Sudden emergence of the zebra chip bacterium, Candidatus Liberibacter solanacearum, nearly destroyed the Southwestern-US potato industry. The Pacific Northwest (PNW) states of ID, WA and OR, home to the bulk of US potato production, were initially thought to be safe from this threat; the pathogen was unknown here and its potato psyllid (Bactericera cockerelli) vector was thought to be rare. A surprising, widespread zebra chip outbreak in PNW potatoes in 2011 was followed by discovery of both year-round-resident and apparently migratory psyllid populations. The specific source of pathogen-carrying psyllids in our region nonetheless remains frustratingly unclear, perhaps reflecting the complexity of vector-pathogen ecology in our unique climate, ecological context, and cropping systems.
To fill these knowledge gaps, our “MAP-PSILDS-PNW: Mapping and Predicting Psyllid Sources, Immigration and Locality-Specific Disease Spread in the PNW” project will (1) map the full range and spatiotemporal patterns of crop and non-crop host-plant use by vector and pathogen, and determine how this is impacted by climate; (2) deploy cutting-edge genomics approaches to infer fine-scale movement of psyllid and bacterium into and across the region; and (3) use this knowledge to build predictive, GIS- and weather-based models of disease risk delivered to growers through an easy-to-use mobile decision-support tool. Additional work will document the economic viability and grower adoption of our new pest-management approaches. Our ultimate goal is to allow PNW potato growers to replace calendar-based treatments with targeted sprays based on real-time, locality-specific pest/disease information.
This work is supported by a new, $2.7 million grant from the USDA’s SCRI Program.
Key collaborators include Snyder-lab postdoc Daisy Fu, entomologist Dave Crowder, outreach specialists Carrie Wohleb and Tim Waters, and meteorologist Gerrit Hoogenboom at WSU; entomologists Joe Munyaneza, Dave Horton and Rodney Cooper at USDA-ARS; extension entomologists Stuart Reitz and Silvia Rondon, and social scientist Molly Engle, at Oregon State University; Extension Entomologists Erik Wenninger and Arash Rashed at University of Idaho; economist Gina Greenway at College of Idaho; and industry entomologists Andy Jensen at the Northwest Potato Research Consortium and Matt Blua at the Washington State Potato Commission.
