The Florida Keys Mosquito Control District (FKMCD) and Oxitec announced the completion of initial active releases of Oxitec-developed genetically engineered mosquitoes to control invasive Aedes aegypti mosquitoes in the Keys in November.
Some basic facts:
Aedes aegypti mosquitos are non-native to the United States. They are a nuisance and have the potential to spread vector illnesses including chikungunya, dengue fever, Zika and yellow fever.
The current methods of mosquito control in the Florida Keys utilize integrated pest management, which is a combination of source reduction coupled with aerial and ground spraying of various insecticide and larvicide products. However, over time some of these products are becoming less effective at controlling Aedes aegypti mosquitoes.
With that in mind, FKMCD is actively seeking new tools and technologies that can effectively reduce mosquito populations, specifically Aedes aegypti, now and into the future.
Oxitec-bred mosquitos are intended to be one of these tools with the potential to thwart the vectors of mosquito-borne diseases while helping neutralize insecticide resistance.
How does the program work?
The project received regulatory approval from the U.S. Environmental Protection Agency with review by the U.S. Centers for Disease Control and Prevention and the authorization of eight State of Florida entities including the Department of Health, according to project officials.
FKMCD is collaborating with Oxitec, a biotech company, on the pilot project to control Aedes aegypti mosquitos in a sustainable, environmentally responsible and potentially more cost-effective way. Oxitec scientists have engineered a strain of the male Aedes aegypti mosquito that targets itself to help control the species.
Oxitec releases male mosquitos because males cannot bite or spread disease. Those genetically modified male mosquitos are released to do all the hard work of finding invasive, unmodified females to mate with. Only the male subsequent offspring survive, resulting in reduced local populations of Aedes aegypti after successive releases, according to Oxitec.
When and where will it start?
The Oxitec program for a Keys-based pilot project received approval from the U.S. Environmental Protection Agency and Florida Department of Agriculture and Consumer Services among others.
In stage one of the project, also called "Project A," which launched at the end of April, release boxes were originally placed in six locations: two on Cudjoe Key, one on Ramrod Key and three in Marathon (Vaca Key only). Throughout all release locations, about 12,000 Oxitec male mosquitoes were expected to hatch and emerge each week for approximately 12 weeks.
The project timeline incurred brief interruptions due to tropical storm Elsa and Fred passing over the Keys in early July and August.
Project A was comprised one box on Big Coppitt and two on Vaca Key, according to Oxitec-FKMCD project managers. In phase two of the project, also referred to as "Project B," placement areas included one box in each: Vaca Key, Little Torch Key and Big Coppitt. Throughout all release locations, mosquitoes were expected to emerge each week for approximately 16 weeks.
In November 2021, the Florida Keys Mosquito Control District (FKMCD) and Oxitec announced the completion of initial active releases of Oxitec-developed genetically engineered mosquitoes to control invasive Aedes aegypti mosquitoes in the Keys.
What is the potential for success of the program?
In the Cayman Islands, Mexico and Brazil, where the technology has been used successfully, the local Aedes aegypti mosquito population was reduced by up to 95 percent, according to Oxitec. Other sites’ results have not been as positive.
Keys project officials said that release boxes have been removed from their sites and ongoing monitoring will continue, likely until February 2022.
Officials said that Oxitec’s non-biting male mosquitoes emerged from boxes placed in selected regions of the Keys and dispersed as expected, mating with invasive females. They added that a project steering committee is to evaluate results of the study to determine how Oxitec mosquitoes affected populations of Aedes aegypti in the test regions.
Will Oxitec mosquitoes harm birds, bees, bats, fish, turtles or other wildlife?
Officials said the EPA and various Florida state agencies have confirmed Oxitec’s research to indicate no adverse effects. The male mosquitos present no risk to human health, and no risk to the environment, including endangered or threatened species or their critical habitats, according to Oxitec.
Oxitec and FKMCD claim the technology is self-limiting, so once released, mosquitoes and their offspring die; they do not remain in the environment for an extended period, Oxitec officials said, adding that the suppression effect is specifically targeted to this single species of mosquito, leaving non-target species such as bees and butterflies unharmed. Passionate opponents of genetic modification do not agree and believe there is a risk to other species, though that has not been confirmed.
Oxitec and FKMCD are to evaluate release rates and demonstrate effectiveness of the modified mosquitos in small areas. Both Oxitec and FKMCD said that releases can be stopped at any time, and once they are, officials claim that the modified mosquitos will soon die off and no longer have an effect on other mosquitos or the environment.
- 1-888-308-1859, weekdays 9 a.m. to 5 p.m., or contact FKMCD at 305-292-7190
- FKMCD – Oxitec Mosquito Project
Oxitec officials say that non-biting male mosquitoes will emerge from the boxes to mate with the local biting female mosquitoes.
FKMCD and Oxitec officials say they have received regulatory approval from the U.S. Environmental Protection Agency, U.S. Centers for Disease Control and Prevention and seven State of Florida agencies including the Department of Health.