The California Department of Food and Agriculture (CDFA) has established a quarantine of approximately 19 square miles straddling Sonoma and Napa counties following the detection of two light brown apple moths (LBAM). CDFA’s trained inspectors are working closely with plant nurseries and related businesses in the area to inspect facilities and advise on treatment, if infestations are uncovered. This safeguards the public and farmers in adjacent areas.

“This quarantine is designed to keep the moths from moving out of the area,” CDFA Secretary A.G. Kawamura said. “It is a necessary step so that we can contain and eventually eradicate this pest from California and to protect the rest of the state from added quarantines and increased pesticide use over the long term.”

A moth was found in a trap in Napa County on July 23, triggering increased trapping efforts to determine if more moths were present. The second moth, detected nearby in Sonoma County on August 8, prompted the quarantine. The quarantine boundaries were developed in cooperation with the Napa and Sonoma County Agricultural Commissioners’ Offices and the United States Department of Agriculture (USDA). A map of the quarantine zone is available at: http://www.cdfa.ca.gov/phpps/pdep/lbam/pdfs/maps/quarantine/LBAM_QUAR_NAPA_SONOMA_08.pdf.

State quarantine regulations prohibit the movement of all nursery stock, all cut flowers, and all host fruits and vegetables and plant parts within or from the quarantined area unless it is certified as “free-from” the pest by an agricultural official; is purchased at a retail outlet; or was produced outside the area and is passing through in accordance with accepted safeguards.

The quarantine applies to residential and public properties as well as plant nurseries, farms and other commercial enterprises. Residents of the quarantined area are asked to consume fruits and vegetables from yards and gardens on-site rather than removing them from the property. Landscapers and yard maintenance companies will be among the businesses placed under compliance agreements to ensure that yard waste is disposed of properly. People who are unsure if they are within the quarantine zone are asked to assume that they are.

Moth traps have been set at a rate of 100 in the core square mile and 25 per square mile in the surrounding area.

The light brown apple moth is native to Australia and is also found in New Zealand, the United Kingdom and Hawaii. The range of host plants is broad with hundreds of plant species known to be susceptible to attack by this pest, including more than 250 crops. It threatens California’s environment — including cypress, redwood and oak trees — by destroying, stunting or deforming young seedlings and damaging new growth in the forest canopy. The moth also feeds on host plants favored by a number of endangered species; spoils the appearance of ornamental plants; and damages citrus, grapes, and deciduous fruit tree crops.

A USDA study indicates that, if California becomes generally infested, the moth could cause billions of dollars in crop damage annually. Additionally, it would hinder export opportunities and interstate commerce due to quarantine restrictions, as demonstrated by the quarantines already enacted by Canada and Mexico. California agricultural exports to the two countries totaled more than $2.4 billion in 2006.

A cooperative eradication program run jointly by CDFA and the U.S. Department of Agriculture (USDA) is already underway to suppress and eradicate infestations in nine other counties along California’s Central Coast and Bay Area. Since its detection in February 2007, the light brown apple moth has been found and quarantines have been enacted in the counties of Monterey, Santa Barbara, Santa Cruz, Santa Clara, San Mateo, Contra Costa, Marin, San Francisco, Alameda and Solano. Small, isolated infestations detected last year in Los Angeles and Napa counties have already been eradicated. Twist ties were utilized in both counties.

For more information on light brown apple moth, visit www.cdfa.ca.gov.