GMO mosquitoes

This post was updated at at 12:15 p.m. on Sept. 12

The prospect of genetically modified mosquitoes is back for the Florida Keys — just as a new study raises concerns about the technology.

Scientists have launched a major new phase in the testing of a controversial genetically modified organism: a mosquito designed to quickly spread a genetic mutation lethal to its own species, NPR has learned.

For the first time, researchers have begun large-scale releases of the engineered insects, into a high-security laboratory in Terni, Italy.

"This will really be a breakthrough experiment," says Ruth Mueller, an entomologist who runs the lab. "It's a historic moment."

People who live in the Florida Keys have been waiting for years to find out whether the island chain will be the first place in the U.S. to try genetically modified mosquitoes as a method of controlling the pests.

They're going to have to wait awhile longer.

As the rainy season returns — along with the disease-carrying mosquitoes that reproduce in standing water — the public is getting another chance to comment on one proposed method for fighting mosquitoes.

The company that wants to hold the first U.S. trial of genetically modified mosquitoes in the Florida Keys and Keys residents who oppose the trial don't agree on much.

But representatives from both sides said Thursday they are happy with the recent announcement that federal oversight of the proposed trial will be moved from the Food and Drug Administration to the Environmental Protection Agency.

"We think it's a good thing," said Derric Nimmo, principal scientist at Oxitec, the company that has developed a genetically modified Aedes aegypti mosquito.

Matti Parkkonen (Wikimedia Commons)

U.S. Food and Drug Administration officials say genetically modified mosquitoes are not "drugs" and should be regulated by environmental authorities.

When Monroe County held a nonbinding referendum last year on whether  to allow the experimental release of genetically modified mosquitoes, most voters said yes.

This was as the mosquito-borne Zika crisis was exploding. The Food and Drug Administration had already started to clear the way for the field trial.

But residents of Key Haven--the proposed site of the mosquito control experiment--voted against it. And the company that breeds the mosquitoes started looking for another site.