White-nose syndrome has devastated bat populations in eastern North America. In Midwestern United States, prevalence increased quickly in the first year of invasion (2012-13) but with low population declines. In the second year (2013-14), environmental contamination led to earlier infection and high population declines. Interventions must be implemented before or soon after fungal invasion to prevent population collapse.
Keywords: Myotis lucifugus; Pseudogymnoascus destructans; United States; bats; disease invasion; environmental reservoir; fungal disease; fungi; invasive species; white-nose syndrome.