Rich Pedroncelli / AP Gov. Arnold Schwarzenegger, left, meets with lawmakers and environmentalists Thursday in Sacramento. He said the state will postpone all aerial sprays until Aug. 17.

FRESNO — A California judge dealt a major setback to the state's campaign against an invasive moth on Thursday, ruling that aerial sprays over Santa Cruz County must be halted until agricultural officials do a full environmental review of their anti-pest program.

The ruling could keep planes from releasing a pesticide there targeting the light brown apple moth for up to a year, while the state studies the spray's effect on people and the environment, said county spokeswoman Dinah Phillips.

Secretary of Food and Agriculture A.G. Kawamura vowed the state would appeal the ruling immediately. In a statement, he said the decision was delaying "the safest, most progressive eradication program available."

After meeting with lawmakers and environmentalists, Gov. Arnold Schwarzenegger said Thursday the state would postpone all aerial sprays until Aug. 17, more than two months after the Santa Cruz area was scheduled to be dusted with a fine chemical mist. The state will take the extra time to evaluate acute tests of the human health effects of all new proposed pheromone formulations, he said.

"The light brown apple moth is a serious threat to California's forests and agriculture. If left uncontrolled, the moth would have a devastating impact on our state's environment and economy," Schwarzenegger said in a statement.

Hundreds of people complained of feeling sick when planes applied the first round of spray in the area surrounding Monterey and Santa Cruz last fall. State environmental health experts recently said those reported illnesses can't conclusively be tied to the pest eradication efforts.

Soon after the sprays, the county and city of Santa Cruz sued the state, saying Kawamura broke state law by authorizing the aerial campaign without the benefit of environmental review.

Environmentalists filed a similar suit in Monterey County Superior Court, which is scheduled to be heard May 8.

Superior Court Judge Paul Burdick ruled Thursday morning that the state had not proved the moth infestation constituted an emergency, a category that would have allowed authorities to skirt the lengthy review process.

Steve Lyle, a spokesman for the California Department of Food and Agriculture, said the agency believes Burdick's decision only affects the state's plans in Santa Cruz County, but wouldn't speculate about how it would affect aerial treatment programs in other counties.

Assemblyman John Laird, D-Santa Cruz, who has written two bills critical of the program, said he hoped the ruling would "make way for additional science-based, independent third-party review" of the state's plans.

Dozens of Santa Cruz residents rejoiced on the courthouse steps Thursday, Phillips said.

"When the judge announced his decision, a tremendous cheer was raised," she said.