Prompted by the trap catch of a second light brown apple moth in Davis, the California Department of Agriculture has created a new 38-mile quarantine around the find.
That brings to 3,213 square miles of land now under quarantine in California, according to a news release.
The first moth was trapped in Davis on April 1, triggering intensive trapping radiating from the find.
The second moth was trapped May 15 2 miles from the first.
The quarantine restricts the movement of plants and produce within and out of the area. Commercial operations must follow protocols if they want to ship out of the quarantined area.
Since the moth was first identified in the state in February 2007, more than 93,000 have been trapped in 16 counties.
For quarantine maps, visit http://www.cdfa.ca.gov.
A technical working group comprising experts and state and federal regulators will meet June 20-24 to review the eradication program's progress.
The U.S. Department of Agriculture's Animal and Plant Health Inspection Service is conducting an environmental assessment of a sterile moth release program.
A pilot program is expected to start this summer.
Similar programs have been successfully used to control the pink bollworm moth in cotton and the Mediterranean fruit fly.
Millions of male insects are sterilized and released over an infested area. The theory is the sterile males will breed with fertile females, but no eggs will be produced. Eventually, the population dies out due to a lack of reproduction.
Native to Australia, the light brown apple moth also is found in New Zealand, the United Kingdom and Hawaii.
It has a host range of more than 250 crops, including citrus, grapes, stone fruit and pome fruit.