Orange County Mosquito and Vector Control District
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The Orange County Mosquito and Vector Control District (District) balances its mission of protecting the people of Orange County from vectors and vector-borne diseases with a profound concern for the environment. It is District policy to use the most selective and least toxic vector control protocols. Whenever possible, District staff utilizes non-chemical procedures such as source reduction and public education to reduce vector production. The District works cooperatively with stakeholder groups including property owners, municipalities, resource managers, and other interests to help ensure that vector production is avoided or minimized and when necessary controlled to protect both human and environmental health.

The District is available to meet with any interested party and offer advice on how to reduce vector concerns associated with any new, proposed, or existing situation. Much of the needed information is available on this website, however if you cannot find answers to your questions here, please contact the District at 714-971-2421.

Integrated Vector Management

Integrated pest management (IPM) is an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties. Pesticides are used only after monitoring indicates they are needed according to established guidelines, and treatments are made with the goal of removing only the target organism. Pest control materials are selected and applied in a manner that minimizes risks to human health, beneficial and non-target organisms, and the environment. - Official University of California Definition

The District employs these widely recognized principles of IPM to control for vector species through an approach called Integrated Vector Management (IVM). These techniques guide the District's comprehensive vector control programs to meet human, domestic animal, and wildlife needs for protection from nuisance and disease that may be spread by vector insects and animals. Our Integrated Vector Management (IVM) Program's focus is to control the production of mosquitoes, filth flies and black flies, Red Imported Fire Ants (RIFA), and rats. The IVM Program consists of the following activities: 1) Surveillance for vectors, vector habitats, and associated pathogens/diseases; this includes field and laboratory analysis of vectors in order to evaluate populations and emerging disease threats; 2) Source reduction to limit breeding by vectors; this includes management of vegetation, land, and water with appropriate landowners to minimize vector production; 3) Education and outreach efforts targeted toward the public and private landowners in ways to facilitate source reduction and minimize disease-carrying vectors; 4) Distribution of mosquito fish (Gambusia affinis), a biological control measure used to reduce mosquito production in isolated aquatic features, such as neglected residential swimming pools; and 5) Application of pesticides to minimize vector populations and reduce the threat of potential vector-borne disease transmission to humans.

  • Integrated Vector Management and Response Plan - The IVM Plan outlines surveillance and control measures for vectors in Orange County. The purpose of the IVM Plan is to provide guidelines to the District's staff and information to stakeholders regarding the various responses made to prevent and control disease vectors as well as introduced diseases and vectors in Orange County.
  • Other Integrated Pest Management resources
Vector Reduction Program

The Vector Reduction Program (VRP) is based on the proven strategy that cooperative land management practices are an effective means to reduce vector populations. This Program aims to work with property owners and land managers to advise and assist them with information and specific Vector Reduction Guidelines that, when implemented, will help to greatly reduce or eliminate significant vector breeding and harborage problems. These long-term solutions result in cost savings to property owners and decrease the need for pesticide use. These practices help to protect public health and are an integral part of the District's Integrated Vector Management approach to mosquito and vector control.

  • Vector Reduction Manual - This manual describes how the District aims to work with property owners to reduce or eliminate vector-favorable conditions by encouraging the implementation of Vector Reduction Guidelines, which are based on IVM techniques and strategies. This document includes specific vector reduction guidelines for mosquitoes, rats, Red Imported Fire Ants, and black & filth flies in the following land use settings:

    • Residential and Commercial Mosquito Sources
    • Low Impact Developments (LIDs)
    • Ornamental Ponds and Water Features
    • Tire Storage
    • Sprinkler and Irrigation Systems
    • Nurseries
    • Cemeteries
    • Golf Courses
    • Equestrian Facilities
    • Agriculture
    • Wetlands
    • Agriculture
    • Stormwater Systems and Urban Runoff
      • Above Ground Structures
      • Underground Structures
      • Flood Channels
      • Natural Watercourses
      • Freeway Drains
      • Wastewater Management
    Environment - Collage

  • Vector Minimization Workshop - The District offers a free workshop to address planning, design, and maintenance considerations related to the potential for vector production in a variety of land uses. Proper planning can largely avoid or eliminate vector problems and reduce liability. Vector minimization principles associated with structural stormwater BMPs, constructed wetlands, water management, and landscape design are emphasized in this workshop. This workshop can be tailored to meet the needs and focus of any audience including, HOAs, engineering firms, municipalities, etc.
Vector Habitat Remediation Partnerships

In keeping with the objectives of the District's Vector Reduction Program to work cooperatively with landowners in resolving significant vector sources on their properties, the District has established a program based around Vector Habitat Remediation Partnerships. This effort aims to help, at this phase, other public entities with funding or other assistance, to support qualified projects that will significantly reduce or eliminate chronic mosquito breeding sites and/or present other vector hazards. Candidate projects would involve the physical alteration of conditions at chronic mosquito breeding sites, which the District has identified, in ways that will reduce mosquito breeding habitats and improve the effectiveness of mosquito control measures in a more environmentally friendly way. The Program provides a strong focus on designing, modifying and maintaining wetlands and stormwater facilities to function in a way that would reduce or eliminate mosquito breeding habitat while balancing resource objectives.

For more information on project qualifications and assistance opportunities please contact the District at 714-971-2421.

Consultation / Plan Review

The District actively participates in the review and planning processes for proposed development and environmental projects in Orange County. The District works cooperatively with the regulatory agencies, the 34 cities within the district boundaries, the County of Orange, and project proponents to minimize the potential for mosquito production and public health issues. For example, the District consults on wetland restoration and enhancement projects, stormwater facilities, a variety of new and redevelopments projects in Orange County with a particular emphasis on reviewing projects that include ornamental water features, stormwater treatment controls and LIDs, irrigations systems, water retention basins, constructed mitigation wetlands, and any other types of water impoundments.

Proactive planning, design, and maintenance are key factors in avoiding the development of significant mosquito or vector sources. Incorporating practical considerations to minimize the potential for vector issues with a project in the planning phases has the potential to save costs, lower liability, decrease pesticide use, and provide better protection for people and the environment.

The District recommends that municipal planning department personnel and project proponent consultants (i.e., engineers and wetland designers) contact and notify the District of any project that includes the aforementioned project features that could potentially create mosquito breeding sites or affect resident's contact with mosquito or vector species.

Please contact Amber Semrow at 714-971-2421 to submit a project for review or other consultation considerations.

  • For a Vector Control Clearance Letter please email
  • For a Red Imported Fire Ant soil inspection please contact the California Department of Food and Agriculture at 951-782-3271.
Southern California Vector Control Environmental Taskforce

The District proudly administrates the Southern California Vector Control Environmental Taskforce which is a group of local vector control/public health agencies that work cooperatively with environmental resource agencies, municipalities, research institutes, private firms and other interests to raise the awareness of vectors control issues and prevention, facilitates interagency communication and coordination, and advocates for policy changes that aim to reduce vectors though environmentally sound measures.

Efforts by the Taskforce include presenting annual forums, conducting workshops, and participating in stakeholder groups and public commenting opportunities on issues and projects that are related to vector control/public health protection and the environment.

Please contact Mike Saba at 714-971-2421or with any inquires.

Resources to Reduce Vectors
 Orange County Mosquito and Vector Control District