Magicicada cassinii, sometimes called the 17-year cicada, Cassin's periodical cicada or the dwarf periodical cicada, is a species of periodical cicada. It is endemic to the United States. It has a 17-year lifecycle but is otherwise indistinguishable from the 13-year periodical cicada Magicicada tredecassini. The two species are usually discussed together as "cassini periodical cicadas" or "cassini-type periodical cicadas." Unlike other periodical cicadas, cassini-type males may synchronize their courting behavior so that tens of thousands of males sing and fly in unison. The specific namecassinii was in honour of John Cassin, an American ornithologist.
Description
The adult Magicicada cassinii is very similar in appearance to other periodical cicadas. It is between long, measured from the front of the head to the tip of the wings folded over the abdomen. The head is black, the eyes are large and red, the pronotum is black apart from a narrow orange band at the edge of the sternites, and the abdomen is black. The legs are orange and the wings are translucent, with orange veins and dusky markings near the tips.
Distribution and habitat
Magicicada cassinii is endemic to North America, its range extending across the northern belt of the United States and the southern part of Canada.
Life cycle
These cicadas are true bugs and after having emerged from underground, the adults feed on sap sucked from trees and shrubs. Males amass in great numbers and sing in unison to attract females. The calllasts for two to four seconds and is a series of ticks followed by a drawn-out buzz which rises and falls in pitch. At the end of a chorus, males move to a new perch before starting the song again. After mating, the females insert their ovipositors into shoots and lay their eggs. These hatch about two months later and the first instarnymphs drop to the ground where they move underground and suck xylem sap from small rootlets. This sap is very low in nutritive value and the nymphs grow very slowly. They will moult five times, moving on to larger roots deep in the soil as they grow over a period of seventeen years. Finally, they all tunnel up through the soil and emerge into the open air, before climbing up the vegetation and shedding their skins for a final time to become adults. Although each population has a seventeen year life cycle and emerges in synchrony, past environmental events have occasionally disrupted this pattern and there are several different broods in existence in various parts of the insects' range which emerge in different calendar years.
