Why Google wants to release millions of mosquitoes in the US

What's the best way to combat disease-spreading mosquitoes? More mosquitoes! At least that's the plan of scientists at Google's Debug program. The researchers want to release 16 million mosquitoes each in the US states of Florida and California in a first step. And then they want to do it all again next year.

Trying to reduce the mosquito population by adding millions more sounds counter-intuitive at first. But to understand the project, you have to look at what kind of mosquitoes the researchers are fighting — and what kind they're looking to release.

In a nutshell, it's good mosquitoes vs. bad mosquitoes.

Google's 'mosquito army'

The researchers' plan is to "raise sterile males and release them into wild insect populations," it says on the Debug website. "When a wild female mates with a sterile male, her eggs won't hatch. The population gets smaller with each generation."

The male mosquitoes will be infected with bacteria called Wolbachia, which makes them sterile.

In theory, that should lead to two things: The next generation of mosquitoes should shrink when the females' eggs are left unfertilized. And there won't be more bites for humans through the additional mosquitoes, because male mosquitoes don't bite.

Separating male and female mosquitoes is not an easy feat. That's why the Debug researchers are working to develop "technologies that combine sensors, algorithms, and novel engineering to… quickly and accurately sort males from females."

The technology isn't the only challenge — you can't just release millions of mosquitoes into the wild willy-nilly. Google filed for a permit with the US Environmental Protection Agency; the organization's decision is still awaited.

Wanted dead: the Aedes aegypti mosquito

The target of the Debug program aren't any mosquitoes native to Florida or California. The researchers aim to fight Aedes aegypti, an invasive species that's originally from Africa.

This invader spreads dengue, yellow fever, Zika virus and chikungunya, a disease that comes with excruciating joint pain that can last for months or even years.

According to Debug, 40% of the world's population is at risk of contracting a disease spread by this very mosquito, which has invaded tropical, subtropical, and temperate regions across the world.

Aedes aegypti is "a very bad mosquito," says Nathan Burkett-Cadena, an associate professor at the University of Florida's Medical Entomology Laboratory.

Because it is not native to Florida, there aren't any animals that rely on this specific mosquito for food, Burkett-Cadena explained in an email to DW.

"If Google began to target native mosquito species, then I would be concerned with cascading environmental consequences," he said. 

Since Aedes aegypti is not native to Florida, this shouldn't be a problem.

'I love mosquitoes'

The World Mosquito Program, an organization run by Australia's Monash University, fights disease-spreading mosquitoes in various countries across the world. They, too, release mosquitoes infected with the Wolbachia bacteria in 15 nations across Asia, Oceania and the Americas.

According to the World Mosquito Program's monitoring, Wolbachia gets passed from one generation of mosquitoes to the next, decreasing the number of disease-spreading mosquitoes long-term.

And, crucially, the organization states that "in areas where high levels of Wolbachia are present, we have not seen any dengue outbreaks."

So, it seems like there really is a way to shrink the Aedes aegypti population.

But is it ethical? Do humans have the right to interfere with nature to such a degree? Should we reduce populations, even pest populations, just because we can? Entomologists say 'yes.'

"I 'love' mosquitoes," Burkett-Cadena said. "Most species do humans no harm whatsoever and they are actually beautiful organisms. However, in many places, human life is truly threatened by invasive… mosquito species, and those charged with protecting human life must take action."

Edited by: Zulfikar Abbany