2021, the year of emergence.
By: Emma Cockerill
Summary. Brood X debuted in North America with a mighty chorus earlier this summer. Trillions of Cicadas emerging across North America after 17 years underground did not disappoint. Blanketing the North East, Mid-Atlantic and Mid-West regions, the unmistakable sound of male Cicadas battling for attention filled the air. Cicadas are unmistakably loud, their song can reach 100 decibels, almost as loud as an ambulance siren. Brood X is particularly important as it is the largest of all Cicada broods. Broods are groups of Cicada which emerge either annually or periodically depending on the species. Periodical broods are groups of Cicadas which share the same years of emergence after a period of time. There are 15 periodicals which emerge on either a 17-year or 13-year cycle. During their time a couple of feet underground, nymph Cicadas develop and feed on sap from tree roots. On the year of emergence when the soil temperature hits about 64⁰F, after soaking rain, Cicada’s tunnel to the surface to mature and grow wings. It is a survival strategy of Cicadas to emerge in such large groups for predator protection. The purpose is to overwhelm the potential predators with a great number in the hopes that enough will survive to reproduce. Broods are numbered by Roman numerals corresponding to the emergence year since records began in the late 1800’s. Given each Broods scarce visibility over such long periods of time, research during the scheduled year of emergence is critical. Ecologists have been anticipating the arrival of Brood X in 2021, a unique opportunity to take advantage of technologies not in existence 17 years ago. Cicadas are harmless and native to North America and have been tracked and cataloged by scientists and citizens alike for over a hundred years. Not until recently, however, does every person have a smart phone with a camera and GPS. Citizen science was of great importance this year, with every willing person able to take a picture and upload the location of Brood X to community maps. Two mapping programs were created in preparation for Brood X’s arrival earlier this year. Cicada Safari and iNaturalist both launched free apps for citizens to participate, yielding results never possible 17 years ago. Tracking Brood X and comparing to historical maps can give us clues to how urbanization and climate change has affected the biodiversity and habitability of the land.
Why we should care? Cicadas are an indication of environmental health and provides essential ecosystem services. As humans ravage the landscape, it is more important than ever to preserve the Cicadas for our own benefit.
Howard Russell is interviewed in this article by Michigan Radio in April, before the emergence of Brood X began. Russell is an Entomologist at Michigan State University. He explains the historical Brood X distribution specific to Michigan and why it is so important to preserve our mature trees. Cicadas need mature trees for their roots as a food source when burrowed underground. Deforestation in the Mid-West has limited habitats available for many broods. Russell also revealed that past cycles of Brood X in Michigan have been sighted in Washtenaw, Lenawee, Genesee, Oakland and Livingston Counties. He explained that undisturbed preserves such as Cherry Hill Nature Preserve near Ann Arbor provides the perfect accommodation for the insects to live.
Science in Action.
Dr. Gene Kritsky is the Dean of Behavior and Natural Sciences Mount Saint Joseph University, Cincinnati, Ohio.
Dr. Kritsky is an entomologist who has published numerous books and journals on insects and evolution. This year, he published a book on Brood X, ‘Periodical Cicadas: The Brood X Edition’. He has studied Cicada brood history over many centuries. His previous research in Ohio discovered that the distribution of 17-year periodical Cicadas match the geographic regions created by the ice ages. Kritsky and his colleagues developed the app, Cicada Safari, to track sightings during the Brood X emergence. He explains the importance of tracking Brood X as the distribution is an indication of how their survival is faring. Periodical broods are fairly resistant to climate change but Kritsky insists habitat loss is the main threat to Brood X due to deforestation.
I found it interesting to read this article because last year around this time is when I heard the news about how this event would happen and since I was so young when the last of these emergences happened I was uncertain it would actually happen especially since I never really looked into the topic further until now. I even one day a month or so ago had my mom come in my room while I was doing homework and had my window opened when she commented " Shut your window how can you focus with all the loud cicadas right outside your window" Then I focused and actually heard them it was almost like since I was a kid I was filtering that noise out so much since I grew up with a big plot of land filled with cicadas as loud as you can imagine filling the trees of the whole 20 acres.I also really liked how in your article I got to learn about how they play a significant role in our environment through the soil and I found it very interesting to find that their food source while they are stuck underground for 14-17 years is nutrients form the tree roots. That is why as you mentioned in your article we must protect our mature trees that are in the area of major emergence of these insects. I am now happier knowing more about this bug I am very familiar with as I grew up so close to them with so many and now at this age knowing the are insects and not just scary noises coming from the trees as I thought as a child when first introduced to this insect.
