Twist ties will be used to eradicate apple moth

While aerial spraying has been used in some California locations to try to eradicate the dreaded light brown apple moth, the tactic isn’t being seriously considered in Sonoma County, where just two of the creatures have been found — neither of them in the Petaluma area.

Instead, beginning June 16, state agricultural employees will be putting pheremone-infused twist ties to fences and trees in a 200-meter area in Sonoma Valley where the two moths were found. This tactic has been suggested in such cases by officials from the State Department of Food and Agriculture in a 2008-2009 action plan to eradicate the moth.

The moths found in the Sonoma Valley might have been “hitchhikers” that came there with plant materials, said Lisa Correia, Sonoma County’s agricultural commissioner.

“They were found in mid-February and the latter part of April, after we set up 600 traps around the county to catch them,” Correia said. “The good news is, it’s now been a good month since the last find.”

Still, the two finds prompted the state to establish a quarantine area covering 15 square miles in Agua Caliente, Boyes Hot Springs, El Verano and west Sonoma in which homegrown plants, vegetables, flowers and fruits cannot be removed.

The moth, found in Australia, New Zealand and Great Britain, wasn’t discovered in the United States until February 2007, when it turned up in California. It can cause significant damage to foliage and fruit, and this could result in an annual state loss of up to $640 in crop damage, state officials say.

This scary possible scenario has triggered a $75 million state and federal program to eradicate the moth, and sparked a heated debate over how to do so.

Some people advocate the aerial spraying of a synthetic pheromone that is designed to interrupt the mating process, rather than immediately kill the moth. This was done in Santa Cruz, where some 14,000 of the moths were found, but afterward, more than 100 people reported feeling sick.

Some state officials claim that the spraying doesn’t present health hazards for human beings, but others disagree. The Sonoma City Council voted 4-1 on May 7 to pass a resolution opposing the use of aerial spraying to eradicate the moth. Also, the state has suspended the aerial spraying until at least Aug. 17 so that toxicological tests can be done by the California Office of Environmental Health Hazards Assessment.

Correia says that the application of pheremone-infused twist ties in the area around where the two moths were found is a more appropriate approach.

“This process is pretty laborious, and is best used when small quantities are involved,” Correia said.

Meanwhile, 958 traps — including some in the Petaluma area — now are set up in Sonoma County to help identify possible additional moths.

(Contact Dan Johnson at dan.johnson@arguscourier.com)