How terrible is the locust plague?

Among all insects, locusts are one of the most serious disasters to us. Although the locusts we usually see are so honest. And those swarming migratory locusts from far away places will bring us serious disasters. Whenever locusts erupt in groups, it indicates that a deep disaster is coming.

Almost all arid grasslands and deserts will have migratory locusts. They are in different areas, and there will be different kinds. In China, there are mainly oriental migratory locusts, and in Africa there are red locusts, African migratory locusts and desert locusts. All these kinds of locusts will form large-scale migratory communities from time to time. If a swarm of locusts cross the border, the crops and grasslands there will be destroyed by them. Because every appearance will bring great disaster, locusts have always been the object of people's interest and fear. When swarms of locusts come, they cover the sky like dark clouds. It will make a loud whirring sound.

There are records about locust plague in China ancient books and the Western Bible. 1957, a locust plague occurred in Somalia, Africa. It is estimated that there were about16 billion locusts in this locust plague, with a total weight of 50,000 tons. Locusts eat food equivalent to their own weight every day, which means that these locusts eat more than 50 thousand tons of green plants every day, which shows how big the disaster caused by this locust disaster is! According to China's "History of the Yuan Dynasty", in the 19th year of the Yuan Dynasty (A.D. 1359), "In May, in Shandong, Hebei, Henan, Guanzhong and other places, locusts flew all over the sky, and people could not walk, and the gullies were flat. In August, locusts flew from Hebei to Bianliang and ate in Tian He." What a terrible disaster this is!

Before liberation, there were frequent locust plagues in China. /kloc-a locust plague in 0/929 destroyed more than 360 million mu of crops and lost more than 1000 million silver dollars. In the same year, in Xiashu Town, east of Nanjing, locusts covered the railway tracks, which made the train unable to move forward and delayed for two hours. What's more, in 1938, Kuomintang planes bombed the Yellow River levee at Huayuankou, Zhengzhou, causing the Yellow River to burst, and ten million mu of fertile land became wasteland and a breeding ground for locusts. Since the early 1940s, there have been locust plagues every year, which have caused millions of people to be displaced and suffer. Among the farmers in this area, there is a saying that "a four-toothed mule and horse can't feed a two-toothed grasshopper."

The most peculiar feature of migratory locusts is that they have two different forms. That is, social (also called migratory) locusts and scattered locusts.

Although these two kinds of locusts belong to the same species, their appearance and habits are completely different. The members of social locusts are long and thin, dark, with orange or yellow stripes and large wings. They have strong social skills and a strong desire to gather to form a large group. The color of scattered locusts is very light, and other physical characteristics are very different from those of social locusts.

These two kinds of locusts are so different that they are considered as two different species for a long time. However, after careful study by Russian scientist Valov in the 1920s, it was found that the two kinds of locusts were genetically identical. As for what adults will look like, it is determined by their growth conditions, and a key factor is the population density of locusts. If only a few locusts are kept in a big cage during the growing period, they will become scattered locusts. However, if many of the same small locusts are squeezed into a small cage, they will develop into swarming migratory locusts!

The eggs laid by migratory locusts may hatch the same small locusts or smaller light-colored locusts. The latter has the habit of dispersion and does not show any desire to gather in groups.

In nature, scattered locusts are widely distributed. If there happen to be a large number of locust eggs, and these eggs are laid in a place where there is enough food next spring, then the hatched locusts may form a large migratory group. For these locusts, the most reliable food source is the reed field along the river valley, from which many migratory locusts "broke out". However, in arid hilly areas, sometimes plants beneficial to locusts grow because of heavy rain, which may also lead to a "big outbreak" of locusts in this area, which is how desert locusts in North Africa are produced.

How do locusts lay eggs? And how do small locusts get together? Locust eggs are laid in the soil. When female locusts lay eggs, they often insert their abdomen and tail into the ground to form a small pit, thus laying eggs in the soil. Small locusts (also called locusts) have no wings when they first hatch. They only walk on the ground. They tend to gather in small groups and then hunt together, so that they gather more and more. When two small groups meet, they will get together to form a big group. In this way, the locust swarm will gather more and more, and the scale will become larger and larger. In the process of gathering in groups, small locusts gradually develop into migrating adults. When their wings grow after the last molting, small locusts begin to fly short distances. Every time they stop, they will greedily eat the plants where they stop. In this way, a swarm of locusts can eat up crops in a field in a few minutes, or even a wet dress hanging on the clothesline in a few seconds. At this stage, when locusts swallow a lot of food and use these foods to accumulate fat, the disaster they caused to human beings reached a climax. If small locusts can't get together, they will develop into scattered locusts, which may not be as harmful as social locusts!

When locusts breed, they begin their last long flight. This time, they are not looking for food, because at this time, their bodies have been filled with fat and their stomachs have been greatly elongated. At this time, the motive force of locust migration seems to be generated inside their bodies, which may also be related to sexual maturity. Anyway, once a swarm of locusts comes out, they will keep flying until they run out of energy or some very unfavorable weather conditions force them to land. Locusts have no expected flight direction, they just drift with the wind. Some locusts will fly to the sea to commit suicide. Others end up living in the wildest desert or the thickest forest. If locusts fly in the direction of departure, they may fly for three days and three nights, and the distance can reach hundreds of kilometers. If they happen to meet something edible when they land, they will continue to eat there, then lay eggs underground, and then the adults will spread out and die.

What will happen next year? It depends on what happens to the larvae when they are born. If there is enough food and the density of eggs is high, then the density of larvae is high, which may produce new migratory groups. But it is common that due to the aimless flight of locusts, their eggs will also encounter some extremely unfavorable conditions, at that time, only scattered larvae will hatch and develop into scattered locusts. Although locusts are harmful to human beings, they are much less harmful than those migratory locusts!

The locust is so harmful, what methods can we use to prevent its harm? When locusts "break out", we can use chemical pesticides to kill them, but this effect is not good. Because, although many locusts have been killed in this way, locusts will often occur in the coming year, and locusts will also develop drug resistance and resist the killing of chemical agents. Drugs can also do harm to the environment. The best way to deal with migratory locusts is to predict and prevent them. According to geography, climate and other factors, scientists can predict where locusts may "explode", and then by transforming the environment there and combining chemical killing, the harm of locusts can be eradicated. In the early days of the People's Republic of China, there were several locust plagues. Later, through the research of scientists, the Party and the government led the masses to adopt the policy of "combining reform with governance" and achieved good results in preventing locust invasion. There has never been a locust plague in China since 1952.

In addition to the migratory locusts we introduced, there are many kinds of scattered locusts living in deserts all over the world. They all feed on green plants and are also the food of many desert animals. Most desert locusts are very similar in color to the environment. For example, there is a locust in the Gobi desert in northwest China. Their body colors and patterns are exactly the same as the local red sandstone ground. If they don't move, it's hard to find them even if they come.