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Mosquito control in areas affected by wildfires

What role does the District play in the recovery efforts?
The District wants to continue its constructive role in helping the community recover from the recent disaster by doing its part to protect public health. The District’s Vector Control Technicians continue to work diligently to identify current and potential sources of mosquito production on properties impacted by the fires such as unmaintained swimming pools, ponds, compromised septic systems, containers, debris and depressions that can hold water (e.g. voids from removed foundations) for extended periods of time. Water sources found to be producing mosquitoes will be treated with environmentally compatible mosquito larvicides to control mosquito populations and minimize the potential for mosquito-borne disease transmission. 

How long will you monitor my property?
The District will continue to monitor and conduct mosquito control until all properties have been rehabilitated and/or all sources are no longer producing mosquitoes.

What mosquito control materials will be used in water sources on my property? (e.g. swimming pools, spas, depressions)
The life stage of the mosquito and the specific conditions of a particular source of mosquito production (e.g. water quality) determine the type of material(s) used for control. The materials most commonly used to control mosquito larvae are Bacillus thuringiensis israeliensis and Bacillus sphaericus, which are derived from natural soil bacteria. Other materials include oils and monomolecular films to control mosquito larvae and pupae.

In cases where long-term mosquito control is necessary methoprene may be used to treat mosquito larvae. Methoprene is an insect growth regulator that prevents the mosquito from completing its life cycle and reaching adulthood. In swimming pools impacted by the fires, District staff will be applying methoprene briquettes allowing for long-term (up to 3 months) mosquito control. Due to the large amounts of debris, ash and sediment in many of the swimming pools, the briquettes may be attached to small pieces of styrofoam. This will allow the briquettes to float and will likely maximize the level of mosquito control achieved. 


All materials used by the District are approved by the EPA and the State of California for mosquito control and are applied in strict conformance with the label requirements. 

If your property was affected by the recent fires and you have questions regarding mosquito control or would like to schedule an inspection, please call the District at 707-285-2205.

The Marin/Sonoma Mosquito and Vector Control District’s programs and services are funded through property taxes and benefit assessments and are provided at no additional cost to all residents of Marin and Sonoma counties.

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