Small Pest, Huge Controversy

The decibel level is so high in the debate over aerial spraying in Marin to eradicate a tiny moth that it’s difficult for solid information to sink in.

Here’s what I do know. Federal and state officials maintain the light brown apple moth, a native of Australia, threatens California’s and the nation’s vast agricultural interests. “Left unchecked, this moth could destroy more than $2 billion worth of California crops each year,” U.S. Secretary of Agriculture Ed Schafer said recently. “We are working closely with the California Department of Food and Agriculture to eradicate this invasive species using the safest and most effective means possible.”

Currently, the state plans nighttime spraying in August over parts of the Tiburon Peninsula and Sausalito only, as that is where the moth has been found. What would be sprayed is not a pesticide but a pheromone, often called a “perfume,” that disrupts the reproductive cycle of the moth. The spray’s predominant ingredient, by far, is water. Mixed in the water are microscopic droplets of pheromones encapsulated in biodegradable polymer capsules the diameter of a human hair. “The application rate is about four tablespoons of product for every acre treated,” says Fred Crowder, Marin’s deputy commissioner of agriculture.

Here are the points of contention: the chemical makeup of both the pheromone and the encapsulation material, and how they interact while biodegrading. Conclusive evidence that these items are harmless to humans must be provided before spraying commences.

Opponents to spraying include Marin’s board of supervisors, several city councils, environmental groups and state elected officials. Personally, I live at apple moth ground zero—they’ve been trapped by county inspectors outside my front door—and I’m not at all comfortable with government planes passing overhead spewing chemicals. Equally unappealing, though, is watching California’s agriculture take an economic nosedive.

At press time, about 18,000 of the moths have been trapped in the Bay Area. More than 100 have been found in Marin. For years, the U.S. government has banned the import of fruits and vegetables from places where even the slightest indication of apple moth infestation has appeared. Still, the bugs made their way into California. As a result, Bay Area agricultural shipments to other states, Canada and Mexico have been quarantined, meaning costly delays while inspections and certifications take place.

Sprayings similar to those proposed for Marin occurred in parts of Monterey County in September and October. In November, three spray planes targeted parts of Santa Cruz County where moths had been found. Of importance: 1) Santa Cruz County went to court opposing the spraying, but failed to meet the legal burden of proof necessary to obtain a restraining order and stop the spraying. 2) The effectiveness of these sprayings has not been evaluated. 3) The product used in these sprayings, CheckMate, may or may not be used in the Marin sprayings. That has yet to be decided. Steve Lyle, a public affairs officer for the state department of agriculture, assured me that whatever product is used, “a complete disclosure of the product’s ingredients is expected to be issued prior to spraying.”

Also important: those opposed to spraying repeatedly state that after the Monterey and Santa Cruz County sprayings, over 600 people suffered chest pains, asthma attacks, nausea and headaches. California law requires physicians to report pesticide-related illnesses to their local health departments within 24 hours; the data is forwarded to California’s Office of Environmental Health Hazard Assessment for evaluation. According to that agency, 44 physician-initiated reports were received during the spraying periods. Hundreds of additional complaints were compiled by the website Hope for Truth. Sam Delson, spokesperson for the state health hazard office, says all illness complaints, regardless of origin and including the 44 physician-reported cases, have been investigated and that results are inconclusive. “Many were generalizations, several were duplicates, and a few appeared valid,” he explains. “Yet even one illness is one too many.”

In November, the respected environmental group National Resources Defense Council gave qualified support to aerial spraying of pheromones. Its reasoning: “We hope the prompt use of this strategy averts future use of toxic insecticides to control this pest.”

Let’s hope it doesn’t come to that drastic step—yet it might. I believe all aspects of this emotionally charged issue must be brought to light before judgments are made. That’s my point of view. What’s yours?

Mill Valley Mayor Shawn Marshall explains why her city council passed a resolution against apple moth spraying (see below).

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Why Mill Valley Opposes the Apple Moth Spraying

On March 17, 2008, the Mill Valley City Council joined other Marin and Bay Area cities in opposing the state’s proposed aerial spray program to eradicate the light brown apple moth in Marin. We took this action for a number of reasons. Among them:

Insufficient analysis of potentially harmful side effects. A primary responsibility of local government is to protect the safety of its residents. Because the apple moth is classified as a “class A” pest, the state’s aerial spraying proposal is allowed to bypass critical human and environmental health analysis of the synthetic pheromone pesticide known as CheckMate. No verifiable analyses of the product have been conducted and its cumulative short- and long-term effects are unknown. Some studies indicate harm to honeybees and the moth’s natural predators, which could counteract the effects of any spray program. CheckMate is sprayed in tiny plastic capsules that will remain in the environment indefinitely and could be mistaken for food by wildlife. A study from UC Davis found that the product can lodge in our lungs, potentially causing respiratory inflammation and infections, both of which were reported after spraying occurred in Monterey County.

With lack of consensus, we invoked the Precautionary Principle. There appears to be no consensus about the true threat posed by this moth. In New Zealand, its place of origin, it is considered a minor pest. Experts can’t agree on how long the moth has been in California, with estimates ranging from two to 40 years. Moreover, experts don’t agree on whether the moth’s eradication is even possible. Given these unknowns, the City Council invoked the Precautionary Principle, which states that “if an action or policy might cause harm to the public, the burden of proof falls on those who would advocate taking such action.”

A less toxic approach is available. There is growing consensus, supported by the Marin County Farm Bureau, Marin Organic, the Board of Supervisors and the county agricultural commissioner, that in the absence of a full health and environmental analysis of CheckMate the best way to proceed is a concerted ground-based eradication effort. This less invasive and less toxic method involves pheromone twist-ties and other nonspray approaches that can be geographically targeted to specific outbreak areas.

Until CheckMate checks out from a health and safety perspective, Mill Valley remains opposed to its aerial use in our region.

Shawn Marshall, mayor, Mill Valley and Carol Misseldine, sustainability director