Since 1868 or 1869, when it was introduced near Boston, the gypsy moth has been slowly expanding its range to include the entire northeastern United States and portions of Virginia, West Virginia, North Carolina, Ohio, and Michigan (Liebhold et al. 1992, 1996). It is inevitable that the gypsy moth will continue to spread south and west over the next century.
Liebhold, Andrew M.; Gottschalk, Kurt W.; Mason, Douglas A.; Bush, Renate R. 1997. Forest susceptibility to the gypsy moth. Journal of Forestry. 95(5): 20-24.