Frequently Asked Questions

How is the Marin/Sonoma Mosquito & Vector Control District funded?

The Marin/Sonoma Mosquito & Vector Control District is a California Independent Special District. California Independent Special Districts are funded by a small annual service charge assessed on all non-exempt land parcels in the service area. Like other forms of local government, the districts are audited and subject to state and local oversight.

Marin and Sonoma county homeowners are typically assessed between $10 and $20 per year for mosquito and vector control services. Prior to the passage of Proposition 13 in 1978, the Health and Safety code allowed mosquito control districts to set a tax rate sufficient to fund their proposed budget. Since Proposition 13, the District, like other public entities, has received only a very small share of the 1% general county property tax, equivalent to its share prior to 1978.

In 1996, the District's Board of Trustees formed a Benefit Assessment District in order to provide sufficient funding to protect the public health of those we serve. In 2004 the District expanded its services to cover the entirety of Marin and Sonoma counties.

During this process the District formed a second Benefit Assessment District in the annexed areas in order to fund the provision of program services to the newly expanded service area.

Exemptions

The laws governing Benefit Assessments do not provide for any exemptions such as the senior, disability, low income or veterans property tax exemptions. Benefit Assessments are fundamentally different from property taxes as they reflect the provision of a direct benefit to the property and its residents, as opposed to a general tax assessed according to the property’s value (ad valorem tax).

Why is mosquito control important?

Not only are mosquitoes a nuisance, they are also a public health threat. While most mosquito species in Marin and Sonoma counties are considered nuisance mosquitoes, their bites can cause severe allergic reactions in some people. High populations of mosquitoes can also have an impact on livestock, negatively affecting milk production in dairy cows.
More importantly, mosquitoes must be controlled because of the risk to human health. Mosquitoes have the capability of transmitting diseases such as West Nile virusdog heartworm and western equine encephalomyelitis. The goal of the District's mosquito control program is not to eradicate all mosquitoes, but to successfully reduce nuisance mosquito populations and prevent mosquito-borne disease transmission.

How do you control mosquitoes?

Mosquito and vector control is based on scientifically planned management tactics and control strategies that reduce the abundance of target pests in a timely manner. This method is commonly referred to as “Integrated Vector Management” (IVM). This comprehensive program incorporates five basic methods: public information and education, mosquito and vector surveillance, source reduction, biological control and microbial and chemical control. Click here to learn more about our mosquito control program. 

How does the District notify residents of adult mosquito control (fogging)?

The District has implemented an Adult Mosquito Control Notification Program as a courtesy to the residents of Marin and Sonoma counties. This program utilizes CodeRED, a high speed notification system that sends out pre-recorded messages 48 hours in advance to homes within a 0.5 mile radius of the area scheduled for truck mounted adult mosquito control (fogging). Maps of the scheduled treatment area can be viewed by clicking on the View Fogging Maps link.

Telephone numbers for each community have been provided via the Emergency Communication Network. Residents that do not have landlines can still be contacted via cell phones, text messaging, or email. Click here to learn more. This will take you to the Community Enrollment Page where residents can input and manage their contact information and preferred method of message delivery. Residents can also choose to opt out of receiving notification messages on the Community Enrollment Page.

Please note: It is the responsibility of the individual to maintain their current contact information.

What does the District use to control adult mosquitoes?

Adult mosquito control is conducted when all other methods of control have been exhausted or when larval control measures are unsuccessful or not possible. Most importantly, it is used for the quick knockdown of adult mosquitoes to break the disease transmission cycle.

The District uses products containing pyrethrins for adult mosquito control. Pyrethrins are a group of naturally occurring compounds with insecticidal properties that are extracted from chrysanthemum flowers. When formulated, pyrethrin is used as an adulticide to target flying adult mosquitoes. Pyrethrins are widely used for control of various agricultural, public health, and nuisance pests.

The materials are applied in an Ultra Low Volume (ULV) form, similar to a fog. The tiny (micron-sized) pyrethrin particles impinge on flying mosquitoes. Pyrethrin affects the nervous system of insects by causing multiple action potentials in the nerve cells by delaying the closing of the ion channel. Pyrethrin formulations usually contain a synergist, piperonyl butoxide, which restricts an insect enzyme used to break down toxins. Pyrethrin based adulticides are labeled for use in both agricultural and residential areas for the quick knock-down of adult mosquitoes.

