You might think the only good mosquito is a dead mosquito, but science begs to differ.

In fact, the idea that you can stop bad bugs with good bugs is at the heart of a plan by Google to release up to 64 million mosquitoes ­in America over the next two years.

While most people wouldn’t associate the tech giant with disease control, the proposal is part of a global project called Debug created through its parent company Alphabet.

Debug is developing AI-powered technology to raise and release non-biting sterile male mosquitoes in the environment. These “good bugs” are infected with a naturally occurring bacteria called Wolbachia pipientis, which means that when they mate with uninfected females (so-called “bad bugs”) the eggs won’t hatch.

“So the next generation gets smaller, and smaller, and smaller, until all the bugs are practically gone,” explains a Debug video.

With the US Centres for Disease Control and Prevention describing mosquitoes as the world’s deadliest animal due to their spread of viral diseases such as dengue, malaria, zika, chikungunya and yellow fever, efforts to control their population can potentially save millions of lives.

Mosquitoes at Debug’s Singapore facility. Photo: Google

Google’s efforts have so far focused on a species of mosquito known as Aedes aegypti, with its Singapore-based operation releasing millions of male Wolbachia mosquitos into the community in recent years to reduce the risk of dengue fever  among residents.

Its latest proposal, however, targets southern house mosquitoes (Culex quinquefasciatus), which are found in tropical and sub-tropical regions including parts of the United States and can spread diseases such as St Louis encephalitis and West Nile virus.

In an application to the US Environmental Protection Agency, Google proposes releasing up to 16 million male Wolbachia-infected southern house mosquitoes in both Florida and California in the first year of a two-year trial, then a further 16 million in each of the two states in the second year.

Because Wolbachia occurs naturally in around half of all insect species and poses no known health risks to humans, Google argues that the Debug method is both more effective and less toxic to the environment than using insecticides to control the insects.

Most scientists seem to agree.

“Wolbachia-based strategies are generally species-specific and do not introduce novel toxins into the environment,” mosquito expert Karthikeyan Chandrasegaran, an assistant professor at the University of California, told Live Science website.

Google’s US application, which is still being considered after the deadline for public submissions ended on June 5, has gained widespread global attention. However, the Wolbachia-based approach to controlling mosquitoes is not new – in fact, field trials were first conducted in Australia 15 years ago.

According to the website of the World Mosquito Program  – a non-profit group of companies owned by Melbourne’s Monash University – pioneering Australian scientist Scott O’Neill began working on the tiny bacterium in the 1980s.

In 2009, researchers made a crucial breakthrough when they discovered Wolbachia could prevent the transmission of dengue and other viruses by Aedes aegypti mosquitoes.

Two years later, they released Wolbachia-infected mosquitoes in Cairns as part of a field trial, with the WMP conducting further trials over the past two decades in places such as Colombia, Fiji, Vanuatu, Mexico and Sri Lanka, as well as other parts of Australia.

The program has reported a huge drop in dengue cases in treated regions, stating in 2022 that its Wolbachia method “now protects more than 10 million people”.

The WMP approach is different to that of Debug in that it is based on a technique described as “Wolbachia replacement”. It involves releasing both male and female mosquitoes to facilitate the spread of Wolbachia in the wild mosquito population.

Last year, Google announced that Debug and the World Mosquito Program were teaming up in their efforts to combat mosquito-borne diseases.

“Debug’s automated release technologies have the potential to significantly increase the speed and efficiency of our Wolbachia releases, accelerating our goal of protecting as many people as possible worldwide,” Scott O’Neill, CEO and founder of the World Mosquito Program, said at the time.

Debug’s tech includes automated mosquito-rearing robots and AI-powered sex sorting systems. Photo: Google

Debug also announced last month that it was expanding its research and development and mosquito production facilities in Singapore to create its first international R&D hub.

“This expansion builds on its years of production and releases in communities across countries like Singapore, Italy, Australia, and the US, and comes as the initiative crosses a milestone of releasing more than one billion male mosquitoes globally since inception,” it said.