A project backed by Google's parent company is seeking federal approval to release 32 million mosquitoes in California and Florida, all in hopes they can help eliminate others that spread deadly viruses.
That may sound like the beginning of a disaster movie, but this is far from the first time mosquitoes have been released in the U.S. A Florida Keys trial conducted by the British company Oxitec was deemed a success in 2022 and the Alphabet subsidiary, Verily, behind the new proposal, dubbed "Debug," released one million sterile mosquitoes in California in 2017.
The need for these programs is great. Mosquitoes kill more people than any other creature in the world, and 120 Americans die due to infection with West Nile virus each year, federal data shows.
Still, the tests have raised ethical questions regarding how far humanity should take the war against mosquitoes. Around since the age of the dinosaurs, they're both an important food source for pollinators that support our food systems and pollinators themselves.
Verily's efforts to fight off disease-riddled mosquitoes have recently fueled concern on social media, with X users questioning the tech giant's ties to the project — despite a documented history of success in America, Singapore and Australia.
"Why does Google have 32 million mosquitos? Have we not learned our lesson with Kudzu, Sparrows, Black Birds, Asian Carp? Should I go on?" asked Tennessee Republican Rep. Tim Burchett. "Don't mess with the balance of nature."
A request for comment from Verily about social media and Alphabet's hand in the project was not immediately returned.
Targeting the Yellow Fever Mosquito
The project targets "bad," human-biting female Aedes aegypti, also known as the Yellow Fever mosquito. These aggressive mosquitoes are not native to the U.S., and can spread Zika, dengue, yellow fever and chikungunya.
But targeting these mosquitoes doesn't mean eliminating them. Instead, the males the project will release – which are non-biting – are infected with Wolbachia, a sterility-causing bacterium already living in more than half of all insect species.
When released, the Wolbachia mosquitoes can still seek out females to reproduce like wild mosquitoes. But when the females reproduce, their eggs don't hatch. That essentially controls the population from the inside.
Ecological Impact and Community Concerns
Verily's project website says the general consensus among scientists is that the ecological impact of removing the species they are targeting from the urban environment would be small, and that they are not a significant food source for other animals.
"The main ecological impact would be to restore the ecosystem to how it was before the mosquitoes invaded. Debug team is committed to working with communities and regulators to ensure the safety and acceptability of our field trials and releases," the project says.
There's no timeline yet for when the release could take place, and dormant eggs can remain in the environment for months after adults are removed. That requires continuous treatment of an area.
"We are first looking to reduce mosquito populations below the level required to transmit disease," the project said.
In the future, the team hopes to apply the same approach to other insects. There are field trials underway with the Aedes albopictus, also known as the Asian tiger mosquito.
"We'll need to validate this with research," the project said.
Challenges and Climate Change
The method has been deployed in Brazil — but dengue has reportedly outpaced the "good" mosquitoes.
This isn't a perfect fix. When the mosquitoes are no longer released into an area, their numbers slowly return to "normal levels," the U.S. Centers for Disease Control and Prevention stated.
Mosquito populations, including invasive species, are spreading farther due to human-caused climate change. They thrive in warmer and more humid environments. Recent research shows they're also adaptable. "We found that mosquitoes have the potential to evolve on pace with climate warming, suggesting that we may be under-estimating future disease risk," Lisa Couper, a postdoctoral researcher in Environmental Health Sciences at U.C. Berkeley, said last year.
Dengue, chikungunya and Zika outbreaks have occurred in Florida, Hawaii, Texas, Puerto Rico, the U.S. Virgin Islands and American Samoa, the CDC said.
