In summer you can hear long, often shrill sounds coming from trees and bushes. This is sung by male cicadas. Cicadas are the loudest representatives among insects. Their singing is more varied than the chirping of grasshoppers and locusts. And they reproduce sounds with a completely different instrument - eardrums.
Insect taxonomy
What order of insects do cicadas belong to? Scientists attributed them to the homoptera proboscis (Homoptera). Homoptera - because all 4 wings are the same or almost the same density. Proboscis - because they have a piercing-sucking proboscis. They feed on plant sap. This order also includes aphids, scale insects and mealybugs.
Cicada characteristics
Despite the fact that the cicadas are a separate suborder, they have common signs of insects. So, in representatives of this taxon, the front wings are either transparent or leathery. They fold up like a roof. The body is thick, the wings protrude far beyond the tip of the abdomen. Antennae short, segmented. On a wide head there are 2 compound eyes and threesimple.
The larvae are delicate, with thin covers, so they live in shelters. At first they live under the bark of trees, then they fall to the ground and burrow quite deeply. Sometimes a full meter deep. Some representatives protect themselves from predators and desiccation by forming a foam around their body.
Length of cicadas - from 2 to 70 mm. Smaller representatives jump perfectly, using the hind jumping limbs for this. In large species, all limbs are walking.
Singing cicadas
Selected in a separate family. The family is also called "real cicadas". They have a number of common features. The description of song cicadas is as follows: large insects with a thick abdomen, walking legs and well-developed transparent wings. Fore femora thickened, with two or three teeth. All representatives have a remarkable ability to sing loudly. There are about 1500 species in the world of song cicadas. These creatures live mainly in warm climatic zones.
Signs of insects are the same for all representatives of song cicadas. Therefore, remembering one cicada, it is easy to determine the belonging of other species to the same family.
Singing cicadas
Cicadas sing in different ways. The description of the song is individual for each species. The voice may sound like a circular saw or a monotone train signal. Some songs are distinguished by the presence of two parts, different in sound.
Timbal organs that reproduce sound are located on the ventral side of the body. Special plates cover the device. The cymbals themselves consist of three membranes. The outer membrane is connected to powerful muscles. Muscles change the bulge of the membrane to concavity, and vice versa. Muscles attached to the center of the instrument tense up, bending the membrane. Sound is played. Further, the muscles relax, and the membrane takes its previous position. At this stage, the sound may or may not be audible to the human ear. The result is a chirping sound, like playing with the domed lid of a tin can. The remaining membranes (anterior and posterior) resonate with the external or have their own muscles. The back membrane is called the "mirror". It shimmers beautifully in different colors.
Vibrations occur up to 4000 times per second when there is enough heat. However, a hundred times per second is enough for the cicada to chirp. Large air cavities amplify the sound - they are resonators. The cavities are connected to spiracles for air supply. By the way, only large representatives sing loudly. Smaller ones also sing, but so quietly that they cannot be heard by the human ear. For a long time it was thought that only males sang. In 1959, 19 species of European leafhoppers were studied. It turned out that females also sing. However, sound amplifiers are needed so that a person can hear their sounds.
Some representatives sing so loudly that the human ear can't stand it. This is excellent protection from predators. Such loud cicadas are common, for example, in the deserts of North America.
The cicada with the longest life cycle lives on the same continent. The larva turnsinto an adult after 17 years. This is a record among insects. However, not all species of the family have been studied. Perhaps other amazing representatives of song cicadas will open.
Lifestyle
What does a cicada eat? The larvae live underground, where they feed on the juice of young plant roots. They also suck the juice of the underground part of the stem. What does a cicada eat when it grows up? Adult representatives pierce the cell walls of plants with a proboscis and drink juice. After eating insects, the juice continues to stand out. A droplet of nutrient fluid is formed. She freezes in the air. Manna is the name of such droplets.
Thus, the habitat of song cicadas is a biotope that has vegetation. Adults like to sing while sitting on trees and bushes. The larvae live in the soil under the same woody plants. Song cicadas are distributed all over the world.
Signs you are hearing a cicada
How to distinguish the singing of a cicada from the sounds of orthoptera? Cicadas usually chirp during the day, especially during the hot afternoon hours. The fact is that singing requires a lot of energy. This energy is provided by solar heat. Only a small number of representatives are awake at dusk. In this case, energy is generated by the work of the muscles that are normally used for flight.
Singing cicadas sit on trees and shrubs, usually taller than human height. So if the song is heard from above, then most likely it is a male trilling.
