BIO disputes latest study on butterflies, 'Bt' corn

22 August 2000 20:15  [Source: ICIS news]

WASHINGTON (CNI)--Biotechnology industry officials Tuesday rejected the conclusions of two Iowa State University entomologists who say they have found more evidence that pollen from bioengineered corn could be deadly for Monarch butterflies.

The study comes at a time when the US Environmental Protection Agency (EPA) has launched its own review of the safety of corn and cotton plants modified to contain bacillus thuringiensis (Bt), a pest-fighting gene.

Iowa State researchers John Obrycki and Laura Hansen said their research showed Monarch butterfly caterpillars were seven times more likely to die when they ate milkweed plants carrying pollen from Bt corn, compared to conventional corn.

But Val Giddings, vice president for food and agriculture at the Biotechnology Industry Organization (BIO), said that finding is disputed by more than 20 independent scientific studies that concluded Bt corn does not pose a significant risk to the Monarch butterfly.

"This report considers only one small area of this complex topic and the conclusions put forth by the authors stand in stark contrast to those of the broader scientific community's research," said Giddings.

The Iowa study analysed the impact on larvae from two types of Bt corn developed by Novartis AG and sold under the brand names NatureGard and Attribute.

Novartis defended the safety of its Bt corn, saying the new study did not duplicate real-world conditions.

"Research conducted outdoors doesn't indicate what happens in a field environment," said a company spokesman. "The weight of evidence of published and preliminary research indicates that milkweed within one metre of Bt corn fields are highly unlikely to be dusted with toxic levels of Bt pollen."

A dozen university researchers are currently studying Bt corn fields to determine whether the pollen harms migrating Monarch butterflies. A year ago, Cornell University scientists created a stir when they reported Monarch larvae died when fed relatively large amounts of Bt corn pollen in the laboratory.

In June, University of Illinois scientists said they found no ill effects for black swallowtail butterfly caterpillars who ate pollen from a variety of Bt corn developed by Pioneer Hi-Bred International, a unit of DuPont.

EPA deputy administrator Steve Johnson said the agency would review the new Iowa study, along with other scientific research as part of a broad risk assessment of Bt corn and cotton. EPA plans to publish its views by mid-September.

"Based on what we've seen so far, we're not seeing any impact on any non-target organism, particularly the Monarch butterfly," Johnson said.

Giddings noted that just last week, EPA extended the registrations of Bt corn and cotton through the 2001 growing season. And in April, EPA dismissed a Greenpeace lawsuit challenging the Bt plant registrations, saying that "...available scientific data and information indicates that the cultivation of Bt crops has a positive ecological effect when compared to the most likely alternatives."

"To imply that Bt corn has a negative effect on Monarch butterflies flies in the face of that fact that last year, more than 28m acres were planted with Bt corn, an increase of approximately 40% over the previous year," said Giddings.

"In the same time period, the Monarch butterfly population flourished and increased by about 30%, according to Monarch Watch," the BIO official added.

By: Glenn Hess
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