Egg nests on many trees attest to the reproductive success of cicadas above ground this year. In a few weeks, nymphs will hatch and plummet to earth seeking plant roots on which to feed. Good luck underground, you wild early risers!
Over the last six weeks, we explored the biology surrounding a surprisingly large emergence of Brood X cicadas that graced the Washington metropolitan region. We learned about accelerating Brood X cicadas, watched the emergence of cicada nymphs from their subterranean crypts, discovered how male cicadas make their ethereal sounds, witnessed oviposition by females, and learned about their lethal STD. Last week while visiting what had been a rollicking cicada chorusing zone a few weeks ago, I was greeted by eerie silence. The reason for the hush was immediately apparent. Beneath trees and shrubs, the ground was littered with hundreds of spent exuviae, the shed skins of cicada nymphs, and bodies of adult cicadas that had survived the onslaught of hungry sparrows, blue jays, robins, squirrels, dogs, and other predators. Also scattered about were wings and fragmented body parts of cicadas that were not so lucky.
Beneath a large pin oak tree in Columbia, MD, remains of accelerating Brood X cicadas presage the main event four years from now.
What was the legacy of this vanguard of Brood X? Despite the blitzkrieg of predators and nasty pathogens like the Massaspora fungus, an abundance of egg nests in the canopies of maples, elms, zelkovas, and red buds in my neighborhood provide evidence that at least some of these early risers completed their biological imperative to mate and reproduce. Excavations of breeding grounds where this year’s cicadas appeared reveal bountiful numbers of Brood X cicada nymphs still underground, primed and ready to emerge in 2021. In four years these teenagers will surface as adults to rock the eastern US from Georgia to Michigan and New York to Illinois.
A foot below the earth’s surface in my yard and up and down the east coast, white eyed teenage Brood X cicada nymphs will spend the next four years preparing for their grand appearance in the spring of 2021.
Cicada experts believe some of the precursors appearing this year will return again in 17 years, in 2034, to join the ranks of Brood VI, while others may try a 13 year jailbreak and reappear in 2030 along with their compatriots, members of Brood II. Regardless of how it goes, it will be interesting to see when and where these early risers show up next. Now is the time to get ready for Broods VII, VIII, and IX before the main event in 2021. To learn more about when and where they will appear and discover all other things cicada, please visit the following web site: http://www.cicadamania.com/where.html
On a sidewalk beneath a tree, fallen cicadas are no match for hungry sparrows.
References
We thank Chris Simon for providing inspiration and information for this episode. Two wonderful articles “Evolution of 13- and 17-year periodical cicadas (Homoptera: Cicadidae: Magicicada)” by C. Simon and “The ecology, behavior, and evolution of periodical cicadas” by K. S. Williams and C. Simon were used to prepare this episode.