The good news is: the state announced there will be no twist ties for Sonoma – since no new light brown apple moth (LBAM) has appeared in the quarantined area since the first two LBAMs were found. The bad news is: just a few hours later, in the southeastern part of the county, a third moth appeared.
The new find is in the area of Ramal Road, about a mile from the Napa County border, and about seven miles from where Sonoma’s two LBAMs were found. It is too far away to constitute an increase in that original population and therefore will not affect the CDFA’s decision to put the twist tie plan on hold.
“So that’s good news for the community,” said Sonoma County Agricultural Commissioner Lisa Correia. Twist ties, laced only with the moths’ own pheromones, are designed not to kill but to confuse them, preventing them from mating. Nevertheless, in July, as the CDFA was preparing to install the twist ties in Sonoma’s quarantined area, some residents protested. The CDFA delayed putting out the twist ties until the Department of Fish and Wildlife declared they would not harm aquatic species. The halt to the twist tie plan came, as CDFA representative Steve Lyle said, after the Fish and Wildlife determined that the twist ties will do no harm to aquatic species, and the CDFA was cleared to proceed. At that point, however, the CDFA determined that, since there had been no new find, it seemed reasonable to continue trapping and monitoring until the third life cycle has completed itself – end of September or beginning of October – and if there are no further finds in that area, the quarantine can be lifted. “We certainly hope that there’ll be no further finds,” Correia said, “that [this one] doesn’t kick in a quarantine.”
Dave Whitmer, Agricultural Commissioner for Napa County, said he was not in a state of urgency over the find so close to his border. “This wouldn’t be the first time we’ve seen an LBAM in a trap,” he said. “We’ve had other traps in that area and our staff found no additional moths, no larvae, no eggs. You’d think if there was a population around there, you’d find more than one insect.”
Correia agreed. She said she thought isolated moths might be blown in from infested areas such as Solano County, where, as of Friday, in Mare Island, there have been 17 moths discovered so far. Solano County Agricultural Commissioner Jim Allan confirmed there had been 10 discovered last year and seven this year. “It’s going to be an on-going problem because there’s no treatment in the core areas,” he said. “Without the treatment, we’re going to run out of fingers to put into the dike.” He said there are heavy LBAM infestations in San Francisco’s Golden Gate Park and also in the landscaping around the Ferry Building, but that the city has an ordinance against any pesticide treatment. He said Solano County has responded to every LBAM discovery with pheromone twist ties and has had no negative results from them. “There’s no insecticide associated with it,” he said. “Other than choking on one, I don’t see how it could have a deleterious effect.”
According to the California Department of Food and Agriculture, the LBAM was first detected in Alameda County on February 27, 2007. It is a native of Australia and considered an invasive, “actionable” pest, subjecting infested areas or hosts to quarantine. Other countries, including Mexico, Canada, Japan and China also treat LBAM as a quarantine action pest. Programs to eradicate the insect through aerial spraying of CheckMate, a bio-chemical mating disruptor, have met with stiff resistance from residents and some scientists who disagree with both the technique and the plausibility of eradication itself.
