The California Department of Food and Agriculture in Sacramento has established a 78-square mile quarantine zone in northern San Diego County after five Mexican fruit flies were trapped in two locations.

For a map of the quarantined area near Bear Valley Parkway and Oak Hill Drive in Escondido, visit

Agricultural shipments from the quarantine zone will be regulated to minimize movement of potentially infested commodities.

Locally grown crops, such as citrus and avocadoes, will be regulated, except for the Haas variety, which is thick skinned and not a good host for this pest. 

Crews will work with local growers, packinghouses, transporters, farmers markets and other related facilities over the next several weeks to ensure compliance with the quarantine regulations.

Within a few weeks, CDFA plans to begin releasing about 4.5 million sterile Mexican fruit flies each week by plane over about 9 square miles around the infested sites. 

This method has been used successfully to eradicate other fruit fly infestations in California since the technique was developed in the 1980s.  A similar project is underway in the Dixon area of Northern California to eradicate a recently discovered Mediterranean fruit fly infestation. 

While state staff prepares to supply the necessary sterile flies, short-term treatments are scheduled to be applied in the immediate infested area starting Nov. 8 to prevent additional flies from spreading. An organic formulation of the pesticide spinosad will be applied by hand-held hoses directly to landscaping, trees and other plants. 

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