The San Gabriel Valley Mosquito and Vector Control District is a public health agency that provides ongoing mosquito and vector control for its residents. The District was formed as an independent special district in 1989 to protect residents from vector-borne diseases, more specifically at that time, to address a local outbreak of a mosquito-borne disease called St. Louis encephalitis.
The District provides mosquito and black fly control services to nearly two million residents in 26 cities in the San Gabriel Valley, and some unincorporated portions of Los Angeles County. This is a total area of 287 square miles.
The District's services are funded with a benefit assessment on each parcel in the District. The assessment is based on land use and parcel size. In fiscal year 2018-2019, the assessment ranged from $11.98 to $20.00 per parcel.
The 26-member cities include: Alhambra, Arcadia, Azusa, Baldwin Park, Bradbury, Claremont, Covina, Duarte, El Monte, Glendora, Industry, Irwindale, La Puente, La Verne, Monterey Park, Monrovia, Pasadena, Pomona, Rosemead, San Dimas, San Gabriel, Sierra Madre, South Pasadena, Temple City, West Covina and Walnut.
A "vector" is defined in the California Health and Safety code Section 2002 as "any animal capable of transmitting the causative agent of human disease or capable of producing human discomfort or injury including, but not limited to mosquitoes, flies, mites, ticks, other arthropods, and rodents and other vertebrates."
The District follows a comprehensive integrated vector management stratagy that includes:
Disease Surveillance – Vector populations are surveyed with a variety of sampling tools and laboratory techniques to determine whether vector-borne diseases are prevalent. The abundance of vectors like mosquitoes indicates the level of public health risk. Mosquitoes are tested routinely for evidence that West Nile (WNV), St Louis encephalitis (SLE), western equine encephalomyelitis (WEE) viruses are circulating. The risk for emerging diseases caused by chikungunya, dengue, and Zika viruses is also evaluated.
Prevention and Control – Areas where vectors may rest, develop, or reproduce are identified and treated. The broad control strategies are:
Source Reduction –standing water or other harborage that may support mosquitoes and other vectors is reduced or eliminated.
Environmental Control –the environment is be altered to make it less conducive to develop or harbor mosquitoes and other vectors.
Biological and Chemical Control - natural predators such as mosquito fish, or biorational pesticides are used to eliminate or manage vector populations.
Public Education and Outreach –information for residents and local agencies is provided at no cost through print literature, press releases, community fairs, classroom programs, social media, and local events.