Contra Costa County will spray part of Antioch this week for invasive yellow fever mosquitoes. The county’s mosquito and vector control district will go after the day-biting mosquito species, known as Aedes aegypti, between 2 a.m. and 5 a.m. Tuesday through Saturday. The mosquitoes are capable of transmitting Zika, dengue fever, Chikungunya, and yellow fever viruses. The area being treated is bordered on the north by State Highway 4, on the south by Bluerock Drive, on the east by Deer Valley Road, and on the west by Lone Tree Way. The district will be using truck-mounted equipment to apply public health pesticide Vectobac WDG, at a rate of 8 ounces per acre, to kill mosquito larvae. The district first identified Aedes aegypti mosquitoes in Antioch in late September, when they were collected during a backyard inspection. As additional trapping and inspections were conducted in the neighborhood, more invasive mosquitoes were found, prompting the district to set mosquito traps throughout the area and conduct door-to-door inspections to determine how widespread the infestation was. The district found mosquito larvae in common backyard items that can hold water, including potted plant saucers, buckets, wheelbarrows, fountains and toys. As more adult and young mosquitoes are found, the district’s search area continues to expand. Yellow fever mosquitoes are very small (about 1/4 inch), with black bodies and white stripes. First introduced to Southern California more than a decade ago, they’ve since moved from Southern California to Shasta County and are now established in 24 counties across the state. Because they lay sticky eggs above the water line in any size container that holds water, they can be transported to new areas easily and are often introduced through travel, particularly as people move from area to area and accidentally transport them in potted plants or other outdoor containers. To reduce risk of these mosquitoes, it’s important that residents dump out any amount of standing water and scrub the containers with soap. The district asks people to report any day-biting mosquitoes by contacting them at (925) 685-9301.