Monokara21 July 2016
Avdou Kera Apotiposi31 July 2016
The sweet noise of the summer
If you are lucky to spend your holidays in Crete you will find that the chrachteristic sound of the summer is a continuous tz tz tz tz tz that comes from the trees and interapts the serenity of the noon.
For some people it is an anoiing unstopable noise that does not let them to relax or sleep. For the people who love nature, like cyclists, it sounds as a sweet melody and reminds them that it is hot
It is the sing of the cicadas. The tettix of ancient Greeks or the tzitzikas for the modern Greeks
Cicadas’ song is the loudest of all the insect produced sound.
Only males can sing and while singing they disable their tympana (membraneous structures that detect sounds) to prevent their hearing.
Unlike other sinking insects produce their song with a noisemaker membrane between chest and belly called tymbal
Their sing is more active during the hottest hours. Some small species sing so high in pitch that humans can not hear the noise
There at least 1300 cicada species on all continents except Antarctica
The Latin name cicada means "tree cricket"
Most cicadas are 2 to 5 centimetres in total length. The empreror cicada of Malaysia (Megapomponia imperatoria), is about 7 centimetres in lengh, its wingspan is 18 to 20 cm. They live about 2 to 5 years.
The North American Magicicada lives 17 year as a nymph under the ground.
According to the myth ancient Greek goddess Io fall in love with Tythonous, a very beautiful mortal young man. She begged Zeus to give him immortality but she forgot to ask for eternal youth. The years passed by and Io was still young and beautiful but Tythonus was very old and ugly people could hear only his voice. Gods felt pity for him and transform him to the insect that makes this loud noise.
In the ancient fable of Aesop "Cicada and Ant" the lazy cicada is sleeping and singing all the summer while the hardworking ant was collecting food. When the winter comes the ant enjoys the food in his warm nest but the cicada is hard to survive.
The surface of their wings is the first-known biomaterial that can kill bacteria. Nano spikes on their wings tear apart the membrane of bacteria that land on them
They have an excellent camouflage and and their wings are antireflective to evade hunters that hunt by vision.
Nymphs and adults cicadas drink sap from plants by inserting into them their long sharp trunk.
Cicadas do not bite or sting people. Sometimes may mistake a person's arm for a tree branch and try to feed
After mating female cicadas cut the bark of the trees to deposit their eggs under it.
After incubation young nymphs drop to the ground and live the most of their life underground at depths down to 2.5 meters. They dig chambers close to roots where they can feed on sap.
Some cicadas built towers above ground to aerate their barrows.
When it is time they dig an exit to surface and emerge. They climb on a trees and transform, to an adult. They cannot fly before their wings are completely dry and hardened after some hours.
The abandoned exoskeletons still remain on the trees.
Ancient Greeks used to eat cicadas. Today you can eat them in China,Malaiysia, Burma, Latin America, and central Africa.
In China the shells are used to produce traditional medicines
For Chinese cicadas symbolises the rebirth and immortality
Watch the amazing video of Samuel Orr for the life of cicadas that live 17 years under the ground.