Before the African locust attacked, the edible and raw desert locust has spread all the way from East Africa to India and Pakistan, across the Himalayas to Yunnan Tiger. On March 2, China's State Forestry and Grassland Administration issued an emergency notice saying that although the risk of desert locusts invading China is low, once it occurs, there will be many uncertainties such as unknown laws, lack of monitoring technology, and difficulties in prevention and control.
Shi Wangpeng, director of the Department of Entomology at China Agricultural University, once said that compared with the grassland night moth, the desert locust has a wider diet, stronger mobility, greater reproduction, stronger adaptability and greater harm. If the two pests are superimposed, it will be a disaster for the planting industry.
A few days later, Pan Wenbo, director of the Department of PlantAtion Management of the Ministry of Agriculture and Rural Affairs, said at the spring production conference that according to monitoring, this year's grassland moth has a large source base, and the time for moving north should be earlier, which is expected to be a recurrence. This will lead to more than half of China's corn-growing areas (about 100 million mu, close to the area of Ningxia) facing serious threats.
Figure | On February 20, China's Ministry of Agriculture and Rural Affairs released the "National Grassland Nightcrawler Prevention and Control Plan" (source: official website)
In January 2019, the grassland nightcrawler invaded from Yunnan Province and subsequently spread in many parts of the country. Because it is an invasive alien species, it is difficult to prevent and control, and it has spread to most of China in only half a year. In September, data released by the Ministry of Agriculture and Rural Affairs showed that in 2019, the area of grassland night moth occurred in more than 15 million mu, and the actual harm area was 2.46 million mu.
At the time, it was believed that the main crop of the grass moth was corn, but signs of harm were later found on 17 other crops and 5 weeds.
Due to the fear of cold in the grasslands, the grassland moth has previously appeared mainly in the tropical regions of the Americas, and then accidentally came to the African continent through "smuggling", and the vast vegetation and hot climate of Africa, as well as the lack of natural enemies, make it breed rapidly. Then, riding the monsoon, it invaded India, Bangladesh and Sri Lanka step by step, and then to China.
Because of its fear of cold, it generally enters the dormant period of spawning in the winter and erupts in the spring and summer. This year, China is still a warm winter, creating a good large-scale spawning winter environment for the grassland nightcrawler, and after the first "test of water" in 2019, the first large-scale spawning colonization was achieved, and the size of the insect swarm is expected to be more than 100 times that of last year. Therefore, agricultural experts judged last year that there is almost no suspense in this year's large-scale outbreak of insect pests.
Figure | Meadow Moth (Source: Flicker)
Since its invasion of Yunnan in January last year, the grassland moth in the six provinces of southwest China and south China has bred for 1 to 2 generations after more than a year of breeding and incubation, and the accumulation base of insect sources is huge. Pan Wenbo recently said that the current initial area of insects is about 16 million mu, and the area of insects seen in 2019 is only 16 million mu. The data on February 10 was only 600,000 mu, which is equivalent to nearly 27 times more in a month's time.
In Laos, next door to Yunnan, the area of grassland moths has exceeded 1.12 million mu, and the source base of insects has also increased sharply year-on-year. Domestic and foreign insect sources are double superimposed.
Figure | Number of countries where the top 10 plant pests are located (Source: State of the World's Plants 2017)
The spodoptera frugiperda, also known as the "pseudo-armyworm" and "fall army worm", was originally an omnivorous agricultural pest distributed in the tropical Americas, especially the grass family, mainly corn and rice. It has been named one of the top ten plant pests in the world by the International Centre for Agricultural and Biological Sciences. Its harm is mainly reflected in:
Can be born. Single-headed females lay 100-200 eggs at a time, and the total number of eggs in a lifetime can reach about 1500. At a temperature of 11°C-30°C, it can reproduce normally, without diapause, and about 30 days is a generation;
Can eat. It is an omnivorous pest, with hosts covering 353 plants in 76 genera, especially preferring grass crops, such as corn, sugarcane, rice, sorghum, etc., and eating an amazing amount, an adult insect can eat fresh leaves close to its own weight;
Can fly. Adult grassland moths have high flight ability and will use wind power to move in a distance of several hundred meters. In the absence of wind, it can fly 50 kilometers a night, and if there is wind, 200-500 kilometers a night. Females can fly 500 kilometers before laying eggs, equivalent to the distance from Shanghai to Hefei, and can fly long distances across continents under the blessing of the monsoon;
Resistant. It has been "baptized" by various pesticides in North America, and the current grassland moth in the Americas has developed resistance to at least 29 pesticides. Pharmacological experiments have shown that the grassland moth has a high rate of resistance gene variation to traditional organophosphorus pesticides, organochlorine pesticides and pyrethroid pesticides. At present, there is no specific pesticide specifically targeted at the grassland night moth.
In the United States, Canada and some countries in South America, the cultivation of genetically modified corn is one of the main means of controlling the grassland night moth. However, at present, under the premise that the domestic planting has not been approved, it is still based on prevention and control, and at the same time, it is also actively developing pesticides.
The Ministry of Agriculture and Rural Affairs has issued four plans for the prevention and control of the grassland night moth. The Ministry of Finance has allocated 1.4 billion yuan of funds for agricultural production and water conservancy disaster relief, of which 490 million yuan has been arranged for the prevention and control of grassland moths. In addition, the Ministry of Agriculture and Rural Affairs issued the "Recommended List of Drugs for the Emergency Prevention and Control of the Grassland Nightcrawler", and the "Kale Noctus Karyo polyhedrovirus insecticide" jointly developed by the Wuhan Institute of Virology of the Chinese Academy of Sciences is listed.
Pork prices are just expected to fall, and grain is probably going to take over again.