Skip to content

A Large and Very Loud Summer Insect.

August 27, 2011

Cicada

To me, fireflies are the quintessential early summer insect.  Late summer however is dominated by a larger and very noisy bug that is hard to ignore.

Cicada is a Latin word meaning ‘tree cricket’.  There are over 2,000 species of this insect worldwide in temperate & tropical environments.  They are even considered a culinary delicacy in several countries of the world.

A cicada ‘singing’ from his perch under some leaves

There are two basic types of cicadas- the most common one we see are the annuals.  Annual cicadas typically live 2 to 5 years and spend much of that time underground in a nymph stage, digging through the soil to tap tree and bush roots to suck the juice contained therein.  As you can imagine, they have strong front legs for digging.  Near the end of their lives, they emerge from the ground usually in July and August in Ohio, attach to an object and then molt, turning into the adult form that we are used to seeing (and hearing).  They live a month or so in this final life stage.  Most of their time is spent looking for a mate; females lay hundreds of eggs in tree branches.  The eggs hatch and the nymphs drop to the ground and dig for cover, starting the life cycle anew.

The second type of cicadas are the periodicals, which get the most publicity.  Periodical cicada nymphs emerge from the ground in Ohio usually in May and June, but they do not do this every year.  There are 2 major types of periodicals, 13-year cicadas and 17-year cicadas.  They emerge from the ground every 13 or 17 years respectively, though there are different broods in different geographical areas, which makes the situation a little more complicated.  For instance, in the current year 2011, the Great Southern Brood (also known as Brood XIX) of 13-year cicadas have hatched in parts of 16 states from North Carolina to Missouri.

Why do periodical cicadas emerge every 13 or 17 years in different areas?  Chances are that this is a strategy to deal with predators- a predator with a shorter life cycle than the periodical cicada broods (which happen in prime numbered years, by the way) will not reliably be able to make this insect a regular part of its diet.  However, periodical cicadas, unlike their annual cousins, emerge in great numbers in a short period of time, many millions of insects covering the landscape in their brood years.  This phenomenon is known as predator satiation, a reproductive strategy by which a creature appears in huge numbers all at once, during which many are eaten by predators but many more survive simply due to the fact that its predators have eaten so many of them that they are too full to eat the others.

Ohio’s most recent experience with periodical cicadas came in 2008, when Brood XIV emerged from the ground in the southwestern part of the state.

Cicadas- particularly periodical species- can damage trees by laying their eggs in young branches, which are split open by the emerging nymphs.  This is known as ‘flagging’.  There are various ways to limit this damage, including pesticides, netting, and delaying the planting of young trees.

This cicada was rather absurdly perched upon a stem of grass

Cicadas are rather startling-looking bugs when you see them up close, with their large bodies, nearly transparent wings and bulging eyes.  They have 5 eyes, believe it or not- 2 large prominent ones, and 3 smaller ones on the forehead in between them.  But their most interesting characteristic is the very loud buzzing sound that the males make to attract a mate.  Unlike crickets which rub their wings to generate sounds, cicadas use membranes in their abdomens called tymbals which are vibrated to generate sound.  Chambers within the insect’s body modulate and amplify the noise.  Each cicada species have their own specific ‘calls’ distinguishable by their own species.  It can be quite a racket.  Periodical cicadas may even coordinate such calls, perhaps to drive predators off.  It would certainly drive me off!

This sound can reach a volume of up to 120 decibels, which can cause permanent hearing damage if done very near a human ear for a period of time (which luckily rarely happens- people get the heck away from that kind of close-range racket).

Unless you let one ‘sing’ on your shoulder, cicadas are harmless to humans.  They don’t bite, though if they land on you they may mistake you for a tree and try to suck some sap from you- I’d recommend shooing them away ;)

The cicada’s main predator are birds.  Just last week I saw a House Sparrow carrying a still-buzzing cicada in its beak as it flew over a building.  Squirrels, Praying Mantises, and the apt-named Cicada-Killer Wasp also prey upon them.  But judging by their numbers, I don’t think we’re going to run out of cicadas any time soon.

Here are a couple photos I took of an adult cicada newly-emerged after molting in mid-August.

Notice the sturdy front legs on the nymph body shell, designed for heavy digging

You can see the 3 small eyes on the forehead between its 2 large eyes if you look closely

The sound of cicadas and high summer go hand in hand.  It’s curious to think that these insects spend most of their lives beneath the ground and then emerge for their final month of life out in the sun.

YouTube clip: Amazing Cicada life cycle – Sir David Attenborough’s Life in the Undergrowth – BBC wildlife

About these ads
28 Comments leave one →
  1. August 27, 2011 10:18 pm

    What a timely article. They are noisy, noisy this year! Like hearing them better than seeing them up close and personal!

