Yellow fever mosquito detected in Placer County. District implements response plan.

ROSEVILLE, Calif., July 19, 2022 – The Placer Mosquito and Vector Control District detected an invasive (non-native) species of mosquito on Thursday, July 14. The Aedes aegypti, commonly known as the yellow fever mosquito, was found in a residential Granite Bay neighborhood just south of Granite Bay High School. The California Department of Public Health confirmed the invasive species detection.

“We are following our invasive mosquito response plan to determine the extent of the infestation,” said Joel Buettner, General Manager. “We ask residents to help us by allowing our technicians to inspect front and back yards of nearby properties.”

The District uses a science-based, Integrated Vector Management approach to assess mosquito activity and risk and conduct appropriate mosquito control. The District’s approach for the detected mosquito area is conducting door-to-door property inspections and setting mosquito traps to determine the infestation level.

The Aedes aegypti mosquito has been steadily spreading through California since it was first detected in Southern California in 2013.  In 2021, several northern California counties reported detections including Shasta, Yuba, Butte, Yolo and Sacramento. The mosquito is small and dark with a white violin-shaped marking on its back. Aedes aegypti can transmit several viruses, including Zika, dengue, chikungunya and yellow fever. These viruses, however, have not been found circulating in California. “While we are not aware of any local transmission of viral illnesses due to Aedes aegypti, the local appearance of these mosquitoes warrants extra precautions,” said Placer County Interim Health Officer Rob Oldham.

The public can help protect themselves by reporting unusual, daytime mosquito biting. The District also urges the public to eliminate standing water and runoff or pooling from irrigation systems since these mosquitoes can breed in small amounts of water and cryptic sources. Residents can also prevent mosquito bites by using EPA-registered repellents.

For more information, contact the Placer Mosquito and Vector Control District at (916) 380-5444 or Follow the District on FacebookTwitterInstagram and TikTok: @placermosquito. For a list of EPA-registered repellents, please visit or