In this century of rapid scientific discovery, there still exist natural
phenomena with the power to inspire wonder and mystery. The cicada, an insect
known since ancient times, is one such phenomenon. Because scientific knowledge
of the cicada contains many gaps, these mysterious insects can still stimulate
our imagination or lead us into confusion. At the present time, the cicada is
many things to many people: it is a curiosity that should be approached
scientifically; it is a source of superstition and dread; it is also little more
than an annoying, seasonal inconvenience. The cicada is a stout, black insect
about an inch in length. Various species of this insect can be found all over

North of the America. When the cicada is at rest, its large, transparent, veined
wings are folded over the top of its body and extend about a quarter of an inch
beyond it. Cicada wing veins are and information reddish orange in color, as are
its eyes and legs. The front legs are sharp and crablike, allowing the animal to
hold tight to the bark of trees. The species of American cicada most written
about by scientists and most wondered about by the general public is known as
the periodical cicada. Its scientific name is Magicicada septendecim. This
species of cicada appears above ground only once every seventeen years. What the
cicada does underground for most of its seventeen-year life span was a mystery
until fairly recently. In the early part of this century, a man named C.L.

Marlett, who worked for the United States Department of Agriculture, decided to
find out. He began burying cicada eggs in his backyard and digging them up
periodically for observation. He soon found out that the cicada begins life as a
tiny nymph about six hundredths of an inch in length. A nymph is an immature
insect, before it has fully developed wings or reproductive organs. During their
sixteen years and ten and one-half months underground, cicada nymphs are nestled
against tree roots from which they gently suck the juices. Nourished by this
root sap, they begin to grow. They shed their skin four times before they reach
adult size. Once matured, a cicada does not necessarily leave its underground
nursery. All cicadas of the same generation in a region wait for a seventeenth
spring before they come creeping forth from the ground as a group. The eeriness
of this group effort has puzzled humans for centuries. People have responded to
the mystery with a host of superstitions, educated guesses, and scientific
theories. One of the earliest explanations for the mass appearance of cicada
populations after their long absence in an area was that the insects had come to
foretell war. This idea stems from an observation of the adult cicada shortly
after it appears above ground. It immediately sheds its skin for the last time
and begins to darken in color. Near the outer edge of its front wings, a black
mark appears that looks distinctly like the letter W. Some thought this W stood
for "war." In the past, people who saw a group of cicadas emerge from
the ground like an invading army were filled with panic. The sight was
especially frightening because literally millions of insects can appear within
an area of a few square miles. Later explanations for the mass appearance of
cicadas stem from more scientific observations. Dr. L. L. Pechuman, a professor
at the New York State College of Agriculture and Life Sciences at Cornell

University, has suggested that coming above ground only once every seventeen
years is an excellent way for a species to discourage its natural enemies.

Perhaps the cicadas have evolved a special kind of biological time clock to
protect them from predators. James Heath, an insect physiologist at the

University of Illinois, theorizes that the cicadas all emerge at around the same
time in a certain year because the soil has reached a temperature of 64 degrees.

Theories like this have still not been proved absolutely, but they do a lot to
dispel the fear, awe, or confusion experienced by many people who witness
millions of cicadas surfacing at once. Once cicadas surface, they lose no time.

At this point in This their life cycle, they have only 5 or 6 weeks of life
remaining. They head quickly for the nearest tree or bush and climb onto it.

Then, holding onto the bark with their clawlike front legs, they shed their skin
for the last time and become large-winged adults. These adults will mate, and
the females will then dig