Emblem of the Provence, the cicada is best known for the sounds it makes when playing with its cymbals. Living underground for years, the cicada becomes extinct after seeing the light of day. Portrait of an insect that will only have sung one summer.
The origins of the cicada
The cicada is an insect of the order of hemiptera and the cicadidae family. Its scientific name comes from the Greek kiccos (membrane) and ado (to sing). With the plebeian cicada or great common cicada (Lyrists plebejus), the cicada grey (Cicada orni) is one of the most common species in the South from France.
The cicada: a rigid trunk and hairy legs
The body of the cicada is usually black, brown or green, and has spots of different shape and color depending on the species. Its broad, flattened front head features a pair of large eyes, two short antennae and a long deceived rigid (rostrum) that it plants in roots and trees for food. As for his paws hairy, they allow it to cling to plants. The thorax has characteristic wings: long, transparent and adorned with black lines or dots. The common cicada is 5 to 8 centimeters long.
Why is the cicada singing?
In cicadas, only the male utters a call typical of the species. Called song, it is actually a cymbalization. Indeed, the insect has two membranes (cymbals) inside his abdomen which he snaps with a muscle, up to 900 times per minute. In addition to inviting a female to thecoupling, its call has the effect of attracting other males and enticing them to sing. By forming a chorus, the suitors have a better chance of capturing the attention of females who are far away.
Why does the cicada stop singing?
Because the temperature conditions the flexibility membranes used for the cymbalization of cicadas. Below 22 ° (24 ° for some species), the membranes contract to the point of no longer being able to be deformed by the muscles of the abdomen. Usually all cicadas stop singing almost simultaneously. The wind also can cut their whistle! On the other hand, when the weather conditions are favorable, the males resume their song. nuptial at the top of your lungs, from morning to night. Very fearful, the cicada no longer emits sound when it feels in danger: the appearance of a predator or when it is taken in the hand.
The cicada spends its life underground
From the United States to Europe, more than 4500 species cicadas are scattered around the world. In France, there are about twenty and sixteen in the south of the country. The gray cicada, the most common species in Provence, is also the most sound all. The first – and longest part of its existence – the insect lives in the soil. Once out of the earth, it evolves in the pine groves and forests of coniferous, dense scrub and thick vegetation. There she settles on a rod or a trunk, in trees or bushes.
The cicada, fond of sap
The larvae and pupae of cicadas live underground where they dig galleries in search of roots plants whose sap they suck up using their rostrum. When they live in the open air, adults also use their proboscis to pierce the bark of branches and take sap from trees. Despite its diet, the singing insect is not harmful in the garden.
Up to 400 eggs for the female cicada
After mating, females dig slits at the base of the trunk of shrubs and grasses thanks to their ovipositor, located at the end of their abdomen. This is where they drop up 400 eggs, similar to grains of rice, which hatch after a month to give larvae. These civont burrow in the ground where they will stay at least two years (up to 17 years for certain American species) while feeding on the suction of roots.
The adult cicada lives only one season
Before reaching the imago stage, the nymph leaves the ground, climbs on a tree or other plant support and clings to it with the fur of its paws. After several moults, the emergence of the adult usually occurs at night in order to escape predators. When its wings and exoskeleton have dried up, the insect flies away in search of food. As soon as the heat will stimulate it, the male will proceed to the cymbalizations to attract the female and to mate. At the end of the reproduction (four to six weeks), the cicada will die.
The cicada: dangers on every floor
In each life cycle, the cicada is threatened by predators. Starting with the mites which can attack directly the contents of its eggs. Become larva, the cicada is attacked by centipede or ants type insects. When it comes out of the earth, the cicada is particularly vulnerable when it transforms into an adult (the hours during which the animal dries and spreads its wings). Once outside, it falls prey to spiders, praying mantis, grasshoppers, provided, wasps or even bedbugs. Birds like magpies, chickadees, owls and swifts also enjoy it. The cicada is not considered a species threatened.