Brood X Cicadas: 2021

Right now, at this very minute, billions of cicada nymphs are snug in their tunnels, just waiting for the warm spring night when they'll emerge from the ground, shed their skins, unfurl their wings, fly, sing, mate, lay eggs, and die. It's a spectacular phenomenon, and we in the eastern United States are lucky to see it.

Thanks to iNaturalist and the power of citizen science, we now have the opportunity to create the most complete and detailed map in history of a periodical cicada emergence. Although all of the observations of periodical cicadas on iNaturalist provide valuable data, I've put together a project ( to collect the observations that go a step further, including photos or sounds that enable species-level identification of individual cicadas or choruses.

This data and genus-level observations of Magicicada for 2021 will be pooled with records from Cicada Safari, a free smartphone app developed by Dr. Gene Kritsky* and the Center for IT engagement at Mount St. Joseph University in Cincinnati, Ohio (

Ideal observations for this project should include photos of the underside of the cicada. We all love to get that beautiful photo of an unmolested cicada perched on a branch with the morning dew beading its gossamer wings, but that's not gonna help with species ID. We need to see that cicada belly! (Lateral views are also helpful.) Species are differentiated by orange markings that appear on the abdomen and pronotum:

Magicicada septendecim: orange patch behind the eye; orange pleura; orange bands on abdomen that are about half the width of each segment
Magicicada cassinii: no orange anywhere on the body; all black
Magicicada septendecula: narrow orange bands on abdomen, about one-third to one-quarter the width of each segment; no orange on pronotum or pleura

Sounds are also useful for species-level ID, especially if you can get one male singing on its own.

Observations will be added to the project automatically if they meet its criteria, but if you join, you'll be in the loop to see journal posts and get updates on cicada sightings. Thanks in advance for all your contributions!

*Full disclosure: he's my husband. :)

Posted on March 31, 2021 09:30 PM by weecorbie weecorbie


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