Periodical Cicada Emergence 2024

Periodical Cicada Emergence 2024

BY : Rhiannon Nevinczenko

It can take a long time to learn how to sing. After spending over a decade hiding underground, periodical cicadas (like the one pictured) emerge en masse and belt it. Cicada songs are called chirps. “Chirp” is an onomatopoeia – a thing named with its sound. If you’ve ever heard cicadas singing, “chirp” will seem like a drastically understated, diminutive description. Cicadas hold the world record for being the loudest insects, with records reaching 106 decibels in some North American species. That’s as loud as a motorcycle!
You may have heard tell that this year will be a particularly deafening one, as two cicada broods (Broods XIX and XIII) are co-emerging for the first time since Thomas Jefferson was in office. This has created more hullabaloo about periodical cicadas than usual for the year. However, these two broods inhabit different areas, with hardly any overlap in their collective 17-state range. So no, you will not be subjected to a double-dose of cicada love songs. (They sing to attract mates using a unique organ called a tymbal.)
So, a bunch of annoying, harmless bugs are going to be noisy for a bit before disappearing. So, what? Why all the excitement?
Brood XIX emerges every 13 years, whereas Brood XIII emerges every 17 years. Because of that timing difference, they only co-emerge once every 221 years. Cicadas are unique among insects for this unusually long life cycle, spending most of their lives as nymphs (immature form) underground. When it’s time to bring forth the next generation, they undergo metamorphosis, rising with new wings and voices to seek out a mate. They have a brief window of time to mate and lay eggs before the end of their natural lifespan. Periodical cicada broods leave millions of sheds and remains behind, replenishing the soil. Cicada broods also give a boost to those higher up on the food chain, as animals that eat insects get far more food opportunities.
Budding entomologists outside of their range may be disappointed to miss the co-emergence of Broods XIX and XIII (only certain Southeastern and Midwestern states will be so lucky – or unlucky, depending on your perspective). If this is the case, you may have better odds with local annual broods of cicadas (species with yearly life cycles). Regardless, these phenomena present an opportunity to learn about insects, their life cycles, and their ecological significance. It may not be your favorite concert, but still a fun and worthwhile one to attend.
Pictured: A periodical cicada, credit John J. Mosesso at USGS (public domain).

Leave a comment