(News alert: Katy did it!) Seventeen-year cicadas were just an opening act. Now the woods are rolling with the rhythm of our annual insects.

Written by Stephen Lyn Bales

 Bales Common true katydidA true katydid is shown here. It's one of the main insects that provides a permanent soundtrack to your summer life in the Knoxville area. Stephen Lyn Bales/Hellbender Press

What’s that buzz? We thought Brood X was over.

In case you haven’t noticed: It’s hot!

The “dog days of summer,” are so called because the season coincides with the period of time when the brightest star Sirius, aka the Dog Star, rises and sets with the Sun: early July through August into September.

The ancients believed that when Sirius and the Sun were in the sky together, the days were hotter. I think they got it right.

August has never been that thrilling to me, more of a month to endure. The birds have finished raising their families and are going through their late-season molt. Some of the migratory birds have already started to move south. But that doesn’t mean that our backyards are totally silent because late summer is cacophonous with insects.

During the day, the trees are filled with large, green cicadas that generally spend three years underground in their larval stage, but they are not all in sync like Brood X was, so each summer we have plenty that mature to collect en masse in our neighborhoods.

To attract females, the male cicadas do the chainsaw buzzing, but the songs are not made with vocal chords but rather special organs on the sides of their abdomens called “tymbals.” In effect, their sides vibrate loudly.

Locally in the Knoxville region we have five species of these annual cicadas. Early in the morning and into the afternoon, swamp cicadas (Neotibicen tibicen) are calling. They are also known as morning cicadas because they usually crank up by 10 a.m. with a long uninterrupted rattle that builds in intensity.

During the hot part of the day we hear Robinson’s cicada (Neotibicen robinsonianus). They are plodding and rhythmic: creeeeeak, creeeeeak, creeeeeak, creeeeeak.

And from afternoon to twilight the scissor-grinder cicada (Neotibicen pruinosus) takes over. It supposedly sounds like someone sharpening a pair of scissors on a grindstone, with hyper-rhythmic pulses that build in intensity. Their calls have also been compared to a circular saw cutting though a two by four: zeeeer, zeeeer, zeeeeeer.

The last two local annual cicadas species: Lyric (Neotibicen lyricen) and Linne’s (Neotibicen linnei) are very high-pitched. They sound similar to Swamp Cicadas but their buzzes are at 7 kHz, a range that many people cannot hear or barely hear.

Did someone say “katy-did-it”?

Scissor-grinder cicadas buzz until darkness falls when they are replaced by the nighttime orthopterans that are in the same order as grasshoppers, locusts and crickets. Like the others in that insect group, katydids (Pterophylla camellifolia) have long legs in the rear that enable them to jump quickly. They are camouflaged to look like green leaves and spend their entire lives in the canopy, rarely being seen on the ground unless they fall.

Their common name comes from the sound they seem to make in the dark: katy-did-it, katy-did-it, katy-did-it!

Being able to identify these various insect courtship sounds make the Dog Days of summer a little cooler. And you can impress your friends sitting on the back deck or whiling away a few days in the woods.

Stephen Lyn Bales is a natural historian, the author of three UT Press books: "Natural Histories," "Ephemeral by Nature," and "Ghost Birds." He’s also a monthly speaker (via Zoom) for the UT Arboretum Society. He can be reached via email at This email address is being protected from spambots. You need JavaScript enabled to view it.

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  • Brood X is not a bust. Wait for it...
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    cicada 1 EVAEva Millwood holds Brood X cicadas on her property in South Knoxville in this submitted photo.

    We will see a groundswell of East Tennessee 17-year cicadas as the heat comes on.

    We have been hearing about it for weeks, online and on TV and in print. After 17 years underground, millions of cicadas are going to climb out of their burrows, shed their juvenile skins, unfurl their wings and fly up into the trees for one last grand jester of panache and reproduction and death. You even read about Brood X cicadas in Hellbender Press.

    The Tennessee Wildlife Resources Agency posted a recent Instagram photo of a wild turkey jake with a crop stuffed full of cicadas, and there are reports of cicadas emerging en masse in parts of Tennessee. But your local searching self may ask: Where are they?

    Insects are largely ectothermic. That means their body temperature comes from the surrounding air, water or ground temperature. The periodical cicadas need a ground temperature of roughly 68 degrees, eight inches deep to become very active. And we really have not had that for a sustained length of time.

    Last week seemed to be destined to be the first big week of the emergence of Brood X. Monday started strong but the weather turned unusually cool for early May with daytime highs in the low 60s. Some of the cicadas started to ease out but it was primarily dozens, not hundreds or thousands, and certainly not 1.5 million per occupied acre. And remember, they are not everywhere.