cicadas

Song of the Cicada

(Part two of a series on cicadas)

By Marcia Anderson

Cicadas on Staten Island

Cicadas on Staten Island

Billions of flying bugs known as cicadas are currently sweeping over the East Coast. What were you doing in June of 1996?  Do you remember the terrible sound they made? Cicadas are a true marvel of nature and one that should be enjoyed whenever possible. Once it starts, the emergence typically lasts only four to six weeks: long enough for the males to sing their mating song, the cicadas to mate, the females to lay their eggs, and then they all die, leaving their 2-inch corpses for us to clean up.

The song of the cicada was used to signify summer in Japanese cinematography. Standing near an especially loud chorus of cicadas can be like standing near a motorcycle, with a racket reaching up to 100 decibels. Because cicadas produce extremely loud noises while requiring very little power, they are being studied by the U.S. Navy. They are of particular interest in naval sonar research related to underwater exploration and communication.

How do the cicadas make that sound? First, only male cicadas make the sound. Males have organs that resemble drum-like plates, called tymbals, on both sides of their abdomen. The cicada moves his muscles to pop the tymbals in and out, which creates the sound we hear. These chirping and clicking noises can be heard by females up to a mile away.

The naval research facility in Newport, Rhode Island uses microcomputer tomography to image a cicada’s tymbal. This is like a CT scan that picks up details as small as a micron in size. The tymbal is made of a thin membrane connecting thicker sections known as ribs, each of which is thinner than a human hair. According to researchers, the male cicada pulls all the tymbal ribs inward and together. The ribs make a short, sharp noise when they draw together and again when they snap apart. The cicada repeats the action 300 to 400 times per second, creating the characteristic deafening chirp. Producing noise in this way is unusual in the insect world. For example, crickets, locusts, and katydids rub their legs to create their chirps.

Interestingly, the cicada’s left and right tymbals can act like two speakers that produce sound waves that combine. Imagine two water waves in the ocean, generated by separate storms converging toward each other. Where the peaks of the two waves perfectly overlap, they add together and spike much higher than the peak of either wave alone. We call this very large wave a rogue wave, which is known to have sunken many an unsuspecting ship in the deep sea. Similarly, if the waves are sound waves traveling through the air, the peaks would be spots where the volume is very high. The cicadas may use this effect to pump their volume to very high levels without expending as much energy as if a single tymbal had to do it alone.

Children and adults can experience this phenomenon by catching a male cicada and then gently closing their hands around it to feel the vibrations emitted by its chirping.

Warning: During cicada season they may land on you if you’re using a power tool or lawn mower. Why? Cicadas think the sounds made by power tools and lawn maintenance equipment are made by other cicadas. They get confused and will land on the people using the equipment! So either cut your lawn in the early morning or near dusk when the cicadas are less active, or let the grass grow a little longer for a few weeks.

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.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.

A Return of the Cicadas (Part 1)

By Marcia Anderson

Cicada

Cicada

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.

Cicada Nymph

Cicada Nymph

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.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.