The cicada (the name is Latin and means "tree cricket") counts 3,000 different species (and more are being discovered). An adult cicada can become two to five centimeters in length. Cicadas have two prominent eyes set wide apart on the sides of the head and large, membranous wings.
Cicadas have a life cycle of two to five years. Almost their whole life they spend underground as nymphs feeding on the sap of roots. They have strong front legs for digging and use these in the final nymphal stage when they emerge to the surface. They then shed their shell on a plant or tree and become adults. You can sometimes see these abandoned shells - in fact exoskeletons - still clinging to the bark of a tree or to a twig.
Now the mating season starts and that is when that big sound is made by the male cicadas! Their songs are meant to attract the females. They produce their characteristic sound by using tymbals, membranes in the abdomen, which are rapidly vibrated, while the largely hollow abdomen serves as a sound box. Every type of cicada has its own, particular song, to attract the right female. To hear this song, male and female crickets have tympana, the equivalent of ears. As the sound produced is so large (even 120 dB), the male cricket disables his own tympana while singing. Besides the mating song, crickets also have a distress call (when they are caught, for example) and some sing a courtship song, after the female has been attracted by the mating call.
After mating, the female cicada deposits her eggs in the bark of a tree, after slitting this open. She may lay several hundreds of eggs in different places. When the eggs hatch, the small nymphs fall to the ground, where they burrow and then the life cycle as described above starts again. The underground phase of their life is by far the longest, as it can take several years.
Cicadas feed on the sap of twigs or trees; their enemies are mainly birds.
As the cicada sheds its shell to start a new life, in Japan it is seen as a symbol of Buddhist reincarnation; and the shortness of its life as cicada (as opposed to its life as nymph), during which it sings its life out, mates, reproduces and dies, is seen as a symbol of the evanescence of life.
In his book Shadowings, the Irish-Japanese author Lafcadio Hearn, who had a deep interest in weird and exotic things, has dedicated a whole chapter to cicadas. He starts by quoting a senryu that deftly expresses the feeling of the transience of life induced by the cicada:
their voices all consumed
by their crying -
the shells of cicadas
[Koe ni mina / naki-shimote ya / semi no kara]
The "shells of cicadas" in the above poem does not refer to the shell of the nymph, but to the dead bodies of grown-up cicadas.
Nowadays, people in Japan close their windows and huddle by their air conditioners, shut off from nature. In this most seasonal country of the world, in that way the true feeling for summer is lost. Without hearing the cry of the cicadas, it is not really summer in Japan!
Hearn also describes how over the several weeks of summer, different cicadas appear with their different songs. In early summer the aburazemi ("oil cicada") appears, so named because its shrilling resembles the sound of oil or grease frying in a pan. The aburazemi begin to sing at sunrise, when, as Hearn describes it, a great hissing seems to ascend from all the trees - the sound with which I woke up this morning. Hearn also quotes the following senryu:
has the dew taken life
with that voice?
[Ano koe de / tsuyu ga inochi ka / aburazemi]
In early summer next the mugikarizemi or "barley harvest cicada" appears, which makes two distinct sounds in different keys, resembling the syllables shi-in, shin -- chi-i, ch-i.
While all cicadas make their music only in the full blaze of day, pausing even when clouds obscure the sun, at around this time also a cicada appears which sings only at dusk (and is therefore called Higurashi) and is one of the really musical cicadas. Hearn describes its sound as kana-kana-kana-kana-kana, slowly descending from a very clear, high key - somewhat like the sound of hand bell, very quickly rung. It has a great sonority.
Extremely loud is the minminzemi, which sings during the hottest period of the year. It derives its name from the fact that its note is thought to resemble the syllable "min" repeated over and over again, first slow and very loud, then more often and quicker, until it dies away in a sort of buzz: mi-in - mi-in - min-min - minminmin -dzzzzz.
The sound is plaintive and not unpleasant, although it means emphatically that it is very hot outside! Hearn mentions that the chant of this cicada is often compared to the sound of the voice of a priest chanting the sutras.
But it is rather loud, so it probably inspired the following senryu:
cicadas add to the heat -
I wish to cut down
the pine tree
[Semi atsushi / matsu kirabaya to / omou made]
Sometimes the noise is so great that you would think the whole tree was covered with cicadas - while it is only a single one:
thicker than the tree
the cicada's voice
[Naite iru / ki yori mo futoshi / semi no koe]
One of the last cicadas to mature is the tsukutsukuboshi, the most musical of all, whose song resembles that of a bird. I am not sure I have ever heard this one, but perhaps I mistook it for a bird! This is probably the type of cicada that in the past was caught and sold in a small cage.
And then the final cicada to appear is the autumn cicada, tsuriganezemi or "Temple Bell Cicada." Its voice is light and does not resemble so much the big peal of a temple bell itself, but rather the soft, deep and sweet humming which follows the peal, wave upon wave. The song of this cicada is much "cooler" (it has a silvery substance) and signifies that summer is coming to an end and autumn is approaching.
Japan's major haiku poet Basho wrote a famous haiku about cicadas when visiting Yamadera Temple in Yamagata (how quiet / sinking into the rocks / the voices of cicadas) - emphasizing the quietness of the venerable temple, for even cicadas voices don't disturb it, but seem to sink into the very rocks. Here is another one by Basho, which, in Hearn's words, "preaches the Sutra of Impermanency:"
soon to die
without realizing it -
the voice of a cicada
[yagate shinu / keshiki wa miezu / semi no koe]
The title for this haiku is mujo jinsoku, which means "the vicissitudes of life are swift, and our life is ephemeral," a phrase much loved by Basho.
The sound of cicadas is sad and nostalgic to human ears - it is certainly not just noise. Life is short and fragile, not only for a cicada, but also for humans. That makes it all the more important to appreciate each moment as precious.
[Based on information from Lafcadio Hearn's Semi chapter in Shadowings (freely available at Gutenberg), as well as cicada data from Wikipedia (incl. the photos). The quotation about "mujo jinsoku" is from Basho's Haiku by Oseki Toshiharu (Maruzen: Tokyo, 1990). The literal translations of the senryu and haiku are my own.]