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California Department of Food and Agriculture

Media Contacts: Steve Lyle, CDFA Public Affairs, (916) 654-0462, Larry Hawkins, USDA, (916) 930-5509

California Department of Food and Agriculture
Release #08-028
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Harder/Rosendale report called unfounded and scientifically unjustified

SACRAMENTO – The Technical Working Group (TWG) has provided written comments to the Harder/Rosendale report: Integrated Pest Management Practices for the Light Brown Apple Moth in New Zealand: Implications for California. 

The TWG response, available at, states that the Harder/Rosendale report offers a narrow perspective and is scientifically unjustified  in its recommendation that California should abandon the Light Brown Apple Moth (LBAM) eradication program.  Among the findings:
• Until recently, LBAM was the plant pest of greatest impact in New Zealand.
• Harder/Rosendale’s “account of the LBAM situation in New Zealand fails to recognize the natural resistance of New Zealand’s native plants and bio-control program developments that have just recently resulted in the reduction of this pest’s impact on the country’s agricultural sector.” 
o “Until the biocontrol organisms became established…producers relied heavily…on the use of insecticides as the primary means of controlling the pest.”
o “It is unlikely that the United States government would allow the entry and use of similar biological control agents…that present a potential risk to native species…”
• “…the timing of their field visit did not correspond with peak periods of LBAM activity…”
• Their report asserts that New Zealand has never attempted widespread LBAM eradication efforts, but that is because LBAM has been present in New Zealand “…for over 100 years, and such area-wide pest detection and eradication techniques were only developed more recently.”
• The report is “unjustified” and their “approach is inadequate given the significant environmental and crop production differences between New Zealand and California…”
• "The issue is not just with LBAM becoming established along California’s central coast, it also involves its potential establishment in other parts of California, and in other States.”

“California must eradicate the Light Brown Apple Moth because it poses a complex threat – not only to our environment and habitats but also – to our local farms, nurseries and farmers’ markets,” said CDFA Secretary A.G. Kawamura.  “Not only does this pest attack over 250 crops and 2000 host and ornamental plants, but a statewide infestation could cost California billions of dollars annually.”

More on the Technical Working Group (TWG):  Comprised of 10 scientists, the TWG was appointed by the U.S. Department of Agriculture (USDA) to evaluate California’s LBAM infestation. The USDA/CDFA eradication program was based on the TWG’s recommendations. Its members, from Australia, New Zealand, California and the USDA, are considered the world’s foremost experts in the biology of the pest.  The scientists are:

Vic Mastro, USDA-APHIS-Plant Protection and Quarantine (PPQ)-Chairman
Eckehard Brockerhoff, ENSIS, New Zealand
Ring Carde, University of California
Marshall Johnson, University of California
Don McInnis, USDA-ARS
Bob Staten, USDA-APHIS-PPQ (Ret.)
Max Suckling, HortResearch, New Zealand
Bill Woods, Department of Agriculture and Food, Western Australia

More on the Light Brown Apple Moth (LBAM): is native to Australia and is found in New Zealand, the United Kingdom and Hawaii. The range of host plants is broad with more than two-thousand plant species known to be susceptible to attack by this pest, and more than 250 crops. It threatens California’s environment 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 injures 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 damage annually. Additionally, it would hinder export opportunities and interstate commerce due to quarantine restrictions, as demonstrated by quarantine restrictions in Mexico and Canada. 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 currently underway to suppress and eradicate infestations in ten 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 Cruz, Santa Clara, San Mateo, Contra Costa, Marin, San Francisco, Alameda, Solano and Santa Barbara counties. 

Isolated detections last year in Los Angeles and Napa counties have already been eradicated, primarily using twist ties that emit moth pheromone.  In Sonoma County, where a single moth has been detected, intensive trapping is underway to determine if there are more.

For more information on the Light Brown Apple Moth, please visit



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