Pheromone Mating Disruption of Filbertworm Moth (Cydia latiferreana) in Commercial Hazelnut Orchards

Oregon produces 99% of the hazelnuts grown in the United States. Currently, most growers control the key pest, filbertworm (FBW, Cydia latiferreana), with one to two applications of esfenvalerate (Asana XL), a broad-spectrum pyrethroid. Pheromone mating disruption is an alternative or accompaniment to pesticides used to control related lepidopteran pests. Mating disruption trials were conducted from 2009 to 2011 in two commercial orchards in the Willamette Valley of Oregon using a synthetic sex pheromone. Dispensers containing components of FBW sex pheromone were placed at different densities: 93 and 49 dispensers/ha during 2009, 49 dispensers/ha during 2010, and 49 and 24 dispensers/ha during 2011, always paired with an untreated control. Pheromone traps containing septa of the compound at two strengths (1x and 10x) were placed in each test plot in 2009 and 2010. Greater mean FBW per trap counts were recorded in control plots versus the treatment plots in one orchard in 2009 and 2011. Greater numbers of FBW were captured in control plots versus treatment plots in all replications. Nuts examined for infestation of FBW were below the industry rejection threshold of 1%. Percent trap shutdown ranged from 58.2 to 81.7%. Observed trends in FBW trap counts using sex-pheromone mediated mating disruption are promising and warrant further research of this method for FBW control.