Wednesday, September 22, 2010
I Say Cicada, You Say Cigarra
We had the most wonderful - yet unexpected - learning opportunity the other day while we were at the park for a little break. Right as we were leaving, my daughter spotted this beautiful cicada on the ground. Her squeals of delight were joined by mine as I had never seen a cicada that had just emerged from its exoskeleton. Normally, they do this at night to avoid predation, as they are extremely vulnerable at this time.
As you can see from the picture, a newly emerged adult is so beautiful! I couldn't get over its bright, translucent green coloration, and its wings were still limp like a long flowing cape. Apparently, it takes a while for their wings to fill with blood and their new skin to harden. As it turns out, I really knew very little about these insects, so we did a little digging around our home library and on the internet...
Do they bite?
My daughter wanted to pick it up, but from what I had read, these little suckers (literally) can pierce you with their beak if they mistake you for a tree, which it sounds like they frequently do (there's not that much room in there for a brain). So we used a dead leaf to flip it over on the ground and it promptly made a bee-line for the nearest tree.
What's their diet?
Have you ever wondered what a cicada eats? I hadn't, at least not until my daughter asked me. And then I found out that the reason for said beak was to pierce and suck from the xylem of plants. The xylem is the tube that carries water and nutrients from the roots to the leaves.
Natural History...
Now there are over 100 different species of cicada found in North America alone, and more than 2000 around the world. They are, in fact, found on every continent except Antarctica.
Like many insects, their life cycle begins as an egg laid into the crevice of a tree. When they hatch, they enter their nymph stage, which is when they do most of their growing. During this time, they drop down to the ground and tunnel underground until they find a root to feast on for the next two to 17 years, depending on the species. Finally, they dig their way out and climb up the nearest tree where they shed their old skin and emerge as an adult, or imago. Most of us have only noticed them in their adult stage, after they have emerged from their exoskeleton.
There are two main types of cicada. The periodical, also known as the 17 year cicada, is the one that emerges by the millions every 17 years. But the more common one here in America is the annual, which emerges every year in small numbers.
I found out that there will be NO MAJOR PERIODICAL emergences this year. And if you'd like to find out when the next major emergence is coming to your state, check out this Cicada Mania page. This site is a wealth of information on cicadas.
Vocalization
Now I'm sure that everyone recognizes the song of the cicada. It is the intense buzzing sound outside that most of the world associates with the hot days of summer. In fact, it is the loudest of all insect calls, and one of the loudest noises found in the animal kingdom. Only the males create this racket with their "tymbals," which are structures found on either side of the base of their abdomen. But if you try to find a cicada by listening for its song, olvídatelo. They are deliberate ventriloquists whose sound cannot be pinpointed by the vertebrate ear. Only a receptive female cicada can locate her mate. Females also make noise using their wings, but the sound is completely different.
The Bilingual Edge
Growing up, I remember hearing the story of la cigarra y la hormiga. So, I dug around some, but sadly, could find very few on-line resources for this story. I hope you enjoy these.
la cigarra y la hormiga :: Cody's Cuentos (a podcast)
The story of la cigarra y la hormiga :: Guía Infantil
La cigarra y la hormiga :: Combel Editorial
Música amiga: corre al coro :: Latin Baby Book Club
Con mucho cariño...
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Science and Nature