Silicon Valley researchers are attacking flying bloodsuckers in California's Fresno County. It's the first salvo in an unlikely war for Google parent Alphabet Inc.: eradicating mosquito-borne diseases around the world.

A white high-top Mercedes van winds its way through the suburban sprawl and strip malls as a swarm of male Aedes aegypti mosquitoes shoot out of a black plastic tube on the passenger-side window. These pests are tiny and, with a wingspan of just a few millimeters, all but invisible.

"You hear that little beating sound?" says Kathleen Parkes, a spokesperson for Verily Life Sciences, a unit of Alphabet. She's trailing the van in her car, the windows down. "Like a duh-duh-duh? That's the release of the mosquitoes."