This would be the first time genetically modified insects were released in the US for disease control.

Voters in the originally-proposed test site—a small island called Key Haven—rejected the proposal in a non-binding referendum during the election this month, but a county-wide vote was 57 percent in favor of releasing the insects. On Saturday, the local government board, the Florida Keys Mosquito Control District, voted 3-2 in favor of continuing with the project, only in a different location.

"We all have our opinions, we all have to listen to our constituents, and this is a tool mosquito control needs," Jill Cranney-Gage, one of the board commissioners, said during the meeting. "We need to think long and hard about this decision that we make today, and make the decision that's in the best interest of protecting the health in the county."

The mosquitoes are a genetically modified version of the Aedes aegypti species, which spreads Zika and other viruses capable of sickening humans, such as Dengue.