Cicadas in the Smokies

Our Monday morning started as a wildflower hike. We'd stopped at one of our "secret" spots to check on the status of a large grouping of pink lady's slipper plants when we heard what seemed to be the passing of a high altitude jet plane. The 'jet nozzle exhaust' noise just seemed to go on and on until we realized that it wasn't a jet plane at all--it was cicadas! Now we've heard cicadas every summer for most of our lives so you can understand our befuddlement when we realized we'd never heard THESE cicadas. Yep, this racket was being made by Brood XIV--one of those 17 year cicada broods that we either missed hearing altogether back in 1991 or just didn't remember the sound they make. You see, each species of periodical cicadas makes a unique sound. My excuse was that in 1991 I was living in Atlanta--a place too far south for Brood XIV.

All the rest of the day during our hikes along the Foothills Parkway and the western end of the Smokies we were able to hear the distinctive noise being made by cicadas. It was unlike anything we'd ever heard before.

And then we saw them. It was about 2 pm and I was about to check out the flower for a Hearts-a-busting plant when I spotted my first cicada from Brood XIV. Those beady red eyes and gold wing veins gave it away immediately. Soon, it seemed that on every branch we looked there were either cicadas or their discarded nymph phase exoskeletons. It was so neat. Here is a link to some of the cicada photos.

Most people who've visited the eastern U.S. in the summertime have heard the sounds of male cicadas in search of mates. Sometimes known as "locusts" or "17 year locusts", the cicada family of insects occur worldwide. Here in Smokies we have two general types of cicadas: Periodical cicadas and annual cicadas. They are not locusts.

Periodical cicadas found here in the Smokies are of the genus Magicicada of which there are 7 species--four with 13 year life cycles and three with 17 year life cycles. Near the end of their life these nymph phase insects emerge from their underground tunnels, break out of their exoskeletons (a process known as molting) and become winged adults. Each of these 7 species has been labeled with a "Brood" number. This year, 2008, Brood XIV of the periodical cicadas will, after 17 years underground as nymphs, emerge as adults. In fact, they've already been spotted the first week of May here in the Knoxville, TN area. In addition to the link at the beginning of this paragraph, you might find the info on Wikipedia and Cicada Mania (great photos!) of interest.

Annual cicadas, sometimes known as dog-day cicadas or "jar flies", are of the genus Tibicen. They have 2-3 year life cycles and emerge as adults during the "dog days" of July and August. Due to overlapping generations these annual cicadas appear every summer here in the Smokies--a fact well-known to those of us who enjoy the outdoors.

Other than the obvious difference in time of emergence (May/June vs. July/August), I think that most of the periodical cicadas in our area have red eyes vs. their black-eyed annual cicada cousins. I've also read that each species of cicada makes a unique sound. To my ears their sounds are in one of two categories: Loud or Very Loud.