Brood XI (Extinct)

Records of Brood XI in Rhode Island seem doubtful, because of sandy and wet soils (Manter 1974). Brood XI was last recorded near the Ashford/Willington town line in eastern Connecticut. The last recorded emergence was on a dairy farm in 1954; no sightings were recorded in 1971, 1988, or 2005 despite deliberate searches. Species distribution models suggest that the extinction of this brood is not explained by deforestation and development, since New England currently has more forest cover than at any time in the recent past; rather, this brood’s extinction seems related to the fact that it is at the edge of the general periodical cicada distribution and at the edge of these species’ climatic tolerances (Cooley et al. 2013). The only specimens from this brood are of the species M. septendecim.

In the map below, cicada symbols are verified presence records and red crosses are verified absence records in our database as of August 2023. 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, Marlatt, and symbols in the upper layers may obscure symbols in lower layers. This map may not be reproduced without written permission.