County-level detection dates for beech scale in Canada and the United States

This dataset contains the years beech scale (Cryptococcus fagisuga; a predisposing agent of beech bark disease) was first detected in counties of Canada and the United states. These data were aggregated from observations made from 1890 to 2015 in order to map the spread of the insect throughout its invaded range in eastern North America. Detection year data are organized by country, province/state, and county for a total of 389 records with references to their original reporting literature.