Genetically Engineered Insects

The first time genetically engineered insects were released into the environment and local communities in the United States was April 2021. The U.S. Environmental Protection Agency (EPA) allowed a British biotech company called Oxitec to release half a billion genetically engineered (GE) mosquitoes in Monroe County, Florida as part of an experimental trial, despite widespread community opposition. In March 2022, EPA approved a second experimental use permit to extend the Florida trial for two years, and to introduce what could be the largest release of GE insects in the U.S. to date — up to two billion GE mosquitoes across the Central Valley’s Tulare County, California. In May 2022, Florida authorized the extended release trial for another two years, until April 2024. The California Department of Pesticide Regulation’s decision is pending.     

These experiments are the first step toward Oxitec selling its proprietary GE mosquitoes to state mosquito control boards and American taxpayers.

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Frequently asked questions

What is the basis of Oxitec’s experiment? 

The proposed experiments are investigating whether Oxitec’s mosquito can reduce the population of a type of mosquito called Aedes aegypti. This species can carry diseases like yellow fever, dengue, chikungunya and Zika. While addressing mosquito borne diseases is clearly a critical issue, these diseases are not a pressing concern in the continental United States. Yellow fever has been eradicated, there have been no reports of zika transmission since 2018 or chikungunya since 2016, and nearly all reported dengue cases are from travelers infected elsewhere. 

Are the GE mosquitoes a Trojan horse? 

Gaining approval for release via an experiment related to public health — albeit one that is not addressing a public health need in the U.S. — may be a Trojan horse for future use of GE insects in agriculture given Oxitec’s research pipeline.  

To date, Oxitec’s GE mosquito trials have failed to reduce mosquito populations 

Oxitec has conducted field trials in other countries, from Malaysia to Panama, and there has not been peer reviewed data to show that these trials have successfully reduced mosquito populations. For example, one peer reviewed study in Brazil found that releasing Oxitec’s GE mosquitoes continuously over two years failed to reduce the wild mosquito population. 

Genetic material from GE mosquitoes could transfer to wild mosquito populations 

Another study found that the GE mosquitoes in Brazil transferred parts of their DNA to wild mosquitoes. Researchers warn that these hybrid GE-wild mosquitoes could prove more difficult to eradicate or more effective at spreading disease.  

Populations of biting mosquitoes could increase in the communities where GE mosquitoes are released  

Oxitec’s trial application states that female offspring — which bite and spread disease — will die while still in their larval stage. But females have been inadvertently released in previous Oxitec’s experiments, and a reported 3 to 4% survive in laboratory conditions. Because of the very large numbers of GE mosquitoes proposed to the EPA for release (up to 30,000 mosquitoes per acre, per week), even a small percentage of surviving female GE mosquitoes could lead to an increased biting mosquito population in the communities where GE mosquitoes are released. 

GE mosquitoes could expose people to new allergens 

Oxitec’s GE mosquito could expose people to novel allergens. Yet, information about allergenicity — and a great deal of other data — was blacked out as “confidential” in Oxitec’s 2021 proposal to the EPA. 

Assessments of potential harm to endangered species are insufficient 

During releases of GE mosquitoes, species that feed on adult Aedes aegpti could have an increased proportion in their diets. Oxitec’s GE mosquito uses a synthetic protein called tTAV (tetracycline transactivator). Research shows that, when engineered into mice, tTAV can result in neurotoxicity, behavioral abnormalities and adverse effects on the lungs. Yet there are no known feeding trials examining the potential impacts of consuming GE mosquitoes on birds, mammals, reptiles or amphibians. Biting female GE mosquitoes may inject this novel engineered protein into humans and other animals.i  

There is a major lack of transparency around GE mosquitoes  

The potential risks of this experiment and novel technology must be assessed publicly, not behind closed doors. An independent group of experts should be convened to review the available data. And the people who live in areas where the GE mosquitoes could be released should have the right to free and prior informed consent and given the opportunity to have input in decisions that will affect them. Yet, Oxitec’s process has been marked by a major lack of transparency. Significant data was blacked out as “confidential” in Oxitec’s 2021 proposal to the EPA, such that independent experts are not able to adequately assess the potential risks of the GE mosquito. And neither Oxitec nor the Florida Keys Mosquito Control District have released any data about the 2020 trials. 

There is a lack of regulation to adequately govern GE insects 

EPA’s greenlighting of these experiments is happening in the absence of state or federal regulations for assessing, monitoring or evaluating genetically engineered insects. The GE mosquitoes are being regulated as “pesticides” under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). When FIFRA was written in 1910 and revised over 50 years ago, no one anticipated the development of genetically engineered insects that would be released into the wild. Oxitec’s public health and endangered species assessments were inadequate, and the requirements for monitoring, run by Oxitec, may be too insufficient to catch any escaped female GE mosquitoes.  

This is an open-air genetic experiment 

Once GE mosquitoes are released into the environment, they cannot be “recalled.” Rather than proceed headlong with an experiment that could have serious environmental and public health consequences, we must have regulations based on the precautionary principle, engage independent experts and all potentially affected communities, and have transparency about the public and environmental health impacts from genetically engineered mosquitoes. 

Safer alternatives already exist 

There are already more effective mosquito abatement techniques that cost less and have been peer reviewed by independent scientists. Trials with the Wolbachia mosquitoes, and public sanitation techniques pioneered over 100 years ago appear to be effectively reducing Aedes aegypti populations.