  2. August 27, 2011 10:56 pm

    I find it amazing you got photos of them, usually they are just heard and not seen. I especially like the picture where it’s hanging from the stalk of tall grass. It is fascinating to think that their time in the sun is so short.

  3. August 28, 2011 7:24 pm

    When we drove through Nebraska in August, 2003, we stopped along the road by a big cottonwood and were amazed at the noise of what I am sure must have been cicadas. Thank you for the information. Love those transparent wings! Jane

    • August 28, 2011 8:12 pm

      The sound is very intense indeed. Funny to think that fireflies communicate visually through light, and cicadas go the opposite route and make a noisy din. I guess it’s hard for them to miss each other this way!

  4. August 30, 2011 10:03 am

    what an interesting post! i have only ever heard of them – have never seen/heard any live. some great images, especially the one demonstrating its acrobatic ability on the grass. :)
    thanks for sharing!

  5. September 1, 2011 3:03 pm

    They are considered a culinary delicacy in West Virginia, too. I was there during one of those 17-year outbreaks (sometime in the 90s). The television and print news media both had recipes for them. (It was probably a joke, but you never know…)

    Fantastic photos, and a very interesting post.

    • September 2, 2011 12:28 pm

      The media does like to hype the 13/17 year cicada story :) The last outbreak here it didn’t seem especially bad, but I’ll definitely pay more attention the next time…

  6. September 2, 2011 4:23 pm

    Wow, I always assumed the skin shedding was in the way that snakes shed skin every once in a while. No clue it was a transformation. Just yesterday I saved a cicada from the terror of being stuck upside-down on a campus sidewalk. Ever since I can remember they’ve been there at night singing me to sleep with their buzzing. It was quite interesting reading about them after feeling like they’ve oddly been in my life for so long, you’re quite knowledgeable on the subject!

    • September 2, 2011 10:50 pm

      I’m sure the cicada was happy to be right-side-up again- they don’t have long in their adult forms, they need to breed new nymphs! :)

  7. September 2, 2011 8:11 pm

    This is amazing! My husband and I just returned from a short trip to Arizona and heard them for the first time. I wasn’t sure what they were and then just found your post.
    So well written and the photography is terrific. Thanks for the nature lesson.

  8. September 5, 2011 12:51 pm

    Very Loud indeed!! It’s somewhat unbelievable the level of noise these tiny fellows can emit. During the hottest part of the Summer you could hear them inside the house with the windows closed and the AC running, they were so loud. Their season of ‘song’ is nearly over now. Great photos, as always! :)

    • September 5, 2011 1:52 pm

      I’d say the height of the cicada chorus here was in August. I was out at a park and walked into a patch of woods with a trail going through it. The cicadas were so loud my ears rang and it was difficult to concentrate!

  9. September 5, 2011 5:44 pm

    I love to hear the cicadas whirring at dusk – they are very very loud! Thanks for the informative post!

    • September 6, 2011 11:58 pm

      The cicadas are quieting down here now- I’m guessing that young nymphs are burrowing in the ground as I type this…

  10. Barbara Rodgers permalink
    September 6, 2011 7:36 pm

    Fascinating little creatures – thanks for teaching us so much about them. Although I’ve heard them I had no idea what they looked like. Your pictures are sensational!

  11. September 8, 2011 5:13 am

    Fascinating Cicadas. Those photos makes us appreciate the beauty of these insects. No I don’t have to wonder where those sounds are coming from….thanks for the information.

  12. September 22, 2011 8:08 pm

    Cicadas always look like aliens to me.

  13. Dawn permalink
    June 23, 2013 9:38 pm

    The 17 year Cicada have arrived!!!!! Thankfully they didn’t make it to southeastern ct. I do enjoy the annual cicadas in August. Summer wouldn’t be the same without them.
    Dawn

    • June 25, 2013 8:18 am

      It’s a big year in certain areas of the country for the cicadas! So far where I am they’ve been flying below the radar so to speak.

  14. Hez permalink
    August 19, 2013 9:23 pm

    My neighbor and I were just sitting outside talking about how loud they are this year. I didn’t realize that they aren’t everywhere. I used to love this time of year when I was a little girl because they would sing me to sleep. Summer wouldn’t be the same without them.Thanks to your post, now I know that it’s the 17 year brood that makes their song so loud this year. Thanks for the informative post.

    • August 20, 2013 8:35 am

      Thanks, Hez! The Cicadas have been fairly sparse this year in central Ohio- I usually just hear a couple of them from my front door. Glad to be of help!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Follow

Get every new post delivered to your Inbox.

Join 251 other followers

%d bloggers like this: