At present, it is a critical period for the growth of crops such as spring corn in our province, but due to the invasion of a foreign moth, Zhejiang farmers are really restless.
This moth is called the meadow moth, also known as the autumn armyworm, and is native to the Americas. In January 2019, the invasion was found for the first time in China's Yunnan Province. As of June 4, in less than 5 months, the insect continued to spread northwards and has been found in 18 provinces (autonomous regions and municipalities), seriously threatening the safety of China's agriculture and food production.
Zhejiang is precisely the transition area for the migration of grassland night moths, and is a bridge area for pests to move north and south, and the strategic position of prevention and control is quite important. As of now, in addition to Zhoushan City, Zhejiang has found the worm in 10 cities and 56 counties (cities, districts). Doing a good job in prevention and control is not only a necessity to ensure the safety of corn production in our province, but also helps to control the large number of insects moving north and reduce the pressure of prevention and control in the main corn-producing areas in the north.
An obstruction war has been launched in zhejiang.
How terrible this strange bug is
"It's it, it's it!" In Shen Xiaofu's cornfield, Xu Weigen pulled out a corn plant and caught a larva that was nibbling on young leaves.
In the palm of Xu Weigen's hand, the reporter saw a flesh worm bent into a "C" shape, with black stripes all over its body and about two centimeters long. With the four black dots arranged in a square shape at the end of the abdomen of the insect, and the obvious inverted "Y" pattern on the head, Xu Weigen, chief expert of the Department of Agriculture and Rural Affairs of Zhejiang Province and the monitoring and early warning section of the Provincial Plant Protection and Quarantine General Station, concluded that this is the culprit that has made farmers sleep unsteadily in the past month - the grassland night moth.
Shen Xiaofu, a farmer in Siqian Village, Songxia Town, Shangyu District, Shaoxing, on May 22, encountered an unheard of "moth" in his 110-acre cornfield, the grassland night moth, and the young corn leaves and corn cobs became the rations of this strange moth.
"At first I thought it was a common corn borer." Shen Xiaofu said, but if you look closely, unlike the corn borer that eats corn stalks, this insect even nibbles on the core of the leaf, and there are more and more corn leaves full of insect eyes.
"This is the meadow moth, native to the Americas, and is an insect that has been a headache for local farmers for hundreds of years." Lou Yonggen, a member of the monitoring and prevention expert group of the Ministry of Agriculture and Rural Affairs and a professor at the Institute of Entomological Sciences of Zhejiang University, introduced that in January 2016, the grassland moth invaded Africa, and in just two years, the insect has been endangered in 44 African countries south of the Sahara; in 2018, it invaded India from Africa and was introduced to Myanmar and Thailand, and in January 2019, it was found for the first time in Yunnan Province, China.
On May 8, relevant personnel first discovered this moth invading our province in the corn field of Ximen Village, Shouchang Town, Jiande City. On May 10, the Department of Agriculture and Rural Affairs issued an urgent notice to the whole province on the investigation, monitoring and prevention and control of the grassland moth.
Although Zhejiang is not the main corn producing area, it is one of the areas that like to eat corn the most, and the grassland night moth seems to love such a fresh and sweet taste.
"The grass moth is a big stomach king and is very edible." Xu Weigen said that this moth has 6 ages, and the larvae above 4 years old can eat the most, can nibble the entire corn leaf, and seriously cause corn death, which will lead to corn yield reduction or even harvest failure.
It is understood that this year, Zhejiang corn planting area of about 1.3 million mu, of which more than 70% is fresh corn, which is what we often call sweet corn, waxy corn. If the meadow moth is allowed to harm the cornfield, it will be difficult for local corn to reach our table this summer and autumn and winter.
What the plant protection personnel said is not false. Even in the patches of cornfield, standing on the ridge and looking at it, the reporter quickly found corn plants that had been eaten, not only because their leaves were full of holes, but also because they were significantly shorter than healthy corn plants.
