In summer, you can hear long, often piercing sounds coming from trees and shrubs. The males of cicadas sing it. Cicadas are the loudest representatives of insects. Their singing is more diverse than the chirping of grasshoppers and locusts. And they reproduce sounds with a completely different instrument - eardrums.
Taxonomy of insects
Which insect order does cicadas belong to? Scientists attributed them to the homoptera proboscis (Homoptera). Diptera - because all 4 wings are the same or almost the same density. Proboscis - as they have a piercing-sucking proboscis. They feed on the juice of plants. Aphids, scale insects, and worms also belong to this order.
Characteristic of Cicadas
Despite the fact that cicadas are allocated in a separate suborder, they have common signs of insects. So, representatives of this taxon have front wings either transparent or leathery. Folding roof-shaped. The body is thick, the wings protrude far beyond the tip of the abdomen. Antennae short, articulated. On the broad head there are 2 complex eyes and three simple eyes.
The larvae are tender, with thin integuments; therefore, they live in shelters. At first they live under the bark of trees, then they fall to the ground and bury rather deeply. Sometimes a meter in depth. Some representatives protect themselves from predators and drying out, forming a foam around their body.
The length of the cicadas is from 2 to 70 mm. Smaller representatives jump perfectly, using the hind limbs for this. In large species, all limbs are walking.
Song Cicadas
Allocated to 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. The hips of the front legs are thickened, with two to three teeth. All representatives have a remarkable ability for loud singing. There are about 1,500 species in the world of singing cicadas. These creatures live mainly in warm climatic zones.
Signs of insects are the same for all representatives of song cicadas. Therefore, having remembered one cicada, it is easy to determine the belonging of other species to the same family.
Singing cicadas
Cicadas sing in a variety of ways. Description of the song individually for each species. The voice may be like the sound of a circular saw or the monotonous signal of a train. Some songs are distinguished by the presence of two parts, different in sound.
The timbal organs that produce sound are located on the ventral side of the body. Special plates cover the device. The cymbals themselves consist of three membranes. The external membrane is connected to powerful muscles. Muscles change the convexity of the membrane to concavity, and vice versa. The muscles attached to the center of the instrument tighten, bending the membrane. The sound is played. Then the muscles relax, and the membrane takes its former position. At this point, sound may be reproduced, or may not be heard by the human ear. The result is chirping, as when playing with a convex lid of a can. The remaining membranes (front and back) resonate with the outer or have their own muscles. The back membrane is called a “mirror”. She beautifully shimmers with different colors.
Oscillations occur up to 4000 times per second in the presence of sufficient heat. However, a hundred times per second is enough to chirp a cicada. Large air cavities amplify sound - they are resonators. The cavities are connected to the spiracles for air supply. By the way, only large representatives sing loudly. Smaller ones also sing, but so quietly that they can not be heard by the human ear. For a long time it was believed that only males sing. In 1959, 19 species of European cicadas were studied. It turned out that the females are also singing. However, sound amplifiers are needed so that a person can hear their sounds.
Some representatives sing so loudly that the ear of a person cannot stand it. It perfectly protects 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 turns into 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 singing cicadas will open.
Lifestyle
What does cicada eat? Larvae live underground, where they feed on the juice of young plant roots. 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 a meal of insects, the juice continues to stand out. A droplet of nutrient fluid is formed. She freezes in the air. Manna - such droplets are called.
Thus, the habitat of song cicadas is a biotope with vegetation. Adults love to sing, sitting on trees and shrubs. Larvae live in the soil under the same woody plants. Song cicadas are common throughout the world.
Signs that you hear a cicada
How to distinguish cicada singing from orthoptera sounds? Cicadas take their trills usually in the afternoon, especially in the hot midday hours. The fact is that a lot of energy is needed for singing. This energy gives solar heat. Only a small number of representatives are awake at dusk. In this case, energy is generated through the work of the muscles that are commonly 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, the male trills it.
Life Cycle of Cicadas
The female makes an ovipositor hole in the bark of a fresh young twig of a tree or bush. Lays eggs in the recess. Larvae come out of them. At first, they can remain on the branches and eat the juices of the aerial parts of the plant. But then they necessarily fall to the ground and immediately begin to dig into the ground, where it is difficult to find them for consumers of insects. Enough moisture under the ground, cool, lots of food. Larvae have digging limbs. Young insects are looking for insects. Pierce the beak proboscis vegetation 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 an adult grows out of the larva. This is a long, not a 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, the pupal stage is absent.
Symbiosis with cicadas
Plant juice is basically a sweet carbohydrate liquid. Cicadas, like all animals, must receive protein to build their body. For this, in their body there are symbiotic fungi. Their colonies supply insects with protein.
The representative of central Russia
Mountain cicada (Cicadetta Montana) - the only representative living in central Europe. The rest of the real cicadas live south. Mountain cicada is smaller than its tropical relatives. The name "mountain" 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 singing of Australian green cicadas (Cyclochila australasias).
Creation of this, sitting on a tree, begins to sing. After some time, the remaining males living nearby join the "soloist". It turns out a whole choir. Usually one insect sings for several seconds or minutes. The invertebrate chorus continues to sing for a long time. So males attract females.
The singing of the green cicada is perceived as a continuous loud sound without changing the tonality. David Young, choosing an individual sitting alone, recorded a song on a tape recorder. Next, we analyzed the recording on the computer. It turned out that cicada singing is a lot of impulses. Moreover, the right and left instruments work in turn. The number of pulses was usually 230 and at times reached 4000 per second.
In the process of chirping, singing cicadas take a special stance. The male lifts the abdomen, while the wings diverge slightly to the sides.
Other representatives of the cicadas suborder
In addition to singing representatives, the cicadas include the families of the Cicadas, Gorbatki, and Pennitsa. They all have the same appearance. However, they also have hind limbs.
Cicadas are smaller than real cicadas. The front wings are dense, leathery. These creatures are very mobile, they fly better than cicadas of singers. Both larvae and adults live on grassy vegetation.
Humpbacks have curly outgrowths on the pronotum. Most diverse in South America.
Pennies are often brightly colored. Their front wings are dense. They jump perfectly, but in danger they fall to the ground, where it is more difficult to notice them. Pennant larvae have a special adaptation against drying out. They form a foamy mass around them, for which they got their name.
The larva secrete a special liquid - plant sap that is not absorbed by the body. The larva is inhabited by symbionts that secrete mucin. Mucin is added to the secretion. It provides fluid viscosity. The larva foams the juice of plants with mucin, releasing air bubbles into the mass from the spiracles and whipping it with quick movements of the legs. So she finds herself in her wet house. Penicidal cicadas live all over the world. In Madagascar, for example, drops of foam are falling from the trees - the release of cicadas, as if it was raining.
The attitude of people to cicadas
Among peoples, attitudes toward cicadas vary greatly. So, the Romans really did not like the crackling singing of these insects. The ancient Greeks respected cicadas, loved to listen to their music, and even depicted insects on coins. In Spain, cicadas are very fond of. You can always see souvenirs with the image of these creations on sale.
Nanotechnology
Psaltoda claripennis is a cicada whose wing surface is seated with microscopic needles. Such a surface kills bacteria falling on the wings. Scientists plan to use the discovery to create bactericidal materials.
Insects are interesting if you look closely at them carefully. 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 are distinguished by an unusual structure, are record holders among insects. Moreover, they are very beautiful. Anyone who has seen a mass exit of adult song cicadas from the last stage of a nymph larva will obviously not remain indifferent.