Rootworm gains ground in US fields
 
EXCERPT: The agency is taking a tougher stance because the industry’s efforts haven’t done enough to stem the spread of pesticide-resistant rootworms in the Midwest, officials said. “It is getting worse,” said Bill Jordan, the EPA’s deputy head of pesticide programs. “What’s happened so far hasn’t prevented these problems from arising, so we see need for something more.”
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Limits sought on GMO corn as pest resistance grows

Jacob Bunge
Wall St Journal, 5 Mar 2015
http://www.wsj.com/articles/limits-sought-on-gmo-corn-as-pest-resistance-grows-1425587078

* Rootworm gains ground; seed producers criticize EPA proposal

U.S. regulators for the first time are proposing limits on the planting of some genetically engineered corn to combat a voracious pest that has evolved to resist the bug-killing crops, a potential blow to makers of biotech seeds.

The measures proposed by the Environmental Protection Agency represent a bold step to thwart the corn rootworm, a bug that ranks among the most expensive crop threats to U.S. corn farmers.

The plan is aimed at widely grown corn varieties sold by Monsanto Co. , the first to sell rootworm-resistant corn, and rival seed makers including DuPont Co. and Dow Chemical Co. Such corn seeds have been genetically modified to secrete proteins that are toxic to destructive insects, but safe for human consumption, helping to reduce farmers’ reliance on synthetic pesticides.

The EPA’s proposal would require seed companies to limit some Midwestern farmers’ practice of sowing fields with corn year after year in areas harboring resistant rootworms, whose cream-colored larvae gnaw on corn roots and stunt plants’ growth. The EPA is concerned that if the resistance continues, it will lead farmers to use more synthetic chemicals to thwart the bug, creating environmental risks.

Representatives of the biotech-seed industry have criticized some parts of the proposal, which was released in January and is subject to a public-comment period until March 16, after which the EPA will finalize any new requirements.

The agency is taking a tougher stance because the industry’s efforts haven’t done enough to stem the spread of pesticide-resistant rootworms in the Midwest, officials said.

“It is getting worse,” said Bill Jordan, the EPA’s deputy head of pesticide programs. “What’s happened so far hasn’t prevented these problems from arising, so we see need for something more.”

Seed-company officials say they already encourage farmers to alternate planting of corn and other crops like soybeans to prevent resistant rootworms from establishing themselves. Other efforts also have helped, such as planting small quantities of non-biotech corn in parts of farmers’ fields to slow the bugs’ evolution, they say. Each year, the rootworm costs U.S. corn farmers about $1 billion to $2 billion in damages and outlays to thwart the insect, according to Michael Gray, an entomologist at the University of Illinois at Urbana-Champaign.

Parts of the EPA’s plan are “quite prescriptive,” said Jeff Bookout, head of U.S. commercial stewardship at Monsanto and chairman of the Agricultural Biotechnology Stewardship Technical Committee, an industry group. “We need to make sure we provide choices and options for growers…not a one-size-fits all [solution].”

Genetically modified corn capable of producing the bug-killing protein Bacillus thuringiensis was planted on an estimated 80% of U.S. cornfields last year, up from 19% in 2000, according to the U.S. Department of Agriculture.

Midwestern farmers’ embrace of pest-resistant corn since the first varieties’ launch in 1996 has diminished its power over some bugs like the corn rootworm, however. Repeated exposure to the corn’s bug-killing proteins means that the small number of rootworms that are able to consume the BT toxin and live can reproduce by the thousands and spread across fields that are used to grow corn year after year.

Researchers at Iowa State University in 2011 documented rootworms in an Iowa corn field that had evolved to withstand a biotech corn variety created by Monsanto and first sold in 2003. Last year, Iowa State scientists separately confirmed rootworm resistance to a separate corn variety developed by Syngenta AG , which has been on the market since 2007. Researchers also have documented resistance in Illinois, Nebraska, and Minnesota.

Researchers have yet to confirm rootworm resistance to a separate, newer strain of Syngenta corn, along with a variety developed by DuPont and Dow Chemical.

“The worst-case scenario is, over large areas, the [insect-resistant] corn plants will lose effectiveness, and growers will be forced to rely much more on insecticides,” said Bruce Tabashnik, an entomology professor at the University of Arizona. “That’s bad for their bottom line, and it’s bad for the environment.”

Among its proposed changes, the EPA would require makers of rootworm-resistant corn to curb some repeated corn planting in areas badly afflicted by the pest. In portions of Iowa, Illinois, Nebraska and some surrounding states — what EPA officials called the rootworm “red zone” — the agency is pushing for about 35% of corn fields to be planted with another crop, such as soybeans, after two consecutive years of planting of rootworm-resistant biotech corn. Other high-risk fields should be planted with newer corn that can produce multiple types of bug-killing proteins, according to the EPA proposal.

Seed companies could incorporate such requirements into the agreements farmers sign when they buy biotech corn, or use incentives to encourage participation, according to regulators. The EPA said it is open to discussing other approaches.

Adding leverage for the EPA: 15 varieties of insect-resistant biotech corn must be re-registered with the regulator by Sept. 30, which requires producers such as Monsanto, DuPont, and Syngenta to outline current plans to stem pest resistance.

Boyd Epperson, a Nebraska corn farmer who has grappled with resistant rootworms since 2013, bristled at the EPA’s proposal, saying it could limit his business choices. “To me, it should be more an individual decision and not the government telling us what to do,” he said.