Periodical cicadas are unique in that all (or nearly all) members of the population emerge in one year and then are absent in the intervening years.
Periodical cicada Brood VIII emerged in Western Pennsylvania, eastern Ohio, and the West Virginia Panhandle in 2019.
By now, the eggs from these emergences have hatched, and the new nymphs have entered the soil.
Look for Periodical Cicada Brood IX in 2020!