STOCKTON, Calif. -- Increased aerial and ground spraying will take place in San Joaquin County this week to kill mosquitoes that carry West Nile virus.

The recent heat wave created perfect conditions for the virus to expand in local mosquito and bird populations, and the virus is now being detected in numerous urban, suburban and rural areas, the San Joaquin County Mosquito and Vector Control District said.

"Residents of San Joaquin County should take precautions to avoid mosquito bites and to eliminate standing water on their property," district manager John Stroh said in a news release.

Residents may access spray information and schedules by calling the district at 209-982-4675 or toll-free at 1-800-300-4675 during business hours from 7 a.m. to noon and 12:30 p.m. to 3:30 p.m., Monday through Friday, or by visiting the district's Web site at www.sjmosquito.org.

Spraying for mosquitoes is done near sunset or sunrise with trucks and airplanes when mosquitoes are most active. The district will apply a very fine mist of material that kills adult mosquitoes on contact.

Spraying is contingent upon favorable weather conditions and if canceled will typically be rescheduled to the following morning or evening.

Areas planned for spraying this week include:

Tuesday, July 15: ground spraying from 7:30 p.m. to 11 p.m. in White Slough, Wright/Elmwood Tract and the area of the Stockton sewer plant.

Wednesday, July 16: ground spraying from 7:30 p.m. to 11 p.m. in the Escalon area.

Thursday, July 17: aerial spraying from 4 a.m. to 6 a.m. along some Delta islands.