It sounds like science fiction: A research program funded by the U.S. government plans to create virus-carrying insects that, released in vast numbers, could help crops fight threats such as pests, drought, or pollution. “Insect Allies,” as the $45 million, 4-year program is called, was launched in 2016 with little fanfare. But in a policy forum in this week’s issue of Science, five European researchers paint a far bleaker scenario. If successful, the technique could be used by malicious actors to help spread diseases to almost any crop species and devastate harvests, they say. The research may be a breach of the Biological Weapons Convention (BWC), the piece argues.