Though some species are called annual cicadas because they present every year, all species take at least four years to mature in the ground. Among periodical cicadas, numerous different "broods" occur.
All periodical cicadas of the same life cycle (that emerge in the same year) are categorized into broods, or “year class.” Some broods are on 13-year cycles (in the south) and some on 17-year cycles (in the north). Each brood has its own unique range, population size, and emergence cycle.
There are 20 to 30 different broods in North America, five of which occur in New England. (Scientists have identified each brood and designated it with a Roman numeral.) Brood XIV, the one Governor Bradford recorded in 1624, may be the most spectacular one to occur in Massachusetts.
This brood extends from Plymouth and Bristol counties south to Georgia and west to Illinois. Writing of the 1923 emergence for the Bulletin of the Boston Society of Natural History, veterinarian Langdon Frothingham noted on June 25 that, "The air is full of them, often landing on you and singing in your ear."