This summer, the East Coast of the United States is expecting to be swarmed by billions of cicadas. They are the periodical cicadas, or Magicicada tredecassini, that are unique to the East Coast. After 17 years spent underground in their nymph stage, they’re prepared to emerge in May of this year to cover as much as 1.5 million cicadas per acre in some states. This particular cicada army is known as “Brood X,” as periodical cicadas are geographically grouped and assigned Roman numerals to help with identification. Some states, like Maryland, are already spotting cicadas. As 2021’s summer will be filled with the cacophony of cicada cries and trees will be flooded with these insects, it’s no surprise that people are rescheduling outdoor events as a result of so many insects preparing to swarm the skies. 

Scientists are not certain why cicadas have such long life cycles, and they are still trying to understand how the cicadas know 17 years have passed. There’s speculation that their huge numbers allow them to successfully reproduce and survive any birds or mammals that prey on them. However, billions of these cicadas emerging is still an unsolved phenomenon in nature. Periodical cicadas spend these long years underground feeding on fluids from tree roots. These nymphs burrow out on warm summer nights and scale up trees to molt into their adult form, and males are notorious for their calls that can reach 100 decibels (equivalent to a bustling subway). The adult cicadas will survive for 4-6 weeks and reproduce the next generation of periodical cicadas to again swarm the East Coast in 17 years. 

Fortunately, cicadas are not harmful to humans or the environment, and they deal minimal damage to the trees they feed off. Although such large numbers of cicadas, like Brood X, are appearing decade after decade, periodical cicadas might be going extinct. Recently, especially in urban areas like New York, trees that are being chopped down are causing cicadas populations to decrease as cicada nymphs die along with the trees they feed off of. Thus, scientists seek to do more research on these insects and have introduced an app, https://cicadasafari.org/, that can be used to easily help track Brood X cicadas. Another app, https://www.inaturalist.org/ , can be used to record cicada cries and is similarly helpful in gathering data. 

Sources:

https://www.atlasobscura.com/articles/brood-x-cicadas

https://www.theguardian.com/us-news/2021/apr/19/brood-x-cicadas-eastern-us-emerge