NEWS: Biotech corn not so bad for butterflies

From: David Blenkinsop (blenl@sk.sympatico.ca)
Date: Sat Oct 02 1999 - 14:41:31 MDT


The September issue of the journal _Nature Biotechnology_ has a
refutation of the claims we've been hearing about genetically modified
corn being dangerous to Monarch butterflies. The intended modification
to the corn is that it contains a gene referred to as "Bt", for Bacillus
thuringiensis. This particular gene produces an insecticide meant to
kill the corn borer insect. The claim, from the May 20, 1999, issue of
_Nature_, was that Monarch butterflies are killed by feeding on pollen
from the modified corn plants. Both the originator of this idea, John
Losey, and his critic, Anthony Shelton, are entomology professors at
Cornell University in Ithaca, New York.

According to the _Nature Biotechnology_ article,

"The recent short correspondence in Nature reporting a
 laboratory study in which pollen from Bt-transgenic corn was fed
 to Monarch butterflies has attracted considerable coverage in
 the popular press and widespread rebuttals and criticisms in
 the scientific press. It is surprising, then, that a previous and
 more relevant and realistic field study has been largely
 overlooked. In that study, the authors examined Bt-corn pollen
 deposition on milkweed plants within, and adjacent to, field corn
 and then assayed the leaves with first instar larvae. Pollen levels
 were highest within the field (where Monarchs are scarce), but
 even there Monarch mortality was only 16%."

You can access the article at http:\\biotech.nature.com by signing up
for a free account and searching for "Shelton" in the "authors last
name" field of the search form.

David Blenkinsop <blenl@sk.sympatico.ca>



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