For many on the East Coast, an encounter of an only-every-17-kind is about to occur: the cicadas are coming.
Periodical cicadas are red-eyed, black-bodied insects. Females laid the eggs (400 to 600 at a time) for the current brood back in 1996. After these developed for a few weeks, they hatched and the larvae emerged, en masse, under the ground. In parts of the East Coast, they’ve remained there for the past 17 years, sucking sap and fluid from tree roots.
After they emerge as far north as Connecticut and as far south as North Carolina, the cicadas will mate, die and the cycle will start all over again.
What’s the point of such a life cycle?
Even though cicadas’ time on (though not under) earth is very brief, there are more than a few reasons to herald their long-awaited reappearance.
1) Cicadas aerate the soil of trees when they emerge.
2) Cicadas also prune the weak branches of trees and could be called nature’s garden helpers.
3) Cicadas also help out trees after they die, by†releasing a vast amount of nutrients into the soil. All those added nutrients can help spur growth in trees as well as seed production come the next spring.
4) Since so many cicadas appear at once, they form an important link in the food chain among trees, carnivores and omnivores. One site even suggests that when cicadas emerge it is “like 17 years of Christmas, Thanksgiving and birthday parties rolled into one incredible month” for birds and other animals who find themselves with more than their fill of cicadas to eat.
5) Cicadas also provide a big “feast” for fungi who get to work digesting their dead bodies.
6) Cicadas provide a revealing example of the workings of evolution and natural selection. If a stray cicada appears outside the cycle of the brood (while most stay underground for 17 years, some do for 13 years), its chances for survival are basically nil. The cicadas’ all-at-once appearance at the end of these cycles is their survival strategy; aside from their numbers, cicadas have few defenses against predators and are clumsy in a fight.
As Carl Zimmer writes in the New York Times: “There simply arenít enough birds at any moment to eat a few billion cicadas at once.”
7) As cicadas emerge when the soil reaches 64 F, seeing some appear too early is yet another sign of how climate change is affecting the earth.
8) Cicadas are edible and, indeed, a low-carb, gluten-free food (there are some recipes here; they are said to have a “green, asparagus-like flavor”).†No one less than the United Nations has suggested that insects could be the answer to food insecurity;†cicadas are specifically mentioned, as well as worms and grasshoppers.
9) Cicadas have also served as a food source for Native Americans. Members of the Onondaga Nation near Syracuse even have an oral tradition of being saved from famine by the periodical return of hordes of cicadas.
10) The cicadas born from the eggs that will be laid this year will, after spending their years underground, be back in 2030. The appearance and reemergence of the cicadas is a way to mark the passing of time, not based on the numbers flicking by on the clock on your cell phone but in a far more ancient way that has evolved in nature, over years and years.