Mosquito Surveillance and Control Overview

About Mosquito Trapping

• Season and Strategy: Technicians deploy adult mosquito traps from April to October, guided by historical data, local insights, and public reports of increased mosquito activity.
• Types of Traps: The primary traps used are the Encephalitis Vector Surveillance (EVS) traps, also known as Carbon Dioxide (CO2) Traps, which use dry ice to mimic the carbon dioxide exhaled by animals and humans, attracting blood-seeking adult female mosquitoes.
• Operation Times: Traps are set during the day to operate overnight, targeting dawn and dusk when local mosquito species are most active.

Data Collection and Processing

• Post-Collection Procedure: Captured mosquitoes are frozen in a lab-grade ultra-low temperature freezer to preserve potential viral particles.
• Sorting and Analysis: Mosquitoes are sorted individually, and those species capable of spreading diseases are sent to the California Department of Public Health (CDPH) for disease testing. Trap and test results entered into the CalSurv database. Disease results are accessible to the public at https://westnile.ca.gov/.
• Quality Control and Monitoring: This process also enables the evaluation of control measures' effectiveness and identification of control failures, such as undetected breeding sites, pesticide resistance, and equipment failure.

Mosquito Control Activities

• SCCMVC prioritizes Larval Mosquito Control and does not conduct aerial spraying or wide-area fogging for adult mosquitoes as a routine control strategy. Managing mosquito populations at the larval stage is most effective if breeding sites are known and accessible.
• Methods of Larval Control
  1. Source Reduction: The most effective method, involving the elimination or alteration of mosquito breeding habitats.
  2. Larval Identification: Identifying and inspecting potential breeding sites is crucial but can be challenging, especially for species that prefer hidden or difficult-to-access locations.
  3. Pesticide Application: When larvae are detected, EPA-registered larvicides are applied according to label instructions by trained and certified staff. Information on these pesticides can be found at Controlling Mosquitoes at the Larval Stage.