Modified crops 'silence' insect pests for good

New Scientist: "GENETICALLY modified plants that can kill just about any insect pest without harming beneficial insects or the environment may soon pop up in farmers' fields. The plants exploit a mechanism called RNA interference (RNAi), which organisms naturally use to switch genes off. To to this, the organism produces a double-stranded piece of RNA (dsRNA) whose sequence matches part of the gene to be silenced. Adding just a few of these to a cell shuts down the target gene. "