FOODWEB: A Public Voice on Food, Farming, and the Environment
Union of Concerned Scientists
September 2000
Part 1 of 2
CONTENTS:
FIELD STUDY COMFIRMS LAB RESEARCH ON MONARCH BUTTERFLY
Bt-corn Pollen from Iowa Field Plots Kills Monarch Caterpillars
GOOD NEWS FOR BLACK SWALLOWTAIL CATERPILLAR IN A COAL MINE
The EPA and USDA Act on Last Year's Warning Signal
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These documents are not in this e-mail version of the Foodweb pt 1. They are posted at www.ucsusa.org/agriculture
ACTION ALERT
Clarify Regulation of Pesticidal Crops
FAO REPORT
Enough Food in the Future - Without Genetically Engineered Crops
FDA APPROACH TO ANTIBIOTIC REGULATION
The Framework Document
DOCUMENTS AVAILABLE AT WEBSITE, VIA POSTAL MAIL OR EMAIL ATTACHMENT
*Foods on the Market: Genetically engineered crops allowed in the US food supply
*Letter to Centers for Disease Control to Strengthen Federal Action Plan on Antibiotic Resistance
*Letter to EPA to Limit Vital Antibiotics in Factory Farm Effluent
*Biotechnology and Health-Enhanced Food
*These documents are not in this e-mail version of the Foodweb. They are posted at www.ucsusa.org/agriculture or available by postal mail, fax, or e-mail from Pam Abhyankar, UCS, 1707 H Street, NW, Suite 600, Washington DC 20006-3919: phone 202-223-6133; fax 202-223-6162; e- mail This email address is being protected from spambots. You need JavaScript enabled to view it..
All documents listed in the table of contents are available at www.ucsusa.org/agriculture.
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FIELD STUDY CONFIRMS LAB RESEARCH ON MONARCH BUTTERFLY
Bt-corn pollen from Iowa field plots kills monarch caterpillars
Iowa State University scientists reported August 19 in the journal Oecologia that one kind of Bt-corn pollen naturally deposited on milkweeds in and near corn fields kills monarch butterfly caterpillars. This research confirms a laboratory study published in Nature last summer which showed that Bt-corn pollen is lethal to monarchs (see www.ucsusa.org/agriculture/monarch.html).
The Iowa scientists conducted three kinds of studies using two types of Bt corn marketed by Novartis Seeds: KnockOut, which contains a Bt gene named Event 176 and YieldGard with a Bt gene called Bt 11. KnockOut pollen typically contains more Bt toxin than YieldGard pollen. The three experiments were:
First, to learn how much pollen caterpillars might be exposed to under field conditions, they counted pollen that fell on milkweeds, the favorite food for monarch caterpillars, within and near KnockOut, YieldGard, and nonBt-corn plots.
Second, to assess mortality of caterpillars exposed to natural, field-deposited pollen, they placed caterpillars on pieces of leaves taken from within and at the edges of plots of KnockOut and nonBt-corn and counted the number of dead larvae remaining after two days' feeding.
Finally, to determine the impacts of a range of Bt- pollen densities likely to be encountered in the field, the scientists conducted a laboratory study exposing larvae on pieces of leaves to three levels of KnockOut, YieldGard, and nonBt pollen. They counted dead caterpillars and monitored the survivors until they emerged into butterflies, looking for side effects like slowed development time and smaller butterfly bodies.
In the first study, the scientists found that milkweed plants placed in and near both KnockOut and YieldGard corn fields received amounts of Bt pollen that could kill monarch caterpillars. The second experiment revealed that significantly more caterpillars died after feeding for two days on pieces of leaves taken from KnockOut corn fields compared with leaves taken from nonBt fields and leaves with no pollen. In the laboratory study of different pollen densities, caterpillar mortality was significantly greater on the two highest densities of both KnockOut and YieldGard pollen than on nonBt pollen. At the lowest density, larvae survived equally well on Bt and nonBt pollen. Caterpillars that survived exposure to Bt and nonBt pollen appeared to develop similarly into adult butterflies.
The authors suggest that the effects of Bt-corn pollen on monarchs will be greatest where most of the pollen falls-inside Bt-corn fields or within three meters of the edges. Milkweeds are found both within and along the margins of corn fields.
