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