By Marcia Ishii-Eiteman, cross-posted from PAN's website
The ecological, economic and agro- nomic disaster accompanying
herbicide-tolerant transgenic crops is by now well known: over 10
million acres of superweeds resistant to Monsanto’s weedkiller, Roundup; farm machinery breaking on Roundup-resistant pigweed thick as a baseball bat; Monsanto paying farmers to spray their fields with competitors’ herbicides; a new gener- ation of transgenic crops in the pipeline engineered to withstand older even more dangerous chemicals like 2,4-D.
Last week brought more bad news for Monsanto: the same phenomenon is
also occurring in insect pest populations that are developing resistance
to transgenic “Bt corn” in the Midwest. The Wall Street Journal
recently reported Iowa State University’s findings that the corn
rootworm is for the first time proving resistant to the insecticidal
toxin, Bt, in transgenic corn in Iowa. Four days later, Business Week
reported Bt corn plants in northwestern Illinois toppling over after
root damage caused by the same insect, apparently as impervious as its
Iowa cousins to the engineered Bt toxin. Likewise, insect resistance to
transgenic Bt crops in India (where dramatic crop failures resulted) and South Africa has been reported.
This is a classic case of the pesticide treadmill.
A pesticide application (whether sprayed the old-fashioned way or
applied through a crop plant engineered to contain that toxin in its
cells) typically kills many–but not all–of the targeted pests. Of those
that survive, some will pass on their genetic traits of pesticide
resistance to their offspring, gradually leading to a more and more
resistant population. Farmers get trapped on this treadmill as they are
forced to use more — and increasingly toxic — chemicals to control pest
populations that continue to develop resistance to each new type or
class of pesticides.
The shakiness of the chemical and GE-based industrial model doesn’t
stop with the evolution and emergence of superbugs. By eliminating one
pest (even if only temporarily), Bt crops increase their vulnerability
to other “secondary” pests that can quickly fill the ecological niche
and become serious pests in their own right. In the Makathini Flats of
South Africa, farmers have resorted to using large amounts of acutely
toxic organophosphates to control secondary pests that have emerged
(aphids, jassids, thrips and true bugs). In China, Bt cotton has not
only provided a safe haven but also become a source of mirid bugs that
then infest other crops such as grapes, peaches, pears and apples.
Organic farmers have used the naturally occurring form of Bt (a soil
bacterium) successfully for over 40 years as part of organic pest
management. Because it breaks down in sunlight, selection pressure is
low and insects have been slow to evolve resistance to it. Until now.
The impending loss of Bt as an effective tool of the organic farmer adds
insult to an already injurious system.
Industry rules (again)
The worst part about the latest GE fiasco is that it all could have
been prevented. As early as 1993, scientists were warning about the
inevitable rise of superweeds and superbugs. Ten years later, EPA sought
scientific advice on how to manage the likely emergence of insect
resistance to Bt crops. The Center for Food Safety’s Bill Freese
describes how a majority of the scientists consulted by EPA at the time
urged the EPA to require farmers to set aside a refuge of non-GE corn,
comprising 50% of the total crop acreage, in order to slow the
development of Bt resistance. But that would have halved Monsanto’s seed
sales! So EPA quietly sided
instead with the only three dissenting voices in the group, going along
with Monsanto’s recommendation for a much smaller 20% refuge.
From industry's perspective, the emergence of pesticide resistance,
secondary pests and failure of first generation GE crops is actually
good business; farmers will have to keep coming back for stronger
poisons and more expensive products. There's an industry term for this: planned obsolescence.
Fortunately, as Doug Gurian-Sherman
of the Union of Concerned Scientists reminds us, plenty of non-GE
solutions to corn rootworm exist. These solutions lie in agroecological
practices such as long crop rotations, biological control and good soil
It’s not too late for us to get off the pesticide/GE treadmill; but we
will have to give our public agencies a big shove to get them moving in
the right direction.