SOUTH SHORE YMCA NATURAL SCIENCE CENTER

Cicadas!

Posted: Aug. 14, 2013

Cicada

Like many others this year, we’ve witnessed the majesty of the 17-year Cicada emergence. This image was taken on a tombstone in a cemetery in Weymouth – just don’t ask us who found it there or why.

Cicadas spend most of their lives underground as nymphs, living between a foot and 8 feet below. When they do emerge, they shed their exoskeleton, by crawling out of the top of it. The exoskeleton, thereafter called an exuvia, clings to whatever it was clinging to, in this case the edge of that tombstone.

The U.S. has a specialty cicada, one┬áthat lives longer than most, much longer than the two-to-five years cycle of most species. Our periodical cicadas emerge every thirteen or seventeen years. Theoretically (since we can’t get into the minds of cicadas and find out for sure) they do so to avoid predation, quite an adaptation that probably took centuries to develop. Quite frankly, individually, they probably don’t know why they do it that way either.