California Code, Food and Agricultural Code (Formerly Agricultural Code) - FAC § 6521

Except as otherwise provided in Sections 6523 and 6524, if any shipment of any nursery stock, plant, or container of any nursery stock or plant, or appliance, or any host or other carrier of any pest which is brought into any county or locality in the state from another county or locality within the state, is found to be infected or infested with a pest, or there is reasonable cause to believe that the shipment may be so infested or infected, the entire shipment shall be refused delivery and may be immediately destroyed by, or under the supervision of the commissioner, unless the nature of the pest is such that no damage or detriment can be caused to agriculture by the return of the shipment to the point of shipment.