Issue link: http://read.dmtmag.com/i/56260
Pest Management New pests threaten Washington grapes Brown marmorated stinkbug could be the worst. by Melissa Hansen W hile exotic and invasive pests threaten grape industries in other West Coast states, Washington's grape industry has thus far been relatively unscathed. Vine mealybug has not yet been detected in Washington vineyards, and spotted wing drosophila lar- vae do not appear to be able to develop on Washington's juice or wine grapes, says Washington State University's Dr. Doug Walsh. However, the big unknown to grapes is the brown marmorated stinkbug. Last year was the second that university entomologists followed infestations of spotted wing drosophila in Wash- ington State. It was first detected in the United States in 2008 in California. Since then, the small fruit fly has been found along the West Coast and throughout the United States. Literature reports an extensive host range for spot- ted wing drosophila, including tree fruit, berries, and grapes. A national research effort is under way to gain knowledge about the fruit fly, crop damage, monitoring protocols, and management options. Walsh, WSU environmental and agrichemical educa- tion specialist and statewide integrated pest manage- ment coordinator, has spent the two years learning more about the tiny pest and its behavior. Eight species of drosophila have been identified in central Washington in vineyards, backyard fruit trees, and Doug Walsh, holding a mealybug pheromone trap, says that such traps have been used throughout the state to look for vine mealybug. Thus far, the destructive pest that's prevalent throughout California grape regions, has not been found in Washington. "Savings in hand thinning time and/or increases in fruit sizes resulted in a net positive impact of $123/ha to $1368/ha compared with hand thinning alone." - Baugher, Schupp, et al. Mechanical string thinner reduces crop load in various stages of bloom development in peach and nectarine trees. HORTSCIENCE 45(9): 1327-1331, 2010 Manufactured by; 4509 Bartlett Rd. Beamsville, ON Canada www.bartlett.ca Dealer in South Western US: P.O. BOX 550 Fowler, CA 93625 105 N Spokane Rd. Moxee, WA 98936 Dealer in North Western US; 559.834.1588 www.calagenterprisesinc.com 1.800.827.0972 www.bluelinemfg.com 32 MARCH 1, 2012 GOOD FRUIT GROWER www.goodfruit.com 905.563.8261 Melissa hansen