SACRAMENTO – Portions of San Diego and Sacramento counties have been added to areas of California under quarantine for the light brown apple moth.

Nineteen counties are currently part of the quarantine, totaling 5,147 square miles. It is one of the largest pest quarantines in state history.

In San Diego County, 10 square miles are under quarantine near Balboa Park in the city of San Diego.

In Sacramento County, 16 square miles are under quarantine in south Sacramento.

State and federal quarantine regulations prohibit the movement of all nursery stock, all cut flower, 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.

Additionally, federal regulations apply to host commodities from the entire county if the commodities are moving interstate.

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.

Treatment with pheromone twist ties is scheduled to begin Tuesday, Sept. 7, in San Diego County. The pheromones create mating confusion for light brown apple moths and actually prevent them from mating during their lives.

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.

State agricultural officials said the moth 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.