The first-ever release of insects with genetically-engineered "self-destruct" switches onto American farms is being heralded as an insecticide-free solution to the problem of agricultural pests. The effort, which is intended to curb the population of invasive diamondback moths, will be conducted at Cornell University's Agricultural Experiment Station in Geneva, 160 miles west of Albany, reports Phys.org.
"It costs $4-5 billion a year globally to manage this pest," said Anthony Shelton, a Cornell University researcher who's been studying the species for 40 years. "If you can manage it without using insecticides that can affect pollinators and other non-target organisms, that's a real advantage."
The lab-created moths are engineered with a gene that causes females to die before they can reach reproductive maturity. The plan is to release males with this gene into the natural population so they will breed with wild females, thus altering the native gene pool. This should cause a population collapse once the new gene takes hold.
Diamondback moths are known as one of the most resilient of invasive pests. They have evolved to shrug off virtually every major pesticide in the agricultural arsenal, so this is a last-resort attempt to control the foreign bugs. Cruciferous crops like cabbage and broccoli are most under threat.
The unnatural insects are the creation of the biotech firm Oxitec, which also had success curbing mosquito populations in Central and South America by deploying similarly modified insects into those environments.
A go-ahead has already been given for the project by the U.S. Food and Drug Administration, but not without garnering fervent criticism from organic farming organizations and groups opposed to the use of genetically modified organisms. The main concern has to do with ecological consequences that can't be predicted should the engineered genes make it into the wild. Very little research has been conducted on how the protein made by the moth's synthetic gene might affect wildlife that eats the insects. Bits of larvae that remain on produce are also likely to be consumed by humans.
There's also a real question about how the release of these bugs might endanger the organic certification of nearby farms.
Ultimately, though, it comes down to a risk assessment between the very real environmental dangers of pesticide use and the possible dangers of genetically-modified insects escaping into the wild. Since these engineered moths are built with a self-destruct mechanism, it's a problem that ought to solve itself, but there are always consequences that can't be anticipated.
"[Diamondback moths are] getting harder and harder to control, because with climate change, we're having more generations produced every year," explained Shelton. "We know that to really have more sustainable control, you need to have many different tools in the toolbox."