ROSEVILLE, CA – Adult mosquitoes trapped in western Roseville have tested positive for West Nile Virus. To limit the spread of infected adult mosquitoes, the Placer Mosquito and Vector Control District will conduct truck-based mosquito adulticide applications beginning at midnight tonight and ending by 3:00am Saturday morning.

Applications will be targeted in the following areas West of Roseville:

  • The area north of PFE Road to Vineyard Road, and between Cook
  • Riolo Road and Walerga Road.
  • The development west of Walerga just north of Dry Creek.

Trucks will be applying Pyrenone® 25-5 (pyrethrin + PBO) by ultra low volume fog to target adult mosquitoes as they are flying.

For more information, including map of the treatment area and pesticide label please visit or call the District at 1-888-768-2343 between 7:30am and 3:30 pm Monday through Friday.

The District makes every effort to notify the public of planned adulticide operations as soon as feasible. Unfortunately, sometimes there is need to respond quickly to mosquito populations, West Nile Virus activity, and weather conditions in order to best protect public health and maximize the efficacy of our treatments. In these cases, notification prior to treatment may be difficult.

The District urges the public to continue to protect themselves from mosquito bites especially during the hours around dawn and dusk. Wearing long sleeves and pants and using a mosquito repellent containing DEET, Picaridin, or Oil of Lemon Eucalyptus will help limit the risk of getting West Nile Virus.

The District also encourages the public to continue to report dead birds to the State Dead Bird Hotline at 1-877-968-2473 (1-877-WNV-BIRD).

Contact: Joel Buettner, General Manager (916) 380-5440.