Oxitec scientists said they had reduced the population of Aedes aegypti mosquitoes, which carry the virus, by 90 percent or more in other areas where the company’s modified mosquitoes have been released, including Brazil. The male mosquitoes carry synthetic DNA as larvae. They are hatched and then released as adults to mate with females (who do all the biting) in the wild. The DNA infuses their offspring with too much protein, causing them to die.
Pesticides in the Keys, which have one of the best mosquito-control programs in the world, have about a 50 percent success rate with Aedes aegypti, which are rapidly becoming immune to some products, officials in the Keys said.