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 will emerge in Western Pennsylvania, eastern Ohio, and the West Virginia Panhandle in 2019.
Among other 17-year broods, four-year late Brood IV may appear in Kansas and Oklahoma.
Among the 13-year broods, four-year late Brood XXIII may appear.
No four-year early 17-year or 13-year cicadas are expected.