Mosquitoes are a serious vector and a very obvious public annoyance due to their biting. While most evidence points to AIDS not being vectored by mosquitoes, they are however implicated in the spread of malaria, West Nile virus, viral encephalitis, dengue and several other diseases world wide. In Southern California, the mosquitoes can carry malaria and encephalitis and the Vector Control District actively works at controlling the mosquito populations in this area. Carbon Dioxide and light inspection traps are used regularly to monitor numbers and species of mosquitoes in all areas of the District. Routine examinations are conducted on sentinel chicken flocks to determine if a disease is prevalent in an area.

Water sources which breed mosquitoes are either altered so as to cease being a mosquito source or are treated with environmentally sensitive pesticides to control the mosquito larvae. Other means of Environmentally sensitive Mosquito control include the use of Gambusia affinis, commonly known as the Mosquito fish. Mosquito fish naturally consume any mosquito larvea as a food source, thereby acting as a "biological" mosquito control. These fish are provided by the District, at no charge to South Coast residents of the District, for placement in ornamental ponds, livestock watering troughs, and other small, permanant, water sources thereby further reducing mosquito breeding sites.

MOSQUITO FACTS

• All mosquitoes must have water in which to complete their life cycle.
• Only seven days are required to complete their life cycle (egg to adult) during warm weather.
• Mosquitoes do not develop in grass or shrubbery, although flying adults frequently rest in these areas during daylight hours.
• Only the female mosquito bites to obtain a blood meal. The male mosquito feeds only on plant nectar.
• The female mosquito may live as long as three weeks during the Summer or many months over the Winter in order to lay her eggs in the following Spring.

Larval Mosquito Control
Many different water sources exist within the District, such as marshes, creeks, ponds, storm drain systems and poorly maintained pools. Mosquitoes utilize these sources in their life cycle. Specific mosquito species are of great concern in that they are capable of transmitting viral diseases such as West Nile and encephalitis to humans and horses.

Water sources found to be producing mosquitoes will be addressed using integrated vector management procedures involving appropriate physical, biological and chemical control. These inspection and control measures will be repeated on a routine schedule to manage the insect population. The District will monitor pesticide resistance levels and determine the efficacy of available larvicides for local mosquito populations.

Mosquito fish are used to control immature mosquitoes in various bodies of water, both large and small. For backyard sources such as ponds and pools, residents may obtain the fish from the District office. The District will directly bill publicly owned or government owned parcels those costs which are deemed to result from inspection and control procedures performed by the District to manage mosquito production.

Adult Mosquito Control
In the event of a virus outbreak in close proximity to major metropolitan areas where the risk of human disease transmission by mosquitoes or other vectors is high, the District will initiate an expanded and intensified larvicide program in an effort to interrupt the transmission cycle and reduce the adult populations of vector species. If adult suppression is unsuccessful utilizing these enhanced control measures, or human cases of the disease are reported; the District may, as a last resort, institute widespread application of adulticide materials through aerial or ground fogging measures to quickly reduce disease transmitting populations.