The decision to spray came as Texas deals with 465 West Nile infections and 17 deaths.
Officials in Dallas County, the hardest hit region in the state, recently declared a state of emergency, the Los Angeles Times reported Thursday.
"Aerial spraying is considered the most effective and safest way to kill adult mosquitoes in heavily populated areas," Dallas Mayor Mike Rawlings said during a Thursday briefing.
Planes were targeting 49,000 acres north of Interstate 30 in Dallas County, spraying at night when mosquitoes are most active.
"There's a lot of sentiment that people don't want this, and there's a fear of the unknown," Rawlings said, adding, "you have the science, the CDC [Centers for Disease Control] and the EPA [Environmental Protection Agency], and all of these cities across the United States that say this is OK."
Aerial spraying opponents said they approached Dallas County Judge Clay Jenkins Thursday to say they planned to seek a restraining order to stop all aerial and ground spraying, the Times said. Jenkins defended the approach. He said he was told by state emergency managers and lawyers that local state-of-emergency declarations trump any injunction.
"It's not that I'm against pesticides; I'm against pesticides that don't work," Howard Garrett, a Dallas-based arborist, landscape architect and radio host, said during a recent Dallas council meeting. "They're spending a half a million dollars on this stuff and they're not going to control anything."
Instead of aerial spraying, Garrett said, Dallas officials should target mosquito eggs and larvae with organic pesticides on the ground.