Alphabet science unit to target Zika carrying insects with 20m mosquitoes

Doctored mosquitoes will be released in bid to kill off disease-carrying cousin

Twenty million doctored mosquitoes are to be released in California over the next 20 weeks by a company owned by Google's parent company in a bid to kill off a disease-carrying cousin.

Reared by machines, the male mosquitoes are infected with a bacteria that is harmless to humans, but creates non-hatching dead eggs when they mate with wild females.

The swarm’s target is Aedes aegypti, a mosquito breed that carries viruses like zika, dengue, and chikungunya diseases and which arrived in California’s Central Valley just four years ago.

The campaign, which starts on Friday, is run by Verily Life Sciences, which is part of Alphabet – the multibillion company that owns Google, the world's biggest online search company.


After becoming a standalone Alphabet division in 2015, Verily has grown rapidly, taking on numerous health technology projects, partnering with the drug industry and raising significant funds including $800 million (€694m) from Singapore investment firm Temasek Holdings Ltd. While the mosquito project, called Debug, will not generate revenue in the near-term, it's a chance for Verily to show off its technical prowess in the health-care field.

"If we can show that this technique can work, I'm confident we can make it a sustainable business because the burden of these mosquitoes is enormous," said Verily engineering chief Linus Upson, who helped create Google's Chrome web browser and now leads Debug.

Bugs in Bugs

Verily’s mosquitoes are not genetically modified. They are infected with a naturally occurring bacteria called Wolbachia. When infected male mosquitoes mate with wild females, they create nonviable eggs, resulting in population decline over time. A bonus: Male mosquitoes do not bite, so Fresno residents will not spending the summer itching more than normal.

Verily is not the first to use Wolbachia mosquitoes for disease control. Organisations like the Bill and Melinda Gates Foundation have been working on the bugs for more than a decade, running pilot projects in countries including Indonesia and Brazil. Verily's contribution has been to create machines that automatically rear, count, and sort the mosquitoes by sex, making it possible to create vast quantities for large-scale projects. The Fresno project will be the biggest US release of sterile mosquitoes to date, Verily says.

A minimum ratio of seven Wolbachia mosquitoes to one wild male mosquito is needed to control the population, according to Steve Mulligan, district manager of the Consolidate Mosquito Abatement District, which includes the parts of Fresno in this project.

Verily is planning to release 1 million mosquitoes a week over a 20-week period across two 300-acre neighbourhoods. The company's bug-releasing van will start travelling the streets of Fancher Creek, a neighbourhood in Fresno County, on Friday.