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Aerial spraying of apple moth raises more questions than answers

State and federal agriculture officials announced they have dropped plans to spray urban areas in the Bay Area and Monterey Bay region to eradicate the light brown apple moth. Instead, they will release sterile moths starting next year to disrupt the insect’s mating, and use twist ties on trees in urban areas to combat the pest.

The outcry from concerned residents in the coastal communities from Santa Cruz to San Francisco over the aerial spraying to combat the light brown apple moth (LBAM) seems to have caught state agricultural officials a little bit off-guard.

At the very least, the initial spraying of pheromone products above the cities of Santa Cruz and Monterey last fall proved that a complete and proper communication outreach program by state agencies must first accompany any plan which entails the celestial dusting of California residents with an unknown chemical mixture.

Immediately after the spraying hundreds of people complained of feeling sick and environmental groups and city and county governments wasted no time in suing the state, claiming the California Department of Food and Agriculture (CDFA) broke state law by authorizing the aerial campaign without the benefit of environmental review under the California Environmental Quality Act.

Subsequently, two superior court judges ruled that the state failed to prove that the presence of the LBAM constituted an emergency, which would have allowed authorities to avoid the long state review process.

In mid-May, WPHA had the opportunity to listen and weigh in on this important state controversy during a live radio broadcast of “City Visions,” a popular San Francisco call-in show which is a local National Public Broadcasting affiliate. WPHA President Renee Pinel was one of four experts on a panel to address the topic: “Pests and Pesticides: What are the issues with both and how should they be handled?”

Ideally, the program would have encompassed a broad range of subjects dealing with pesticides, but, given the understandable fervor over the alleged spraying threat, callers pretty much kept the focus on the LBAM for an entire hour.

Besides Pinel, the panelists included Rajiv Bhatia, director of the occupational and environmental health program for the San Francisco Department of Public Health; Mary Louise Flint, associate director of Urban and Integrated Pest Management at the University of California, Davis; and Margaret Reeves, a senior scientist with the Pesticide Action Network of North America (PANNA).

Bhatia led off the show by bringing listeners up to date on the legal action and the safety testing requirements of four pheromone products that are under consideration for aerial spraying. The pheromone that was sprayed over Santa Cruz and Monterey last fall is again under consideration but has not been chosen for future sprayings, he was quick to point out. He also defined a pheromone as a substance that confuses the male moth and results in mating disruption. PANNA’s Reeves would later note that pheromones are the least toxic and one of the safer products available to battle the LBAM.

Davis’s Flint pointed out that except for one instance in New Zealand (the LBAM has been established there for 100 years) the aerial spraying of pheromones has never been conducted over large metropolitan cities. On the other hand, she mentioned, the LBAM threatens to become a large economic problem that could mean the loss of millions of dollars to California farmers in crop damage and as other countries refuse to buy crops where LBAM infestation has occurred. Mexico and Canada have already thrown up barriers.

This brought up the subject of the USDA’s decision to place the LBAM on its list of quarantined species. It is not currently a quarantined pest in Europe, where it exists in Great Britain, a U.S. trading partner.

LBAM’s status in Europe prompted Reeves to say that the LBAM is a minor pest at worst, and is not causing ecological damage anywhere in the world. By the U.S. stamping it as such, “We are shooting ourselves in the foot,” the PANNA scientists claimed.

Pinel explained that pheromones are classified as a pesticide in this case because they are designed to get rid of the LBAM. But in actuality, pheromones are not technically a pesticide and therefore are not subject to the intense testing and oversight regulations applied to conventional pesticides.

“The Sierra Club even OK’d use of pheromones in this case,” she said. She noted that pesticide manufacturers spend years and millions of dollars testing pesticides under the stiffest U.S. government safety standards in the world.

Pinel said the LBAM threat is not just about farmers. The government eradication plan would prevent individual homeowners from trying to take care of the problem themselves — by buying stronger pesticide chemicals from stores and spraying their neighborhoods to combat the pest.

When one caller phoned in and mentioned possibly sending out tens of thousands of pheromone “twist ties” that could be applied throughout communities in a ground assault instead of an aerial attack, Pinel pointed out that groups have been quick to criticize CDFA for its plan, but that there have been no citizen groups pushing California legislators to pay for such a strategy. Pressure needs to be put on legislators to fund an alternative plan if communities don’t like the present plan.

Pinel also noted, and Flint quickly agreed, that CDFA funding has decreased year after year, which has resulted in a lack of oversight inspection at cargo docks at which invasive species can enter the country.

“We have got to tighten the screws on what is getting into this country,” Flint said. She also noted that the LBAM is already well established, alive and thriving in 14 of California’s 58 counties.

Callers brought up a slew of questions that the panel said just couldn’t be answered until the ongoing safety risk assessment is done on all facets of the LBAM threat and the pheromones to be used in eradication. However, even eradication was in dispute, with two panelists saying the best we can expect is “control.”

As mentioned earlier, all this largely has been rendered moot with the federal and state decisions to drop aerial applications in favor of alternative methods. Meanwhile, California farmers are nervously standing by and hoping that whatever treatment methods are utilized are successful, and the LBAM threat doesn’t result in millions of dollars in crop damage and trade barriers.

If you would like to listen to the hour-long radio program, please visit

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