Mosquitoes

Mosquitoes can successfully transmit various diseases such as West Nile virus, malaria, canine heartworm, Western Equine Encephalomyelitis virus, and St. Louis Encephalitis. There are approximately 3,500 species of mosquitoes distributed worldwide, 53 different species occur in California and over 20 are found in Sacramento and Yolo counties.

In Sacramento and Yolo counties immature mosquitoes develop in agricultural, industrial, domestic and natural habitats. To see a complete description of mosquitoes found in Sacramento and Yolo counties, please click on the brochure Vectors of Concern.

The Life Cycle of a Mosquito

Mosquitoes need water to exist! This illustration shows the mosquito life cycle from egg to larva to pupa to adult. You can prevent mosquitoes from developing by removing or draining any container that supports this life cycle. In warm temperatures, mosquitoes can complete their life cycle in 7 to 10 days!

Reducing Mosquitoes Around Your Home

Check out these areas around your home where mosquitoes can breed.


View large size (PDF)

Mosquito Sources What you can do to Reduce Mosquitoes
Fish ponds • Stock pond with fish
• Remove excess emergent vegetation
Swimming pools and spas • Keep water off cover
• Chlorinate
• Use filter regularly
Tree holes • Fill hole with sand or mortar
• Contact a tree surgeon
Wading pools • Drain water when not in use
• If water must remain in pool, cover so mosquitoes cannot enter
Containers • Empty water
• Dispose or turn over
• Cover so mosquitoes cannot enter
Bird Baths • Change water at least once a week
Standing water • Eliminate by draining
• Fill in low areas
Watering troughs • Stock with fish
• Change water weekly
Cooler Drains • Prevent water from standing
Street gutter or catch basins • Do not dispose of litter and garden debris in gutter or basins
• Do not over water yard
Pet water bowls • Change water twice a week
Roof gutters • Clean once a year to remove debris
Irrigated lawns or fields • Avoid over irrigation
• Drain standing water