This story has been updated.
The issue comes at a time when debate over genetically modified organisms is at an all-time high. While scientific studies have frequently found that GMOs are safe to eat and even good for the environment, public opinion on the issue has varied widely, with many groups calling for more stringent regulations on GMO labeling. This past Thursday, the issue came to national attention again when the FDA approved the first genetically altered animal in the U.S. — a fast-growing salmon whose approval food safety and environmental groups have opposed for years.
Now the new moth, which is being tested at Cornell University, has ignited debate between proponents, who argue that its existence could provide clear benefits for the environment, and skeptics, who are concerned the benefits might not outweigh the consequences.
The diamondback moth
UK-based biotechnology company Oxitec is in the midst of field-testing a genetically engineered (GE) version of an insect called the diamondback moth through a Cornell University project in New York state. The diamondback moth is considered a global pest to agriculture, and is a particular threat to plants in the genus Brassica, which includes cabbages, broccoli and cauliflower. Oxitec is hoping to use its GE version of the moth to combat natural pest populations without the need for insecticides.
“This insect is a particularly bad pest because it has a very short generation time, about two weeks,” said Anthony Shelton, a professor of entomology at Cornell University, who’s leading the field trials. “The female will lay maybe 150 eggs, so you can start off with a relatively small population and it will just explode.”
Each year, the moth causes an estimated $4 billion to $5 billion in damages, according to Shelton, and is frequently controlled with broad-spectrum pesticides, which have been associated with a host of negative environmental impacts. In particular, the use of pesticides in the U.S. has been hotly debated in recent years because of their potential to harm important pollinators, such as honeybees.
But over the past few years, Oxitec has been working on a potential solution. The company has developed a genetically engineered version of the diamondback moth that, if released, could shrink wild populations through a process called “self-limiting.”
The genetically engineered moths include a special gene that causes female young to die before reaching adulthood, meaning eventually the females die out and the population can no longer reproduce. So when the GE moths are released into the field, “they mate with the pest counterparts,” said Neil Morrison, Oxitec’s lead diamondback moth research scientist. “And they control the population that way.”
The GE moth has already undergone laboratory testing in the UK and has begun “caged” field trials in New York this summer under Shelton’s supervision, meaning the moths were released in an outdoor, but contained, area. The company plans to continue more caged trials next spring, and hopes to segue into open field trials later in the summer.
However, these plans have met with opposition from several organizations, including GeneWatch UK, the Center for Food Safety, Friends of the Earth, Food & Water Watch and the Northeast Organic Farming Association of New York.
“We’re worried about what the effects of these trials outside of the cages [will be],” said Liana Hoodes, policy adviser at the Northeast Farming Association of New York (NOFA-NY), citing concerns that the GE moths could spread beyond their trial sites and begin appearing on private growers’ farms.
Hoodes said NOFA-NY would like to see an impact analysis on the possible effects of GE moths on non-target species — that is, organisms besides diamondback moths — in case they happen to be eaten by birds or other animals or even accidentally consumed by humans.
In fact, Shelton had to apply for a permit from the U.S. Department of Agriculture before proceeding with the trials — a process that required an environmental assessment and a public comment period before the permit was finally approved. The environmental assessment concluded that any potential impacts of the GE moths on the physical, biological or human environment were “unlikely.”
Still, Hoodes expressed the desire for a more comprehensive impact analysis. And in a public release, the Center for Food Safety and other groups expressed concern about the possibility that GE moths could spread and contaminate crops with dead female larvae elsewhere in the state.
But Chris Creese, Oxitec’s communications manager, cautioned that the insects are designed with a disadvantage: Since their populations are designed to eventually die out, “their genes don’t spread,” she said. And Shelton noted that diamondback moths tend not to travel far from their release sites.
But even if the trial moths were to travel outside their study sites and wind up in other areas, Morrison insisted that “there’s no mechanisms of harm identified” when it comes to the insect’s impact on humans or the environment, which is in keeping with the USDA’s environmental assessment.
“The insects are non-toxic, non-allergenic,” Morrison said. “If a predator were to eat one of our moths, it would be the same as eating a pest moth. We’ve done feeding studies with predators and parasitoids on our supplementing insects, and the effect is the same.”
It’s not just the environmental impact that’s worrisome, though, according to Hoodes. She said there’s a possibility that the presence of the GE moths could affect the organic food market in New York, causing consumers to be less likely to buy products that may have come into contact with the genetically modified insects.
“The marketplace expects the product to be free of genetically modified organisms,” she said.
There are other concerns as well. If the open field trials proceed next year, it’s possible that Shelton’s team may choose to import extra non-GE moths in order to supplement the experiments — an idea that some groups find distasteful.
“The whole purpose of this is to test for [the effects on] a plant pest, but in case there’s not enough of the plant pest they want permission to import more so they can test their device,” said Jaydee Hanson, senior policy analyst at the Center for Food Safety. “That’s a little odd.”
However, in a follow-up email to The Post, Shelton noted, “Any insects we release are a drop in the bucket compared to the local endemic population… This experiment will not exacerbate any existing [diamondback moth] populations, but rather its goal is to learn how to reduce existing pest populations of [diamondback moths] in a safer manner than existing strategies.”
A history of genetic engineering
The diamondback moth is just the most recent in a string of Oxitec projects using the self-limiting technique, which Oxitec has been developing since the 1990s. The most famous of Oxitec’s genetically engineered creepy crawlers is likely the yellow fever mosquito, which is known for transmitting a number of diseases including dengue fever and chikungunya.
Oxitec’s genetically modified version of the mosquito, which also self-limits and is intended to reduce the need for pesticides, has been tested in the Cayman Islands, Malaysia, Panama and Brazil, and Morrison said the mosquito has received commercial approval in Brazil. However, there has been significant pushback against proposals to field test the mosquito in the Florida Keys, where many individuals expressed concern about the unknown consequences of releasing the GE bug into the wild.
Oxitec maintains that its GE organisms have the potential to provide an important service to the environment by cutting down on pest populations without the need for large-scale application of harmful pesticides. Morrison pointed to a 2008 USDA environmental impact statement on GE fruit flies and pink bollworms, two other pest species, which concluded that the genetically modified bugs were a “preferred alternative” to conventional pest control.
“I can’t emphasize enough the need for newer technologies to control old pest problems,” Shelton said in his follow-up e-mail. “The evidence is clear that the program of using sterile insects for control of screwworm has saved billions of dollars in control costs, improved animal welfare and replaced the use of traditional insecticides.”
A need for dialogue
Both sides of the debate have emphasized a need for open dialogue as a means of understanding one another’s viewpoints on the issue.
“Our policy is not ‘thou shalt never do GE,’” said Hanson, of the Center for Food Safety. “Our policy is you should do it right, do it well, address food safety issues, address environmental issues. You’re releasing moths that are eaten by other creatures, birds and bats and the like — I would like to say that a really fulsome review was done.”
So far, all of the involved groups have acknowledged that a meeting for discussion has not yet been successfully arranged, although representatives of Oxitec, Shelton and Hoodes, of NOFA-NY, expressed the desire to do so.
“Our interest in having open, honest, transparent dialogue about anything is sincere, and we invite anyone to get in touch with us at any time,” said Creese, of Oxitec. “I think that collaborative feedback is what’s going to help us move forward as a global society in terms of tackling these issues.”
Correction: An earlier version of this article stated that Oxitec’s genetically modified yellow fever mosquito has been tested in countries including the U.S., France, Brazil, Thailand, India and Malaysia. The mosquito trials have only taken place in the Cayman Islands, Malaysia, Panama and Brazil.