Monday, June 03, 2013

Photo of the Week: Periodical Cicada

When I lived in Washington, DC, I experienced the first emergence of periodical cicadas that I can remember: the massive emergence of Brood X periodical cicadas in 2004. This was shortly after I started birding. The noise they produced was so loud that at times I had trouble hearing birds. As the emergence ended, dead cicadas littered the streets and were picked up and carried away by the ubiquitous House Sparrows in DC.

This year I am in New Jersey for the emergence of Brood II. So far I have not seen or heard any around Highland Park, but over the weekend, I encountered a fairly large number of them at Fairview Farm Wildlife Preserve in Bedminster, New Jersey. There was a continuous chorus going in some parts of the preserve, though it was not as loud as some I experienced around Washington. The cicadas I examined closely all seemed to be Magicicada septendecim, with an orange spot in front of the wing and broad orange bands on their undersides. You can read more about identifying Magicicada species here.

Periodical cicadas have adopted an unusual life cycle in which adults emerge at 13-year or 17-year intervals to mate and lay eggs. This emergence lasts for only a few weeks, during which the number of adults in any given location may be massive. They spend the rest of their life cycle as nymphs deep underground, feeding on the roots of trees. When they are ready to emerge, the nymphs dig their way to the surface at night and then molt into their adult form. It is thought that the long, prime-numbered life cycle makes it difficult for any predator to specialize in preying on periodical cicadas, though of course birds, wasps, and other predators take advantage of the bounty when an emergence occurs.

If you see any cicadas from Brood II, you can report them at Magicicada.org.

See more of my periodical cicada photos on Flickr.