On 11 February, the Food and Agriculture Organization of the United Nations (FAO) issued a global warning to the world on high alert for the ongoing locust plague, which threatens to cause famine if it expands further.
According to reports, the locust plague began in Yemen, after which part of it crossed the sea into East Africa, and part of it reached Pakistan and India in Asia, just a step away from China. At present, many countries and regions in Africa, the Middle East and the South Asian subcontinent have entered a state of emergency.
Locusts migrate with the wind and can move as fast as 150 kilometers in a day. Locusts emerged in East Africa around December 2019, and by February this year, countries including Djibouti, Ethiopia, Kenya, Somalia, South Sudan, Sudan, and Uganda began to suffer a serious locust threat, destroying tens of thousands of hectares of farmland. After the farmland was nibbled clean, it was followed by famine. FAO has previously warned that the locusts are "unprecedented in scale and destructive" and could leave millions of people without food. According to the latest United Nations data, an estimated 24 million people are already facing food shortages, with 8 million people in need of food assistance in Ethiopia alone.
Locust plagues have never ceased in human history. Around the world, many countries have been hit by locust plagues.
China has been a country with frequent locust plagues since ancient times, and Zhu Di, the ancestor of Ming Cheng, issued the "Locust Hunting Order", requiring all localities to hunt and kill locusts. Xu Guangqi, an agronomist of the Ming Dynasty, once said that "only drought is extreme and locusts, and in thousands of miles, the grass and trees are exhausted, or cattle or hairs, and the banners are exhausted, and the harm is especially worse than the water and drought", and summarized many methods of locust extermination in his book "The Complete Book of Agricultural Politics". After the founding of New China, with the improvement of economic and scientific and technological strength, the impact of locusts on agriculture has been decreasing day by day, and only small-scale hidden dangers of East Asian flying locusts have occurred in recent years, and they have been quickly extinguished.
Locusts include several types. (1) Flying locusts. Crop damage is the worst. There are two subspecies distributed in China, namely the East Asian Flying Locust and the Asian Flying Locust. It is represented by the East Asian flying locust, which is the most widely distributed and the most harmful. Flying locusts are mainly distributed in Hebei, Shandong, Henan, Jiangsu, Anhui, Xinjiang and Taiwan. It harms crops such as corn, wheat, millet, millet, sorghum, rice, as well as grasses such as reed grass and red grass, and also eats beans, tobacco, cotton, hemp, and even the branches and leaves of trees when hungry and thirsty.
(2) Great green locust. Also known as cotton locust. Distributed in North China, East China, South China, Central China, Shaanxi, Sichuan and other regions. Harmful to cotton, sugarcane, beans, etc.
(3) Jump Hachijo. Also known as the curved-backed locust. It is distributed in northeast China, Hebei, Shandong, Shanxi, Inner Mongolia, Northwest China and other regions. It mainly harms millet, millet, corn, sorghum and other grass crops and grass weeds.
(4) Short-winged locust. It is distributed in Northeast China, North China, Inner Mongolia, Northwest China, East China, Central South China, Guangdong, Sichuan and other regions. Harmful to legumes, potatoes, quinoa, millet, corn, millet, flax, sweet tea, wheat, sorghum, melons, sweet potatoes and a variety of Asteraceae plants.
(5) Asian car locust. It is distributed in the mountainous areas of the northern part of Gansu, Qinghai, Inner Mongolia, Hebei and Shanxi Provinces, and sporadically in the Taihang Mountains and Zhongtiao Mountains. It harms millet, millet, corn, wheat, sorghum and other grass crops. (6) Yellow shin trolley locust. It is distributed in Northeast China, Inner Mongolia, Shandong, Shanxi, Shaanxi, Gansu, Jiangsu, Anhui, Jiangxi and other provinces and regions. It mainly harms millet, millet, corn, yarrow, sorghum and other grass crops.