"Don't underestimate this bug." Lou Yonggen said that they have a wide range of tastes, can eat more than 200 kinds of plants, especially like corn, rice, wheat, sorghum, sugarcane as the representative of the grass; they have a strong reproductive ability, the larva will complete the development within 30 days, pupae out of the adult worm, that is, moths. In a short period of "insect growth", female moths can lay a total of 900 to 1000 eggs.
The moth-turned-moth-turned-moth will continue to multiply and embark on a new migration journey. In the early warning issued by Zhejiang to the whole province, it is pointed out that they have a strong ability to migrate, and under suitable weather conditions, they can fly 100 kilometers a night, and adults can migrate 500 kilometers before spawning.
The grassland moth is also highly adaptable, surviving and developing at low temperatures. As a result, many agricultural experts said that in the future, the occurrence of the grassland night moth may be normalized and become another major pest in China's northward migration and annual cycle.
And this situation is undoubtedly the last thing we want to see. According to the International Centre for Agriculture and Biological Sciences, in the 12 maize-growing countries in Africa that have been invaded, the grassland moth has reduced annual maize production by 8.3 million to 20.6 million tonnes and economic losses of up to US$2.48 billion to US$6.19 billion, according to the International Centre for Agriculture and Biological Sciences.
The staff of Jinyun County Agricultural and Rural Bureau taught farmers the knowledge of identifying and controlling grassland moths.
Although it is menacing, it is preventable and controllable
In a cornfield in Dayuan Village, Qili Township, Jinyun County, on June 5, plant protection technicians examine the presence of a grassland night moth in a white barrel trap.
"There's a sex attractant in there. It is a chemical that mimics the smell of females of the meadow moth, trapping male moths and preventing them from reproducing offspring. Jinyun County Agricultural and Rural Bureau Plant Protection Station Chen Linjie introduced.
Coincidentally, the reporter also saw a similar trap in the corn field of Xu Jianrong, a farmer in the east village of Gaibei Town, Shangyu District.
Xu Weigen introduced that at present, the province has accumulated 190 monitoring points and equipped with 570 sets of sexual attraction equipment. This has become the most commonly used means of monitoring the infestation of grassland night moths, which has greatly promoted the early detection and early control of insect pests.
In the face of the strange species of grassland night moth, many farmers will "rush to the hospital" at the beginning, and do not use the pesticide, resulting in poor spraying of pesticides.
"At present, there is no case of registered pesticides for the grassland night moth in China." Chen Junang, chief of the pesticide and equipment management section of the Provincial Plant Protection and Quarantine Station, introduced that the Provincial Department of Agriculture and Rural Affairs recommended two control technologies of sexual pheromone booby-trap and chemical emergency control to the province on May 21, including 5 kinds of high-efficiency and low-toxicity insecticides. Shen Xiaofu told reporters that through the application of methylaminoavermectin benzoate pesticides, most of the larvae in the corn field can be killed and the insect pests can be blocked in time.
Green is the ecological background color pursued by today's agriculture, how should it be weighed in the face of sudden outbreaks of insect pests?
Lou Yonggen said that pesticide prevention and control is still the most effective method for emergency disposal at present. On June 3, the Ministry of Agriculture and Rural Affairs issued a notice proposing 25 kinds of pesticide products for emergency use, and the selection of these drugs not only considers the factor of "effectiveness", but also takes into account the two factors of "safety" and "economy".
"If you master the time of pesticide application, you can get twice the effect with half the effort." Xu Weigen told reporters that young larvae are the best period for prevention and control, and a small amount of pesticides can be used to kill larvae at this time. Because high temperatures can speed up pesticide volatilization and render them ineffective, he recommends that farmers best apply the drug after 4 p.m. to avoid noon, and also pay attention to spraying on corn cob leaves, male ears and female ears and other areas where larvae like to nibble.
However, the grassland night moth has a strong resistance to drugs, Lou Yonggen reminded that in the use of drugs, we should pay attention to the rotation and alternating use of pesticides with different modes of action, and according to the field population monitoring and economic allowability to decide whether to control and avoid frequent medication.
In the interview, many experts invariably mentioned the importance of biodiversity in combating insect pests. Lu Jianfei, director of the Provincial Plant Protection and Quarantine Station, introduced that the corn planting area in Zhejiang is not large and relatively scattered, and diversified crops are planted around the corn, which has a natural resistance to pests.
