Local Mosquito & Vector Control District Fighting to Suppress Mosquitoes Before They Emerge As Adults

Release date: 
Jan 29

Cotati, CA -The Marin/Sonoma Mosquito and Vector Control District (District) will be using a helicopter to treat mosquito larvae in targeted bodies of water within Marin and Sonoma counties on January 30th and 31st, 2013. District officials stated that the use of the helicopter is the most effective and efficient way to treat large bodies of water that are difficult to reach using ground equipment.

 "The abundance of mosquito larvae in these areas isn't unusual for this time of year," stated Erik Hawk, Assistant Manager for the Marin/Sonoma Mosquito and Vector Control District. "However, the speed at which the larvae are developing is faster than in recent years, which could possibly signify an earlier and more active mosquito season," said Hawk.


The mosquito species being targeted in this treatment are highly aggressive biters that have a long flight range. If left untreated these mosquitoes could cause severe discomfort for surrounding neighborhoods. Targeting the mosquitoes in the larval stage significantly reduces- and often eliminates- the need to take reactive measures such as trying to control the mosquitoes after they have emerged as adults.


The District's mosquito control program is based on scientifically planned management tactics and control strategies that reduce the abundance of mosquitoes in a timely manner, utilizing the most effective and least toxic materials available. This method is commonly referred to as "Integrated Vector Management", and incorporates five basic methods: public information and education, mosquito and vector surveillance, biological control, source reduction, and microbial and/or chemical control.


Larvicides are specialized materials used to control mosquito larvae, and may be used in conjunction with other mosquito control measures to minimize the number of adult mosquitoes that emerge. This not only reduces the incidence and risk of disease, but also decreases the need for adult mosquito control.


The larvicides being used for the applications include Bti (Bacillus thuringiensis israelensis), a naturally occurring bacteria, and methoprene, an insect growth regulator. Due to the fact that the mosquito larvae are in varying stages in the developmental cycle, the use of these two materials enables effective control of the larvae.


The operation is scheduled to take place over a two-day period, weather permitting. If weather conditions are not favorable or if there are operational delays, the treatment will be postponed and resumed as soon as possible.


Since the material is being applied directly to the water source, there are no special precautions to follow; however, we ask that members of the public stay away from the operation sites for the safety of our staff as well as for their own safety.


McInnis Park in San Rafael and Deer Island Basin in Novato  will be included in the treatment plan. Additional areas in rural Marin and Sonoma counties will also receive larvicide treatment.


All products used by the District are EPA registered public health pesticides labeled for mosquito control. Applications of these products are conducted by state certified applicators in accordance with label requirements and limitations. Click here to view the product labels and material safety data sheets (MSDS) for all the materials the District uses.


Residents can minimize mosquito problems by:

  • Check septic tank lids to ensure a tight seal and repair any visible cracks.
  • Screen septic tank vent pipes using a fine mesh screen.
  • Check for and remove standing water that may have collected under your home.
  • Be sure all rain barrels are screened and in good repair.
  • Recycle old tires or store in a sheltered area, away from the rain.
  • Report mosquito problems, neglected swimming pools, or any area that could be producing mosquitoes.
  • Wear mosquito repellent when outdoors at dusk and dawn. Use a repellent containing one of the following active ingredients: DEET, Picaridin, oil of lemon eucalyptus, or IR3535.

The Marin/Sonoma Mosquito and Vector Control District is an independent special district committed to protecting public health from mosquitoes and vector-borne disease. All programs and services are funded through benefit assessments and property taxes. Services are provided to all residents in Marin and Sonoma counties. For more information about us please visit our website at www.msmsoquito.com or call 1-800-231-3236.