A Mediterranean fruit fly infestation has been discovered in El Cajon.

CDFA crews are beginning eradication procedures in the area. On November 14, the aerial release of sterile Medflies began – at a rate of 250,000 sterile flies per mile. The release area is 11.2 square miles. Also, crews are conducting ground treatments in a 200-meter radius — about one-eighth of a mile — from the locations of the detections. The substance being utilized is the organic compound Naturalyte (active ingredient: spinosad), a naturally occurring extract from bacteria. Naturalyte was used in the 2002 Mexican fruit fly eradication program in Valley Center, also located in San Diego County.

The sterile Medflies will be brought in from the joint CDFA — U.S. Department of Agriculture rearing facility in Los Alamitos, which prepares hundreds of millions of sterile flies weekly for release over the Los Angeles Basin. For the El Cajon project, nearly 2.8 million sterile Medflies will be released weekly. The flies, sterile males, have a proven track record in Southern California. Sterile male flies mate with fertile female flies in the environment but produce no offspring. The Medfly population decreases as the wild flies reach the end of their natural life span with no offspring to replace them, ultimately resulting in eradication of the pest.

“This approach is a great example of research and science working to benefit the public and the environment,” said CDFA Secretary A.G. Kawamura. “By utilizing sterile Medflies, we rely on biological control. It’s a great example of progress offered by integrated pest management principles.”

A quarantine in the area is anticipated shortly. People will be urged not to remove fruits and vegetables from the quarantine zone.

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 to $1.8 billion.

The eradication approach in El Cajon is the standard Medfly program used by CDFA and the safest, most effective program available. CDFA has successfully eradicated each and every detected Medfly infestation in California history, dating back more than 30 years.