Bad sign: Local nurseries are feeling the brunt of a USDA directive to eradicate a pesky moth by spraying harsh chemicals.
Little Wings, Big Burden
Spraying nurseries for light brown apple moth in Santa Cruz County: Essential sacrifice for the state's economy or futile attempt to eradicate minor league pest?
By Steve Hahn
As the fight against the light brown apple moth in Santa Cruz County continues into its fourth month, concerns are being raised surrounding the extent of the infestation and the comprehensiveness of the response by state and federal officials.
These concerns are mostly emanating from Santa Cruz nursery owners who say they have been unfairly burdened--forced to close their operations and spray the powerful pesticide Chlorpyrifos--while the moth is possibly allowed to breed nearly unhindered in nearby agricultural fields, home gardens and undeveloped wild lands.
A technical working group contracted by the California Department of Food and Agriculture (CDFA) and made up of entomologists from the United States, New Zealand and Australia is currently refining its recommendations for eradicating the voracious insect, which eats more than 250 different species of plants.
As this process continues, many local nursery owners are adamant that their perspectives be included as well. They believe the dual questions of how large a threat this poses to the agriculture industry and whether inspecting and spraying at nursery sites is enough to completely annihilate the light brown apple moth are being overlooked and require more careful consideration.
"They totally slam wholesale and retail nurseries, but in the meantime nobody else has to deal with this," says Theresa Aquino, who was forced to close her Blue Bamboo nursery after she refused to spray Chlorpyrifos. "No matter what treatment you do, a live moth from surrounding foliage can fly right back in that night and lay a new crop of eggs on any of those plants. My nursery is in the middle of my demonstration garden, which is totally lush with all kinds of plants, and they're not requiring me to treat any of the plants in the ground, so there are live moths all over."
In answering the questions brought up by nursery owners, the first problem is that no one really knows how long the moth has been in the United States. It was originally spotted on July 19, 2006, by retired entomologist Jerry Powell, according to the San Francisco Chronicle. But depending on who you ask, the moth may have been in California for six months to two years before one flew onto Powell's property. Many moths native to California connect leaves together with silk to create breeding sites, as the light brown apple moth does, and only extremely close examination by trained experts can distinguish one from another.
In May 2007, as the CDFA and later the United States Department of Agriculture (USDA) rushed to contain the spread and then eradicate all remaining populations of the moth, nurseries were targeted much more heavily than other industries. According to Aquino, less than 1 percent of agricultural products within the quarantine zone are subject to inspection; all nursery stock is.
"There is a higher risk with nurseries because it's the plants that are moving and not just the crops," explains CDFA spokesman Jay Van Rein. "This insect lays its egg clusters on plants, not the actual crops, for the most part--it's the leaves that are used for breeding, not the actual produce. We still do have to regulate and inspect agricultural commodities besides live plants, but it's the live plants that present the highest risk of spreading the infestation."
Some local nursery owners respond that since the moth has been found spread over such a wide swath of land, it would be reasonable to assume an infected leaf or two might make it from an agriculture field into a shipment of fruit destined for interstate sale.
"Produce sits outside of supermarkets, in farmers markets; it ends up in dumpsters. There's definitely abilities for insects to move around," says Jeff Rosendale, owner of Soquel Nursery Growers.
In fact, Rosendale and others wonder if eradication is even a realistic goal under these circumstances--with the length of time and physical area consumed by the infestation. While over 3,000 moths have been caught in pheromone traps so far, no one knows the true size of the population or how far they have already spread. Are they in home gardens or wooded areas? The traps only attract males, and recent inspections of Napa County forced the CDFA to implement a 10-12 week spraying plan for agricultural crops, raising the possibility that once inspectors begin expanding their search zones they could find the moth in more areas.
"The thought of controlling the pest in nurseries having any impact in adjacent areas is at best naive," says The Garden Company owner Charlie Keutmann. "The USDA is very careful to offer the perception that this pest is under control because they're trying to preserve international trade agreements and domestically California's agricultural industry from boycotts from other states or countries."
Mexico and Canada have both instituted regulatory controls on California produce to prevent the introduction of the moth.
Van Rein doesn't deny the CDFA is concerned with maintaining international and interstate trade, but notes that if eradication is abandoned as a goal, others outside the agriculture industry will suffer.
"The alternative of letting it remain in California would be not only more costly to the industry, but more of an expense to the communities that have the infestations, because they would have to control it as well on an ongoing basis," he says. "This is one thing that can get lost in discussions of this pest. We are talking about agriculture so much, but it's also a pest of everything from oak trees to rose bushes to the Monterey Pine."
Members of the technical working group from Australia and New Zealand, where the pest has been living for several decades, recommend eradication based on the experience they've had in their home countries, according to Van Rein.
According to a USDA pest profile, the light brown apple moth causes Australia $21.1 million a year in control costs and lost production throughout Australia's grape, apple, pear and orange crops. After applying the same percentage of cost, 1.3 percent, to California agriculture and nursery industries, the USDA estimated a total yearly cost of $133 million for California's economy.
"They [Australian and New Zealand scientists] were pretty emphatic that if you have an opportunity to eradicate this then you should," says Van Rein. "Living with it long-term is much worse than trying to eradicate it."
However, Rosendale is skeptical that the moth will result in the level of economic damage projected by the government.
"We're talking about a pest that is a superficial feeder. It just causes light scarring on fruits and doesn't really affect ornamental plants at all," he says. "The berry growers haven't said there's a really big problem and the apple growers haven't said anything. I don't think we'd even know it was here if it hadn't been discovered by a retired entomologist."
Rosendale and other nursery owners instead advocate lowering the rating of the pest, which is currently rated at the highest response level by the USDA, and implementing a tiered response that would control the spread of the pest to other states and countries, but accept the fact that the bug is here to stay in California.
"The tiered response would look like what they do for Sudden Oak Death and the glassy-winged sharpshooter," he says. "What it means is if you're considered an infested county and you're only shipping within those counties, then you don't do anything, you're on the lowest regulatory tier. If you ship out of those counties then you have a level of inspection that's higher. If you ship interstate or international you'd have a still higher degree of inspection."
Van Rein doubts the CDFA will dump the eradication goal any time soon, and with 80 percent of land in the United States projected as habitable for the moth, it's unclear if pressure from the federal government and other states will make the tiered response politically feasible.
On the other hand, no one seems to be deluding themselves that a solution only focused on regulating nurseries will work. Van Rein stresses that the current inspections are only focused on these industries because of the high risk they pose for spreading infestation and that the inspection range will be greatly expanded in future months, including agricultural inspections and plans for treating wild lands.
In the meantime, it may be a rush against time to control the moth. A female can lay up to 1,500 eggs three times a year and the moths are able to survive almost anywhere they can find one of the 250 leaves and fruit they eat. The lack of a comprehensive knowledge base within this country concerning the scope of the problem makes these statistics even bleaker for eradication efforts.
"Even if you spray every two weeks, as long as you have moths in the [surrounding] landscape, they are going to mate at night and the female will fly in and lay eggs," says Rosendale.
Even in the face of these daunting odds, Van Rein believes the experience of the agriculture industry in Australia and New Zealand proves the economic repercussions are real and underlies the importance of eradication.
He understands the frustrations of nursery owners and maintains that the CDFA is looking for ways to decrease the impact on their operations.
"We're working as hard as we can to come up with alternatives for the treatments for these nurseries," he says. "We understand what a difficult position they're in."
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