Health officials in San Joaquin County are on alert after the discovery of an invasive yellow fever mosquito in Stockton — the third consecutive year the pest has been reported there.

Yellow fever mosquitoes, also known as Aedes aegypti, are small black and white mosquitoes that bite aggressively during the day.

They can transmit several viruses such as dengue, chikungunya, Zika, and yellow fever.

The San Joaquin County Mosquito and Vector Control District said crews detected the mosquito in the Brookside area using their mosquito surveillance system.

“This is the earliest find of the yellow fever mosquito in the last three years for San Joaquin County,” district spokesman Aaron Devencenzi said.

The district said crews will be placing traps used to collect adult mosquitoes and eggs in efforts to continue watching for the yellow fever mosquitoes.

Additional measures may also include door-to-door inspections of the residential area near where the first yellow fever mosquito was found.

“The public can help prevent the spread of these invasive mosquitoes by calling in daytime biting mosquitoes to the district,” Devencenzi said.

Yellow fever mosquitoes are not native to California, but according to the California Department of Public Health’s Vector-Borne Disease Section, they have been found in 22 counties in the last 10 years.

The district is urging the public to inspect their yards and the outside of their homes, and dump out any leftover water and remove any unnecessary containers and trash around properties.

Any residents experiencing mosquito bites during the day can report them to the San Joaquin County Mosquito & Vector Control District at 209-982-4675.