[Marxism] Frankenpolitics: The Left defence of GMOs

Louis Proyect lnp3 at panix.com
Wed Jan 8 06:42:08 MST 2014


On 1/8/14 4:38 AM, David P Á wrote:
> Glad to see that there are more people on the left concerned about
> scientific accuracy and truth in regard to these issues.

You want scientific accuracy? Here's scientific accuracy:


Field-Evolved Resistance to Bt Maize by Western Corn Rootworm

Aaron J. Gassmann mail, Jennifer L. Petzold-Maxwell, Ryan S. Keweshan, 
Mike W. Dunbar

Published: July 29, 2011

Abstract
Background

Crops engineered to produce insecticidal toxins derived from the 
bacterium Bacillus thuringiensis (Bt) are planted on millions of 
hectares annually, reducing the use of conventional insecticides and 
suppressing pests. However, the evolution of resistance could cut short 
these benefits. A primary pest targeted by Bt maize in the United States 
is the western corn rootworm Diabrotica virgifera virgifera (Coleoptera: 
Chrysomelidae).

Methodology/Principal Findings

We report that fields identified by farmers as having severe rootworm 
feeding injury to Bt maize contained populations of western corn 
rootworm that displayed significantly higher survival on Cry3Bb1 maize 
in laboratory bioassays than did western corn rootworm from fields not 
associated with such feeding injury. In all cases, fields experiencing 
severe rootworm feeding contained Cry3Bb1 maize. Interviews with farmers 
indicated that Cry3Bb1 maize had been grown in those fields for at least 
three consecutive years. There was a significant positive correlation 
between the number of years Cry3Bb1 maize had been grown in a field and 
the survival of rootworm populations on Cry3Bb1 maize in bioassays. 
However, there was no significant correlation among populations for 
survival on Cry34/35Ab1 maize and Cry3Bb1 maize, suggesting a lack of 
cross resistance between these Bt toxins.
Conclusions/Significance

This is the first report of field-evolved resistance to a Bt toxin by 
the western corn rootworm and by any species of Coleoptera. Insufficient 
planting of refuges and non-recessive inheritance of resistance may have 
contributed to resistance. These results suggest that improvements in 
resistance management and a more integrated approach to the use of Bt 
crops may be necessary.

full: 
http://www.plosone.org/article/info:doi%2F10.1371%2Fjournal.pone.0022629







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