Data from: Emerging wild virus of native grass bioenergy feedstock is well established in the Midwestern USA and associated with premature stand senescence

Field collections and laboratory analysis Plant and leafhopper samples were collected in the field during the 2012 growing season. Virus infection was detected within samples using RT-PCR with specific primers. Detailed methods are described in the associated manuscript. Land cover analysis For land cover analysis, we evaluated relevant regions from the USDA National Agricultural Statistics Service Cropland Data Layer. 2012. Published crop-specific data layer [Online]. Available at https://nassgeodata.gmu.edu/CropScape/. USDA-NASS, Washington, DC. Land cover types included within each aggregate category We grouped all raster cells as belonging to one of the following eight broad land cover groups: Agriculture: Alfalfa, Apples, Barley, Blueberries, Carrot, Cherries, Corn, Cucumber, Dry Beans, Grapes, Oats, Onion, Potatoes, Pumpkins (1.5 km only), Radish, Rye, Soybean, Squash, Sugarbeet, Sunflower, Watermelon (1.5km only), Winter WheatBarren: BarrenForest: Deciduous Forest, Evergreen Forest, Mixed ForestGrass/Meadow: Fallow Cropland, Grassland/Pasture, Other Hay, Sod/Grass SeedDeveloped: Developed/High Intensity, Developed/Medium Intensity, Developed/Low Intensity, Developed/OpenMiscellaneous Perennial Habitat: Shrublands, Clover/WildflowersOpen Water: Open WaterWetlands: Herbaceous Wetland, Woody Wetlands Following Werling et al., 2011 (Werling, B. P., T. D. Meehan, B. A. Robertson, C. Gratton, and D. A. Landis. 2011. Biocontrol potential varies with changes in biofuel-crop plant communities and landscape perenniality. Global Change Biology Bioenergy 3:347-359), we created an additional aggregate category, which contains elements from several categories above: Herbaceous perennial habitat: Alfalfa, Other Hay, Fallow Cropland, Shrubland, Clover/Wildflowers, Grassland/Pasture To quantify how much drought each study site experienced, we calculated a drought index value based on spatially-explicit estimates of the duration and weekly severity of drought conditions as published in the US Drought Monitor (https://droughtmonitor.unl.edu/). Description of methods as excerpted from our associated article: "The Drought Monitor rates moisture conditions as no drought or dryness (no drought rating), abnormally dry (D0), moderate drought (D1), severe drought (D2), extreme drought (D3), and exceptional drought (D4). For each site’s GPS location (i), we thus calculated a Drought Index (DI) as where j = the growing season week, and dj = the Drought Monitor D value rating (0 – 4) for week j. Thus, weekly ratings of D0, D1, D2, D3, and D4 were valued as 1, 2, 3, 4, and 5 respectively. Weeks with no recorded drought or dryness were valued as 0. Switchgrass in this region typically sprout in early May, so we calculated DI for the 16 weeks from the week of May 1 through the week of August 14, when early August field measures were completed (i.e., n = 16)."