Ecol. aspects of transgenic crops summary (fwd)
Paul Cherubini
cherubini at mindspring.com
Wed Apr 19 11:33:41 EDT 2000
Jim Kruse wrote in regard to the executive
summary of the workshop on ecological impacts of transgenic
crops held on UC Berkeley Campus March 2-4, 2000:
> unanticipated effects on non-target herbivorous insects (i.e. monarch
> butterflies) through deposition of transgenic pollen on foliage of
> surrounding wild vegetation;
Jim, I am unaware of any study documenting that even one unmanipulated
monarch caterpillar feeding on an unmanipulated milkweed plant growing
as a weed within or near a Bt corn field ever died from exposure to
Bt corn pollen.
Moreover, as the percentage of the Midwest corn crop planted in Bt corn
rose from roughly 5% in 1997 to 30% in 1999, the size of the
overwintering population of monarch butterflies in Mexico has actually
increased.
SIZE OF MONARCH POPULATION OVERWINTERING IN MEXICO
(total monarch coverage at 5 major overwintering sites in hectares)
Winter of: approx % of Midwest corn planted in Bt corn
1997-98: 3.18 hectares 5%
1998-99: 5.21 hectares 20%
1999-00: 5.97 hectares 30%
Paul Cherubini, Placerville, California
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