(7) Large pad pointed winged locust. It is distributed in North China, Northwest China, Northeast China, Inner Mongolia, Jiangsu and other regions. In summer, it mainly harms corn, sorghum, millet and other grass crops, alfalfa, soybeans, and weeds of grasses, asteraceae, legumes, and quinoa. Autumn harms wheat seedlings in winter wheat areas, the most severe harm in Hebei, Henan, Shandong, Shanxi and northern Jiangsu, and in inner Mongolia and the northern part of Shanxi and Hebei provinces.
(8) Spotted cane locust. It is found in most of the southeast. In the southern provinces, it mainly harms grass crops such as rice and sugarcane. (9) Moment negative locust. It is found in Shandong, Shanxi, Shaanxi, Northeast China and South China. Harmful to cotton, beans, hemp, sugarcane, potatoes, sesame, castor, hemp, green hemp, tobacco, vegetables and other crops.
(10) Chinese rice locust. It is distributed in North China, East China, South China, Southwest China, Northwest China and other regions. It mainly harms rice, land rice, corn, sorghum, sugarcane and reed grass. (11) Small-winged chicks. It is found in Inner Mongolia, Shanxi, Qinghai, Hebei, Gansu and Xinjiang. It mainly harms grass crops such as cherbear, wheat and millet and grass weeds. (12) Stupid locusts. It is found in North China, Inner Mongolia, Anhui, Jiangsu and Zhejiang. Sweet potatoes, potatoes, wheat, barley, maize, sorghum, millet, taro, mung beans, cowpeas, peas, cotton, vegetables, melons and even seedlings of trees are also affected.
Prevention and control methods (1) Fluttering. A primitive method of locust control. People fight in circles with tools or dig trenches to destroy locusts. (2) Drug prevention and treatment. The use of sodium fluorosilicate, hexas6, sodium arsenite to prepare poison bait, or the application of six six, sodium cyanide and other poisons, can receive a good locust control effect. However, due to the harm caused by these drugs to humans and animals and ecological legacy, they have been rarely used. (3) Prevention and control of natural enemies. Flocks of chickens and ducks are used to exterminate locusts. A chicken can eat 1,500 locusts a day, which can both kill locusts and increase the income of farmers and herders. The grassland attracts pink bright birds to kill locusts, and has formed a scale. (4) Biological control. Based on the theories such as the prevalence of locust microsporidium disease in locust populations, countermeasures and technical systems suitable for the continuous management of locust plagues in different locust areas were developed. At a certain scale, it not only protects the environment, but also saves costs. Green zombie is a biological control agent of locusts, which is used in areas near water sources and on farms and pastures where organic agricultural products are produced. (5) Transform locust breeding grounds. Transforming the locust suitable base and eliminating the source of insects can effectively control locust infestation.
China's Yellow River, Huaihe River Ancient Road was once the main occurrence area of locusts, in the drought year, the river beach, lake beach is exposed, forming a very favorite spawning place of locusts, so that locusts overwinter to lay high eggs, population density rose sharply. In the 1950s and 1960s, scientists combined the treatment of the Yellow River, Huaihe River and Haihe River to transform most of the locust areas, so that the area of locust areas was greatly reduced, and the population density was controlled at a low level for a long time.
Research and diffusion of biological control technologies worldwide is also intensifying.
For example, locust microsporidium biological preparations have been commercialized production, locust microsporidium is a protozoa parasitic in the body of locusts, harmless to natural enemies, no pollution to the environment, while having a continuous control effect, that is, a single application, no need for control for many years. The use of locust chemical pheromones such as East Asian locust aggregation pheromones, spawning pheromones, etc., to regulate the east Asian locust aggregation behavior has also achieved remarkable results, no aggregation, no "mutation", can reduce the occurrence of locusts.
In addition, some areas will also adopt the method of herding chickens to control locusts, herding ducks to control locusts, or introducing natural enemies of locusts. These methods also have an inhibitory effect on small-scale locust infestations.