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 Puffer pheromone dispenser in a walnut tree. Photo by S. Goldman Smith
Puffer use increasesIN BRIEF
Central Valley walnut growers continue to use pheromone mating disruption to reduce their reliance on broad-spectrum pesticides to manage codling moth. Building on that success, researchers are applying the technique to navel orangeworm management in walnut and almond orchards. One of the more economical techniques for delivering pheromone into orchards is aerosol puffers. These are easily put in an orchard in a grid pattern of one for every 2 acres, hung in the upper part of tree canopies. UC IPM Advisor Carolyn Pickel said using the puffers along with monitoring the codling moth combo lure has several advantages over traditional pesticides. “It lowers the codling moth population over several years, reducing the risk of codling moth damage,” Pickel said. “It also minimizes the use of broad-spectrum pesticides that cause secondary pest outbreaks.” Since 2008, Pickel and project colleague UC Cooperative Extension Advisor Joe Grant have seen codling moth puffer use grow to 15,000 acres in walnuts with less than half a percent damage. However, researchers still are learning how well the technique works with navel orangeworm. Outcomes from their 2010 research trials, funded by an areawide USDA program, are promising. In large research sites where puffers dispensed navel orangeworm pheromone, traps for live females stopped catching moths. Similarly, after puffers were put up, eggs no longer were found in egg traps for several weeks. These trap “shut downs” indicate that the pheromone is successfully interfering with mating. UC and the USDA are working with private researchers to develop a stabilized navel orangeworm pheromone that can be used as a lure for females. When this becomes available, navel orangeworm puffers will become a viable option for walnut and almond growers. For a timeline of important events that led to the development, testing, and implementation of pheromone mating disruption and puffers, see the 2009 UC IPM Highlights on the UC IPM Web site. Next article >> A new threat to California oaks: Goldspotted oak borer |