Bt corn turns out to be great monarch habitat

Paul Cherubini monarch at saber.net
Fri May 11 23:24:07 EDT 2001


http://www.biotech-info.net/low_risk.html

*  Comparisons of butterfly survival in conventional cornfields and 
in plots of GM corn turned up no significant differences in Minnesota,
Iowa, Maryland, Michigan and southern Ontario.

*  the monarchs fared better at the edges of one Minnesota GM 
cornfield than they did in a nearby wooded area, said William Hutchison, 
an entomologist at the University of Minnesota in St. Paul.

*  the monarchs in the studies seemed to prefer cornfields to other areas 
for laying eggs. 

*  pollen rarely collected on milkweed leaves in lethal concentrations what 
did land on the leaves often was washed away by rain or blown off by wind. 
The concentrations found in the Iowa studies were too low to impose even
minor effects on the monarchs, said Hellmich at Iowa State. 

* In one Minnesota study near Rosemount, researchers placed potted 
milkweed plants at the edge of a cornfield, on a strip of soil around 
the field and close to a nearby wooded area. They monitored caterpillars
on the plants and found no significant differences between those near Bt
and non-Bt corn, Hutchison said. But they were surprised to find that 
more caterpillars died near the forest than near the corn. 

* in Maryland, researchers studied sweet corn, which generally is 
heavily sprayed with synthetic insecticides as an alternative to Bt corn. 
They found the caterpillars quickly died in sprayed fields. But in 
non-sprayed fields, there was no difference between Bt corn and the
conventional varieties, said Galen Dively of the University of Maryland 
in College Park.

 
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