Godzilla versus Mothra

How monumental estimates of a tiny invasive moth's economic and environmental impacts are threatening San Francisco with aerial spraying


When retired entomologist Jerry Powell caught two tiny light brown apple moths in a blacklight trap in his Berkeley backyard last winter, he had no idea of the furor his find would unleash — especially in the communities that were subsequently sprayed with female moth pheromones, a process that could come to San Francisco this spring.

Native to Australia and now found widely in New Zealand and the United Kingdom, the LBAM (or Epiphyas postvittana, as it's known in bug circles) is classified as a plant pest, but it had never before been reported on the United States mainland, though it was found in Hawaii in the late 1880s.

So its discovery, first in Powell's trap in February and then throughout the Bay Area and the Central Coast in March 2007, drove the US Department of Agriculture to declare a statewide emergency and issue quarantine and extermination directives.

The USDA's problem, as Powell explained, is that unlike many moths, which only lay eggs on oak trees or eat holes in sweaters, the LBAM can lay eggs on and eat many, many plants.

"From each batch a hundred tiny caterpillars hatch and feed on a wide variety of shrubs and trees, using silk to tie the leaves up into bundles," Powell told the Guardian.

According to the USDA's Web site, this pest could infest up to 80 percent of the continental US and attack 2,000 types of plants, causing huge economic and environmental damage.

Officials with the California Department of Food and Agriculture estimate the LBAM could cause up to $640 million annually in crop damage and control costs in California alone.

So starting last summer the CDFA required nurseries to either destroy infested plants or treat them with chlorpyrifos, an organophosphate pesticide derived from World War II nerve gas.

The agency also made ground applications of Bacillus thuringiensis (a genetically engineered bacteria) and hand-applied female moth pheromones in other infested areas, including Napa, Vallejo, and Mare Island.

But the agency's most controversial act was the spraying of entire communities, including Santa Cruz, with Checkmate, a synthetic female moth pheromone made by the Oregon company Suterra. Since male moths use the real pheromone to detect females, flooding an area with similar-smelling stuff is supposed to confuse them and prevent mating.

The controversy, according to four lawsuits filed in Monterey and Santa Cruz counties, in which 73 percent of the moths have been found, began when the CDFA acted with minimal notice, without fully disclosing Checkmate's contents until after the spraying occurred, and without adequately demonstrating that the moths were enough of an emergency to exempt the spraying from the California Environmental Quality Act.

Not to mention the sentiment, expressed by numerous members of the sprayed-on communities, that they felt as if they had been airlifted into Vietnam.