Just days after an Asian citrus psyllid was found in a northern San Diego County trap, the citrus and avocado growing area has been hit with a Mediterranean fruit fly infestation.

California records yet another Medfly infestation

Two male flies were discovered in a trap Oct. 29 and a mated female fly was found in yet another trap the following day, a news release from the California Department of Food and Agriculture said. Both Medfly discoveries were in the Fallbrook area.

 â€œWe are ramping up quickly so that we can eradicate this outbreak before it has time to spread throughout this important agricultural region,” Secretary A.G. Kawamura, who heads the agency, said in the release.

State and county agricultural crews have begun stripping fruit from trees near the discovery sites. The fruit will be destroyed to kill any larvae the fruit may contain. The crews also will ground spray insecticides in an eighth-mile radius around the traps where the pests were found, the release said.

Beginning Nov. 10, the state agency will begin releasing 250,000 sterile Medflies per square mile over an area than covers nearly 10 square miles, and an agricultural quarantine is expected to be established shortly, the release said.

Mediterranean fruit flies can infest more than 250 fruits and vegetables. Of concern to many of the area’s grower-shippers is that the 2009-10 citrus harvest is just getting under way in northern San Diego County and the avocado harvest will begin in early 2010.

A female fruit fly pierces the skin of fruit to lay her eggs; the larvae then feed on the flesh of the fruit.

 â€œThe release of sterile Medflies is a proven method of eradicating an infestation,” Kawamura said in the release.

The psyllid, which can carry the fatal citrus disease, huanglongbing also known as HLB and citrus greening, was discovered in a trap near Valley Center, a community about 15 miles south of Fallbrook.

Additional traps are being distributed in the Valley Center area to determine whether there is an infestation of the pest. Psyllids were first discovered in southern San Diego County in August 2008. Small infestations have subsequently been found in parts of Imperial, Orange and Los Angeles counties.

The Valley Center find was the first near any of California’s commercial citrus groves.