mutation....

Steve Gilman sgilman at netheaven.com
Tue Aug 7 11:46:17 EDT 2001


Subject: Re: Mutation....
From: "Bill Shoemaker" <wshoemak at inil.com>
Date: Mon, 6 Aug 2001 15:41:31 -0500
X-Message-Number: 4

Resistance to Bt is not new. Diamondback Moth, a serious pest of
Brassicas,
was found to have resistant populations in Hawaii in the late 80's, before
genetic engineering of the Bt toxin gene. It was clear from the beginning
that widespread use of the Bt gene in plants would lead to resistance in
the
major lepidopteran pests. It's been a waste to use it on major monocrops,
where it's impact  is less important than it is as an organic insecticide.
Such is commerce...

Bill Shoemaker
Sr Research Specialist, Food Crops
Univ of Illinois - St Charles Hort Research Center


Re: Mutation....
	Bill is correct that widespread use of Bt will lead to pest resistance
and earlier spray regimes has already caused resistance to Diamondback
moth in some areas. For organic farmers it is much more than a waste when
Bt is genetically  engineered into major monocrops, however -- its greatly
accelerated and now immanent demise will be a Major Loss. For conventional
farmers other, much more virulent and expensive chemicals will be required
to do the same job and consumers will be faced with more expensive food
with more toxic residues. This also calls into question the right of
commerce (agribusiness-as usual) to willfully destroy a “common good” to
benefit their own bottom line as well as EPA’s complicity in allowing its
use to begin with.
	Up until the wide scale use of transgenic Bt crops beginning in the
mid-1990s, Bt has been used around the world as the premier safe
bio-insecticide for over 40 years with very little resistance exhibited.
Bt itself is formulated from a common soil bacterium that was developed as
a biological pest control because of its ability to target specific
lepidopteran pests in their immature growth stages. The comparatively
benign bacterial Bt formulations sprayed on crops by organic growers,
however, only live for a few days before being broken down by sunlight and
weathering and since it is activated only in the gut of the targeted pest,
causes minimal impact on other ecosystem functions.
	Transgenic crops such as Bt corn, on the other hand, are implanted with
the concentrated Bt toxic gene itself (not the bacteria) in an activated
form which becomes expressed full time throughout all parts of the plant
–– leaves, stems, pollen, roots, root exudates, seed and the corn itself.
While the full time presence of GMOs let loose willy nilly in the
environment poses significant problems, there has been little long range
testing to their effects on the ecosystem. Transgenic crops subsequently
tested by independent scientists well after FDA, USDA and EPA approval and
wide-scale field release has found numerous above ground poisonous effects
on non-target species, such as Monarch butterflies, ladybugs and green
lacewings, as well as genetic pollution from cross pollination into
non-transgenic crops.
	Further, little attention has been paid to the impact on soil organisms. 
A study at New York University found that a common transgenic Bt corn
variety emits the activated Bt toxin through its root exudates where it
stabilizes, binding with soil particles and taking on a life of its own.
They also discovered that it remained highly toxic to soil insects for
long periods, persisting well beyond the eight month scope of the research
project. Pesticides, herbicides and chemical fertilizers have already
proved to disrupt and severely degrade soil organisms. The long term
colonization of soil ecosystems by virulent, self-perpetuating genetically
modified organisms could be disastrous. Over time the impacts could effect
primary soil processes such as nutrient cycling and uptake and control of
pathogens by microorganisms.
	Finally, a recent study by Obrycki, Losey (of Monarch fame), Taylor and
Jess found little justification for the full time presence of transgenic
Bt to combat the primary target, European Corn Borer, which is a part time
pest. The mutations now appearing in transgenic cotton belie the biotech
industry’s contention that any resistance created by their products will
occur many years hence. EPA is now in the process of a mandated review of
transgenic Bt crops and concerned citizens should send their comments.
Clearly, the regulation of transgenic crops must be changed to count the
overall ECOLOGICAL effects of introduced genetic pesticides with a
moratorium on their use until a more holistic appraisal is completed.

Steve Gilman
Ruckytucks Farm



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