From June to July every year, pupae will become adults in just a few days, and then lay eggs. From the beginning of eggs to the process of nymphs living underground, until the last time they shell and become adults, they will make a scene in the trees. This period usually takes one to two years. Among them, in cicadas, their larvae are also called "nymphs". Their male cicada will make sounds to attract the female cicada to mate with him. It is inserting the ovipositor tube at the top into the tree to lay eggs.

The larvae will not hatch until the second year, and then they will live in the soil for several years or even more than ten years before they break out. In the long life, they have to go through many times of shelling, and once shelled, it will become an adult, and when they become adults, it will make a sound.

The sound made by the male cicada is a high frequency of hundreds of times per second, which constantly vibrates the two eardrums in the abdomen and makes a sharp and loud sound. This sound helps the female cicada locate the male cicada suitable for mating.

development by metamorphosis

Insects undergo several major changes in their external morphology and internal organs during their lifetime, which is called metamorphosis. Most insects, such as butterflies, mosquitoes, flies, bees and beetles, go through four stages: egg, larva, pupa and adult, which is called complete metamorphosis. There is also an incomplete metamorphosis, such as mantis, locust, cricket, cicada, psyllid, whitefly, aphid, scale insect and stinkbug. There are only three stages in life: egg, nymph and adult, and there is no pupal stage.

Larvae and adult are basically similar in morphology and living habits, but they are small in size, immature in sexual organs, and only have wing buds, which can't fly but can only jump. This kind of larva is called nymph, which gradually grows up after molting several times and directly develops into a winged and flying adult.

Refer to the above contents: Baidu Encyclopedia-nymph, Baidu Encyclopedia-cicada.