A quarantine is pending in San Luis Obispo County after three adult light brown apple moths (LBAM) were found in Los Osos on July 31.
This is following similar quarantines in Los Angeles County, Ventura County and the Bay Area (approximately 3,473 squares miles or about 2 percent of California) the California Department of Food and Agriculture (CDFA) said.
Native to Australia, the caterpillar stage of the moth can destroy, stunt or deform young seedlings, spoil the appearance of ornamental plants and injure citrus, grapes and deciduous fruit crops such as apples, cherries and pears according to the San Luis Obispo County Department of Agriculture.
“The light brown apple moth has been present for three years in California,” Bob Lilley, Agricultural Commissioner/Sealer for San Luis Obispo County, said.
The first LBAM was detected in Berkeley in 2006 and was positively confirmed by the United States Department of Agriculture on March 22, 2007, according to the USDA Web site.
The quarantine presents a major obstacle for Central Coast farmers who sell their products to areas outside of the quarantine limits, said David Headrick, member of the Environmental Advisory Task Force.
What is a quarantine?
Quarantine regulations instituted by the CDFA are aimed at preventing the spread of LBAM to other areas of California and to other states. It could take up to one year for a quarantine to be lifted, the county said.
State and federal quarantine regulations prohibit the movement of all vegetation within or from the quarantined area unless it is certified as free from the pest by an agriculture official, is purchased at a retail outlet, or was produced outside the area and is passing through in accordance with accepted safeguards, the CDFA said.
Within a quarantined area, regulations require that all known host plant material must meet phytosanitary protocols, Headrick said.
“Loosely translated that means all plant material must be sprayed with pesticides to kill off any light brown apple moths that might be present,” he said.
Exterminating the Light Brown Apple Moth
Quarantines are the first step to controlling LBAM for the CDFA. The ultimate goal is eradication.
The CDFA has reviewed a range of strategies to terminate the moth, including: spraying ground-based pesticide, releasing sterile moths and tying twist ties coated with pheromones designed to disrupt mating on trees and fences in urban areas. The CDFA also evaluated aerial pheromone spraying outside residential areas but was met with considerable public resistance. People don’t want to be inhaling sprays.
The USDA and CDFA recently lifted quarantines for LBAM in Santa Barbara County after success using the pheromone infused twist tie method.
Currently, there are no eradication treatments planned in San Luis Obispo County.
While some think extermination is needed, others believe that the CDFA has exaggerated the threat of LBAM to get money for its budget.
Stephen Scholl-Buckwald, Managing Director of Pesticide Action Network North America, contends the moth doesn’t pose a significant threat to California’s agriculture industry and can be managed without a massive eradication effort.
“This is a pest that is going to have to be managed, it’s not going to be possible to eradicate but it can be managed quite well,” said Scholl-Buckwald. “They have been managing it in Australia and New Zealand for well over a century and Hawaii for 100 years.”
Critics contend that quarantine and eradication measures pose environmental and health hazards and will take an economic toll on some growers.
“Not enough is known in California, if one starts with the notion that this is a pest to be managed and not eradicated they are already down a path that makes a lot of sense,” Scholl-Buckwald said.
The Pesticide Action Network also argues the controversial bug should be taken off the high-threat target list of farm pests.
“It should be reclassified so they don’t have to use extreme measures,” Scholl-Buckwald said.
Local Impact
Locally, the real economic issue is the impact that quarantines have on growers’ ability to sell their products, Headrick said.
The College of Agriculture at Cal Poly is the fourth largest undergraduate agriculture program in the nation. Within the college, the horticulture and crop science department teaches numerous pest management classes.
Dr. Michael Costello says invasive pests have always been a part of his curriculum.
Costello doesn’t think LBAM will have much of an economic impact on local farmers.
“It’s not going to change things that much; a big percentage of grape growers have to pay for other closely related moths already,” Costello said.
Invasive pests are a chronic problem in agriculture.
“We always have to worry about something,” he said.