From Palo Alto Online
February 12, 2018
Santa Clara County will begin its annual treatment Wednesday of the Palo Alto Baylands to prevent the spread of the winter salt marsh mosquito, which lays eggs in moist soil, like the kind found at the popular hiking and biking destination.
The Santa Clara County Vector Control District announced that the marshes will be treated with naturally occurring soil bacteria and “a mosquito-specific hormone” that is not harmful to the surrounding environment, wildlife or humans. The soil bacteria produces an insecticidal protein when consumed by the mosquito larvae, effectively killing them. The eggs can lay dormant for many years, even with repetitive flooding, according the district.
For some of the less accessible marsh areas, including the Palo Alto Flood Basin, a helicopter will be used to “cover large areas and minimize impact to the marsh habitat,” the district said. The helicopter crew may fly at low altitudes over the treatment area within the basin.