Santa Clara County Vector Control will spray insecticides by helicopter on Tuesday morning to prevent the emergence of adult mosquitoes, according to an agency press release.
California Department of Food and Agriculture employees started spraying a pesticide on trees in East San Jose Wednesday to prevent guava fruit flies from damaging fruit crops, officials said.
The discovery of birds infected with West Nile virus has prompted Contra Costa County officials to schedule a mosquito spraying in Brentwood Thursday night.
Mosquitoes could be out for blood earlier than usual this year because of the recent warm weather, and that has vector control officials in Silicon Valley scheduling a helicopter spraying of a prime breeding ground for Friday morning.
Vector control crews plan to spray chemicals in West San Jose Tuesday night to curb spread of the West Nile virus.