency said in the
Monsanto should enact a remedial action plan in fields where resistance to the
Bt insecticide is suspected, the EPA said. That includes having growers use
conventional pesticide to kill adult rootworm beetles late in the season and
alternate pest control methods in the following season.
Monsanto tested rootworms for resistance in Nebraska, Illinois and Iowa and
should expand the monitoring to Colorado, Minnesota, South Dakota and western
Wisconsin because questions about the performance of Bt corn extends to all
seven states, the EPA said in the memo.
|The Genetic Engineering Blog is produced by Thomas Wittman and EcoFarm,
and supported by a generous donation from the Newman's Own Foundation.|