The Environmental Protection Agency (EPA) has determined that pyrethrin-formulated adulticides, when used at labeled rates for mosquito control does not pose unreasonable harm to the environment or humans. Label rates for mosquito control are normally less than one ounce per acre. Pyrethrins are extremely photosensitive and break down within hours in the sunlight. People with chemical sensitivities could experience eye and skin irritation or an allergic type reaction if exposed to a pyrethrin formulated adulticide application.

All products used by MSMVCD are EPA registered public health pesticides labeled for mosquito control. Applications of these products are conducted by state certified mosquito and vector control technicians in accordance with label requirements and limitations. Click here to view all labels and Material Safety Data Sheets (MSDS) for the pesticides used by the District.

For more information on materials registered for mosquito control, visit the Centers for Disease Control (CDC) website.

How will the materials you use to control adult mosquitoes affect the health of humans and other animals?

The Environmental Protection Agency (EPA) has determined that pyrethrin-formulated adulticides, when used at labeled rates for mosquito control, do not pose unreasonable harm to humans, animals or the environment. Label application rates for mosquito control are normally very low (less than one ounce per acre). Pyrethrins are extremely photosensitive and break down within hours in the sunlight. 

There is no need to house your pets or livestock when an adult mosquito control application is being conducted: however, any concerns regarding animal health should be directed to a veterinarian.

People with chemical sensitivities could experience eye and skin irritation or an allergic type reaction if exposed to a pyrethrin-formulated adulticide application, and may want to contact their personal physician with any concerns.

All products used by MSMVCD are EPA registered public health pesticides labeled for mosquito control. Applications of these products are conducted by state certified mosquito and vector control technicians in accordance with label requirements and limitations.

 

What is the best insect repellent to use against mosquitoes?

Repellents can protect you from annoying insect bites and mosquito-borne illnesses. The Centers for Disease Control (CDC) recommend the use of insect repellents containing active ingredients that have been registered by the Environmental Protection Agency (EPA). Registration of these types of products means that they have been tested and proven to be effective and safe for humans when applied according to the label directions.

The following insect repellent active ingredients are registered with the EPA and recommended by the CDC:

  • Picaridin
  • Oil of Lemon Eucalyptus or PMD (not for use on children 3 years and younger)
  • IR3535

Please visit the CDC's Insect Repellent Page for detailed information about any of these repellents. 

 

How effective are bats at controlling mosquito populations?

Many species of bats feed on mosquitoes, but using them as the sole means for mosquito control is unrealistic. In fact, studies show that mosquitoes typically comprise less than 1% of a bat’s diet. Bats are opportunistic feeders and have not shown to prefer any one particular insect over the other. Bats themselves pose a health threat because they have the ability to spread fatal diseases such as rabies and histoplasmosis to humans.

Information source: American Mosquito Control Association

The best way to control mosquitoes on your property is to remove unnecessary standing water, stock mosquitofish in appropriate water features, manage and maintain ponds, swimming pools, hot tubs, and rain barrels, and remove items that can accumulate rain water. If you are experiencing a mosquito problem please contact us for advice.

 

How can I protect myself from ticks and Lyme disease?

Before entering tick habitat, take the following precautions:

  • Consider applying repellent containing at least 20% DEET to exposed skin.
  • Consider treating clothes/personal outdoor equipment with an acaricide containing permethrin.
  • Wear light-colored clothing (this makes it easier to spot ticks).
  • Wear long pants, long sleeves, and long socks whenever possible (this makes it more difficult for the tick to get to your skin).

While in tick habitat:

  • Stay on trails (adult ticks are typically more abundant on the uphill sides of trails).
  • Avoid contact with nymph habitat (leaf litter, logs, tree trunks, etc.).
  • Periodically check for ticks on people and animals.

After exiting tick habitat:

  • Wash all clothes in hot water and dry on high heat.
  • Shower after coming indoors and carefully check for ticks.
  • Properly remove any attached ticks immediately (please see our tick brochure for proper removal technique).

Reduce tick abundance around the home:

  • Utilize landscaping techniques that limit cover for ticks near the home, such as removing leaf litter around homes and using gravel or woodchip barriers between lawns and wooded areas (see the Tick Management Handbook for detailed information).
  • If properly timed, application of acaricides (pesticides designed to kill ticks) can be effective in reducing tick populations near homes. Residents should contact a private pest control company if they are interested in this service.

 

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