Locusts have historically been a major pest for crops in China, with records of locust plagues dating back to 707 BC during the reign of King Ping of Zhou. From that time until 1949, over 300 significant locust plagues were recorded. For instance, a 1927 locust plague in Shandong displaced seven million people who fled in search of food. The 1943 locust disaster in Huanghua, Hebei Province, not only resulted in the consumption of reeds and crops but even led to the eating of the paper used on the windows of farmers’ homes. The threat of locust plagues to agriculture and people’s lives has been substantial, historically described with phrases such as “obscuring the sun,” “covering mountains and fields,” “thousands of miles of red land,” “leaving no grass behind,” and “starved bodies littering the roads.” In the past, locust plagues were an unsolvable problem for agriculture in northern China for thousands of years.
Locusts typically have two generations per year, with the first called the summer locusts and the second the autumn locusts. In dry climates during summer and fall, a third generation may occur; however, in regions like Northwest China, Xinjiang, and Inner Mongolia, only one generation occurs annually. Locusts exhibit gregarious and migratory behaviors, preferring to lay eggs in lake beaches, grass roots, or reeds to overwinter. Thus, during dry years when water levels drop, exposed lake and river beds provide ideal breeding conditions for locust eggs. Conversely, if the fall is rainy and water levels rise, summer locust eggs are submerged, preventing breeding, and autumn locusts find no suitable places to lay eggs, reducing the likelihood of a significant outbreak the following summer. Due to the frequent rains in southern China, conditions are unfavorable for the growth, development, and reproduction of locusts, hence locust plagues are historically rare there. In contrast, the drier climate of the north has made it more prone to locust disasters.
In recent years, humanity has made significant progress in combating locusts, not only through basic measures such as water conservation and land reclamation to eliminate breeding grounds but also through mass locust control campaigns using advanced methods like aerial spraying of the insecticide “666.” These efforts have fundamentally controlled locust populations, preventing them from causing disasters. However, to completely eradicate locust plagues, continuous efforts are still necessary.