PHEROMONE “TWIST TIES” TO AID IN ERADICATION OF LIGHT BROWN APPLE MOTH

Crews apply new, non-insecticide eradication tool in Oakley, Napa

SACRAMENTO – Beginning this week, crews are moving through residential neighborhoods in Oakley and Napa where the light brown apple moth (LBAM) has been detected recently.  The crews’ assignment is to eradicate the infestations, but they won’t be spraying any insecticides.  Moving from yard to yard in a labor-intensive effort, they are placing pheromone-infused “twist ties” designed to distract the moths and keep them from breeding.

These communities have been treated with the organic insecticide Bt (Bacillus thuringensis) over the past several weeks as the first step in the eradication process.  The Bt applications are complete, and the pheromone ties will now be applied in these neighborhoods.

“This is among the most advanced and environmentally sensitive eradication tools ever used in California,” said CDFA Secretary A.G. Kawamura.  “Science has provided a method of eradicating these invasive moth populations simply by interfering with their breeding cycle.”

Napa County Agricultural Commissioner Dave Whitmer indicated he is pleased with the choice to use the pheromone mating disruption technology. He commented, “I was discussing with Supervisor Mark Luce, whose district includes the treatment area, how much we appreciate the cooperation of the property owners there. To be able to go to them and say we will be using this alternative demonstrates our commitment to use the safest methods available.”

Contra Costa County Agricultural Commissioner Ed Meyer added, “We are dealing with a pest that impacts agriculture as well as landscaping, parks and natural habitat so it was important to find an eradication tool that can be effective under all of those conditions and constraints.”

The ties contain an odorless, synthetic insect pheromone (sexual attractant) that confuses the male LBAM, impairing his ability to find a mate.  This method is highly specific to the targeted moth population and is not harmful to other organisms.  Once the breeding cycle of the moth population is disrupted, the infestation will eventually be eradicated from the area.

The “Isomate LBAM Plus” pheromone twist ties, also called pheromone ropes, are twisted loosely around branches, fence posts and other objects at a rate of approximately 40 ties per property.  After approximately 90 days, depending on whether traps in the area detect any additional moths, the twist ties will either be removed or replaced.

The eradication efforts in Oakley and Napa are the first two local projects undertaken as part of state, federal and local officials’ cooperative project to eradicate light brown apple moth from the state.  The moth has been detected in 11 California counties since February. Quarantine restrictions have largely halted the spread of the infestation, which is centered in the East Bay and Central Coast regions of the state.

The light brown apple moth is of particular concern because it can damage a wide range of crops and other plants including many commonly found in our urban and suburban landscaping, public parks, and natural environment.  The list of agricultural crops that could be damaged by this pest includes Napa County’s famed grapes as well as citrus, stone fruits (peaches, plums, nectarines, cherries, apricots) and others.  The complete “host list” contains over 250 plant species.  The pest damages plants and crops by feeding on leaves, new shoots and fruit.