By Kristen Swanberg, Senior Director of Education
Ever wonder what makes all that buzzing on hot summer days?Â A very cool insect called a Cicada is the culprit.Â Cicadas are quite large – one to two inches in length – with long wings and big eyes.Â They are quite impressive to look at, but not to worry – they don’t bite or sting. They just make a lot of noise!
In the insect world cicadas fall into the scientific order called Homoptera along with leafhoppers and aphids.
In early summer when the soil temperature reaches above 64Â°F, cicada nymphs (juveniles) emerge. They have lived underground for years!Â They typically appear at night and climb the closest tree.Â Once these juveniles get a firm grasp on the trunk of the tree, they transform into an adult.Â The nymph’s exoskeleton splits open along the back allowing the adult to emerge.Â The adult cicada is a light green color at first, then darkens to a black/brown color.Â The adult then leaves the exoskeleton behind and continues its climb further up the tree. That’s where the males make that loud buzzing sound you hear. They are looking to attract females.
In a slit made along a twig on the tree, the females lay their eggs.Â The eggs remain there until the young hatch.Â Upon emerging, the nymph drops to the ground then borrows down and remains underground for many years feeding on plant juices from roots.Â As they near maturity the nymph will tunnel up through the ground continuing the lifecycle.
How do they make that sound?
The adult male cicada has two membranes called tymbals on each side of its first abdominal segment.Â Muscles attached to the tymbals cause them to vibrate producing that buzzing you hear.Â They also have a hollow abdomen helping to amplify the sound. Â Their song is a long, continuous buzz that increases in intensity and loudness then dies off near the end.
Looking for Cicadas
Try looking for cicadas this summer.Â They generally live in tall shade trees like oak and maple.Â Your neighborhood might just be the right habitat.Â First listen for the buzzing sound then try to find which tree the cicada is in.Â Check the trunk of the tree for nymph sheds.Â They are light brown and hollow.Â If you find one, look down to locate the hole they emerged from.Â The hole is about the size of your little finger.Â As you look up along the trunk of the tree you just might discover a recently emerged adult cicada.Â Have fun in your search!
The Scoop on Cicadas
– There are 75 different cicada species in eastern North America — all make slightly different buzzing sounds.
– Adult cicadas do not eat solid food, but instead drink fluids to avoid dehydration and live for only a few weeks.
– There are two groups of Cicadas.Â Periodical cicadas which live underground for 13 or 17 years and emerge May to July.Â And the more common annual cicadas that live underground for 2 to 8 years and typically emerge between July and August.
– Cicadas are among the longest living insects.
– Many people confuse cicadas with locusts by calling them the “seventeen-year locust”.Â Locusts are in fact related to grasshoppers and crickets. They also make sounds in the summer but nothing like the cicada.
– Cicadas are eaten in many cultures. They are good source of vitamins and protein and are low in carbohydrates.Â Lunch anyone?
Audubon’s Environmental Education Center is open year-round providing walking trails, nature programs, and exhibits for the whole family to discover.Â For more information and a complete calendar of events, visit www.asri.org or call (401) 245-7500.