Here are two things that cause a lot of controversy: Genetically modifying organisms and spraying pesticides. So of course some scientists asked, "What if we could do both at the same time?" The scientists in question are Keri San Miguel and Jeffrey G. Scott of Cornell University, who in June published a paper in Pest Management Science, describing how they successfully protected potato plants from the Colorado potato beetle by spraying them with a substance that interferes with the beetle's DNA, through a process called RNA interference, or RNAi.

RNAi takes advantage of RNA's essential role in mediating the expression of genes. In 1997, Andrew Fire and Craig Mello discovered that they could use tailored RNA strands to "silence" specific gene expressions, cutting off the process of life at its very roots. This brought them the Nobel Prize for Medicine in 2006, but by this time RNAi was already being used to modify plants, and eventually new genes were inserted into crops that would induce RNAi in the insects that eat them.

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The idea that plants could be modified to themselves modify other organisms is perhaps one of the unsettling concepts driving the growing backlash against GM crops, particularly in Europe (Scotland recently announced a GM ban.) RNAi sprays theoretically avoid existing GM regulations by skipping the crops and modifying the pests directly. Unsurprisingly, agribusiness giant Monsanto is already on board, hoping to have a product on the market by 2020. They're even trying to preempt opposition, sending a letter to regulators saying that, "humans have been eating RNA as long as we have been eating." But according to Technology Review it might not be that easy,

Not everyone is convinced, though, that applying RNA will be commercially feasible or any less controversial than genetic modification. “The public is not accepting GMOs, and this could be more alarming. People are going to say you are taking the RNA and spraying this in the open,” says Kassim Al-Khatib, a plant physiologist at the University of California, Davis. “The acceptance of biotech has to be there before you can deliver another approach. This isn’t a technology for tomorrow. It’s for the day after tomorrow.”

There's an additional queasy footnote: lots of organisms have gene sequences in common. The Cornell study itself notes that their potato bug spray would also kill the common house fly. What about their effect on humans? "That can be tested," Professor of Biology Saskia Hogenhout told New Scientist. "With all technologies, there’s always a risk... My opinion is the RNAi approach would be a better option than pesticides that are less specific." Such less-specific pesticides might include neonicotinoids, a leading killer of honeybees. Let's just hope we don't kill ourselves in the process.