MEXICAN FRUIT FLY INFESTATION DETECTED IN ESCONDIDO AREA OF NORTHERN SAN DIEGO COUNTY

Quarantine will be imposed; Residents urged not to move fruits, vegetables, plants out of the area

SACRAMENTO – Agricultural officials have detected a Mexican fruit fly infestation in Escondido in northern San Diego County.  The California Department of Food and Agriculture (CDFA) and the United States Department of Agriculture (USDA) have expanded insect trapping in the area to detect any additional flies.  Once the boundaries of the infested area have been determined, a quarantine will be imposed to prevent the spread of the infestation.

On November 6, five Mexican fruit flies were discovered in traps on two residential properties in the vicinity of Bear Valley Parkway and Oak Hill Drive in Escondido.  The detections were made by the San Diego County Agricultural Commissioner’s Office staff performing routine trap checking.  The flies were sent to CDFA’s Los Alamitos facility where entomologists confirmed the identification of the pest.

“As a farmer, I know this quarantine will be a hardship to the growers in this area,” said CDFA Secretary A.G. Kawamura. “But I also know they understand that this is a necessary step, and I want to thank them in advance for their cooperation with this eradication effort.  This pest is a major threat to California’s food supply.”

Once a quarantine is established, agricultural shipments from the quarantine zone will be regulated to minimize movement of potentially infested commodities. Locally grown crops such as citrus and avocados will be regulated, except for the Hass variety which is thick skinned and not a good host for this pest.  Crews will work with local growers, packing houses, transporters, farmers’ markets and other related facilities over the next several weeks to ensure compliance with the quarantine regulations.

In addition, people moving through the quarantine zone are urged not to remove fruits and vegetables from the area.  The quarantine requires that local residents not move home-grown fruits and vegetables from the property of origin. Residents may consume fruits and vegetables on-site or dispose of them by double-bagging them and placing the bags in the garbage. 

Crews have already begun placing additional traps throughout the infested area to lure adult flies and help determine the extent of the infestation.  Over the next few days, inspectors will also begin the labor-intensive task of picking and cutting into citrus, avocadoes and other fruits in the neighborhood to inspect for Mexican fruit fly larvae.

Within a few weeks, CDFA plans to begin releasing approximately 4.5 million sterile Mexican fruit flies each week by plane over approximately nine square miles around the infested sites.  This method has been used successfully to eradicate many fruit fly infestations in California since the technique was developed in the 1980s.  A similar project is currently underway in the Dixon area of Northern California to eradicate a recently discovered Mediterranean fruit fly infestation.  Sterile Medfly releases also occur throughout the year in the Los Angeles basin in order to combat the repeated infestations that occur there.

While staff prepares to supply the necessary sterile flies, short-term treatments are scheduled to be applied in the immediate infested area starting today, November 8, to prevent any additional flies from spreading. The organic-approved pesticide Naturalyte (active ingredient: spinosad) will be applied by hand-held hoses directly to landscaping, trees and other plants.  Area residents may recall that the same material was used to eradicate an extensive Mexican fruit fly infestation in nearby Valley Center in 2003. CDFA will first treat the properties where the flies were found, then the adjacent yards.  Once these properties are treated, the crews will treat all other properties in a 200-meter radius from the original find sites.

The Mexican fruit fly, also known as the Mexfly, is native to southern and central Mexico.  The fly attacks over 40 different kinds of fruits and vegetables.  The Mexfly eggs hatch into maggots which tunnel through the fruit and make it unfit for human consumption.  The most common cause of these infestations is travelers who illegally transport prohibited, infested produce and plants into the region.