SUMMARY: "Genetically engineered moths may give farmers a new way to control pests without spraying pesticides."

Genetically engineered moths may give farmers a new way to control pests without spraying pesticides.

Diamondback moths and their larvae cause up to $5 billion in damage to broccoli, cabbage and other cole crops each year, particularly in areas where they can survive over winter due to mild temperatures.

Scientists at Oxitec, a British biotech company, have inserted a gene into the moth that kills female larvae.

The idea is that genetically engineered males will breed with wild females to pass the gene onto the next generation, greatly reducing the population.

“Any females that develop out of that will not live to adulthood, they will not be able to reproduce,” said Anthony Shelton, an entomology professor at Cornell University who is studying the insects.

The moths also have a gene that causes them to glow red when held under certain lights, allowing for easy identification in the field.

“You can tell the pest from the genetically engineered diamondback moth,” said Hadyn Parry, Oxitec’s CEO.

Unlike chemical controls, the fluorescent moths will allow farmers to see where the product is working and actually predict the rate of decline based on the color of larvae, he said.

The company is working with Shelton to test how male moths behave in the field and how much they reduce pest populations.

“It has to be proven in practice,” Parry said.

The USDA recently recommended approving field trials of the moth at a Cornell University experiment station in New York.

The proposal is currently up for public comment before it’s finalized.

Before the biotech moth could be commercialized, it would have to be deregulated by USDA, similar to the way genetically engineered crops are reviewed.

Parry said he expects regulatory clearances and data collection will require at least three more years before his company can sell the insects.

“There isn’t really a precedent here,” he said.

Because cole crops aren’t grown in “monoculture” systems of massive plantings, like corn and soybeans, it’s unlikely the biotech moths would become pervasive, said Shelton.

For that reason, farmers would still have an incentive to pay for the insects, rather than benefit from the gene spreading from other areas.

Cole crop farmers could use the biotech insects to prevent a build-up of diamondback moths, which don’t generally migrate great distances unless they have to, said Parry.

“Once they have food and sex, to put it crudely, they stay where they are,” he said.

Oxitec is developing similar technology for several other crop pests, including the medfly, mexfly, olive fly and pink bollworm, in which male insects produce offspring that can’t survive.

Such insects can improve the performance of biotech traits that protect genetically engineered plants from pests.

Over time, insects develop resistance to the biotech traits.

By reducing the overall population of the pest, Oxitec’s biotech insects can hinder increased resistance, said Shelton. “It prevents that creation of more resistant progeny.”

In the past, scientists have used radiation to achieve similar sterility genes in pests, but those insects often weren’t as vigorous as wild ones.

With Oxitec’s technology, the genetically engineered males are as fit as their wild counterparts, said Parry. “This is very much precision. You know just what you’re doing.”

Critics of genetically modified organisms, however, are nervous about the new technology — particularly in regard to the USDA’s method of regulating biotech insects.

In 2011, the USDA’s own Office of Inspector General recommended strengthening its regulations for transgenic animals and insects, but the agency has shown no sign of doing so in the past three years, said Jaydee Hanson, policy analyst for the Center For Food Safety nonprofit group.

“Our concern is that USDA is venturing into an area of genetically engineered animals that it doesn’t have the expertise for,” he said.

The Center for Food Safety would prefer that the agency set up a uniform system for field trials and other activities involving transgenic insects, instead of working on a case-by-case basis, as with the diamondback moth, Hanson said.

As for the biotech moth, Hanson said it’s unclear how the insect might affect birds or other predators that eat it. While the field trial would occur in an area where the pest does not survive winters, some individuals may travel to other areas on trucks, he said.

“We should not be willy nilly doing releases of genetically modified animals without good regulations in place,” Hanson said.

SOURCE: Capital Press
AUTHOR: Mateusz Perkowski
DATE: 22.09.2014