For the first time, the mosquito that can carry and spread the Zika virus has been found in the San Fernando Valley, and experts are urging residents to take precautions.

The Aedes aegypti mosquito, a black-and-white striped insect, was discovered last month during a property inspection in Pacoima, a block from the city of San Fernando, said Levy Sun, spokesman for the Greater Los Angeles County Vector Control District.

“This is the first time we have identified Aedes mosquitoes in the San Fernando Valley, which increases the risk of a Zika, dengue fever, chikungunya and yellow fever outbreak in the area,” Sun said. “Currently, there is no confirmation that these mosquitoes are transmitting any of these viruses to people.”

Sun said several samples were collected from private properties where a mosquito problem was reported by residents.

So far there is no evidence of local transmission of the Zika virus in the Golden State, but it has been reported in travelers returning home. The California Department of Public Health said there have been 241 cases reported as of Friday, a 28 percent increase from the week before. But public health officials have said not everyone who contracts Zika has symptoms and may not need to visit a doctor, so there could be many more people who have it.

The Aedes aegypti is already present in the eastern cities and unincorporated parts of Los Angeles County, including in Bell Gardens, Bellflower, Boyle Heights, Central Alameda, Commerce, Downey East Los Angeles, El Sereno, Florence/Graham, Highland Park, Huntington Park, La Mirada, Maywood, Montebello, Pico Rivera, San Marino, South Gate, and South Whittier.

Sun said it’s unclear why the Aedes aegypti mosquitos were found in Pacoima, but researchers are considering genetic testing to see if those discovered in the San Fernando Valley are related to those found in the eastern part of Los Angeles county.

He said no mass sprayings are planned though vector control agents are conducting small, “backpack” sprayings. Vector control has set up an emergency plan with both the state and Los Angeles County departments of public health, Sun added.

Officials with the city of San Fernando plan to launch an awareness campaign, to make sure residents drain all containers and other items from their backyards.

“We’re doing a full media campaign in all of our parks and public facilities,” said San Fernando City Manager Brian Saeki. “Obviously, it is of serious concern to the city that we stay vigilant and to notify the public as much as we can.”

Also known as the yellow fever mosquito, the insect can carry dengue and chikungunya and thrives in the daytime.

They lay their eggs in planters, which is why they are difficult to get rid of, vector officials have said. In addition to dumping and draining planters and containers of water, scrubbing also is advised.

State health officials have urged travelers returning home dozens of countries where Zika is spreading to continue to wear insect repellent and to practice safe sex for several more weeks, to help prevent the spread of the virus in the Golden State.

While Zika is spread primarily through the bite of the Aedes mosquito, the virus also can be passed through sex, health officials said. Pregnant women who have contracted the virus are at risk of giving birth to babies with birth defects.

Some symptoms include acute onset of fever, a flat red rash and joint pain. Death is rare and most people won’t have any symptoms, according to the federal Centers for Disease Control and Prevention.