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Where have all the Monarch's gone?
The Effects of Genetic Engineering
(an update)

In 2000 we wrote about a 1999 study:

Although this is only the second study concerning modified Bt corn there appears to be some effect on the Monarch Butterfly from pollen exposure.

At Iowa State University entomologist John Obrycki noted that there was a death rate of 20% of monarch larvae that died due to being exposed for two days to pollen from Bt corn. This had been blown on to milkweed plants that were hosting monarch caterpillars. After three days more than half of the larvae died.

They still feel the potential harm from Bt corn is unclear because of the overlap of the corn pollen flowering and the larvae appearing are not always the same. As always growing times differ in different areas and the planting times would determine the danger.

The final statement would mean future studies of genetically modified crops still need to be done before extensive areas are planted.

Ref: Iowa State site 
CNN story:  www.cnn.com/nature/9905/20/butterfly.killers/
related story: http://www.cnn.com/2005/TECH/science/04/20/monarch.butterfly/index.html 
University of Kansas Entomology Program: http://www.monarchwatch.org/

In 2001: The Proceedings of the National Academy of Science described the "impact as negligible" for the Monarch Butterfly.

As of 2004: The USDA saw no risk to the Monarchs.

And more recently: The Science and Environmental Health Network worried about "unpredictable outcomes" of genetic engineering and the Pesticide Action Network of North America (PANNA) is still concerned.