U.S. launches GMO screwworm fly trials in Panama to combat livestock pest

Scientists at a U.S.-funded facility in Panama are preparing the first outdoor tests of a genetically engineered screwworm fly, called NovoFly. The flies, confined in mesh cages, will be exposed to local heat and humidity to assess their survival before wider field releases. NovoFly produces only sterile male flies that mate with wild females, preventing egg fertilisation and aiming to curb the New World screwworm parasite that recently infested Texas cattle, threatening over $1 billion in losses.

The sterile‑fly program, jointly managed by the U.S. Department of Agriculture and Panama’s Ministry of Agricultural Development, currently produces about 100 million sterile flies weekly, far below the estimated 500 million needed to push the pest back to the Darien Gap. The GMO approach is promoted as a game‑changing tool to augment existing sterile‑fly releases and protect livestock across the United States and Central America.