The East Coast Brood
Brood II emerges along the US Eastern Seaboard. Brood II has a disjunct population in northeast Georgia and, surprisingly, a disjunct population in Oklahoma. The disjunct populations of this brood likely have separate evolutionary histories. This brood includes the species Magicicada cassini, Magicicada septendecim, and Magicicada septendecula.
Both M. cassini and M. septendecula occur surprisingly far north in the Hudson River Valley. Connecticut populations of Brood II are exclusively M. septendecim, with one exception: A small population of M. septendecula exists in North Branford CT.
In the map below, cicada symbols are verified presence records and red crosses are verified absence records in our database as of January 2024. Click on points for details. Gold symbols are from Simon (1988); smaller symbols are records with a lower degree of certainty and black crosses represent records that are considered spurious. Blue symbols are from Marlatt (1923); smaller symbols are records with a lower degree of certainty and question marks represent records that are considered spurious. Symbols are in layered in the order Database, Simon, Marlatt, and symbols in the upper layers may obscure symbols in lower layers. Some absence records in the database are not shown for clarity. Note that the dates shown do not represent dates of adult emergence; rather, they represent dates on which choruses were active. Thus, in any given area, adult emergence may have occurred a week or more earlier than the dates shown on this map. This map may not be reproduced without written permission.