Reengineering Life

Millions of Genetically Engineered Mosquitoes Are Headed for the Florida Keys

The insects are designed to control diseases like dengue and West Nile

Emily Mullin
Future Human
Published in
4 min readAug 25, 2020
Photo illustration, source: Joao Paulo Burini / Getty Images

Reengineering Life is a series from OneZero about the astonishing ways genetic technology is changing humanity and the world around us.

In the first test of its kind in the United States, millions of genetically modified mosquitoes will be released in the Florida Keys sometime in the next two years.

Local officials greenlit the plan in a 4–1 vote on August 18, despite long-standing objection from some residents and environmental advocacy groups. The engineered insects are designed to wipe out Aedes aegypti mosquitoes in an effort to eliminate the diseases they carry. The U.K. company that makes the mosquitoes, Oxitec, had been trying to get an open-air release approved for the past 10 years.

The resulting offspring don’t survive until adulthood and therefore can’t reproduce.

The U.S. Environmental Protection Agency approved the pilot project in May, followed by the state of Florida in June. But Oxitec still needed to get local permission before the mosquitoes could be released at a site in Monroe County, home of the Florida Keys.

Oxitec’s mosquitoes, which are all male, are engineered to have a “self-limiting” gene. When they’re released into the wild and mate with females, they pass on the gene to their offspring. The resulting offspring don’t survive until adulthood and therefore can’t reproduce. Oxitec believes that releasing enough of these designer insects will cause the local mosquito population to eventually die off.

Male mosquitoes don’t bite — only females do — so the EPA and Oxitec say the engineered mosquitoes don’t pose a threat to people. But opponents worry about the possible health and environmental effects of releasing genetically modified organisms into the environment.

Climate change is expected to bring more diseases like dengue and West Nile that are spread by the bite of infected mosquitoes. Florida currently uses aircraft to spray large amounts of insecticides to…



Emily Mullin
Future Human

Former staff writer at Medium, where I covered biotech, genetics, and Covid-19 for OneZero, Future Human, Elemental, and the Coronavirus Blog.