This report follows on the heels of a University of Illinois study published in the Proceedings of the National Academy of Sciences this summer which suggested that another kind of Bt-corn pollen, Monsanto's Bt corn (Mon 810 gene), was not lethal to swallowtail butterflies under field conditions in Illinois
What does the Iowa study mean?
This field study does not resolve whether or not Bt corn will be a serious threat to monarch butterflies in corn- growing areas. Much more research needs to be done. But it does mean that the Environmental Protection Agency (EPA) was remiss in approving Bt corn for commercial use five years ago before fully assessing environmental risks.
EPA is presently engaged in a comprehensive review of all Bt corn and cotton with the aim of deciding within the next year whether and under what conditions the Bt crop registrations should be renewed. Current registrations for Bt corn and cotton expire in 2001.
UCS is urging EPA not to reregister any Bt corn until it has a program in place to thoroughly assess ecological risks of Bt crops, including the risk to monarchs and other beneficial insects. In addition, EPA should require farmers to plant buffers of nonBt-corn around Bt fields in the coming year to reduce the amount of toxic pollen blowing beyond transgenic fields.
Sources:
Laura C. Hansen Jesse, John J. Obrycki. 2000. Field deposition of Bt transgenic corn pollen: lethal effects on the monarch butterfly. Oecologia, DOI 10.1007/s004420000502, published online: 19 August 2000.
C.L. Wraight, A.R. Zangerl, M.J. Carroll, and M.R. Berenbaum. 2000. Absence of toxicity of Bt pollen to black swallowtails under field conditions. Proceedings National Academy of Sciences USA, published at PNAS Online June 2000.
Posted August 21, 2000
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GOOD NEWS FOR THE BLACK SWALLOWTAIL
A new study suggests that pollen from one type of Bt corn is apparently not toxic to black swallowtail butterflies, which are among the largest and most beautiful butterflies found in the United States. The caterpillars of the black swallowtail encounter corn pollen as they munch on plants at the edges of cornfields. The University of Illinois study, published recently in the Proceedings of the National Academy of Sciences, adds to the small body of research on the effects of engineered Bt corn on beneficial insects. Last summer, a Cornell University study revealed that another kind of Bt-corn pollen killed monarch butterfly caterpillars under lab conditions (see www.ucsusa.org/agriculture/monarch.html).
The Illinois researchers set out to determine if one kind of Bt corn, named Monsanto 810, would kill swallowtail caterpillars. They found no difference in caterpillar survival at different distances from a cornfield producing Bt pollen. If the pollen were toxic, fewer caterpillars would have survived near the cornfield where the concentration of pollen on leaves would be higher, and more would have survived farther from the field where pollen concentrations would be lower.
Also, in a companion laboratory study in which caterpillars ate leaves containing various concentrations of Monsanto 810 Bt pollen, the scientists found no differences in survival compared with caterpillars that ate leaves dusted with nonBt pollen.
A small part of the Illinois lab study tested one dose of pollen from another type of Bt corn named Event 176, marketed by Novartis Seeds under the trade name KnockOut. This pollen, which contained 40 times more Bt toxin than Monsanto 810, was toxic to the black swallowtail caterpillars. Further studies would be needed to determine if Bt-corn varieties containing Event 176 would be harmful to swallowtails under field conditions. Last summer's Cornell study, showing toxicity to monarchs, was conducted with yet a third type of Bt corn, Bt 11, sold as YieldGard by Novartis Seeds.
The Illinois study is important -- and is good news -- because it shows that one kind of Bt corn may not be harmful to one kind of butterfly. It is another piece in the puzzle of potential effects of engineered Bt corn on beneficial insects.
The Environmental Protection Agency should have required studies like this, and many more like them, many years ago -- well before it allowed Bt corn to be grown on millions of acres in the US.
C.L. Wraight, A.R. Zangerl, M.J. Carroll, and M.R. Berenbaum. 2000. Absence of toxicity of Bt pollen to black swallowtails under field conditions. Proceedings National Academy of Sciences USA, published at PNAS Online June 2000.
