Why do cicadas like to sing loudly and scream at the top of their lungs? Fabres, a famous French entomologist, was puzzled. He lived for more than 90 years, devoted his whole life to the study of entomology, and wrote a collection of 654.38+100,000 words of research papers-Insects. He has observed and studied cicadas for many years and made a vivid and detailed description. He described the cicada's singing like this: "In the cavity behind the cicada's wings, there is a cymbal-like instrument. It is not satisfied, but also put a castanet on its chest to enhance the intensity of the sound. This cicada really made great sacrifices to satisfy her love of music. Because of this huge castanet, living organs have nowhere to put, so they have to be pressed to the smallest corner. Shrinking the internal organs for placing musical instruments is of course very enthusiastic about music. " However, in order to find out why the cicada sings endlessly with the cymbals on its "belly", did Fabres deliberately raise his "voice" because he didn't hear his loud voice at all, fearing that others wouldn't hear him so clearly? So, he did an experiment to verify whether the male cicada could hear the sound. He stood behind the male cicada, talking loudly at close range, blowing his whistle hard, slapping his face, throwing stones at him ... and scaring the cicada with all kinds of noises. But cicadas continue to sing indifferently. I really turned a deaf ear to what was behind me and only sang one song. Later, fabrice simply found two muskets to shoot wild animals, which were filled with gunpowder and fired again and again beside the cicada. The voice was thunderous, but the "singers" sang leisurely without even showing any fear or anxiety. So Fabres concluded that the male cicada had no hearing. He couldn't hear any sound around him, even his own screams. He is really deaf. Is the male cicada deaf? This is the first mystery about cicadas. Fabres's conclusion has been widely accepted 100 years. Until 1980s, the part about cicada in primary school Chinese textbooks still followed Fabres's view that cicada was deaf. However, more than 100 years ago, it was always thought that male cicadas could hear sounds. And gave the male cicada the reputation of "master of music". Even now, the harp in the world is decorated with cicadas as a symbol. There is also an allusion here: According to legend, there were two famous music masters in ancient Greece, Arnold Moss and aristocrats. On this day, two ancient artists held a national harp championship in Athens. In terms of harp playing skills, Ionomos is slightly better than Aristotle. Unexpectedly, Ionomos was playing a wonderful exciting moment when the strings of the harp suddenly broke. At this urgent moment, it happened that a cicada flew in and continued the sound of the piano. Violet had to push the boat with the current, simulate the chirping of cicadas and pretend to play. Because the simulation is too realistic, it is difficult to distinguish between true and false. Violet won the game. To thank the cicada for its "salvation", Arnold Moss decorated the cicada on the harp as a symbol. Of course, this is only a legend, but it reflects people's views on cicada's hearing. If cicada is deaf, how can it fly in time to save the scene? In recent years, many entomologists have expressed doubts about the conclusion that cicadas are deaf. The male cicada has a highly developed sound generator, which can emit annoying high notes. The chirping of small and medium-sized cicadas can generally reach 80-90 decibels, and that of large cicadas can reach 100- 130 decibels. An Sinian horse cicada in Emei Mountain, Sichuan, China, its group singing resounded through the whole valley, which was deafening and unbearable. Why does cicada cry so hard? The purpose is to attract distant females to mate and reproduce. However, the female cicada's vocal organs have degenerated, and she can only hear the invitation of the male cicada, but she is silent. This means that there is no "duet" between "lovers", and the communication between them is one-way. Therefore, when male cicadas sing, they must be able to hear their own calls, so that they can know how to sing and constantly correct their calls, so as to attract female cicadas more effectively. After dissection, entomologists found that there was a slightly protruding auditory sac at the outer edge of the ventricle (left and right sides of the second abdominal segment) of cicada, and there were about 1500 auditory units in the cavity. When external sound waves excite the vibration of the auditory membrane, auditory nerve cells are excited, and their nerve impulses are introduced into the auditory pathway of the brain along the auditory nerve, resulting in corresponding auditory feelings. Although the auditory membrane of female cicada is smaller than that of male cicada of the same species, the auditory ridge is obviously larger, and the auditory ridge is more sensitive to sound than the auditory membrane. So it is proved that the male cicada is not deaf, but her hearing is not as good as that of the female cicada. However, scientists found that the sound of male cicada was caused by the contraction of the first and second ventral node generators, which affected the forced vibration of the membranes on both sides respectively. The tympanic cavity formed by the back flap (i.e. the "tympanic cover") covering the vocal membrane, the two ventral flaps (i.e. the "acoustic cover") and the left and right ventricles below all have the function of tuning and amplifying sound, while the upper half of the inner wall of the ventricle is an approximately white pleated membrane, and the lower half is an inwardly inclined approximately translucent auditory membrane, which is as bright as a mirror, so it is called "mirror membrane". The pleated membrane, the mirror membrane and the abdominal membrane of the male cicada are the auditory membrane for receiving sound waves and the radiation membrane for singing, which is equivalent to the single card recorder we use. It is dual-purpose and can record and play. Single card recorder can't use two functions at the same time, it can't be played back when recording, and it can't be recorded when playing back. Therefore, some scientists believe that the male cicada is "semi-deaf", that is, he can hear the sound when he is still, but he can't hear any sound when he calls loudly. Then the problem came up again. In fact, many kinds of cicadas have the habit of singing in chorus. You might as well listen carefully. Cicada sings like this: First, everyone calls together in a neat rhythm, and then they stop together. It can be seen that when male cicadas sing, they obviously need to hear other similar songs in order to adjust their songs and participate in the chorus. In this way, it is incomprehensible to say that the mirror membrane of a male cicada is both an auditory membrane and a loudspeaker membrane. It seems that whether the male cicada is deaf or not needs further discussion. Must the female cicada be dumb? This is the second riddle of cicada. On the surface, all the captured females can't sing, so people call them "dumb girls". Judging from the above, the mirror membrane of the male cicada has the functions of receiving and amplifying at the same time, so when it sings, the mirror membrane is amplifying, and it is inevitable that it will not hear its own song. In this way, the female cicada can't talk, and the male cicada can't hear what it is calling. Isn't this what happens when male cicadas bark blindly? How can this make a distant female cicada find her "boyfriend" accurately? Some scientists believe that when a male cicada cries in despair, it can summon a female cicada from Fiona Fang 1000 territory. When the female cicada flies to a close distance, the male cicada constantly emits a unique low-volume "courtship sound" to attract the female cicada to approach. At the same time, female cicadas can also make low-volume responses. Only by getting to know each other can we achieve the purpose of mating. It's just that the female cicada's low-volume infrasound can't be heard by human ears. However, whether they really "talk" at a low volume is still a mystery. How do cicadas time? This is the third riddle of cicada. After mating between male and female cicadas, the male cicada quickly aged and fell to the ground and died, leaving the female cicada behind. The female cicada uses a pointed ovipositor to make a small hole in the twig and lay eggs on the wood of the tree. At the lower end of the twig, she also pierced a circle of phloem with her mouth, which cut off the supply of water and nutrients to the twig and the twig gradually died. In this way, the branches with eggs are easily blown to the ground by the wind, so that the hatched cicadas (called larvae) can get into the soil. The eggs laid by cicadas hatch into young cicadas after half a month. Cicada has a very long life. The shortest is to live underground for 2-3 years, usually 4-5 years, and the longest is 17 years. Young cicadas live underground for a long time, which is warm in winter and cool in summer. There are few threats from natural enemies, but they are also very comfortable. After molting for 4-5 times, they have to drill out of the ground, climb the branches, and molt in turn (called cicada molting) to become adults. What puzzles entomologists is that cicadas can accurately determine the time, complete the transition from larvae to adults in "hell" and climb out of the ground at the right time. This is an incredible miracle. Especially in 17, cicadas never existed again. To be precise, they lived in the "hell" in 17, and the light of the day was revealed. Depending on its children, it must be 17 years again. Therefore, entomologists always wait for the appearance of "17 cicada" just like astronomers wait for solar eclipse and Halley's comet. The baby cicada is in the dark underground, and can't see the sunrise or sunset, and there is no winter or heat. How do they measure time? This is a big unsolved mystery in the scientific community. PS: People from all ages are speculating. What do you think is the secret of strangeness? What's the scoop? "What you know is what you know, and what you don't know is what you don't know." Confucius also taught you. In the voice of "knowing", life is gone, but it lives clearly! What it says is seeking truth from facts! Seriously study and implement Theory of Three Represents, be realistic and pragmatic, and work hard to build a harmonious society! I don't know what Comrade xuchu 1222 said, "Why are cicadas called in summer?" ? "You know what? If you don't know, please continue to look for questions you don't know but want to know in Baidu's knowledge list! All right. I won't keep shouting "know know know". Ask Baidu if you have any questions, I know! References:

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