By Marcia Anderson
Billions of flying bugs known as cicadas are currently sweeping over the United States’ most densely populated region, like a Stephen King novel that nobody dies in.
They began emerging in Georgia and South Carolina in early May, and have worked their way 900 miles northward, to Washington DC, Philadelphia, New York City and Albany. Wooded properties with adjacent open space like Manhattan’s Central Park, the Bronx Zoo, Staten Island or Newark suburbs all have their share of cicadas. In NJ, I have found Metuchen, Fanwood, and Montclair, NJ to have prime suburban cicada love dens. The timing of their emergence was dependent on the weather. When the temperature reached 64oF, the insects rose up, wriggled out of their shells and took wing.
Actually, Cicadas are a true marvel of nature and one that should be enjoyed whenever possible. The bugs are mostly harmless to plants and humans. I found a cicada in our yard today and I remember sharing a huge emergence of cicadas with my children and now look forward to sharing the experience with my grandkids! Do you remember what you were doing in June of 1996? That was the last emergence and it was the year this brood was born. Do you recall how the sidewalks in some places were covered and how they crunched underneath your feet? What about trouble sleeping due to the constant terrible sound they made? (More on the “Song of the Cicada” in part 2 of this story.)
Once it starts, the emergence typically lasts only four to six weeks — long enough for the cicada nymphs to find a tree, shed their crunchy brown exoskeletons, and expand their wings. They will spend their next few weeks mating and laying eggs in tree branches. Then they will all die, leaving their bodies to litter the ground. The tiny newly hatched babies will make their way back to the ground and burrow down for the next 17 years. They bugs will emerge in 2030 to continue the cycle. There are expected to be 30 billion 17-year cicadas this year.
Why so many? One theory called “predator satiation,” suggests that the large number of cicadas is a survival strategy to overwhelm predators. If predators are never able to eat them all, many will survive to mate and continue the species.
There are 13 year cicadas also. Why 17 and 13 years? Since they emerge only once every 13 or 17 years (brood dependent), it is difficult for predators to synchronize with them as no predator species can anticipate their emergence. The long life-cycles could also help these cicadas avoid extinction from long stretches of fatally cold weather, such as what was experienced during the past ice age. The development of 13 and 17 year emergence cycles is a strange coincidence as both numbers are primes. Also interesting is that of 30 known cicada broods, 17 broods have a 17-year emergence cycle and 13 broods have a 13-year cycle. Cicada broods usually don’t overlap geographically, and it is very rare when they emerge in the same year.
Other cool facts about cicadas:
- Cicadas have five eyes: Two are large, red, compound eyes, and three are ocelli, which are believed to be used to detect light and darkness.
- Cicadas actually benefit the health of trees by aerating the soil around the roots, and trimming weak or damaged limbs. They do drink tree fluids, but usually not enough to cause harm to the trees.
The females may harm young trees by splitting the thin bark on slender branches with their egg laying. You can place netting around young trees to prevent female’s access, but this may be impractical for large numbers of trees. Cicadas only feed on woody perennials, so vegetable and/or strawberry crops are not at risk.
- This could be a very bad year for fruit tree orchard farmers.
- Animals eat them. It’s going to be a wonderful year for anything that can eat cicadas. City pigeons and songbirds love them, dogs will gorge themselves, squirrels will eat them like corn on the cob, turkeys gobble them up, plus they make great fishing bait.
- People eat them. If you find yourself with shovel loads of cicadas and do not know where to put them, consider eating some of them. Some insist that cicadas are a delicacy and make delicious high-protein meals. The University of Maryland put together a cook book with recipes like: cicada kabobs, cicada Creole, cicada gumbo soup, pan-fried cicada, and stir fried cicada. There’s pineapple cicada, lemon cicada, coconut cicada, cicada stew, cicada salad, cicada burgers, cicada dumplings and banana cicada bread. You can barbecue, boil, broil, bake or sauté them.
- If you want to totally avoid them: go to the beach. Cicadas don’t like sand.
Above all, put things into perspective. The density of cockroaches in New York City is far greater than the density of cicadas. There are several million cockroaches per city acre, however they aren’t noisy and don’t fly around much. Once the mommy cicadas lay their eggs, they will die, and you won’t even notice the tiny babies!
For more cicada information: The scientific name for these cicadas is Magicicada. The National Geographic Society supports the Magicicada website: http://cicadiamania.com.
About the Author: Marcia is the bed bug and vector management specialist for the Pesticides Program in Edison. She has a BS in Biology from Monmouth, second degree in Environmental Design-Landscape Architecture from Rutgers, Masters in Instruction and Curriculum from Kean, and is a PhD in Environmental Management candidate from Montclair – specializing in Integrated Pest Management and Environmental Communications. Prior to EPA, and concurrently, she has been a professor of Earth and Environmental Studies, Geology and Oceanography at Kean University for 14 years.