Some periodical cicadas belonging to Brood II are emerging in several states along the east coast.  Such accelerations have been observed before, one of the first being Brood XIII emerging in 1969, four years before its expected 1973 appearance.  More recently accelerations of of Brood V in 1995 in eastern Ohio, Brood X in 2000 in several states, Brood XIII in 2003 in Chicago, and Brood XIV in 2004 in parts of eastern Cincinnati have been observed.

Monte Lloyd and JoAnn White proposed that 17-year cicadas will emerge early if their second instar nymphs molt during the first five years of their development.  That was verified in 1991 in Cincinnati when cicada nymphs were examined four years after they hatched.  That led to the prediction that some cicadas would emerge in Greater Cincinnati in 2000.

The extent of this year’s acceleration is not known, but could occur anywhere in the Brood II distribution, which is shown above.  If you see periodical cicadas this year, you are encouraged to report the location by going to the report link above.