Is the cicada a beneficial insect or a pest? A detailed look at its diet and the effects and uses of cicada shells

The common cicada of the Cicadidae family is the cicada, commonly known as (zhiliao), jieliao, or jieluozi, chanhou, zhiliaohou, jieliaogui, and so on. Because dialects differ from place to place, the alternative names vary accordingly. So is the cicada a beneficial insect or a pest? What food does it like to eat? What effects and uses do the shells have?

1. What food do cicadas eat?

The cicada's food is mainly the sap of trees, along with the sap of crops and other plants. Whenever the cicada is singing loudly and is thirsty and hungry, it always uses its hard, sharp, slender mouthparts to pierce the tree trunk and suck sap all day long, drawing a large amount of nutrients and water into its body to prolong its life. At this time, various thirsty ants, flies, beetles and others come at the sound, all coming to suck the tree sap and the honeydew excreted by the cicada; the cicada then flies to another tree, opens another “spring,” and continues to feed on the plant's sap.

2. Is the cicada a beneficial insect or a pest?

The cicada is a pest.

Its larvae stay under the soil, sucking the sap from the roots of large trees. If there are many larvae sucking sap, then the large tree will slowly wither and die. The cicada's larvae will stay under the soil for as long as 3 years, until the adults emerge, shed their shells, and become cicadas.

The cicada uses the needle-like mouthparts below its head to insert into the branches and trunks of trees, piercing and sucking plant sap to sustain life. After mating, the female cicada also uses its spearhead-shaped ovipositor to insert into the xylem of young tender branches to lay eggs; each insertion makes a hole, and often many small holes are made in a single branch.

After the cicada lays eggs, it then uses its mouthparts to pierce a ring through the phloem at the lower part of the branch, so that the upper part of the branch cannot get water and nutrients, and finally it withers and dies; when the wind blows, the dead branch falls to the ground.

A few weeks later, the cicada dies after completing the task of reproducing. The eggs hatch into nymphs, which burrow into the soil and begin a long underground life. They live underground by absorbing the sap of tree roots, for as little as two or three years, or as many as seventeen years. After living underground long enough, they crawl out of the ground, then “the golden cicada sheds its shell” and emerges as an adult cicada.

The cicada's entire life is harmful to plants; it is a destroyer of trees. In the early 1960s, a cicada disaster occurred in South America, turning lush forests into clusters of withered, sallow branches and dead leaves. Later, a cicada-eating bird was introduced, and only then was the spread of the disaster brought under control.

Cicadas can be used as medicine, which is a useful aspect. Cicada slough is the shell shed by the nymph; it is cold in nature and sweet in taste, and has the effects of dispersing wind-heat, dispersing lung qi, promoting rash eruption, and relieving spasms; cicada flower is the club-shaped fungal body that grows on the corpse of a nymph killed by fungal parasitism, and has sedative and anticonvulsant functions.

If one weighs the merits and faults of the cicada, it should be said that the harm outweighs the benefits.

3. The effects and uses of cicada shells

1. The medicinal value of cicada shells

Cicada shell is a traditional Chinese medicinal material that is sweet and salty in taste and cold and cool in nature. It can enter the lung and liver meridians. Dispersing wind-heat, soothing the throat and opening the voice, promoting rash eruption, and improving eyesight are its main effects. It can treat many diseases in humans such as colds, warm diseases, hoarseness, unerupted measles, and tetanus. Its medicinal value is particularly high, and its therapeutic effects are very obvious.

2. Cicada shells can clear the throat and moisten the voice

Cicada shells can disperse wind and clear heat, and can also clear the throat and moisten the voice. They have obvious therapeutic effects on many common diseases with high incidence in humans, such as pharyngitis, sore throat, and hoarseness. In ordinary treatment, an appropriate amount of cicada shells can be decocted together with Chinese medicinal materials such as honeysuckle, great burdock fruit, and mint, and then taken.

3. Cicada shells can relieve pain and itching

Cicada shells are also a traditional Chinese medicinal material that can relieve pain and itching. They can be used to treat various skin diseases in humans. During treatment, cicada shells can be decocted together with Chinese medicinal materials such as schizonepeta, saposhnikovia root, and sophora root for internal use, or the cicada shells can be ground into powder and applied directly to the affected skin area, which can quickly reduce the symptoms of pain and itching.