Monday, August 20, 2012

Annual Cicada

I’ve been hearing the buzz of summer Cicadas for several weeks.  Periodic storms strip the trees of spent nymphal skins, but the continued emergence of adult Cicadas return those decorations to the tree trunks.  Annual Cicadas stage an emergence every summer and often go unnoticed because their song is such a familiar part of the summer experience.  If their song was removed from the summer orchestra, I don’t think the Katydids and Crickets would be able to fill the void.

Cicadas are fun to watch, but they are often hard to get close to.  I think it was just coincidental that I looked up from examining the shed skin to find a Cicada in the branches above me.  I expected it to start singing.  Instead, it moved slowly up and down the length of a dead cedar branch.

Occasionally it stopped and appeared to hug the branch.  The bright background of the sky and my position on the ground made it difficult to see any details of what the Cicada was doing.  Fortunately, the cedar had some stout branch stubs near the ground and I was able to reposition myself upward to a better vantage point.

On closer examination I could see that what I thought was a back leg was actually the ovipositor, AKA egg laying tube.  From where I was perched, it looked as though the Cicada was depositing eggs into the dead cedar branch.  I’ve seen many egg laying Cicadas and they do lay their egg in small diameter tree branches, but I have never seen them use anything but live branches.  Maybe I still wasn’t close enough to properly interpret what I was seeing.

My next step up brought me close to level with the strange bug.  I watched for quite a while and the Cicada was indeed laying eggs.  The white material rising from the branch just below the ovipositor is wood material loosened by the egg laying action.  Eggs are laid in the slit of a branch and I always thought live wood was used because it was softer and provided the proper moisture conditions.  Since the newly hatched nymphs fall to the ground and immediately burrow in search of roots upon which to feed, it seemed that there was a definite survival advantage to be had by laying eggs in a living branch which most likely would be in a position above living roots.

In this case, despite being a dead branch, there are plenty of live roots down below.  I always enjoy making observations that go against what I’ve read or been taught.  It’s something that happens quite frequently.  The problem is that there is very little known about the life histories or behaviors of most animals.  It seems that pest animals are those most thoroughly studied and most of that was in an attempt to learn how to kill them.  Anyone who takes the time to look, will probably see some behavior that is not documented.  It’s a lot of fun.


  1. Very nice post. I would personally like to know more about cicadas as well:) There has to be more to them than just the pretty sounds they make.

  2. Thanks Mona. Maybe you can be the one to do the ultimate Cicada Study and reveal all of the hidden mysteries of cicada behavior.