The California Department of Food and Agriculture has established a 107 square-mile quarantine zone in the El Cajon area of San Diego County, following the detection of a Mediterranean fruit fly infestation.

To date, 18 wild adult Medflies have been detected at 12 sites in the area, and Medfly larvae have been detected at two sites. The quarantine boundary map is available online at http://pi.cdfa.ca.gov/pqm/manual/pdf/403.pdf. (Please scroll to the bottom of the document.)

The Medfly can infest over 260 types of fruits and vegetables, causing severe impacts on California agricultural exports and backyard gardens. A permanent infestation would result in estimated annual losses of $1.3 billion to $1.8 billion.

Agricultural shipments from the quarantine zone are restricted by specific regulations designed to minimize movement of potentially infested commodities. 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 homegrown fruits and vegetables from the property of origin. Residents may dispose of fruits and vegetables by double-bagging them and placing the bags in the garbage.

An eradication program for the Medfly is already underway, consisting of releases of sterile male flies in the area, fruit stripping within a 100-meter radius around sites where larvae are detected, and ground treatments using the organic-approved product Naturalyte (active ingredient: spinosad) within a 200-meter radius of sites where the flies have been trapped.

CDFA has succeeded in eradicating every Medfly infestation in California since the department began such efforts in 1975, and has relied on sterile Medfly releases almost exclusively since 1996.