Life cycle of the song cicada
The female is doingovipositor hole in the bark of a fresh young twig of a tree or bush. Lays eggs in holes. They hatch into larvae. At first, they can remain on the branches and feed on the juices of the aerial part of the plant. But then they necessarily fall to the ground and immediately begin to burrow into the ground, where it is difficult to find them for insect consumers. There is enough moisture underground, it is cool, there is a lot of food. The larvae have digging limbs. Insects are looking for young roots. They pierce the plant cover with a beak-shaped proboscis and suck the juice. So they eat from a year to 17 years, depending on the type of insect. Vegetable juice is not very nutritious, so the development of many representatives is delayed for several years.
In the process of growth, the larvae molt several times. Before the last molt, they come to the surface. They sit on the trunk of the nearest tree. Here the adult emerges from the larva. This is a long, not minute process. After leaving the old skin, the cicada dries its wings for about an hour. An adult lives 1-2 months. Thus, the cicada has a life cycle with incomplete transformation, that is, there is no pupal stage.
Symbiosis with cicadas
Plant sap is basically a sweet carbohydrate liquid. Cicadas, like all animals, must also receive protein to build their bodies. To do this, they have symbiotic fungi in their bodies. Their colonies supply insects with protein.
Representative of central Russia
Mountain cicada (Cicadetta Montana) is the only representative that lives in central Europe. The rest of the true cicadas live further south. The mountain cicada is smaller than its tropical relatives. The name "mountainous" is not entirely successful, because this species lives mainly on the plains.
Studies of a typical representative of Australia
David Young is an Australian research scientist. He is studying the song of Australian green cicadas (Cyclochila australasias).
Creation is, sitting on a tree, begins to sing. After some time, other males living nearby join the "soloist". It makes a whole choir. Usually one insect sings for several seconds or minutes. The invertebrate choir continues to sing for a long time. This is how males attract females.
The singing of a green cicada is perceived as a continuous loud sound with no change in tone. David Young, choosing an individual sitting alone, recorded the song on a tape recorder. The recording was then analyzed on a computer. It turned out that the singing of a cicada is a lot of impulses. Moreover, the right and left tools work in turn. The number of pulses was usually 230 and sometimes reached 4000 per second.
In the process of chirping, song cicadas take a special stance. The male raises the abdomen, while the wings diverge slightly to the sides.
Other representatives of the cycad suborder
Besides singing representatives, cicadas include the families of Cicadas, Humpbacks, and Pennica. They all have the same appearance. However, they also have rear jumpinglimbs.
Cicadas are smaller than real cicadas. Their front wings are dense, leathery. These creatures are very mobile, they fly better than song cicadas. Both larvae and adults live on grassy vegetation.
Humpbacks have figured outgrowths on the pronotum. Most diverse in South America.
Pennys are often brightly colored. Their front wings are dense. They jump beautifully, but in danger they fall to the ground, where they are more difficult to notice. The larvae of pennits have a special adaptation from drying out. They form a foamy mass around themselves, for which they got their name.
The larva secretes a special liquid - plant juice undigested by the body. Symbionts that secrete mucin live in the larva. Mucin is added to the secretions. It provides the viscosity of the liquid. The larva foams the juice of plants with mucin, releasing air bubbles from the spiracles into the mass and whipping it with quick movements of the legs. So she ends up in her wet house. Pennitsy cicadas live all over the world. In Madagascar, for example, drops of foam fall from the trees - the discharge of cicadas, as if it were raining.
People's attitude to cicadas
People have very different attitudes towards cicadas. So, the Romans really did not like the crackling singing of these insects. The ancient Greeks, on the other hand, respected cicadas, loved to listen to their music and even depicted insects on coins. Cicadas are very popular in Spain. You can always see souvenirs with the image of these creatures on sale.
Nanotechnology
Ps altoda claripennis is a cicada whose wings are lined with microscopic needles. Such a surface kills bacteria that get on the wings. Scientists plan to use the discovery to create germicidal materials.
Insects are interesting if you look closely at them. Scientists have yet to study many more species of cicadas and other invertebrates. Many amazing discoveries have been made in science, and we still have to learn new secrets from the life of insects, their structure and behavior. Many arthropods lead a complex lifestyle. Cicadas have an unusual structure, they are champions among insects. Moreover, they are very beautiful. Anyone who has seen the mass emergence of adult song cicadas from the last stage of the nymph larva will obviously not remain indifferent.
