Modified mosquitos debug Florida

There’s a mutant mosquito in the Florida Keys. And there’s something purposefully wrong with it.

In partnership with local government, the U.K.-based biotech firm Oxitec began releasing thousands of genetically modified mosquitoes on April 29 in an effort to control an invasive species known to carry deadly diseases. The genetically modified males mate with native females to produce female offspring that cannot survive to adulthood. The male offspring also carry the mutation, leading to a decline in females and an eventual population crash.

If all goes as planned, the Keys could see a collapse of its local population of Aedes aegypti mosquitoes, whose females transmit disease. Oxitec has demonstrated it can diminish mosquito populations in Caribbean and South American countries. A successful experiment in the United States could lead to more mainstream acceptance of the unusual pest control method.

In 2008, Oxitec worked with the government of the Cayman Islands to release 3.3 million of the modified mosquitoes on Grand Cayman. After 11 weeks, the population of Aedes aegypti dropped by 80 percent, according to a 2011 Nature Biotechnology report. The company said it achieved a 95 percent reduction of mosquitoes in the urban environment of Indaiatuba, Brazil, using the same method.

Officials with the Florida Keys Mosquito Control District first invited Oxitec to crash the local population of Aedes aegypti more than a decade ago. Florida’s native mosquito, of the genus Anopheles, once spread malaria, a disease largely wiped out in the United States by the 1950s. The invasive Aedes aegypti, native to Africa, can carry yellow fever, Zika virus, dengue fever, and chikungunya. The U.S. Centers for Disease Control and Prevention reported 80 cases of locally transmitted dengue in 2020, with Florida responsible for 70 of those. Puerto Rico reported 756 cases of dengue the same year.

The project to release genetically modified mosquitoes in Florida earned the approval of the Environmental Protection Agency in May 2020, but some environmental groups still oppose the program. “History has taught us time and time again that we need serious precaution with new genetic engineering experiments and technologies,” Dana Perls, a program manager at the Washington-based environmental advocacy group Friends of the Earth, told USA Today. “Once you release this genetic material into the wild, you can’t recall it.”