Sacramento-Yolo Mosquito District warns of West Nile and invasive Aedes; announces sterile-insect pilot

Steve Ramos, assistant manager with the Sacramento-Yolo Mosquito and Vector Control District, told the Rancho Cordova City Council that the district found West Nile'positive mosquito samples inside the city limits this season and is stepping up surveillance and control efforts.

"Our mission, of course, is to provide safe, effective, economical mosquito and vector control," Ramos said, describing the district's five-pronged integrated mosquito management program: public information, surveillance (traps and testing), biological control, ecological management and control operations. He said mosquito season typically runs from late spring into October and that breeding sources range from rice fields to backyard containers and vacant green pools.

Ramos said invasive day-biting mosquitoes Aedes albopictus and Aedes aegypti have been detected in the region and are of particular concern because they can transmit dengue, Zika and chikungunya. To target those species, the district plans a pilot release of sterile males using Wolbachia'infected males under the sterile insect technique (SIT); he said the first release was scheduled to begin in Southern Natomas the day after the council meeting.

The district asked residents to report day-biting mosquitoes, request free yard inspections, and report dead birds through the district website. Ramos provided the public service address for requests and reporting as fightthebite.net.

Council members asked about ecological impacts and past uses of SIT. Ramos said the goal of local control is "mosquito control and not elimination," and described biological controls such as fish for rice fields and green pools. He noted that West Nile is primarily a bird disease and that dead-bird surveillance remains part of their detection strategy.

The district urged vigilance and described planned increases in outreach and targeted surveillance where positive samples have been detected.