The Cicada

The Cicada

Cicada

If you are fortunate enough you will hear one of the unique sounds of summer, a loud continuous trilling sound belonging to the Cicada.

In Feng Shui, the Cicada is considered a lucky symbol of marriage, luck and great comebacks. This auspicious little fellow appears only every 17 years, buzzing all summer long.

Here are some facts pertaining to Cicada, as they are truly an amazing creatures:

A cicada is an insect of the order Hemiptera suborder Auchenorrhyncha. It has large eyes set wide apart on the head and usually transparent. There are about 2,500 species of cicada around the world. Cicadas live in temperate to tropical climates. Cicadas are often colloquially called locusts although they are unrelated to true locusts, which are a kind of a grasshopper. Cicadas are actually cousins to leafhoppers and spittlebugs. The name is a direct derivation of the Latin Cicada, meaning “tree cricket”.

Never fear, Cicadas are usually benign to humans in normal circumstances and do not bite or sting them; however they could bite if they want to feed and mistake a person’s arm or other parts with a tree or plant limb.  Cicadas have a long proboscis under their head that they use for feeding on tree sap, and if they attempt to inject it into a person’s body it can be painful, but is in no other way harmful. This sting is not a defensive reaction and should not be mistaken for aggression; it is extremely uncommon, and usually only happens when they are allowed to rest on a person’s body for an extended amount of time.

Cicadas can cause damage to several cultivated crops, shrubs, and trees, mainly in the form of scarring left on tree branches while the females lay their eggs deep in branches. Many people around the world regularly eat cicadas though the female is prized for being meatier. Cicadas have also been known to be eaten in Ancient Greece, china, Malaysia, Burma, Latin America and the Congo.  Shells of cicadas are employed in the traditional medicines of China.

Most of the North American species are in the genus Tibicen: the annual or dog-day cicadas (so named because they emerge in late July and August).  The best-known North American genus is Magicicada, however. These periodical cicadas have an extremely long life cycle of 13 to 17 years and they emerge in large numbers.

The adult insect, sometimes called an imago, is usually 2 to 5 cm (1 to 2 in) long, although some tropical species can reach 15 cm (6 in), e.g. Pomponia  imeratoria from Malasia. Cicadas have prominent eyes set wide apart on the sides of the head, short antennae protruding between or in front of the eyes, and membranous front wings.. Also, commonly overlooked, cicadas have three small eyes, or ocelli, located on the top of the head between the two large eyes that match the colour of the large eyes.

Desert cicadas are also among the few insects known to cool themselves by sweating, while many other cicadas can voluntarily raise their body temperatures as much as 22 °C (40 °F) above ambient temperature.

Cicada Song

Male cicadas have loud noisemakers called “tymbals” on the sides of the abdominal base. Their “singing” is not the stridulation (where one structure is rubbed against another) of many other familiar sound-producing insects like crickets: the tymbals are regions of the exoskeleton that are modified to form a complex membrane with thin, membranous portions and thickened “ribs”. Contracting the internal tymbal muscles produces a clicking sound as the tymbals buckle inwards. As these muscles relax, the tymbals return to their original position producing another click. The interior of the male abdomen is substantially hollow to amplify the resonance of the sound. A cicada rapidly vibrates these membranes, and enlarged chambers derived from the tracheae make its body serve as a resonance chamber, greatly amplifying the sound. The cicada modulates the sound by positioning its abdomen toward or away from the substrate. Additionally, each species has its own distinctive “song”

Average temperature of the natural habitat for this species is approximately 29 °C (84 °F). During sound production, the temperature of the tymbal muscles was found to be slightly higher. Cicadas like heat and do their singing during the hotter hours of a summer day, in a roughly twenty four hour cycle.

Although only males produce the cicadas’ distinctive sound, both sexes have tympana, which are membranous structures used to detect sounds and thus the cicadas’ equivalent of ears. Males can disable their own tympana while calling.

Some cicadas produce sounds up to 120 dB (SPL) “at close range”, among the loudest of all insect-produced sounds. This is especially notable as their song is technically loud enough to cause permanent hearing loss in humans, should the cicada sing just outside the listener’s ear. (Never fear, it’s the most unlikely thing to happen.)

