Google’s sister company Verily has applied for federal permission to release up to 32 million specially treated male mosquitoes across California and Florida over the next two years, as part of an effort to curb mosquito-borne disease.

The proposal, now under review by the United States (US) Environmental Protection Agency (EPA), is part of Verily’s decade-old "Debug" initiative. 

If approved, 16 million laboratory-bred male mosquitoes would be released in the first year, with a further 16 million in year two. 

The EPA is accepting public comments until 5 June before deciding whether to issue an experimental use permit. 

Regulators have not yet named the specific counties or cities where releases would take place.

Researchers say the latest plan targets Culex mosquitoes, a species known to transmit West Nile virus and St Louis encephalitis. 

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According to reports, West Nile remains the leading mosquito-borne disease in the US, with a positive sample confirmed in Riverside County, California, last week.

Unlike conventional pesticide spraying, Verily’s method relies on "Wolbachia," a naturally occurring bacteria. 

Male mosquitoes infected with Wolbachia mate with wild females, but the resulting eggs do not hatch, and over time, this suppresses the population. 

Only female mosquitoes bite humans, so officials say the releases would not increase biting.

"Rather than releasing biting insects, the company plans to release male mosquitoes infected with Wolbachia. 

"When the infected males mate with wild female mosquitoes, the offspring do not survive," the project team explains.

Notably, reports insisted that Verily has tested similar technology before. 

In 2017 it released 20 million Aedes aegypti mosquitoes in Fresno, California, in partnership with local mosquito control districts. 

That species spread dengue, Zika, yellow fever and chikungunya.

The EPA stressed that no decisions have been made and if the permit is granted, Verily would work with local vector control agencies to manage the releases.