January 10, 2012

US scientists rebut claims that GM corn causes new pest

Scientists from  the University of Minnesota deny the finding of a report by Greenpeace Germany that the western bean cutworm (WBC), a new plant pest, is the work of genetically modified corn.

An article in the forthcoming issue of the Journal of Integrated Pest Management (JIPM) refutes claims by Greenpeace Germany that the western bean cutworm (WBC), Striacosta albicosta (Smith), is "a new plant pest" that was "caused by genetically engineered corn."

In "Genetically Engineered Bt Corn and Range Expansion of the Western Bean Cutworm (Lepidoptera: Noctuidae) in the United States: A Response to Greenpeace Germany," corresponding author William Hutchison, professor and chair of the University of Minnesota Department of Entomology, and his co-authors maintain that the Greenpeace report fails to consider broader ecological and agronomic factors which explain why the WBC's range has expanded.

The Greenpeace Germany report, which was written by author Richard Then of Testbiotech, offers a "surprisingly simplistic conclusion" regarding the spread of western bean cutworm over the last decade, according to the JIPM authors.

These additional factors include insect biology, synchrony of insect and corn phenology, reduced insecticide use, increases in conservation tillage, soil type, glyphosate-resistant crops, insect genetics, insect pathogens, pre-existing insect population densities, and climate change.

The JIPM authors focus on several discrepancies of fact and interpretation in the Greenpeace document, beginning with its title, "Agro-biotechnology: New plant pest caused by genetically engineered corn. The spread of the western bean cutworm causes massive damage in the US".

JIPM authors also said that the Greenpeace claim that the WBC has historically "been confined to very limited regions and did not cause any major problems in maize crops" is untrue. Farmers in Nebraska reported major problems as early as 1962, and instead of being "confined to very limited regions," the WBC was documented throughout the western Great Plains from Mexico to Alberta, where it was found in the mid 1950s, despite the Greenpeace claim that it was found in Canada for the first time as recently as 2009.