Green groups relieved as release of genetically engineered mosquitoes averted in California

In what green groups on Friday called “a victory for environmentalists, scientists, and vulnerable agricultural communities across California,” state officials announced a day earlier that a controversial release of genetically engineered mosquitoes in the Central Valley has been suspended.

The California Department of Pesticide Regulation (DPR) said Thursday that Oxitec, a U.S.-owned, U.K.-based biotechnology company that develops genetically engineered (GE) insects, withdrew a research authorization application to conduct a field pilot test of a new type of Aedes aegypti, a mosquito species that in its natural form can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents.

Oxitec, which touts its GE mosquitoes as “an alternative to the use of conventional pesticides,” planned to study the insects’ efficacy at reducing the current Aedes aegypti population in Tulare County.

“The withdrawal of Oxitec’s application is a victory for California residents and wild species,” Rebecca Spector, West Coast director at Center for Food Safety, said in a statement. “This withdrawal is in line with leaders from our state Legislature who demanded a more comprehensive review of the impacts of these genetically engineered mosquitoes before the approval of this permit.”

According to the environmental group Friends of the Earth (FOE), which opposed what it called a “risky insect mass release”:

The withdrawal of the biotech corporation Oxitec’s request halts the controversial proposed release of billions of genetically engineered insects. Scientists and other experts in the field have raised concerns about Oxitec’s proposal to release genetically engineered mosquitoes due to inadequate scientific review and lack of appropriate and relevant regulations, pressuring the company to disclose data critical to assessing potential public health and environmental impacts…

In separate letters to DPR earlier this year, scientists and legislators urged DPR to deny the Oxitec permit because of concerns about risks posed to human health, wildlife, and vulnerable ecosystems, and the lack of regulations to control billions of genetically engineered mosquitoes released into an open-air environment.

“All Californians should be relieved that this permit request has been withdrawn for the foreseeable future,” FOE senior project manager Dana Perls said in a statement. “Significant scientific research on genetically engineered mosquitoes is still needed to understand the potential public health and environmental threats associated with the release of this novel genetically engineered insect.”

Last November, California state Assemblymember Laura Friedman (D-44) said that “there are too many unknown factors when it comes to how [GE mosquitoes] could affect our biodiversity in the long run, including how this might influence populations of birds, bats, fish species, and other insects.”

An unusually wet winter and subsequent spring snow melt and flooding have led to elevated levels of standing water and ideal breeding conditions for mosquitoes, leaving Central Valley officials worried about the spread of diseases.