Beyond Your Backyard: Brood X

If you’ve been watching the news lately there’s a new celebrity everyone’s talking about.

Big bulging eyes, long body in a variety of colors, sturdy wings, and a distinctive call that heralds warmer weather just as surely as its evening costar, the firefly does. This daytime celebrity is none other than the cicada. They’ve been capturing everyone’s attention because 2021 happens to be when brood x hatches out—a population boom of biblical proportions where trillions of cicadas that have been underground for 17 years are getting ready to emerge.

There are over 3,000 different kinds of cicadas and within all those species there are three different kinds of life cycles: annual, periodical, and protoperiodical. It’s the middle category that makes these cyclical populations that emerge at the same time in certain areas after 13 or 17 years. Of course, the timing of this varies depending on the last hatch, the species, and environmental cues. Annual cicadas emerge every year at different times throughout the summer. These cicadas can take one to nine years to complete their life cycles, but because nymphs hatch at different times and intervals (asynchronous), we see cicadas each year. Protoperiodicals have a boom and bust cycle of emergence where they emerge in large groups and in other years are rare.

Ok so how on earth do the cicadas know it’s time? Their tiny cicada alarm clocks of course. I’m only half kidding. Cicadas like most species use a series of cues to mark the passage of time. Their specific cues are unique to where they’re waiting. Periodical cicadas, like most cicadas, are waiting underground as nymphs, feeding on the sap from tree roots. Scientists have found that when trees leaf out the sap (xylem) changes (cue number 1) signifying the passage of another season. There’s still some mysteries here, but more of the puzzle is coming together. Actual emergence is likely triggered by ground temperature in combination with the passage of time marked by trees losing and growing new leaves.

In Minnesota, we don’t have periodical cicadas so we won’t see the booming emergence of epic proportions. But, thanks to annual and protoperiodical cicadas, we will still be serenaded by these amazing winged celebrities.

If you are so lucky to see an epic horde of cicadas don’t panic and no need to reach for the insecticide. They aren’t harmful and even though cicadas lay their eggs in tree and shrub stems, mature trees are well equipped to handle this slight disturbance. Young trees can have their growth stunted so an easy way to protect them is by covering them with mesh netting. This emergence of epic proportions is also a super important buffet for all kinds of wildlife including foxes, squirrels, birds, bats, spiders, and wasps to name a few. People have even been known to eat cicadas as a rich and nutritious food source. 

As an aside, I actually happen to know what they taste like! When I was still in college I was back home in Indiana during one of these epic booms of cicadas and they were everywhere on our farm. It just so happened that my mom had organized a mini Olympics for the family. Well the competitive spirit carried into the rest of the day long after the winners were crowned and my cousin and I found ourselves in the middle of a debate about what cicadas taste like as they were flying all around us. Naturally, there’s an easy way to solve this argument: put one in your mouth and eat it! Some people say they taste like shrimp or almonds. We didn’t fry or cook them, just snatched one off a tree and ate them raw. If you can get past what you’ve just done, they aren’t bad and have a nutty flavor—a lot like peanut butter. I highly recommend removing the wings before eating. I also recommend if you’re competing with a family member that you make them eat it first or at the same time because I found I was the only one who ended up going through with the cicada snack dare—life lessons.

Who knew cicadas were so interesting? Ready to learn more? Check out these excellent resources for all things cicada: