An infestation of the Mediterranean fruit fly, dubbed the Medfly and once a widespread scourge in California, has been eradicated in Sun Valley, agricultural authorities announced Tuesday.
The announcement ended a 129-square-mile quarantine of the San Fernando Valley that began about 10 months ago.
“Detecting and eradicating invasive, exotic pest infestations is an important way to protect our food supply and our environment,” said California Department of Food and Agriculture Secretary Karen Ross. “Our response to Medfly infestations has evolved and improved over the years to the point where we have developed environmentally-friendly techniques that allow us to respond quickly, confidently and effectively.”
A total of 42 flies and more than 100 larvae were detected in the area, indicating a breeding colony.
CDFA released sterile male Medflies at a minimum rate of 500,000 flies per square mile per week as its main offensive in the fight against the pest. Properties within 200 meters of where the flies were detected were also treated with an organic formulation of the insecticide Spinosad. More than 115,000 pounds of fruit on more than 750 properties within 100 meters of breeding populations were removed to eliminate eggs and larvae.
Releasing sterile flies reduces the population as wild flies die off without offspring. The sterile flies are raised at a facility in Los Alamitos in a joint project of the CDFA and the U.S. Department of Agriculture.
CDFA and USDA officials joined the Los Angeles County Agricultural Commissioner in thanking local residents for their cooperation to rid California of the invasive species, which can put billions of dollars in agricultural crops at risk.
The Medfly is known to target more than 250 types of fruits and vegetables, potentially causing severe impacts on California agricultural exports and backyard gardens alike. Eggs laid inside fruit hatch into maggots and tunnel through the flesh of the fruit, making it unfit to eat.
The vast majority of the pests are found in urban and suburban communities and most commonly arrive by “hitchhiking” in fruits and vegetables brought back illegally by travelers as they return from infested regions of the world.
The Medfly is found in much of Africa, southern Europe, the Middle East, Western Australia and Central and South America, as well as Hawaii and is the “most important agricultural pest in the world,” according to the USDA.
Travelers are urged to help protect state resources by not “packing a pest” when in transit or mailing packages. More information can be found at www.dontpackapest.com.
In the early 1980s, a severe Medfly infestation led Jerry Brown — in his first stint as governor — to approve the widespread use of the insecticide malathion, which was sprayed over residential areas by helicopter. Despite assurances that the chemical was not toxic to humans, many Californians had grave concerns about its use.
New infestations broke out later in the decade and in the early 90s and ultimately led to the sterile fly as a more acceptable solution to the problem.