Genetically modified mosquitoes have been released for the first time in the United States as part of an experiment to combat insect-borne diseases such as Dengue fever, yellow fever, and the Zika virus.

UK-based biotechnology firm Oxitec, which is funded by the Bill and Melinda Gates Foundation, said it released the mosquitoes in six locations in Monroe County’s Florida Keys: two on Cudjoe Key, one on Ramrod Key, and three on Vaca Key.

It’s part of an effort to help tackle a disease-transmitting invasive mosquito population—the Aedes aegypti mosquito species—that’s responsible for “virtually all mosquito-borne diseases transmitted to humans,” according to the company. More from The Epoch Times.