Come hear the Buzz

    In a few weeks we'll be opening our Bugs Outside of the Box and Beautiful Beasts exhibitions at the museum, which will focus on insects and spiders, respectively. The opening of the galleries for the exhibits on February 1st will be a huge event, featuring the Bug Chicks and different tables of insect-themed topics, including insect products and foods. As a preview to one of the tables that will also be featured, are Insect Sounds. I'm going to talk about one group of insects that produce some of the loudest, the cicadas.
    Many insects, like humans, use sound to communicate with each other. Some of the most prominent examples that we can hear are cicadas during the summer days, and katydids during the summer nights. Cicadas in particular are some of the loudest insects on earth. Some cicadas can get up to 90 decibels with their humming, which is the volume range between heavy traffic and a NYC subway. Get next to a colony of them, and you can really get a buzz. They produce the sound using their tymbal, which is like a drum that they vibrate rapidly and amplify the sound with.
      Growing up in Virginia, I remember my first experience with being next to a huge colony of them, and they were part of a special group of cicadas, the periodical cicadas (Magicicada septendecim). I was about 5 years old, and it was the first time I was around when Brood X made their appearance in the Northern Virginia area.

Magicicada septendecim, Periodical Cicada face. From Wikipedia.com

 The periodical cicadas are special because they only emerge from the ground every 13 to 17 years, with Brood X coming out every 17. They spend most of their life feeding on the roots of trees, and nobody knows how they "know" to come up, but within a few days whole colonies (known as "broods") emerge together. Thousands, if not millions of cicadas, all coming out of the ground to roost on trees, feed, sing, mate, then die.
     So, within a few days and lasting a few weeks, Brood X came together on the trees to sing to each other, hoping to find mates. I still remember the noise: if you stood near one of their favorite trees to feed and lay eggs on, like a cherry tree, it felt like you were standing next to a giant jet-engine with the loud, constant waves of humming. With 90 decibels on average a cicada, you can imagine what thousands must sound like.

     After they mated and laid their new batches of eggs into the branches of trees to start the next Brood X generation, they quietly died and the yard around my pre-school was covered with their black and red bodies. Another vivid memory was of stepping on all of their exoskeletons since the ground was literally covered with them, and thinking of how fun it was that it sounded like walking on popcorn: a quiet reprieve, though, from the loud sound of them alive.

    Fast forward 17 years, and I got to experience the hum again of the offspring of those cicadas I saw as a kid. Just coming back from my college graduation, I was back with my parents in Northern Virginia for a few months before moving to Texas for my masters...and the cicadas were back as well. Only this time, it seemed like they were louder than ever, and far more numerous. Their increase in numbers was likely due to the increase in reforestation of Northern Virginia from when it was mostly farmland, and the cicadas were VERY happy to have more trees. If you drove around in a convertible, you would be surrounded by the waves of humming vibrating from the trees passing along the Beltway. Dogs were chasing the cicadas for free, yummy snacks. Birds were fat, squirrels happy. And all for a short few weeks before again dying and waiting for the new generation to take hold on the tree roots for another 17 years. I was 22 when I got to experience them again, and unfortunately I'm not sure I'll be back in Virginia again at 39 to see them next. I think my ears might be happy about that, though! Below is a video taken from someone who experienced Brood X in 2004 too.

     Come to the Insect Sound table at the Opening Reception for our two shows February 1st to hear more stories about insect sounds and more!