In California, the primary reasons for controlling mosquitoes are to lessen the annoyance caused by their bites and to reduce the transmission of human and horse viral encephalitis and dog heartworm. Biology and Identification Mosquitoes are true flies, belonging to the family Culicidae in the order Diptera. The most important genera are Aedes, Anopholes, Culex, and Culiseta. The egg is laid on or near water, or where water will eventually cover it. The larva and pupa live under water, while the adult lives on land.
All mosquitoes have a long piercing mouthpiece called a proboscis, which is used for feeding.
All mosquitoes require still water on which to drop their eggs. In urban areas, the most likely larval breeding areas are artificial containers or other small bodies of water such as storm and sewer catch basins and roadside ditches. Use a long-handled dipper to check water for mosquito larvae in ornamental ponds and other standing water. Health Concerns Several of the 48 known species of mosquitoes in California can carry disease under the right conditions. There are two forms of viral encephalitis, St. Louis and Western Equine, transmitted by mosquitoes in California.