Species have different mating songs to ensure they attract the appropriate mate. It can be difficult to determine from which direction(s) cicada song is coming, because the low pitch carries well and because it may, in fact, be coming from many directions at once, as cicadas in various trees all raise one another to make noise in unison. Although relatively loud, cicada song can be comforting and even hypnotic at times, as it is at its loudest during the hottest time of an already hot day.

In addition to the mating song, many species also have a distinct distress call, usually a somewhat broken and erratic sound emitted when an individual is seized. A number of species also have a courtship song, which is often a quieter call and is produced after a female has been drawn by the calling song.

The Folklore of the Cicada

In Ancient Greek mythology, Tithonus eventually turns into a cicada after being granted immortality, but not eternal youth, by Zeus.

The cicada has sometimes represents insouciance (i.e. nonchalance or indifference).  Jean De La Fontaine began his collection of fables with the story   “The Cicada and the Ant”. What child hasn’t read that? I know I have.  It’s based on one of Aesop’s fables: in it the cicada spends the summer singing while the ant stores away food, and finds herself without food when the weather turns bitter.

In Japan, the cicada is associated with the summer season. The songs of the cicada are often used in Japanese film and television to indicate the scene is taking place in the summer. The song of a particular cicada, called “tsuku-tsuku boshi”, is said to indicate the end of summer, and it is called so because of its particular call. During the summer, it is a pastime for children to collect both cicadas and the shells left behind when moulting.

In Japan, the cicada carries further philosophical connotations of re-birth. Since the cicada emerges from the ground to sing every summer, it is a symbol of reincarnation. Of special importance is the fact that the cicada moults, leaving behind an empty shell. But furthermore, since the cicada only lives for the short period of time long enough to attract a mate with its song and complete the process of fertilization, they are seen as a symbol of evanescence.

In the Japanese novel The Tale of Genji, the title character poetically likens one of his many love interests to a cicada for the way she delicately sheds her scarf the way a cicada sheds its shell when moulting. A cicada shell also plays a role in the manga Winter Cicada. They are also a frequent subject of haiku, where, depending on type, they can indicate spring, summer, or fall.

In China, the phrase “to shed off the golden cicada skin” is the poetic name of the tactic of using deception to escape danger, specifically of using decoys (leaving the old shell) to fool enemies. It became one of the 36 classic Chinese Stratagems of “Sun Wu”. In the Chinese classic “Romance of the Three Kingdoms”, Diaochan also got her name from the sable tails and jade decorations in the shape of cicadas, which at the time adorned the hats of high-level officials. In the Chinese classic “Journey to the West”, the protagonist Priest of Tang was named the Golden Cicada; in this context the multiple shedding of shell of the cicada symbolizes the many stages of transformation required of a person before all illusions have been broken and one reaches enlightenment. This is also referred to in Japanese mythical ninja lore, as the technique of “Utsusemi” (i.e. literally cicada), where ninjas would trick opponents into attacking a decoy.

In Mexico, the mariachi song “La Cigarra” (lit. “The Cicada”) romanticises the insect as a creature that sings until it dies

Procreating

After mating, the female cuts slits into the bark of a twig, and into these she deposits her eggs. She may do so repeatedly, until she has laid several hundred eggs. When the eggs hatch, the newly hatched nymphs drop to the ground, where they burrow. Most cicadas go through a life cycle that lasts from two to five years. Some species have much longer life cycles, such as the North American genus,   Magicicada, which has a number of distinct “broods” that go through either a 17-year or, in some parts of the world , a 13-year life cycle. These long life cycles perhaps developed as a response to predators, such as the cicada killer-wasp and the praying mantis.

Cicadas live underground as nymphs for most of their lives, at depths ranging from about 30 cm (1 ft) down to 2.5 m (about 8.5 ft). The nymphs feed on root juice and have strong front legs for digging.

In the final nymphal instar, they construct an exit tunnel to the surface and emerge. They then shed their skins on a nearby plant for the last time and emerge as adults. The abandoned skins remain, still clinging to the bark of trees.

Cicada nymphs suck xylem from the roots of various species of tree, including oak, cypress, ash and maple. While it is common folklore that adults do not eat, in reality they do have their own sucking mouthparts, and also drink plant sap. Cicadas are commonly eaten by birds, and sometimes by squirrels, but a fungal disease (Massospora cicadina) is their worst enemy.

Some species of cicada also have an unusual defense mechanism: because many of them emerge at once it ensures the survival of most of them, predators can eat only so many. The remaining cicadas then can breed in peace.

 

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