Invasive Aedes Mosquitoes

Unfortunately within the past five years, two invasive mosquito species have been discovered in California. These invasive mosquitoes do not occur naturally here in California, but have arrived from other parts of the country or world.

Delano Mosquito Abatement’s first detection of the invasive yellow fever mosquito (Aedes aegypti) was in 2016, in the city of McFarland. The mosquito was captured in weekly routine traps set throughout the city by our mosquito technicians. The following year, Aedes aegypti was discovered in Delano, and recently detected in 2019 in Earlimart. The district is actively monitoring for these exotic species of mosquitoes.

These invasive mosquitoes are aggressive day time biters that will readily enter and follow people into buildings and vehicles. They tend to bite around the ankles and elbows. They prefer to bite humans, but will readily bite animals too.

These two mosquitoes are “container breeders.” Females will lay individual eggs in buckets, flower pot saucers, cups, old tires, and various containers that collect water. Eggs can be laid in containers holding as little as a teaspoon of water. And those eggs, laid just above the water line, can survive dry conditions for months. Aside from containers, they will also utilize natural habitats such as inside tree holes, bamboo, and flowering plants to breed. Backyards are the number one source for mosquito production. Anything that can hold water for more than a week has the ability to produce mosquitoes. For this reason, it is important to dump, drain, or eliminate unnecessary sources of standing water around your home and scrub containers to dislodge eggs.

These two invasive mosquitoes are capable of transmitting dengue, yellow fever, chikungunya, and Zika virus. Rest easy though. There has been no detection of locally acquired dengue, yellow fever, chikungunya or Zika virus in Kern County. However, to protect yourself and prevent the spread and establishment of these two invasive mosquitoes, we here at the Delano Mosquito Abatement District suggest you follow the 5 D’s.

  • DUSK and DAWN: Stay inside if possible. Mosquitoes are most active during dusk and dawn.
  • DRESS in long-sleeve shirts and pants, socks and shoes when outside.
  • DEET: Make sure this ingredient is in your insect repellent.
  • DRAIN standing water in your yard, under potted plants, in bird baths, ornamental fountains, buckets, tin cans and discarded tires. Check your rain gutters to make sure they are not holding water, and clean pet water-dishes weekly.
  • DEFENSE: Be sure your home’s window and door screens are in good repair to prevent mosquitoes from coming inside.

For those traveling to and from regions; such as Central and South America, Mexico, Southeast Asia and Africa, where these viruses are more prevalent, remember the 5 D’s above to help protect yourself. If you are sick with fever, headache and joint or muscle pain after returning from areas where dengue, yellow fever, chikungunya or Zika viruses occur, contact your doctor and stay indoors as much as possible to avoid mosquito bites and help prevent possible spread of those viruses.

If you believe you have a mosquito problem, please contact the Delano Mosquito Abatement District at 661-725-3114.

For more information on these invasive mosquitoes and their associated viruses, please visit:

CDPH – Aedes aegypti and Aedes albopictus

CDC – Aedes aegypti and Aedes albopictus

Aedes aegypti
(Yellow fever mosquito)


The adult yellow fever mosquito is a small (1/4 inch) dark mosquito with white lyre (guitar/violin) shape on the “back” and has white banded legs.

Aedes albopictus
(Asian tiger mosquito)


The Asian tiger mosquito is a small (1/4 inch) dark mosquito with a single white stripe running down the “back” and has white banded legs.

Breeding site examples:


Cemetery flower vase


Plant bucket


Plant axil, where leaf meets stem, can hold water for mosquitoes to grow.


Car tires