Genetically modified mosquitoes could soon be unleashed in Florida.

On November 19th, the Florida Keys Mosquito Control District to formally approved a field trial release of genetically-modified mosquitoes.

Developed by UK biotechnology firm Oxitec, the engineered mosquitoes are intended to be used in the fight against dengue fever as well as the Zika virus as they carry a gene that makes their offspring die early.

New Scientist reports:

By letting the GM mozzies mate with native female mosquitoes in the wild, the idea is to slash the population of mosquitoes carrying dangerous diseases such as Zika and dengue.

Similar initiatives have already been successful. One trial in Piracicaba, Brazil, also led by Oxitec, reportedly reduced dengue cases by more than 90 per cent.

The Florida trial in Key West would only last a few months, ending when the last of the modified mosquitoes die off. In August, the US Food and Drug Administration approved the plan, saying that it would have “no significant impact” on the environment in the long-term.

Floridians, too, have voted in favour of it, endorsing a ballot measure earlier this month.

Local opposition

But in Key Haven, the part of Key West where the trial will occur, 65 per cent of residents oppose the idea.

One online petition, started by a Key West resident, raises concerns that the trial will harm Key Haven’s environment and residents. It says: “There are more questions than answers and we need more testing to be done.”

The spread of Zika earlier this year was especially worrying in the state, which saw some 200 cases – although none in Key West. Last week, the WHO declared that Zika is no longer an international public health emergency.

The opposition among Key Haven residents means the Oxitec team may need to find a new location for the trial.