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In January of this year, an alien species called the meadow moth invaded our country:
(Yunnan)
After that, insects appeared in various places, and the spread of spread was significantly accelerated:
(Guangxi)
(Guizhou)
(Guangdong)
(Sichuan)
……
Up to now (May 24), the area of occurrence involves 385 counties (cities and districts) in 14 provinces, autonomous regions and cities, including Yunnan, Guangxi, Guizhou, Guangdong, Hunan, Hainan, Fujian, Zhejiang, Hubei, Sichuan, Jiangxi, Chongqing, Henan and Anhui.
Now it seems that its spread rate is unexpected!
Draw the point
What is the Meadow Moth?
What impact does it have on agriculture?
What is the grass moth?
The meadow moth is an insect of the genus Nocturnal grey-winged moth in the family Lepidoptera, native to tropical and subtropical regions of the Americas. It was first discovered in Africa in January 2016 and spanned 44 countries and territories in a two-year period, causing billions of dollars in damage. In August 2018, the Food and Agriculture Organization of the United Nations issued a global alert.
The grassland nightcrawler has the characteristics of extensive host, fast diffusion speed, wide range of impact and harm, and strong reproductive ability. Specifically, it has the following characteristics:
Can eat
The grassland nocturnal moth is an omnivorous pest with a wide range of host plants, but a distinct appetite for grasses. It is most commonly harmful to weeds, corn, rice, sorghum, sugarcane, but also to cotton, cruciferous family, cucurbitaceae, peanuts, alfalfa, onions, beans, sweet potatoes, tomatoes and other solanaceae plants (solanum, tobacco, pepper genus), a variety of ornamental phases (Asteraceae, carnations, geranium genus) and other up to more than 80 species of plants.
Can be born
The grassland moth has a strong reproductive ability, a female moth can lay 900-1000 eggs in a lifetime, and up to 2000 eggs. And its growth cycle is particularly short, each egg only takes 2-3 weeks to grow up and have a baby.
Can fly
Strong flight migration ability, nicknamed "marching insect", can fly 100 kilometers a night, and adult insects can migrate 500 kilometers before laying eggs. It has been reported that adult grassland moths can migrate from Mississippi in the United States to southern Canada in 30 hours, covering a distance of 1600 kilometers.
Adaptable
In addition, the grassland moth has a wide range of suitable growth, from 11-30 degrees Celsius, which is its suitable temperature.
What is its harm?
Extremely destructive
The grassland moth can harm more than 80 species of plants, especially corn, rice, wheat, sorghum and other food crops. It is understood that the larvae can cause leaf fall by eating the leaves, and sometimes a large number of larvae harm by cutting the roots, cutting off the stems of seedlings and young plants, causing great losses. Older larvae, like root-cutters, cut off 30-day-old seedlings along the base. Take corn as an example, the corn seedling stage victims can generally reduce the yield by 10-25%, serious damage to the field can cause the destruction of seeds and harvests, is one of the world's top ten plant pests.
Scale fast
The grassland night moth is a migratory pest that has previously ravaged the Americas and Africa, causing serious harm to local agricultural production. After the pest was introduced to Africa in early 2016, as of January 2018, almost all 44 Sub-Saharan African countries had fallen, severely affecting local maize production. In the 12 maize-growing countries in Africa that have been invaded alone, the grassland moth hazard has reportedly reduced annual maize production by 8.3-20.6 million tonnes and economic losses of up to US$2.48-6.19 billion.
China's neighboring countries have basically occurred, and the geographical range of overseas insect sources is wide and the population is huge. With the southwest monsoon, starting from mid-May, overseas insect sources and adult insects that colonize and breed in Yunnan, Guangxi and other regions of China can be further migrated and expanded to the Yangtze River and Jiangzun River Basin, and from June to July, they can continue to move north to Huanghuai, North China and even Northeast and Northwest China, and the insect situation is in danger of spreading. Expert analysis predicts that the area of threatened corn is expected to reach more than 200 million mu, and the task of prevention and control is very arduous.
High resistance
Since the grassland night moth is a new invasive insect in China, there is no registered pesticide available in China. Native to the Americas, the meadow moth has crossed continents from the Americas for decades, experienced dozens of pesticides in dozens of countries, and has become resistant to many pesticides. With the frequent use of pesticides throughout the year, it has inherited this resistance, carrying the resistance gene, which is very difficult to prevent.
How to prevent it?
Grassland night moth is a new invasive insect, the occurrence of harm in China can not be mastered in a short period of time, but it is controllable, according to the "2019 grassland night moth prevention and control technology program (trial)", the specific measures can be effectively controlled:
Ecological regulation and protection and utilization of natural enemies
Areas with conditions can be intercropped with non-grass crops to protect parasitic and predatory natural enemies in the natural environment of farmland, give play to the natural control advantages of biodiversity, and form ecological interception zones.
Adult booby trap techniques
During the occurrence of adult insects, concentrated continuous tablets are trapped by insecticidal lamps, which can be combined with sexual attractants and food attractants to improve the control effect.
Larval control techniques
Grasp the best time for the prevention and control of young larvae, and the best time to apply the drug is in the early morning or evening, paying attention to spraying on the corn heart leaves, male ears and female ears.
(1) Biological control: In the early stage of egg hatching, spray white zombie, green zombie, thuringiensis preparations and polybactericides, matrine, neem and other biological pesticides.
(2) Emergency control: When the density of insect population in corn field reaches 10 heads/100 plants (refer to the insect population density index of the second generation of armyworm prevention and control in corn field), an efficient and low-toxic insecticide spray spray control for the prevention and control of pests of the nocturnal family can be selected. It is worth mentioning that the United Nations Food and Agriculture Organization's guidance manual for the prevention and control of grassland moth and the chemical pesticides registered abroad for the prevention and control of grassland moth include chloranthroprotex benzamide, cypermethrin, bromocyanidine and so on.
However, it should be noted that at present, the grassland moth has a high resistance to organophosphorus, pyrethroids, and carbamate pesticides through the serial use of dozens of countries, and it is not recommended to use them domestically for control.
Grassland night moth has a strong resistance to drugs, the majority of farmers in the use of drugs, should pay attention to the rotation and alternating use of different modes of action of insecticides, according to the field population monitoring and economic hazard level to decide whether to control, avoid frequent medication, but also according to the pesticide use instructions recommended concentration and dosage for appropriate spraying, in order to delay the production of grassland night moth resistance.
The industry believes that as a new biological invasion, whether the harm of the grassland moth in the planting industry will eventually evolve into an African swine fever epidemic similar to that in the breeding industry, thereby having a significant impact on the industry, which needs to be tracked continuously. However, given the "manifestations" of the pest abroad, its harm cannot be underestimated. To this end, the agricultural sector attaches great importance to it, requires encrypted monitoring and early warning, and makes every effort to do a good job in prevention and control, and farmers must also actively cooperate to strive to achieve a bumper harvest of "insects and grain".
Source: Agricultural network Agronet smallholder mushrooms