Posted August 21, 2000
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CATERPILLAR IN A COAL MINE
The EPA and USDA Act on Last Year's Warning Signal
The recognition last summer that Bt crops might harm monarch butterflies was a wake-up call. Americans realized, many for the first time, that genetically engineered crops could be a threat to nature, if not to people themselves. In the year since, the federal government has refused to pull Bt corn off the market until the monarch threat is resolved and has allowed about 20 million acres to be planted this season. Belatedly, and under intense pressure from the public, it is sponsoring research to get to the bottom of the monarch issue.
New Studies Under Way
When the Bt-corn threat to the monarch butterfly hit the pages of the New York Times last spring, it set off a blizzard of publicity about the environmental risks of Bt crops and other genetically engineered organisms released into the environment. The news story reported that Bt-corn pollen was toxic to monarch caterpillars, according to a laboratory study. The story prompted immediate concern for monarchs in the field because the annual migration of the butterflies takes them right through the US corn belt, where caterpillars would encounter the pollen on the leaves of their favorite food, the milkweed, which grows in and around corn fields.
Early comments from industry and government agencies suggested that the pollen risk had already been evaluated and could be dismissed. But it soon became clear that the impact of Bt pollen on monarchs had yet to be assessed and that the question was one the scientific community could answer, given sufficient resources. Subsidiary questions indicate that finding an answer will involve many disciplines. Does milkweed grow within or only on the edges of cornfields? Are all Bt- corn varieties equally toxic? How well does the release of pollen correlate with the timing and route of monarch migration? The good news is that an interdisciplinary team of scientists is taking on the challenge. In March, the US Department of Agriculture (USDA) hosted a scientific workshop to define research priorities in assessing the risk to monarch butterflies. In addition, the department made available $100,000 in research funds, which will allow scientists to get into the field this summer. By the fall, we should have a much better idea of how substantial a threat Bt-corn pollen poses to the monarch butterfly.
Reregistration of Bt Crops
Bt-crop registrations lapse at this year, providing the Environmental Protection Agency (EPA) with an opportunity to protect the monarch and other insects that may be at risk. The EPA's original registrations of Bt corn and cotton for commercial sale were for limited periods. As part of its reevaluation, the agency is looking at information about how the crops can be managed to delay insects' development of resistance to the Bt pesticide, as well as other environmental impacts. Then, this fall, the EPA will decide whether the crops should be pulled from the market, given permanent registrations, or granted another round of temporary registrations. UCS will urge the EPA to hold off renewing any Bt-crop registrations. We will stress the need for a strong EPA program to evaluate the problems that Bt crops may cause in the environment, including threats to insects such as the monarch. And we will press the EPA to require resistance management plans robust enough to significantly delay the evolution of resistance to Bt in insect pests, thereby preserving the utility of this widely used natural pesticide.
The EPA has promised a transparent reregistration process and opportunities for public comment. Check the UCS web-site for opportunities to plug in to this process.
EPA Regulation Still on Hold
To fulfill its mandate to protect the environment, the EPA needs to take a strong stance on pesticidal crops like Bt corn. But it has been slow to do so. This reluctance may stem in part from the EPA's failure to formally establish its authority to regulate pesticidal crops. To do so it must pass a rule that indicates why these crops come under its jurisdiction. The EPA first proposed such a rule in 1994, but six years later it remains in limbo. The rule would clarify the agency's responsibility and its approach. For example, it defines which types of genetically engineered crops are to be regulated as pesticides and are thus subject to the stringent requirements of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and which are not. Industry and much of the environmental community, including UCS, support this rule. However, objections from several professional societies have kept the EPA from moving ahead. A recent report from the National Academy of Sciences, which evaluated the proposed regulation, not only supported it but urged that it be strengthened. That kind of support from the scientific community would seem like enough to kickstart the final phase of the rulemaking process, but this late in an administration inertia is difficult to overcome.
In early May, the White House, responding to criticism of the federal government's oversight of engineered crops, announced a six-month examination of environmental regulation of agricultural biotechnology. Ironically, while administration wide review of biotechnology regulation is long overdue and largely to be welcomed, there is a good possibility that it will delay action on the plant-pesticide rule. UCS is redoubling its efforts to persuade the EPA to make completion of the rule a major priority for the last months of the Clinton administration. See the action alert to learn how you can help.
This article first appeared in the UCS magazine Nucleus Summer 2000.