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The North American native prairie grass Panicum virgatum (switchgrass) is a primary bioenergy feedstock candidate. Its widespread distribution and genetic diversity enable the possibility of developing this perennial grass for high production in a variety of conditions, including on marginal lands. A critical concern in feedstock development and deployment is the risk of novel pathogen emergence.Here, we investigate the landscape-scale prevalence and epidemiology of a littlestudied North American virus that was first detected in switchgrass and other grasses in bioenergy trials in the US Midwest. Switchgrass mosaic virus (SwMV, Genus Marafivirus, Family Tymoviridae) is transmitted by leafhoppers and is phylogenetically a sister to Maize rayado fino virus, a significant pathogen of maize in parts of the Americas. Our goal was to determine whether SwMV is uniquely limited to specific bioenergy trials or well-established and circulating more broadly. We used molecular diagnostics to quantify naturally occurring SwMV infection in leafhoppers and switchgrass in naturalistic stands throughout a large Midwestern landscape, and quantified leafhopper abundances and stand performance. Our analysis revealed that this apparently wild virus is well-established and widespread. Infection was present at nearly all sites, across diverse landscape contexts, with its prevalence ranging as high as 33%-60%. Infection appeared to

Pterostichus melanarius (Illiger, 1798) is a Palearctic generalist predator native to Europe. It was unintentionally introduced to North America at least twice in the mid 1920s and has since become widespread in Canada and the United States. Although P. melanarius is a valuable natural enemy in many different agricultural systems, we are not aware of any effort to compile in one publication details of its life history, diet, distribution, and factors that influence its populations. Some studies in North America have investigated the effects of P. melanarius on pest species and native carabid assemblages. Moreover, given that it is an exotic species whose range appears to still be expanding, it will be valuable to predict its potential distribution in North America. Therefore, the goals of this paper are to: 1) compile information on the life history and biology of P. melanarius, 2) review the effects of various agricultural practices on this species, and 3) use ecological niche modeling to determine the potential range of P. melanarius in the United States and which climate variables are most important for range expansion. Our review revealed that P. melanarius appears to provide benefits most consistently in diverse agricultural systems managed with no-till or reduced till methods, whereas our modeling revealed that P. melanarius likely occupies, or will occupy, more of the northern U.S. than is currently recognized, particularly in the Appalachian and Rocky Mountain regions.