Here in Ohio, June 2021 was the month of the 17-year periodical Cicada.

Cicadas are large mid-summer insects that come out in modest numbers. You usually hear them rather than see them. Here is a post I wrote about them in 2011. They show up every year, and are therefore known as annual Cicadas. They are large and have dark eyes and green bodies.

But in June 2021, a special type of Cicada showed up- a periodical Cicada, named Brood X (in western Ohio- other broods show up in other eastern states at different times). These Cicadas were smaller than the annual Cicadas, and have very noticeable red eyes. They emerge from underground every 17 years- I remember them from back in 2004.

The month of June was a loud month. These insects make a very loud sound to attract mates.

I started noticing them everywhere on a local basis. Some areas were infested with them, others had smaller numbers. After 17 years, the cicadas take on adult form and live for around a month. Other periodical cicadas have a 13-year life cycle. 13 and 17 are prime numbers, and there are various theories as to why they operate on this cycle.

The nymphs come out of the ground and the adult form emerges from them, leaving the skin behind.

In areas where they congregated, they were present in huge numbers. One story estimated 1 million bugs an acre. At their height, I saw hundreds in a crabapple tree next to where I lived. The noise was almost deafening.

I found this article interesting: Brood X had a good run, but now the annual cicadas are taking center stage.

Periodical cicadas are known for coming out in droves so they can survive predators from picking them off before they can mate. “They seem kind of clumsy,” Kritsky said. “They basically satiate their predators and there are still millions of cicadas left.”

When the periodical insects emerge, you can’t miss them. The most periodical cicadas Kritsky has observed at one time was 356 in 1 square yard — it’s a lot more than the one annual cicada per square yard, he estimates.

Another thing I noticed was some damage to trees in the area. Here’s the explanation- Egg laying of Brood X cicadas is killing tree branches.

As the demise of the adult Brood X cicadas approaches, they are leaving something behind. 

Cicada eggs, laid in tree branches, are causing damage to trees, but experts say not to worry, mature healthy trees will survive.

The browning of tree branches is not alarming or surprising to those who care for trees. 

“Yes, it is cicada damage,” said Rick Hartlieb, assistant forester for the William Penn Forest District, in an email. “Any area with heavy cicada populations this summer has the tip browning, called flagging.”

The mature trees will recover. Hartlieb said the trees will send new shoots from the live buds below the damaged parts. The damage is much harder on nursery trees and young trees.

“They seem to really like the oaks,” said Emelie Swackhamer, a Penn State Extension horticulture educator based in Montgomery County. Other trees Swackhamer has seen damaged include beech, pear, sweet gum, katsura and walnut trees. 

It may not look nice, but the damage is not lasting, said Natalie Marioni, Berks County Master Gardener coordinator.

When they were at their most numerous, if you walked outside you might get a few trying to land on you.

But by July, Brood X was fading- the bugs mated, laid their eggs, and died. The larvae will drop off of the tree branches they were hatched in, and they will go underground for another 17 years of sipping tree sap before emerging when their biological clock goes off and the temperatue conditions are good.

I’m enjoying the relative peace and quiet of just the occasional annual Cicada song now. 🙂