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.
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.
Cooley, J. R., C. Simon, C. Maier, D. C. Marshall, J. Yoshimura, S. M. Chiswell, M. D. Edwards, C. W. Holliday, R. Grantham, J. D. Zyla, R. L. Sanders, M. L. Neckermann, and G. J. Bunker. 2015. The distribution of periodical cicada (Magicicada) Brood II in 2013: Disjunct emergences suggest complex origins. The American Entomologist 61:245-251.
Maier, C. 2015. Habitat and estimated density of Magicicada septendecula (Hemiptera: Cicadidae), a 17-year periodical cicada newly discovered in Connecticut, United States of America. Canadian Entomologist 147:51-58.
Marlatt, C. L. 1923. The Periodical Cicada. United States Department of Agriculture, Bureau of Entomology Bulletin 71:1-183.
Simon, C. and Lloyd, M. 1982. Disjunct synchronic population of 17-year periodical cicadas: Relicts or evidence of polyphyly? Journal of the New York Entomological Society, 110, 275-301.
Simon, C. 1988. Evolution of 13- and 17-year periodical cicadas. Bulletin of the Entomological Society of America 34:163-176.