The state's anticipated agricultural quarantine to contain the spread of the destructive light brown apple moths in San Diego officially began Aug. 26, authorities announced Thursday.

A federal quarantine expected to cover the entire county was still pending, county agriculture officials said.

The state's 10-square-mile quarantine near Balboa Park restricts the movement of plants grown around traps where seven moths have been found since July 30, state agriculture officials said.

The quarantines are designed to stop the spread of the moth, an insect that could lead to trade restrictions and cost the county's economy billions in lost crops.

No one ---- not even home owners and backyard gardeners ---- is allowed to move plants or produce grown within the state quarantine's boundaries near the intersection of Interstates 805 and 15 until agricultural inspectors have certified the plants as moth-free, California Department of Food and Agriculture spokesman Steve Lyle said Thursday.

The state's quarantine boundaries are: El Cajon Boulevard, Chollas Parkway, Market Street and Park Boulevard, Lyle said.

Lyle said that beginning Sept. 7, inspectors would begin placing pheramone-loaded bait throughout the county to prevent the moths from mating.

A federal quarantine could begin as early as next month, county agriculture commissioner Bob Atkins said Thursday. A federal quarantine would restrict movement of crops including produce, nursery plants and cut flowers grown anywhere in the county.

Federal quarantine restrictions would apply only to plants being shipped or moved outside the county, they said. Plants could be moved around inside the county without approval or inspection.

A total of 5,147 square miles ---- an area slightly smaller than Connecticut ---- is under quarantine in 19 counties statewide to stop the moth, Lyle said.

The quarantines might seem like a lot of fuss over a little moth, but federal agriculture officials have said an infestation could devastate the county and state economy.

According to the U.S. Department of Agriculture, an infestation of light brown apple moths in California could cost the state $2.4 billion in annual crop losses.

The light brown apple moth, bearing the scientific name of Epiphyas postvittana, was identified in California in 2007. It is native to Australia, and can harm more than 1,000 kinds of plants and trees ---- including 250 fruits and vegetables.

Plant nurseries, which represent about $1 billion of San Diego County's $1.5 billion agricultural industry, are most at risk, Atkins said.

The county narrowly avoided a quarantine earlier this year. On March 2, one light brown apple moth was discovered in a trap in Bonsall. It takes the discovery of two bugs to trigger a quarantine.

Call staff writer Morgan Cook at 760-739-6675.