The Merced County Mosquito Abatement District has launched its annual campaign against the bothersome insects - which can pose health risks as well as being a warm-weather nuisance.

This year, that endeavor includes a countywide aerial survey of swimming pools to identify those which are neglected and pose the potential to be breeding grounds for mosquitoes.

Rhiannon Jones, the district’s general manager, told Mattos Newspapers that the aerial campaign identified 1,679 neglected pools - including 49 in the Gustine and Santa Nella areas.

Neglected swimming pools and ornamental ponds can be fertile breeding grounds for the types of mosquitoes which carry West Nile Virus and St. Louis Encephalitis Virus, Jones noted.

“This is the first time the Merced County Mosquito Abatement District has used aerial photography to assess the neglected swimming pool situation,” she commented. “The number of neglected swimming pools in our area is much higher than expected.”

Property owners and/or current residents will be notified by the district and strongly encouraged to remedy the potential mosquito-breeding source, Jones explained. The district will work with residents in regard to treating sources until a permanent solution is reached, she added.

District staff members have also started their efforts to eradicate mosquitoes, with an early-season focus on larval control.

“The less larvae, the less adults in the warmer months,” Jones told Mattos Newspapers. “It is much easier to control mosquitoes when they are still in the larval stage because we can treat the water. Once they become adults and (are) mobile, it is more difficult to control.”

In addition to the mosquitoes which carry West Nile and St. Louis Encephalitis viruses, Jones said, the invasive Aedes mosquito species has been detected in the city of Merced.

“It is paramount that we take a pro-active approach to control mosquitoes in individual back yards before the summer months when mosquito populations are at their highest,” Jones stated.

Nine human cases of West Nile Virus were confirmed last year in Merced County.

Jones said she anticipates more virus detection this year, and encouraged residents to do their part in keeping mosquito populations in check.

Residents are encouraged to eliminate any sources of standing water on their property in which mosquitoes may breed. A small amount of stagnant water can produce a large number of mosquitoes, officials said.

Residents are also reminded to protect themselves against exposure to mosquitoes by using repellents which contain DEET, Picaridin or oil of lemon eucalyptus, and urged to avoid being outdoors when mosquitoes are most active, which is typically dawn and dusk.

Mosquito outbreaks or potential breeding sources may be reported to the district by calling 722-1527. Reports of neglected pools and other potential mosquito sources may be filed anonymously.