Two groups of mosquitoes trapped by authorities in Rohnert Park have tested positive for West Nile virus, officials with the Marin-Sonoma Mosquito and Vector Control District reported late Friday.

The insects were trapped near Wilfred Avenue.

Residents are urged to check their yards for standing water and report suspected mosquito sources to the vector control district, 800-231-3236 or

Common mosquito sources can include neglected swimming pools, discarded tires, ponds, water features, septic tanks, water troughs and plant saucers.