A cash-strapped Environmental Protection Agency is awaiting results of a $100,000 industry study on exposures of monarch caterpillars to Bt corn pollen in their natural habitat before deciding whether to take steps to place restrictions on future uses of the genetically engineered corn. An EPA official said the agency does not have funds to conduct the studies.

EPA officials are not convinced that monarch caterpillars in the corn belt are exposed to enough Bt corn pollen on milkweed leaves - their sole source of food - to cause butterfly deaths. Janet Andersen, director o the biopesticides division in EPA's Office of Pesticide Programs, said the agency is waiting for the outcome of an industry-funded study before deciding whether Bt corn poses a real threat to monarch butterflies.

"What we've heard from some of the researchers, and this is all speculative, is that there isn't a problem in the field," Andersen said in a recent interview.

Four months ago, Cornell University entomologist John Losey stunned the world with a letter to Nature reporting laboratory finding that half of the monarch caterpillars fed milkweed leaves dusted with Bt corn pollen died within four days. Bt corn is genetically engineered to express a toxin from the soil bacterium Bacillus thuringiensis, which kills the European corn borer. When EPA approved the first commercial plantings of Bt corn in 1995, the agency did not know that the pollen from Bt corn would be toxic to the caterpillars of monarch butterflies. In the 1999 growing season, an estimated 20 million acres of farmland, representing more than one-quarter of the nation's corn crop, were planted with Bt corn varieties.

"We didn't know [Bt corn plants] would be lethal to monarchs because they are not lethal to every butterfly and moth," Andersen said.

This summer, soon after Losey's research findings appeared in Nature May 20, Monsanto, Novartis, AgrEvo, Pioneer and Mycogen, the five companies that produce Bt corn, contracted with Richard Hellmich, a researcher at USDA's Agricultural Research Service at Iowa State University in Ames, to coordinate scientific studies and oversee the field tests geared at determining the actual exposure of monarch caterpillars to Bt corn pollen.

Preliminary results of the $100,000 study are expected to be discussed in early November, at a closed meeting which the Biotechnology Industry Organization is planning to hold in Chicago. Final results of the study will be released in a public forum mid-December in Atlanta.

EPA scientists plan to review the data generated by the study, but the agency is not conducting its own independent research. "We don't have any money in our budget to fund studies," Andersen said.

Hellmich said the Agricultural Biotechnology Stewardship Working Group, which includes representatives from agricultural biotechnology companies, a number of academic researchers and the Biotechnology Industry Organization, is still in the process of gathering data. "We're looking at larval behavior and what leaves they choose. There's a lot of interest in how far the pollen moves and in dose-response, if any are killed. We want to get the bottom line," he said in a September 29 interview.

A large portion of the research money is funding a survey across the corn belt from the east coast to Nebraska. Scientists marked milkweed plants around the sides of corn fields and staked them. They then returned to the sites throughout the time periods when pollen was flowing strong. The researchers clipped off the leaves, put them in plastic bags, and later counted the pollen grains on the leaf tissue. During the field studies, scientists also made observations about the behavior of monarch butterflies and larvae.

Questions the survey seeks to answer include: Do monarch butterflies avoid milkweed leaves with pollen when they lay their eggs? Do monarch larvae avoid leaves coated with pollen when they eat? Does the pollen which blows from corn fields to nearby milkweed plants just slide right off the leaves? How far does corn pollen drift from the fields?

"We don't want to take an action before we know there is a risk," Andersen said. If the scientists were to find a threat to monarch butterflies, however, there are a number of mitigation actions EPA would consider, she noted.

"if we found that we really believe significant impacts were happening to non-target butterflies in the field, we would have to do a risk-benefit [analysis]," she said. The agency would weight the risk to butterflies from the Bt pollen against the benefits derived from reduced use of synthetic pesticides.

EPA staffers believe that Bt corn, which is genetically engineered to express high levels of a toxin from the soil bacterium Bacillus thuringiensis, is beneficial for the environment because it reduces pesticides use. Bt corn kills the European corn borer, a pest that used to cause about $1.2 billion a year in crop damage in the United States. Fewer than 7% of farmers traditionally used pesticides to combat the pest, however, most simply opted to absorb the crop loss.

Andersen said EPA is carefully considering a petition submitted by the Environmental Defense Fund (EDF) in July which asks the agency and biotech seed producers to require buffer zones around Bt corn fields. The environmental group suggested that planting a non-Bt corn buffer zone 40-feet to 60-feet wide would dramatically reduce the flow of toxic pollen from Bt corn to butterfly habitats.

"Toxic pollen is a prime example of genetic engineering gone awry," Rebecca Goldberg, an EDF senior scientist said. "Bt corn was engineered to produce insect poisons, but these poisons do not discriminate between pests and treasured butterflies. Unfortunately, EPA has failed to consider the risks of toxic pollen from Bt corn to butterflies, including a number of rare and endangered species."

EPA officials met last month with Goldberg, Jane Rissler and Margaret Mellon, scientists with the Union of Concerned Scientists, and naturalist Gary Nabhan to discuss the environmentalists' grave concerns about the ecological effects of Bt corn technology.

"We got protestations of concern, but no plan for action from EPA, Jane Rissler said, following the meeting. "I think EPA made a mistake not to have caught and resolved the monarch problem."

"I left that meeting with considerable uncertainty," said Goldberg. "Although EPA was adamant in saying they were taking this issue seriously, they provided no concrete actions."

"Monsanto and Novartis have a tremendous amount of power to keep these crops going. Clearly, pulling the registrations on these Bt corn plants is the right thing to do," Rissler said, adding, "There are powerful forces promoting the technology, and it will take a lot of courage for EPA to do the right thing."

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