STOCKTON -- Agriculture authorities are expanding a quarantine zone in San Joaquin County as they try to prevent the spread of the European grapevine moth.
The expanded quarantine area totals 96 square miles near Stockton.
Authorities say farmers and residents in the zone should not move plants and fruits that host the moth from their properties unless they meet treatment and screening protocols.
The containment effort announced Thursday builds on the state's efforts to halt the moth from feeding on the state's grape crop. The insect also makes vines more susceptible to damaging mold.
Since being discovered in Napa County in September of 2009, the moth has prompted quarantines in seven other counties.