Invasive Mosquitoes Found in San Bernardino County

SBCoArrow - Color

By Staff Reports

(Victor Valley)– On Oct. 15, 2015, the San Bernardino County Department of Public Health, Division of Environmental Health Services (DEHS), Mosquito and Vector Control Program (MVCP) discovered Aedes albopictus (the Asian tiger mosquito) in the city of Upland, and Aedes aegypti (the yellow fever mosquito) in the city of Colton. Specimens were confirmed by the State of California Department of Public Health (CDPH), Division of Communicable Disease Control Vector-Borne Disease Section.

The Asian tiger and the yellow fever mosquito bite primarily during the day, both indoors and outdoors. The adults are small (about a quarter-inch in size), are dark brown or black, and have distinctive white markings around the body and legs. Both species of mosquito are not native to California, but are found elsewhere in the U.S. and in many other regions of the world (the yellow fever mosquito prefers tropical and subtropical areas).The Asian tiger mosquito was discovered in Los Angeles County in 2011 and has recently been detected in Kern and San Diego counties. The yellow fever mosquito was discovered in urban areas of Fresno, Madera and San Mateo counties in 2013 and is now found in 12 California counties. Most recently, the yellow fever mosquito was detected in Riverside County and the city of Montclair.

Both species of mosquito have the potential to transmit several viral diseases including dengue, chikungunya, and yellow fever, although the risk of transmission in California is still low.

At the beginning of the 2015 season, the MVCP established a Mosquito Day-Biting Surveillance Program in anticipation of the arrival of invasive Aedes mosquitoes to the County. Specialized traps were placed in target areas to monitor changes in mosquito populations and to collect mosquitoes for disease testing.

Artificial or natural water-filled containers that are within or around the home are ideal habitats for these mosquitoes. Female mosquitoes can lay eggs in any container holding as little as a teaspoon of water– plant saucers, cups, bird baths, old tires. Eggs have the ability to dry out and survive for several months.

“I strongly encourage the public to be aware of mosquito activity around their homes as well as other outdoor areas and take action to protect themselves and their family by taking appropriate precautionary measures,” said Dr. Maxwell Ohikhuare, M.D., Health Officer. Residents can help control these aggressive and highly invasive mosquitoes by taking the following precautions:

  • Drain or Dump – Remove all standing water around your property where mosquitos lay eggs such as birdbaths, old tires, pet watering dishes, buckets, or even clogged gutters.
  • Clean and scrub any container with stored water to remove possible eggs.
  • Dress – Wear shoes, socks, long pants and long-sleeved shirts whenever you are outdoors to avoid mosquito bites.
  • DEET – Apply insect repellent containing DEET, PICARDIN, IR3535, or oil of lemon eucalyptus according to manufacturer’s directions.

Doors – Make sure doors and windows have tight-fitting screens. Repair or replace screens that have tears or holes to prevent mosquitos from entering your home.

If you notice these small black and white mosquitoes in or around your home, please contact the County of San Bernardino Department of Public Health, DEHS MVCP at (800) 442-2283. For more information, you can call us or visit our website at, or the CDPH website at .

Leave a Reply

Your email address will not be published. Required fields are marked *