A 93-square mile area of San Diego County was placed under a Mediterranean fruit fly quarantine after four of the destructive insects were discovered in La Mesa, the California Department of Food and Agriculture announced Tuesday.
The agency said the Medfly quarantine will affect any growers, wholesalers and retailers of susceptible fruit, as well as home gardeners, who are urged to consume the produce they grow on site and not move it from their property.
The quarantine will protect against the spread of the infestation to nearby regions where it could affect the state's food supply, and backyard gardens and landscapes, according to the California Department of Food and Agriculture.
The affected region is bordered on the north by Prospect Avenue in Santee, on the south by Mount Miguel Road in Chula Vista, on the west by Fairmount Avenue in San Diego, and on the east by Vista Grande Road in Dehesa, just east of El Cajon. It encompasses all of La Mesa, El Cajon and Spring Valley, the southern border of Santee, northeastern section of Chula Vista and eastern neighborhoods in San Diego.
The flies were found between July 22 and Aug. 4, according to the county Department of Agriculture, which is helping to eradicate the pest. County officials set up 1,300 traps in the quarantine area last weekend.
The agency is also releasing 250,000 sterile Medflies per mile per week in much of the quarantine area. Sterile male flies mate with fertile female flies in the environment but produce no offspring.
Properties within 200 meters of a Medfly trapping are being treated with an organic formulation of Spinosad, which the California Department of Food and Agriculture said originates from naturally-occurring bacteria in soil, in order to eliminate mated females and reduce the density of the population.
The Department of Food and Agriculture will also remove fruit within 100 meters of detection properties in order to get ride of any that are infested with eggs and larvae.
"This invasive fruit fly is considered to be the most harmful agricultural pest in the world," said county Agriculture Commissioner Ha Dang. "Effective eradication measures help to safeguard the local food supply, fruit export and the environment."
The Medfly can infest more than 250 types of fruits and vegetables, impacting California agricultural exports and backyard gardens.
The most recent local infestations occurred in 2009 in Escondido, Imperial Beach and Mira Mesa, and in 2008 in El Cajon.
Residents who believe their fruits and vegetables are infested with fruit fly larvae are encouraged to call the state's toll-free Pest Hotline at (800) 491-1899.
