Periodical Cicadas are those Cicadas of the genus Magicicada. Magicicada is sometimes abbreviated as "M." and contain 7 species. They have the longest juvenile period (nymph stage) and are considered the longest-lived of all insects when their juvenile period is factored into the equation. Three species emerge en-mass every 17 years and 3 species emerge en-mass every 13 years.

The three 17 year species of Magicicada are M. septendecim, M. septendecula and M. cassini. The three 13 year species of Magicicada are M. tredecim, M. tredecula and M. tredecassini. There has recently been reported a fourth 13 year species known as Magicicada neotredecim.

Periodical Cicadas appear in different regions of the United States and are broken down by year of appearances known as Broods. Today there are 15 different broods of Magicicadas. Twelve being 17 year Periodical Cicadas and three being 13 year with each Brood assigned a Roman numeral.

The reason for these mass emergences is due to Periodical Cicadas being developmentally synchronized. That is all adult Magicicadas of the same brood in any given region will emerge at roughly the same time every 17 or 13 years. In fact since Periodical Cicadas are so developmentally synchronized, if all the Magicicadas of any given Brood were to be wiped out in the year of their emergence before the females could deposit their eggs after mating, then that particular brood would become extinct. This happened with Brood XI which was from the Connecticut River valley region of the United States and was last seen in 1954.

Periodical Cicadas are smaller than Annual Cicadas and are mostly black with clear membranous wings, orange wing veins and fiery red eyes. Some hybrid Magicicadas have been recorded as having silver, blue or grey eyes and are considered quite rare.

If this page was found through a search engine:

Go To Massachusetts Cicadas | Contact Page Author