Aerial spraying with the insecticide naled and larvaecide Bti most likely contributed to the current pause in local spread of Zika virus in the Wynwood neighborhood of Miami, according to a report released today by the Centers for Disease Control and Prevention. No increases in short-term health effects were associated with the spraying, the authors said. “This is certainly a new tool for our toolkit and the strongest one we have for where we have local transmission,” said CDC Director Tom Frieden, M.D., noting that spraying by truck and naled alone were not as effective. Florida Surgeon General and Secretary Celeste Philip, M.D., an author of the report, said she was “cautiously optimistic” that aerial spraying in Miami Beach will have similar results. “As we see more introductions of Zika, from travelers in particular, we have to stay vigilant,” she said.