Australian backyard mosquito: A non-native mosquito new to Santa Barbara County!

A close-up image of Aedes notoscriptus on human skin, showcasing its distinct black and white striped body and long legs.
Photo credit: Lek Khauv - https://www.inaturalist.org/observations/1682027, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=162499483

Several specimens of adult Aedes notoscriptus, aka the "Australian backyard mosquito" have been found recently in a sample from a residence in the Westside neighborhood of the City of Santa Barbara.

This mosquito is an aggressive, daytime biter which means if it becomes established here in Santa Barbara County it will severely impact our quality of life. 

The backyard mosquito is highly adapted to living around humans and their dwellings. Female mosquitoes lay  their eggs just above the water line in small containers and vessels that hold water, such as dishes under potted plants, bird baths and feeders, ornamental fountains, empty food and drink cans, children’s toys, discarded tires, yard drains, buckets, horse troughs, rain barrels and other sources (click here for examples).

It's important for residents to look around their yard and outside their home and dump out even the smallest amount of standing water. Clean and scrub bird baths and pet watering dishes weekly and dump the water from overflow dishes under potted plants. Scrubbing destroys mosquito eggs that can hatch when the containers refill with water, even if the containers have been empty for several months.

In Australia, the backyard mosquito is the primary carrier of dog heartworm.  A native species, Aedes sierrensis, the so-called treehole mosquito, is the primary vector of dog heartworm in California. Fortunately,  medications are readily available to prevent dogs from getting the heartworm so be sure that your pet is protected. Consult your veterinarian for more information.

Treehole mosquitoes breed in the water that fills holes and cavities in trees. This mosquito is more commonly found in wooded areas and parks. Contact an arborist for professional advice on how to fill holes in trees on your property.

A tree hole filled with stagnant water. If you look closely, you can see mosquito larvae in the water.
Close-up view of water filling a hole in the trunk of an oak tree. If you look closely, you can see mosquito larvae at the water surface on the left.
An oak tree with a large tree hole. The holes and cavities can fill with water and some mosquito species, such as the appropriately-named "tree hole mosquito, Aedes sierrensis, commonly lay their eggs and develop in these.
A photo taken at Toro Canyon Park of an oak treehole .

The Australian backyard mosquito looks very similar to the "ankle biter" mosquito, Aedes aegypti, which is found throughout southern California and northward up the Central Valley along the I-5 corridor to Shasta County. The major difference between these two species is the backyard mosquito has a band of white scales around the middle of the mosquito's "beak" (the proboscis).

The image shows a close-up of a Australian backyard mosquito feeding on skin, with a yellow arrow pointing to the white band midway down the mosquitoes "beak".
Yellow arrow pointing to the white band on the "beak" of an Australian backyard mosquito. Ankle biter mosquitoes look nearly identical to this mosquito except they don't have a white band on their beaks. Credit for the original photo: Lek Khauv - https://www.inaturalist.org/observations/1682027, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=162499483 

California’s three non-native Aedes species (which includes the Asian tiger mosquito, Aedes albopictus) all share similar behavior, breeding sites, and eggs that are resistant to drying out - although Aedes notoscriptus blood-feeds only outdoors on a wider variety of animals.

Like all mosquitoes, only the females feed on blood. Male mosquitoes only feed on nectar (as will the females).

Please contact the Mosquito District if you suspect you might have any of these mosquitoes at your residence or place of business by calling us at 805-969-5050, or by filling out an online request at our "Contact Us" page.

Together, we can "Fight the Bite"!