Millions of Mutated Mosquitoes Could Be Set Loose in Florida

A female Aedes aegypti mosquito. This species spreads the dengue and chikungunya viruses. CDC

A British company hopes to release millions of genetically modified mosquitoes in the Florida Keys this spring, the Associated Press reports. The goal of the plan is to reduce populations of the insects, which spread dengue and chikungunya, two painful viral diseases.

The company, Oxitec, has developed a method to breed genetically modified male mosquitoes. When these males mate with unmodified females, genes inserted into the male make the resulting larvae die. Oxitec plans to only release genetically modified males. Male mosquitoes (modified and otherwise) do not bite humans—only females do, as they need the nourishment to produce offspring. So it's unlikely that any modified DNA would make its way into humans, the company says.

But many remain wary. Nearly 140,000 people have signed a petition to prevent the move. The plan won't go ahead unless the U.S. Food and Drug Administration gives its approval. An agency representative said no field tests would go forward before the agency "thoroughly reviewed all the necessary information," the AP noted.

Oxitec has previously release genetically modified mosquitoes in the Cayman Islands and Brazil. In the Caymans, the move reduced populations of the insects by 80 percent in the areas the genetically modified males were released, with similar results in Brazil.

The company has "now released 70 million of its mosquitoes in several countries and received no reports of human impacts caused by bites or from the synthetic DNA," Oxitec spokeswoman Chris Creese told the AP.

There have been two small outbreaks of dengue in the Florida Keys, in 2009 and 2010, according to the Florida Department of Health, though no dengue cases have been reported since 2010. Chikungunya remains rare but is spreading throughout the Caribbean, and the CDC reported the first instance of local transmission in Florida in July 2014.