Editor’s Note: This story was updated to include information from the U.S. E.P.A. permit, which changed details previously reported.

News of the approval to release genetically-modified mosquitoes in Tulare County and Monroe County, Florida has drawn the ire of activists who say the company behind the project has not provided data demonstrating the insects are safe.

At the same time, the company says it has the studies to demonstrate the safety of the program it calls “another tool in the integrated approach to pest control.”

The U.S. Environmental Protection Agency has granted U.K.-based Oxitec an experimental-use permit giving the company the first green light to release male, non-biting mosquitoes in Tulare County and Monroe County in Florida, according to Rajeev Vaidyanathan, director of operations for Oxitec.

The test is to see whether the engineered mosquitoes can reduce the number of Aedes aegypti mosquitoes that have spread throughout the country with the potential to carry tropical diseases such as dengue, yellow fever, Zika and chikungunya.

Before they can begin the program, the California Department of Pesticide Regulations has to approve the proposal.

The male mosquitoes would then breed with local females. The mosquitoes have been engineered to pass on a trait that kills female larvae and only allows males to reach adulthood. Once mature, those males then pass on the same trait, continuing the cycle to eliminate female, biting mosquitoes.

A number of organizations have concerns surrounding the program.

The permit from the EPA states they can release up to 2.5 billion across Florida and California until April 2024.

Organizations including the Center for Food Safety, Friends of the Earth and others state it would represent the largest-ever release of mosquitoes at 2.5 billion. Vaidyanathan said Oxitec doesn’t know how many it will release.

A previous project deployed in the Fresno-Clovis area by a Google sister company introduced about 20 million modified bugs into the area.

Results of local study that released 20M mosquitoes? Fewer bad bugs

 

Before any releases can be done, the state of California must receive research authorization, according to Leia Bailey, assistant director of communications for California Department of Pesticide Regulation.

They have not received the application yet, said Bailey, and if an application is submitted, review will “entail the same rigorous scientific evaluation that all such applications are subject to.”

At the step of the approval process Oxitec is in, no numbers have been released save an upper limit of how many could be released. Vaidyanathan did not have that number readily available.

In addition, it wasn’t until Monday that the company received the first approval from the EPA.

The EPA permitted use in Stanislaus, Fresno, Tulare and San Bernadino counties. Vaidyanathan said they only received approval for Tulare County and one county in Florida.

Oxitec has been releasing mosquitoes in Brazil and Florida throughout 2021 and those numbers didn’t reach 10 million, Vaidyanathan said.

Concerns aren’t limited to numbers, however.

Jaydee Hanson, policy director with Center for Food Safety, says the studies that show the impact the mosquitoes have on the environment as well as human health have not been released out of Oxitec’s insistence that making that data public could jeopardize patents.

“The EPA has agreed in the sections of the public reports that include discussion of environmental health and human health,” Hanson said. “We think those need to be made public.”

Hanson said the impacts the mosquito could have on the environment and on humans is unknown because data has been withheld. The EPA does require testing for things such as allergic reactions and impact to environment.

“It’s irritating to read down through what the EPA will release and when it comes to allergenicity it says ‘redacted as confidential business information,’” Hanson said.

Hanson says the EPA has acquiesced on the side of business before.

Lawsuits in California surrounding the use of the chemical glyphosate found in the herbicide Roundup asserted that the EPA knew about the harms of that chemical and still approved it for household use.

For their part, Vaidyanathan said the public comment period hosted by the EPA answered in depth all questions raised by the public.

Another concern Hanson has is the presence of Tetracycline in the area. Tetracycline is used on citrus groves to treat citrus greening disease. Tetracycline can also be found on ranches in the form of antibiotics given to cattle.

With the chemical readily available, the young mosquitoes may be able to sustain themselves, Hanson says.

Vaidyanathan said that the presence of Tetracycline could affect the effectiveness of the genetic trait, but that none of the boxes with the mosquitoes will be within one kilometer from a site where Tetracycline is available. And the known flight distance of the engineered mosquitoes would keep them from getting close to any source.

But Hanson says Aedes aegypti made the trip from Africa and 1,000 meters does not pose a safe-enough distance.

“We don’t think they should even be doing the study any place you have this much antibiotic around,” Hanson said.

Hanson said releasing all of their data on environmental and human-health effects would be a large step toward satisfying his concerns about the mosquito release.

Through all of this, Vaidyanathan said mosquito-control districts throughout California and Florida as well as regional and national bodies supported the proposal for the environmental-use permit.

Vaidyanathan said the program has received support from the Mosquito and Vector Control Association of California as well as Florida Mosquito Control Association and American Mosquito Control Association.

Hanson says EPA certification would help market the treatment in places such as the Philippines and Honduras.

But the goal of the pilot program is to ensure the treatment works in ecosystems outside of Florida and Brazil. Vaidyanathan said he would love to see the program deployed in other areas, but it has to get approval first.

“This is just a pilot in California so that we know No.1 — it’s all males, how far can they fly, how well do they mate with wild-type Aedes aegypti — and No. 4 — how well will they survive in a very different, arid climate than we see in Florida,” he said.