I'm glad you included what conditions need to be met in order for the cicadas to emerge from the ground, I have always wondered what exactly caused them all to emerge at the same time. I also found it super interesting that they all emerge at the same time in order to overwhelm predators. I saw the news coverage this year and I was expecting them to see more of them then I did. It will be interesting to watch how a changing climate is going to further impact the range and timing of the broods.
As someone who thought of cicadas as terrifying and gross, this post gave me a new insight to how special these insects are. I also did not realize the important role mature trees played in the growth of Broods, but I believe this information should be more widespread. I'm sure not many people know how Broods get their nutrients, but if they were willing to learn, we may have the upper-hand in spreading deforestation prevention awareness. As someone who resides in an area where Brood XIII will be hatching, I will make it a point to educate those in my community about the significance of these harmless creatures to our environment and why we should protect their breeding grounds.
I was so excited to read this article because I find the emergence of the cicadas fascinating. I first heard of them about a year ago and I was a bit disappointed that there was little to no cicadas emerging around the Metro Detroit/Wayne County area (or at least from what I could tell). As you mentioned in your post, they are being affected by deforestation in the Mid-West and considering that Metro Detroit seems to lack large, forested areas that explains why Brood X didn't make a big appearance. When Brood X first came out of the ground, I recall seeing numerous posts about the cicadas all over twitter and tik tok, however I was unaware of the environmental importance. The fact that they're habits date back to the ice age is something that is so interesting, and I had absolutely no idea. It really shows their ability to adapt and their true resilience. I also can’t believe that Brood X has been stewing underground for almost my whole lifetime and I had absolutely no idea until the past year. I would not expect such small (and somewhat ugly) bugs to have such an interesting and unique story to them.
It was interesting to finally see this article after months of hearing about this big emergence of cicadas. It was cool to finally learn what their queue was for them to all come from the ground, and also very interesting to hear that they come out all at once as a survival method, I would have never guessed that. It was nice to hear how much technology has changed within in the past couple decades as far as ways of researching these insects. Hearing that every person’s easy access to cell phones and how much of an impact that made on the scientific research is awesome to hear because as we keep advancing more and more people can be involved so easily which can help scientific research advance much faster than it can now. It was interesting to hear about just how long this group has been waiting underground before they depart to the surface is almost scary to think about because 17 years is a long time, especially for a bug.
It really is crazy how these cicadas can reach up to 100 decibels. When you hear them outside they do sound loud but after a while you get used to them. It really just amazes me how they can almost be as loud as an ambulance but we get used to their noise. It is also interesting to see how technology is playing a role on tracking Brood X by citizens just downloading an app and uploading pictures.
Having been away from Michigan all summer, it is a bummer to have missed hearing them in a loud swarm. Maybe I was lucky not to have been trapped around their ambulance-level loud songs, but there is something unique about the presence of a species in such a large number. What I am interested to see is how their populations have changed due to urbanization/deforestation.
I have always been fascinated with cicadas and their emergence from their underground sojourn en masse. I was waiting in anticipation for their arrival this year and was disappointed when I didn't see them. Fortunately, I am old enough to remember cicada broods emerging from the ground as a child growing up in Chicago. I used to be scared of them because there were so many of them everywhere on every tree, on every house, on the cars, grass and sidewalk singing their eerie tune. The freakiest part to me was the millions of carcasses left on trees due to the newly emerged cicadas molting and gaining wings. Another cool thing to witness was the birds drunk and fat from having consumed to much cicada. So much so that they stopped eating cicada. Not just the birds, but but dogs and squirrels as well. I suppose the cicada broods are a buffet feast for the eco system. I can only imagine that the cicada broods in the time of the passenger pigeon was a major feast for them, as their flocks darkened the sky for hours, while they traversed North America over a forest full of biodiversity.
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