Listen!  Do you hear it?  How can you not?  It’s the summertime sound of cicadas.  I found it rather daunting when I first arrived in South Carolina for I never noticed them in other areas of the country, though, they were there!   Their high pitch screech can reach 80 to 100 decibels in volume…equal to the sound of a jackhammer and can be heard up to a mile away.  But writing this article has given me a different perspective on the life of a noisy cicada…an amazing story.  And, that noise is their love song! 

In the world of cicada bugs, there are over 190 varieties in North America and over 3,390 varieties around the world.  They are found on every continent but Antarctica.   North of Mexico there are about 170 different cicada species that include both the annual, dog-day cicadas that we hear every summer, and the periodical cicadas that have a 13 or 17 year life cycle.  Generally, periodical cicadas are found east of the Mississippi River with the 13-year cicadas found in the more southern states and the 17-year cicadas found in the more northern states.  That’s not to say we don’t have 17-year cicadas.  They are just more limited to certain areas of the state…. the northwestern tip of Oconee County.

So, what is a cicada?  It’s a BIG bug, a true-bug!  They are in the biological classification ‘Insecta’ an insect just like butterflies and beetles.  They have stocky bodies, short antennae, wide-set eyes, and as an adult have 2 pairs of often transparent wings.  They are located in the order ‘Hemiptera’ due to its piercing-sucking mouthparts, making them a ‘true bug’.  This order also includes well-known insects such as aphids, leafhoppers, scale insects, and stinkbugs.  But note that not all insects are bugs but all bugs are insects!  

To understand cicadas, it’s important to know that the life cycle of a cicada has 3 stages: egg, nymph, and adult.  I mention that because the noise we hear in the summer of an adult cicada is a very short part of its life, 2 to 8 weeks.  The longest part is spent underground as nymphs with the 17-year cicada being among the longest-lived insects in the world.  What we see and hear in adult cicadas is less than 0.5% of that lifespan.  Almost 99% of its life is spent underground.  And, it is a long process of 2 to 5 years for annual cicadas and 13 to 17 years for periodical cicadas to become adults.  During that time, they molt or shed its exoskeleton 4 to 5 times, each time increasing its body size.  The nymphs don’t eat, they drink on the sap from hardwood tree roots.  

The process starts when the male cicada sings his song to attract the female….she flicks her wings if she likes him.  They come together to mate and then its life-cycle starts.   The female creates slits in small tree branches and lays 20 to 30 eggs in a slit, with a single female laying up to 500 eggs.  The eggs are about the size of a grain of rice.  After 6 to 8 weeks, the eggs hatch into tiny nymphs.  The nymphs fall to the ground, dig in the soil, and tunnel down to about 24 inches and deeper to feed for years on the sap from the tree roots.  

As years pass nymphs continue to feed on roots until they emerge.  When the ground temperature reaches about 64 degrees F at a depth of 8 inches, the nymphs emerge from the soil, climb a tree, and molt one last time to become a winged adult.  Once they harden the males begin to sing their song ‘screech’ to attract females for mating and the cycle begins again.  

Many more 13-year and 17-year periodical cicadas emerge than annuals…as many as 1.5 million per acre.  It is believed that this is due to the length of time underground.  This large population helps the preservation of the species ‘safety in numbers’ for they are a major food source for birds and other critters including humans.  In 2024, we experienced the co-emergence of the 13-year and 17-year cicadas, trillions of them.  This rare occurrence, only happens every 221 years.  The last time these two groups emerged together was in 1803 when Thomas Jefferson was president.  

Cicadas are harmless insects that pose no danger to humans.  They do not bite or sting, nor do they carry any diseases.  They are not venomous or poisonous, so they are no threat to your pets,  and do not damage flowers or crops.  In fact, cicadas benefit our environment by providing a great food source for birds and many other predators including copperhead snakes!  They also help with aerating the soil with their underground burrows, prune small branches on trees (may damage young trees), and when they die, they feed the soil.  They benefit our ecosystem!

So, maybe cicadas are a little noisy especially when you are looking forward to a peaceful summer evening. But try a different perspective, too.   And, consider that the screeching noise of a male cicada is his  ‘once-in-a-life-time’  love song for his ONE true love…amazing! 

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