SACRAMENTO - The California Department of Food and Agriculture was to have begun aerial releases of sterile Mediterranean fruit flies in a 251-square mile area of San Diego County, between the international border to the south and the community of Lakeside to the north, and between the Pacific coastline to the west and the community of Alpine to the east. (link to map here:http://www.cdfa.ca.gov/phpps/docs/MED_SIT_SDIEGO_04.pdf).

The action will be taken as part of an international, multi-agency effort to eradicate a Medfly infestation in Tijuana, just six-and-a-half miles south of the border. CDFA is working with the USDA, the San Diego County agricultural commissioner's office, the Mexican national agricultural agency SAGARPA, and the Baja California Fomento Agropecuario (Department of Agriculture).

CDFA will make the releases as part of its Preventive Release Program (PRP), which has been distributing sterile Medflies over the Los Angeles Basin since 1996, with outstanding results. In a seven-year period prior to the start of the PRP, an average of 7.5 Medfly infestations were detected in California each year. Over the last eight years, there have been just two infestations.

The sterile flies are effective because they mate with wild flies and biologically force wild populations out of existence. In San Diego County, 15 million sterile Medflies will be released each week.

"The Medfly is a serious threat to agriculture. We must act quickly to continue to ensure a safe, secure food supply," said CDFA Secretary A.G. Kawamura. "Due to good planning and sound science, we can turn to the Preventive Release Program. Sterile Medflies are an outstanding, environmentally responsible tool for combat against a major pest."

Increased trapping

To increase detection capacity, CDFA has increased trapping density by 150 percent in a two-mile border buffer zone between the coastline and Otay Mesa, and is planning to check passenger vehicles at the agricultural inspection station at Winterhaven.

The PRP, funded jointly by CDFA and the USDA, is headquartered at the Los Alamitos National Guard station in southeastern Los Angeles County. The fixed-wing aircraft that will make the releases over San Diego County will use Los Alamitos as a base of operations. CDFA also utilizes the National Guard facility to rear sterile Medflies and prepare them for release. The flies are bred in Hawaii and Guatemala.

The Medfly can attack more than 250 commercial and backyard crops. If it were to become permanently established in California, the estimated economic loss would be as much as $1.9 billion annually, due to direct crop loss, loss of jobs, trade embargoes, and increased pesticide use.

For more information on national efforts against the Medfly, please check the USDA Web site at www.usda.gov