The Iowan Brood
17-year Brood III, the Iowan Brood, emerges in Missouri, Iowa and north western Illinois. In many areas, it is in close contact with 13-year Brood XIX.
In the map below, cicada symbols are verified records in our database as of February 2021. Gold symbols are from Simon (1988); smaller symbols are records with a lower degree of certainty, and 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. This map may not be reproduced without written permission.
Illinois presents a particular challenge for understanding periodical cicada biology, because it contains both 13 and 17 year life cycles, all 7 currently recognized species, and five separate broods, some of which include disjunct populations.
Stannard (1975) published a map of all Illinois periodical cicada broods. Stannard’s map shows an eastern disjunct of Brood III in DeWitt, Piatt, and Champaign Counties. However, these populations occupy a more restricted area than suggested by Stannard’s map and belong to 13-year Brood XXIII.
In the map below, cicada symbols are verified records in our database as of February 2021. Closed circles are records of the brood from Stannard (1975); open circles represent absences of the brood. The shaded area represents Stannard’s estimation of the brood boundary. This map may not be reproduced without written permission.
Cooley, J. R., D. C. Marshall, A. F. Richards, R. D. Alexander, M. D. Irwin, J. R. Coelho, and C. Simon. 2013. The distribution of periodical cicada Brood III in 1997, with special emphasis on Illinois (Hemiptera: Magicicada spp.). The American Entomologist 59:9-14.
Irwin, M. D., and J. R. Coelho. 2000. Distribution of the Iowan Brood of periodical cicadas (Homoptera: Cicadidae: Magicicada spp.) in Illinois. Annals Of The Entomological Society Of America 93:82-89.
Marlatt, C. L. 1923. The Periodical Cicada. United States Department of Agriculture, Bureau of Entomology Bulletin 71:1-183.
Simon, C. 1988. Evolution of 13- and 17-year periodical cicadas. Bulletin of the Entomological Society of America 34:163-176.
Stannard, L. J. 1975. The distribution of periodical cicadas in Illinois. ll. Nat. Hist. Surv. Biol. Notes 91:3-12.