California Agriculture April - June 2008 News Release

FOR IMMEDIATE RELEASE: April 10, 2008
CONTACT: Janet Byron, janet.byron@ucop.edu, (510) 642-2431 x19

The light brown apple moth: Everything you always wanted to know but were afraid to ask

California’s newest invasive pest, the light brown apple moth, is fully described in the current issue (April-June 2008) of the University of California’s California Agriculture journal. The roughly 1/2-inch moth has become the subject of intense debate in recent months as the state grapples with eradication and control plans, including proposals to apply pheromones aerially over much of the Bay Area.

UC researchers reviewed global research on the light brown apple moth for the peer-reviewed article, which includes a full description of the insect, and detailed information on its host plants, life cycle, and potential crop damage and control options in California. (Read "Light brown apple moth’s arrival in California worries commodity groups" online or in print.)

The light brown apple moth (Epiphyas postvittana) is a tortricid leafroller. The pest, native to Australia, most likely arrived in California in contaminated nursery stock. It was first positively identified in March 2007 from a specimen collected in Berkeley. As of February 2008, about 17,000 male light brown apple moths had been caught in pheromone traps, in 14 California counties.

Known to feed on at least 250 plants species, the light brown apple moth prefers plants in the aster, legume, knotweed and rose families.

“If light brown apple moth continues to spread, several vegetable and fruit crops may be affected, such as apples, pears, caneberries and peppers,” wrote the authors, led by Lucia Varela, UC Statewide Integrated Pest Management advisor. “California growers already deal with one or more leafroller pest species on most of these crops, and the same approaches would be used against light brown apple moth. However, the primary concern is the trade restrictions imposed by importing countries.”

A related news story in California Agriculture reports that Mexico and Canada have already restricted imports of crops and plants from areas infested with light brown apple moth. China may follow with similar restrictions, while other countries, including Chile, Korea, Peru and South Africa, “list the moth as a quarantine pest and might require certification that a California export is pest-free.”

The California Department of Food and Agriculture and the U.S. Department of Agricultural are working jointly to control the moth’s spread, with a $74.5 million budget in 2008 for eradication, research, monitoring and regulation.

Protecting the earth is getting harder for growers on California’s Central Coast, where the need to ensure food safety conflicts with environmental rules aimed at improving water quality and wildlife habitat.

In response to a number of food safety outbreaks — most recently an E. coli O157:H7 outbreak associated with bagged spinach in September 2006 that killed three people and sickened 200 others — some growers are removing conservation measures adjacent to croplands, according to a survey of Central Coast growers published in the University of California’s California Agriculture journal (April-June 2008).

Researchers found that 8 percent (of 181 growers surveyed in spring 2007) had crops rejected by buyers based on the presence of practices to improve water quality and wildlife habitat on the farm. Likewise, 15 percent of the growers (managing some 30,000 acres) had removed or discontinued the use of previously adopted conservation practices, including ponds and reservoirs, irrigation reuse systems, and noncrop vegetation buffers such as grassed waterways, riparian habitat, buffer strips and trees.

However, authors Melanie Beretti, program director of the Monterey County Resource Conservation District, and Diana Stuart, UC Santa Cruz doctoral candidate in environmental studies, cite research showing that discouraging or actively removing such conservation practices could, in some cases, actually increase the risk of crop contamination.

“Keeping produce as safe as possible is a critical goal,” the authors write in California Agriculture. “However, the means to achieve this goal should be carefully investigated to insure that those measures actually reduce risks of crop contamination, do not increase other human health risks as a result of environmental degradation, and are cost-effective and practical to implement.”

Media contact: Diana Stuart, UC Santa Cruz doctoral candidate, Department of Environmental Studies, dstuart@ucsc.edu or (415) 613-9951.

California Agriculture is the University of California’s peer-reviewed journal of research in agricultural, human and natural resources. For a free subscription, visit our subscription page online, write to calag@ucop.edu or call (510) 642-2431 x33. For a hard copy of the journal contact Janet Byron, (510) 642-2431 x19 or janet.byron@ucop.edu.