Southern California seems to be a hotbed for invasive fruit fly pests.

This time, the culprit is the Mexican fruit fly, of which four have been trapped in the Azusa part of Los Angeles County since Dec. 3, according to reports from the Los Angeles County agriculture commissioner's office. Of the catches, one was a mated female.

The state has established a 70-mile quarantine around the area, and members of the California Conservation Corp will strip fruit from host plants at 64 sites within 100 meters of the trap finds.

A map of the quarantine area is available online at

Inspectors will apply a pesticide-laced bait to tree trunks in the area.

The state also plans to release millions of sterile male Mexican fruit flies aerially over a 13-square-mile area.

The idea is to inundate an area with so many sterile males that female won't be able to find a fertile partner with which to mate. If female don't mate, they won't lay eggs.

The county also is waging a battle against the Oriental fruit fly, which was discovered in the western San Gabriel Valley in July.

The finds came a week after the state declared the area free of Mediterranean fruit flies, which had infested parts of the county since 2007.

In addition, the state currently is using releases of sterile Medflies to fight an infestation near El Cajon in San Diego County.

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