New technology can be heralded a success or branded hazardous very quickly – and once that label is attached, it’s hard to change.

Bacillus thuringiensis, or Bt, corn pollen received the label of being a risk to monarch butterflies. It has taken the work of 29 researchers and six papers to disprove it.

“The question, `Is there an immediate and significant risk to monarchs?’ has been answered – no,” said Richard Hellmich, U.S. Department of Agriculture, Corn Insects and Plant Genetics Research Unit and collaborator with the ISU Department of Entomology.

The question arose from research done by John Losey at Cornell University in 1999, showing pollen from Bt corn could poison monarch butterfly larvae when ingested.

A committee composed of stakeholders from groups including academic and government scientists, Environmental Protection Agency, growers, industry and environmental groups, decided what the goals are and who would be doing research, Hellmich said.

The corn is altered to produce a protein called Bt, which in turn attaches to the stomach of the corn borer moth and kills it, he said.

Organic farmers have used this protein for several decades to control the European corn borer, a moth-like insect that eats away at the corn plants, Hellmich said.

The goals of the research, conducted in five states and Ontario, Canada, were designed to determine if the pollen from Bt corn had a significant effect on non-target insects, such as monarch butterflies, and to look at insect resistance management, Hellmich said.

“Our goal was to assess the risk of Bt corn pollen to a non-target – monarch larvae – in both field and lab studies,” said Heather Mattila, research technician in the Department of Environmental Biology at University of Guelph in Ontario, Canada. “As well, we wanted to evaluate the other factors that would affect this risk, such as the presence of milkweed in and around corn fields versus other habitats, and the overlap of sensitive larval stages with corn pollen shed.”

There were a couple of surprises when the research was conducted, Hellmich said. Bits of broken tassel were found in the samples when the pollen was collected, he said.

Researchers also were surprised at the stage at which butterflies entered the cornfields, said Galen Dively, professor of entomology and extension specialist at the University of Maryland.

“We were surprised to find that butterflies go into cornfields after [the cornfields] canopy,” Dively said.

The issue of non-pollen material in the pollen samples, mainly anther parts, caused a higher level of toxicity. However, anther parts do not fall far from the field, Hellmich said. This problem was also noted in previous studies, but at a much higher occurrence rate, he said.

The beginning pollen samples were lethal to the butterfly caterpillars, Hellmich said.

However, once the pollen was cleaned, it was not lethal, he said.

“This explains why Losey was killing insects with Bt 11 pollen,” Hellmich said. “When we sifted and got rid of the contaminates, there wasn’t any effect.”

Considering the toxicity of the pollen of different Bt corn hybrids and the frequency of the use of these hybrids, the risk Bt corn pollen poses to monarch larvae specifically is minimal, Mattila said.

“The question is evolving from `Does pollen spread outside of the field and affect nontargets?’ to `How do pollen and anthers affect nontargets within the field?'” said John Obrycki, ISU professor of entomology.

The results of the research show that the pollen from Bt corn does not cause an immediate and significant risk to monarch larvae.

However, researchers are in the process of answering other questions.

“We are looking at the effect of anthers on milkweeds in the fields,” Hellmich said.