Google to release 32 million mosquitoes in Florida: How it will reduce Dengue

Google-backed researchers want approval to release 32 million Wolbachia-infected male mosquitoes in Florida and California. The plan is being watched as a major biological alternative to insecticides against dengue and other mosquito-borne diseases.

In Short

• Wolbachia-infected male mosquitoes mate with wild females, making eggs fail
• Only male mosquitoes are used because they do not bite humans
• California trials cut mosquito numbers by over 95% at some sites

Google-backed researchers are seeking permission to release up to 32 million specially treated mosquitoes across parts of Florida and California in what could become the largest mosquito-control experiment ever attempted in the United States.

The proposal, currently under review by the US Environmental Protection Agency (EPA), would involve releasing male mosquitoes infected with a naturally occurring bacterium called Wolbachia into the wild. The public has until June 5 to submit comments before regulators decide whether to approve the plan.

At first glance, releasing millions of mosquitoes may sound counterintuitive. However, scientists say the strategy is designed to eliminate mosquito populations rather than increase them.

WHAT IS WOLBACHIA?

Wolbachia is a common bacterium found naturally in many insects, including butterflies, moths and beetles. It does not infect humans and is considered harmless to people and animals.

When male mosquitoes carrying Wolbachia mate with wild female mosquitoes that do not carry the bacterium, the eggs fail to hatch.

Over time, repeated releases of infected males reduce the number of offspring produced in the wild, causing mosquito populations to shrink dramatically.

Importantly, only male mosquitoes are released because they do not bite humans. Their sole purpose is to mate with females and disrupt reproduction.

The technology has been developed through Google's Debug Project, a subsidiary focused on disease control and ecological technologies.

SUCCESS IN CALIFORNIA AND SINGAPORE

The approach has already produced impressive results.

Google's earlier trials in California's Central Valley reportedly reduced mosquito populations by more than 95% at some test locations, with several sites seeing local mosquito populations nearly disappear altogether.

Even more striking results have emerged from Singapore, where Wolbachia-based mosquito control programmes have been deployed to combat dengue fever. Authorities reported that dengue cases in treated neighbourhoods fell by approximately 70% within a year compared with untreated areas.

The success in Singapore has attracted global attention because dengue infections have surged worldwide in recent years due to urbanisation, climate change and expanding mosquito habitats.

MORE THAN A BILLION MOSQUITOES RELEASED

Google's mosquito-control strategy follows six steps: infect male mosquitoes with Wolbachia, breed them in large numbers, separate non-biting males from females, release them into the wild, reduce mosquito populations through sterile mating, and continuously monitor affected areas.

Repeated releases gradually suppress or potentially eliminate disease-carrying mosquito populations.

According to project data, Google and its partners have already released more than one billion Wolbachia-infected mosquitoes across four continents. The proposed Florida and California deployment would represent the largest such operation ever undertaken in the US.

Scientists view the method as a potential alternative to widespread insecticide use, which can harm beneficial insects and become less effective as mosquitoes develop resistance.

A GROWING BATTLE AGAINST MOSQUITOES

The proposal comes as researchers continue to uncover surprising aspects of mosquito behaviour.

A recent study published in the Journal of Experimental Biology suggested that mosquitoes may be capable of learning. Researchers found that repeated exposure to the smell of a commonly used insect repellent appeared to alter how mosquitoes responded to it.

"This study shows that it's not the chemistry of the molecule itself that is toxic" to mosquitoes. Instead, the insects appear to be repelled by how they "interpret this chemical information," lead researcher Claudio Lazzari told AFP.

As mosquito-borne diseases such as dengue, Zika and chikungunya continue to threaten millions worldwide, scientists are increasingly turning to innovative biological solutions.

Whether regulators approve Google's ambitious mosquito release plan could determine the future of one of the most unusual disease-control strategies ever attempted.

- Ends