Cabbage-chomping moths genetically modified to be real lady-killers may soon take flight in upstate New York. On July 6, the U.S. Department of Agriculture OK’d a small open-air trial of GM diamondback moths (Plutella xylostella), which the agency says do not pose a threat to human or environmental health.
These male moths carry a gene that kills female offspring before they mature. Having fewer females available for mating cuts overall moth numbers, so releasing modified male moths in crop fields would theoretically nip an outbreak and reduce insecticide use.
Originally from Europe, diamondback moths have quite the rap sheet: They’re invasive, insecticide-resistant crop pests. The caterpillar form munches through cauliflower, cabbage, broccoli and other Brassica plant species across the Americas, Southeast Asia, Australia and New Zealand.
After completing successful lab and cage trials, Cornell University entomologist Tony Shelton and colleagues now plan to loose the moths on 10 acres of Brassica fields at the New York State Agricultural Experiment Station in Geneva. The team has clearance to release 10,000 moths at a time, and up to 30,000 weekly.
This GM strain comes from Oxitec, the same firm behind controversial GM mosquitoes proposed for release in Florida (SN Online: 8/5/16). Several agricultural and environmental groups oppose the moth trial, too. While these will be the first GM moths released with a so-called female lethality gene, this won’t be the first genetically modified moth released in the United States. In 2009, researchers in Arizona tested transgenic pink bollworm moths, which threaten cotton fields.
The trial’s exact timeline remains up in the air. The scientists need approval from the New York State Department of Environmental Conservation before going forward.