No, Genetically Modified Mosquitoes Will Not Turn the Florida Keys Into Jurassic Park

The goal is to drastically reduce the population of disease-carrying bloodsuckers.


Non-biting male mosquitoes genetically modified to contain a self-limiting lethal gene are finally set to be released by on three islands in the Florida Keys. When the insect control company Oxitec's male Aedes aegypti mosquitoes mate with wild females, they will pass along a gene that overproduces a protein that kills larvae before they mature into biting disease-carrying adults.

Aedes aegypti mosquitoes often carry Zika, Chikungunya, and dengue fever viruses. Last year 47 cases of locally acquired dengue fever were reported in the Florida Keys. So Oxitec's creations could be a boon to public health.

Yet it has taken the company 10 years of fending off activist challenges and wending its way through a thicket of state and federal bureaucracies to get permission to launch this project. Some overwrought activists, referring to the 1993 movie in which cloned dinosaurs wreak havoc on an isolated island, have denounced the plan as a "Jurassic Park experiment." But in its May 2020 risk assessment, the U.S. Environmental Protection Agency "determined that there will be no unreasonable adverse effects for humans as a result of the experimental permit to release Ae. aegypti OX5034 male mosquitoes."

The plan is to allow about 12,000 of the modified Aedes aegypti males to hatch each week for 12 weeks from six locations: two on Cudjoe Key, one on Ramrod Key, and three on Vaca Key. That species makes up about 4 percent of the Keys' mosquito population but is responsible for virtually all the mosquito-borne diseases transmitted to human beings there.

Prior studies in Brazil, the Cayman Islands, Malaysia, and Panama have found that the technology works, reducing the targeted disease-carrying mosquito populations by as much as 95 percent. And since the larvae hatched with the gene all die before they mature, the modified mosquitoes do not persist in the wild. Oxitec's mosquitoes will not transform the Keys into an out-of-control Jurassic Park, but they will make a walk in the park there safer and more pleasant.