Locusts are so hateful, can they be exterminated?

Produced by: Science Popularization China

Author: Xiao Xiaobo (popular science creator)

Producer: China Science Expo

As we all know, locusts are very common agricultural pests, widely distributed in all continents of the world (except Antarctica), and more than 10,000 species have been recorded worldwide. There are about 500 species of locusts that can cause damage to pastures and crops, of which about 50 species are considered major pests.

When the climate is suitable, locusts will reproduce in large numbers and gather to form huge populations. Large-scale outbreaks of locusts will cause locust plagues. In my country's history, locust plagues have been called the "three major natural disasters" together with floods and droughts.

Plague of locusts

(Photo source: veer photo gallery)

So what exactly do locusts have to be able to become one of the three major natural disasters?

On the one hand, locusts have a very wide diet. They feed on common crops such as wheat, corn, sorghum and rice, and also cause damage to crops such as cotton, soybeans and vegetables. Large swarms of locusts will quickly devour crops and crops in farmland, causing crop yields to decrease or even completely destroy them, seriously affecting farmers' livelihoods and human food supply.

In history, locust plagues have had a significant impact on human food security many times. For example, the "Book of the Later Han Dynasty: Records of the Five Elements" once recorded that "In the 15th year of Yongping in the reign of Emperor Ming of the Later Han Dynasty, locusts rose from Mount Tai and spread across Yan and Yu. Yuzhang was hit by locusts, and the crops failed, and the people starved to death." Bai Juyi, a famous realist poet in the Tang Dynasty, also wrote: "After the Xingyuan War, the yin and yang were damaged, and the harmonious qi was poisonous and turned into locusts. They started from the two rivers and the three auxiliary provinces, and the food was provided like flying silkworms and rain. The rain flew and the silkworms ate for thousands of miles, leaving no green seedlings but only red soil." From these historical records, we can see the significant harm that the locust plague caused to human food security at that time.

Nowadays, we are often threatened by locust plagues. In 2014, 3,000 mu of the Yellow River beach in Henan, my country, was hit by a locust plague. Wherever the locusts passed, large tracts of corn fields were eaten up and only the stalks were left. Even with the timely implementation of measures such as large-scale spraying of pesticides, huge losses still occurred. In 2022, the Food and Agriculture Organization of the United Nations issued a warning regarding the current African desert locust plague that has attracted worldwide attention: if it is not controlled, the locust plague will threaten the food security of 19 million people. It can be seen that controlling locust plagues to ensure human food security is a challenging task worldwide.

On the other hand, locust plagues can cause serious damage to the ecosystem. Locusts devour vegetation, leading to vegetation reduction, increased soil erosion, water pollution, and disruption of ecological balance. This will have a negative impact on the survival and reproduction of other animal and plant populations, and may even lead to the extinction of other species.

Harvesting crops

(Photo source: veer photo gallery)

Therefore, locust plagues can cause serious harm to agriculture, economy, society and ecosystems. Many countries and regions are taking measures to monitor the number and location of locusts in order to prevent and reduce losses caused by locust plagues.

Since locusts are so hateful and modern science and technology are very advanced, would everything be fine if the locust species were completely exterminated?

To answer this question, we need to understand the role locusts play in human society and the entire ecosystem.

In human society, there are many areas engaged in locust trading, and locusts are creatures that many people depend on for survival.

Locusts are rich in protein and are considered a nutritious food. Eating locusts has been around since ancient times. The Qing Dynasty book "Records of Catching Locusts at Liuyun Pavilion" records that "the locusts that fly in the sky and cover the sun have both fat and meat. Remove their wings and legs, dry them, and they taste like dried shrimps. They can be stored for a long time without spoiling. People in the north often eat them with wine." Nowadays, the food culture is more open. In areas where insect food is more accepted, locusts are regarded as a food resource and are used for eating or making food.

In some areas, locust trading is still carried out to meet the needs of the breeding industry. The agricultural book "Complete Methods of Locust Control" also mentioned: "Locusts can be fed to ducks and pigs. Some people in the mountains raise pigs and feed them with locusts. The pigs initially weigh 20 kilograms. After eating locusts for ten days, they suddenly grow to more than 50 kilograms in weight." This shows that locusts are also excellent feed and can be used to feed poultry and livestock.

In addition, locusts have a huge appetite and produce a lot of feces, which can be used as organic fertilizer. The agricultural books "Catching Locusts" and "Treatment of Locusts" written in the Qing Dynasty both record that locust feces and themselves are excellent fertilizers that can be used to fertilize the land.

Therefore, the extinction of locusts is likely to cause losses to the economy and social life of regions engaged in locust breeding and trading. They will no longer be able to rely on locusts as food and other resources, and may face economic difficulties.

locust

(Photo source: veer photo gallery)

In the ecosystem, locusts have a complex food chain relationship in nature.

Locusts are an important intermediate link in the food chain between herbivores and predators. They feed on plants and can control plant growth. Locusts themselves are also one of the main food sources for many animals (such as carnivorous insects, birds and reptiles). If locusts become extinct, it may lead to a sharp decline in the number of some species that feed on locusts, or even species extinction.

In addition to the food chain, locusts also have important impacts on other aspects of the soil and ecosystem. For example, a large number of locusts often lay eggs in the soil, leaving behind excrement and dead insect bodies, which can promote soil fertility and increase biodiversity. After the locusts become extinct, the soil lacking locust excrement and corpses will experience nutritional imbalance and reduced biodiversity.

In addition, as a "well-known" agricultural pest, locusts will form a competitive relationship with various other agricultural pests with the same feeding habits . After the extinction of locusts, other types of crop pests may reproduce in large numbers due to the lack of strong competitors, thereby causing more serious damage to crops, resulting in reduced crop yields and reduced farmers' income.

Considering these possible consequences, completely eradicating locusts could have huge negative consequences . Therefore, it is very important to maintain the contribution of locust species to human society and ecosystems, and we should take measures to prevent and mitigate the damage of locust plagues and effectively manage the number and distribution of locust species.

References:

【1】Guo Fu. Biology of Chinese migratory locust[M]. Shandong Science and Technology Press, 1991.

【2】Kang Le, Wei Liya. 60 years of locust research in China[J]. Acta Phytophylacica Sinica, 2022, 49(01): 4-16.