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1: habits of cicadas: representative species of Cicadaceae. The male's abdomen has a sound generator, which can constantly make sharp sounds. The female doesn't make a sound, but she has a hearing device in her abdomen. Larvae will live in the soil, suck the roots of plants, and adults will eat the juice of plants. Cicada is an incomplete metamorphosis, from eggs and larvae to adults after several molts. Tongchan originated from Buddhism. Cicada larvae live in the soil and have a pair of powerful digging front legs. Sucking the sap from the roots of plants with mouthparts weakens the tree, makes the branches die and affects the growth of trees. Usually they will stay in the soil for several years or even more than ten years, such as three years, five years, and 17 years. These numbers are * * * similar, and they are all prime numbers. This is because there are few prime factors, which can prevent them from drilling out with other cicadas when they drill out of the soil, competing for territory and food.
2. Life cycle of cicadas: Actually, it is not said that cicadas can only live for seven days, and the longest life span of cicadas can reach about 70 days. Moreover, cicada is considered as the longest-lived insect in the world, and its life cycle is different in different places. For example, the life cycle of French cicadas is generally four years, while that of North American cicadas is as long as 17 years. The life span of cicadas in China is generally 3 to 7 years, and the life cycle of about half of cicadas is 5 years. As for why cicadas can only be seen in summer, it is because cicadas live in the soil for most of their life cycle before they break through the ground and become cicadas.