Integrated vector management (IVM) is a decision-making process for the optimal use of resources in the management of vector populations. These decisions are made in order to reduce or interrupt transmission of vector-borne diseases, and prevent nuisance vector populations from impacting the quality of life.
The approach seeks to improve the efficacy, cost-effectiveness, ecological soundness and sustainability of vector control activities.
The key objectives of Integrated Vector Management include:
- The selection of proven vector control methods based on knowledge of vector biology and ecology, and disease transmission.
- Utilizing of a range of interventions, separately or in combination and often synergistically, integrating all available and effective measures, whether chemical, biological, or environmental.
- Collaborating within the health sector and with other public and private sectors that impact vector control.
- Engaging local communities and other stakeholders.
- Knowledge and compliance with public health regulatory and legislative frameworks.
- The rational use of insecticides.
The District’s management policy for Red Imported Fire Ant (RIFA) control is to use education, biological control, and chemical control within the IVM framework.
To learn more about RIFA IVM practices please refer to the District's IVM Plan.
The District has a multifaceted RIFA education program that includes:
- Presentations and participation in local outreach events to educate the public about RIFA control practices.
- The creation and distribution of training DVD’s for landscape professionals to educate their staff about RIFA biology and control strategies.
- Extensive literature on RIFA control practices, local ants that resemble RIFA, and many other publications are available in print and electronically.
- Inspectors educate homeowners and neighborhood groups about how to identify the presence of RIFA on their property and how to eliminate them.
- Staff attends local and national educational conferences to learn about advances in RIFA control techniques, products, and other measures to better educate and protect the public from Red Imported Fire Ants.
Many biological control agents are currently being studied to combat RIFA. These agents are not available for widespread use. The District has worked with the University of California Riverside, Urban Entomology Program, to investigate the use of Thelohania for RIFA control in Orange County. At this time, location of a suitable test site has not been determined.
The District's primary method for control of RIFA is the application of pesticide ant bait containing an insect growth regulator or toxicant. The District currently uses five pesticide ant bait formulations containing four active ingredients. The active ingredients work as an insect growth regulator (IGR) or a metabolic inhibitor (MI) as means of controlling the current adult population and emerging juvenile population. The metabolic inhibitor interferes with the metabolism of food, resulting in the death of the ants by starvation. The colony eventually dies out as a result of ants consuming the bait, then starving, and not being replaced. Results are sometimes visible within a week. The insect growth regulator essentially sterilizes the colony, as ants die through attrition, and they are not replaced. This is a slow acting material, and results may take a month or more to be recognized.
Prior to treatment, District staff confirms the identification of RIFA at a site. The District performs RIFA control in cooperation with private pest control companies at residential sites. In large area sites, such as commercial buildings, schools, parks, rights-of-way, and multifamily housing, the District performs RIFA control. In heavily infested neighborhoods, the District abates RIFA through community-wide management of the pest.
Many neighborhoods in Orange County are heavily infested with RIFA. Heavily infested neighborhoods are determined by analyzing reports of RIFA occurrence. District staff visits these neighborhoods and distributes notifications that a pesticide ant bait treatment will be made within the next week. Residents can opt out of the treatment by contacting the District or taping the notification to the door on the date of the treatment. District staff records the presence of RIFA mounds in the neighborhood. On the treatment day, pesticide ant bait is applied to the front lawns, and sometimes backyards, and communal areas of the neighborhood via a hand-held granular application device. Residents are instructed not to irrigate their property for 24 hours following treatment and to refrain from applying pesticides or other chemicals for 72 hours following treatment.
Broadcast treatments of pesticide ant bait are effective because ants from all colonies in the treated area can collect the bait. This is also easier than an Inspector trying to locate individual mounds. Pesticide ant bait not collected by the ants rapidly decomposes in the environment. Bait broadcast in the environment is effective for a short period of time as the active ingredients degrade in sunlight, and exposure to environmental factors can breakdown the food carrier.