What We Do
Objectives
Orange County Vector Control District’s (OCVCD) primary
objective is to protect the people of Orange County from the dangers
of vector-borne disease. A major component of our program
is to educate the public about the shared responsibility of vector
control. The District works hard to abate existing mosquito
breeding sources and prevent new ones. The common goal is to
permit full use and enjoyment of our backyards and the many recreational
facilities within the County. We also want to permit mosquito-free
agricultural and industrial working conditions.
The District’s Responsibility
The District controls mosquitoes in the County’s wetlands and other chronic breeding sources created by standing water in street catch basins, subdivision drains, roadside ditches, flood channels, ravines and similar places on public right-of-ways. The protocol is routine larviciding operations throughout the year and treating for adults only when necessary. We work with city, county, state, and federal agencies toward permanent correction of these sources whenever it is advisable.
The Orange County Vector Control District does a number of things to control mosquitoes throughout the county.
Surveillance
Initially, and most importantly, OCVCD does surveillance all over the county. If
we don’t know where the mosquitoes are we can’t treat for them! OCVCD
has about 100 mosquito traps placed all through the county to collect mosquitoes
to see how many are in that area as well as to test them for possible diseases
they could be carrying (i.e. West Nile virus, St. Louis and Western Equine
Encephalitis). Orange County Vector Control District uses two different
types of traps: a carbon dioxide trap and
a gravid
trap. The carbon dioxide trap is used as an attractant for
recently mated females. After females mate, they need to find a
blood-source to be able to produce eggs. Carbon dioxide is what all
animals exhale when they are breathing so the trap mimics a potential blood-meal
to the mosquito. Every time you exhale when you are outside you are attracting
mosquitoes! The gravid trap is a foul-smelling trap that egg-laying
female mosquitoes are attracted to as a potential place to lay their eggs.
As well as the surveillance conducted by our lab every week, our Inspectors are also doing surveillance every day by looking for mosquito breeding sources in their areas. In between service requests, our Inspectors are checking drains, gutters, and ditches. Anything that can hold water for longer than one week has the potential to be a breeding source.
Control
OCVCD uses many different means of controlling mosquitoes.
Mechanical Control
One of the best and easiest ways of controlling mosquitoes is to keep water moving. Marshes, wetlands, and other swampy areas become breeding sources when the water becomes stagnant and cannot flow properly. OCVCD has a crew whose job is to go to these areas and remove vegetation so the water can flow properly to deter mosquito breeding sources.
Biological Control
OCVCD’s primary source of biological control
is a little fish, the mosquito fish (Gambusia affinis). These
fish are indispensable to our mosquito control program. They eat mosquito
larvae as fast as the larvae hatch from their eggs. Mosquito fish are
provided free of charge at our District for stocking ornamental ponds, unused
or “out-of-order” swimming pools, and animal watering troughs. They
feed themselves and care is limited to protecting them from garden sprays and
from chlorine or other chemicals used to clean the pond. The District
also stocks thousands of these fish each year in artificial lakes, reservoirs,
waste water disposal lagoons, and drainage channels to eliminate the need for
frequent spraying with a mosquito insecticide. The District is careful
not to place mosquito fish where they could enter a natural system. Click
here for more information on mosquito fish.
Chemical Control
While, technically this is the chemical control category, OCVCD uses biological agents for larval control. OCVCD routinely applies “biorational” pesticides countywide to control mosquitoes. The term “biorational” relates to the application of naturally occurring mosquito pathogens and predators in a manner that provides effective mosquito control with the least amount of impact on the environment. Currently, OCVCD uses several biorationals including two microorganisms, Bascillus thuringiensis israelensis (Bti) and Bascillus sphaericus plus an insect growth regulator, methoprene. Click
here for more information on biorational control.
Education
Another integral facet of vector control is education and outreach. OCVCD attends hundreds of outreach events each year to educate the public on vector control issues. Our website is another means for educating the public on vector issues and what the homeowner can do to manage their vector problem. OCVCD also gives presentations throughout the county to numerous groups and community organizations on vector topics. We are also in the process of creating a school program in order to get the vector message to the next generation. OCVCD has pamphlets at the office that you can pick up or we can send them to your residence free of charge. We have also created public service announcements for both radio and television for educating the public on health issues. Click here for more information on OCVCD’s outreach program.
MOSQUITOES
