Drought Conditions and Water Conservation Tactics May Cause Banner Year for Mosquitoes

Release date: 
Apr 21
~West Nile Virus & Vector Control Awareness Week encourages residents to protect themselves from mosquitoes and vector-borne disease. 


Cotati, CAThe California State Legislature has declared the week of April 20-26, 2014 as West Nile Virus and Mosquito & Vector Control Awareness Week in California. This declaration coincides with the beginning of what appears to be an aggressive and busy mosquito season for the Marin/Sonoma Mosquito & Vector Control District.


District officials stated that requests for service are up 42% from last year, at this same time. The increase in requests for service could be due to the unseasonably warm weather allowing treehole mosquitoes to emerge earlier, coupled with drought conditions and an increase in the use of rain capturing systems that have not been mosquito-proofed.


"Drought years do not necessarily mean there will be less mosquitoes," stated Jason Sequeira, Field Operations Supervisor for the Marin/Sonoma Mosquito & Vector Control District. "In fact, what we typically find is higher concentrations of mosquitoes in what little water has accumulated," said Sequeira.


As the need for water conservation increases, so does the use of make-shift water containment systems, such as rain barrels and buckets. These containers, if not properly mosquito-proofed, can produce thousands of mosquitoes.  


Residents are encouraged to follow these simple mosquito-proofing tips to eliminate mosquito production and reduce the risk of West Nile virus transmission: 

  • Cover rain barrels and other containers with a mosquito-proof screen (fine mesh-1/16 of an inch).
  • Keep your containers free of organic materials such as leaves and debris.
  • Inspect rain barrels and other containers on a regular basis to be sure there are no cracks or leaks and that all seals and fittings remain intact.
  • Cisterns (above and below ground) should be completely enclosed with no openings to the outside environment.
  • Cover all inlets, outlets, and vents with fine mesh screening (1/16 of an inch).
  • Learn more about mosquito prevention at www.msmosquito.com

According to the California Department of Public Health (CDPH), 372 human cases of West Nile virus were reported in 2013. Of the reported cases, there were 14 fatalities. The CDPH and the Centers for Disease Control and Prevention predict West Nile virus will again pose a public health threat in California in 2014. 

Residents in Marin or Sonoma counties should contact the Marin/Sonoma Mosquito & Vector Control District to report mosquito problems or potential mosquito production sites where they live or work. To learn more about local mosquito control, disease surveillance and public education efforts, please contact the Marin/Sonoma Mosquito & Vector Control District at (707) 285-2200 or visit www.msmosquito.com.

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.