Recently, the "Zhejiang Provincial Grassland NightcrawlEr Emergency Prevention and Control Technical Plan (Trial)" was issued to various localities, proposing that the prevention and control strategy should adhere to sustainable governance. Among them, it is mentioned that it is necessary to make full use of the crop layout of Zhejiang maize and non-grass crops, give full play to the natural advantages of biodiversity in our province, protect parasitic and predatory natural enemies in the natural environment of farmland, and form ecological interception belts.
Lou Yonggen revealed that the expert group is also actively carrying out experiments, and in the future, the method of treating insects with insects is expected to be promoted.
According to the latest news from the Chinese Academy of Agricultural Sciences, field experiments and indoor experiments carried out by the Plant Protection Institute of the Academy in Anning, Xundian, Mohei, Menghai and other places in Yunnan have shown that the cockroach has a significant control effect on the grassland night moth. At the same time, a species of parasitic natural enemy insect cocoon bee and a chicken bee were also found, and follow-up biological observation and expansion technology exploration are currently being carried out.
Lu Jianfei said frankly that although the grassland night moth is menacing, it is preventable and controllable, and there is no need to panic. As long as early detection, early medication, early disposal, and grasp the critical period of young larval control, we can effectively curb the spread of harm. At present, our province has implemented emergency prevention and control of 50,715 mu of corn that has been found to be harmful, and the effect is ideal.
A protracted battle is inevitable
Lu Jianfei did not dare to relax his vigilance at any time, he told reporters that because adult insects can fly and have strong mobility, the current control of adult insects is more difficult.
Plant protection technicians on the front line of insect resistance expressed the same feeling to reporters, and it is a protracted battle to block the grassland moth. "Spring corn is connected to summer corn, and summer corn is connected to autumn corn, that is to say, the rations of the grass moth will not be broken." Xu Weigen said that it is estimated that in a short period of time, the spread of the grassland night moth will expand, ushering in a peak period in June and July.
"What is now found in Zhejiang is a corn-type grassland moth." Lu Yaobin, director of the Institute of Plant Protection and Microbiology of the Provincial Academy of Agricultural Sciences, told reporters that the grassland moth is actually divided into corn type and rice type, the former takes corn, sugarcane, tomato, kale, cotton, sorghum, and the latter mainly eats rice and various pastures. The rice-type night moth undoubtedly has a greater impact on our province.
Lou Yonggen also expressed concern, according to his understanding, at present, agricultural experts in Guangdong Province have found mixed grassland moths when measuring the genome, that is, they eat corn and rice.
It can be seen that a protracted war is inevitable.
"Disease and pest monitoring should be one of the most important links in this protracted war." Lu Jianfei explained that this is to make a prediction of the harmful trend of future diseases and insect pests, just like the weather forecast predicts the weather and provides reference information for farmers.
On May 14 and 15, the province's grassland night moth identification and monitoring technology training was held in Dongyang, after which the localities organized farmers to carry out corresponding training to popularize the prevention and control methods.
Recently, the Provincial Plant Protection and Quarantine Station issued the "Zhejiang Provincial Grassland NightCrawlEr Detection and Reporting Survey Method and Emergency Prevention and Control Technology Plan" for reference and implementation by all localities.
Hu Yongjie, director of the Jinyun County Agricultural and Rural Bureau, said that for more than half a month, agricultural technicians in 18 townships and streets in Jinyun have been busy non-stop, and they have carried out field investigation and monitoring in the corn field according to the frequency of once every two days.
Shaoxing issued the "Notice on Doing a Good Job in the Investigation, Monitoring and Prevention and Control of the Grassland Nightcrawler", and on the basis of the implementation of the "One-Week Report" on the insect situation, it also allowed the majority of farmers to fully understand the morphological characteristics, occurrence habits and prevention and control methods of the grassland nightcrawler through mobile phone text messages, networks, WeChat and the distribution of wall charts and manuals.
In Lu Jianfei's view, the prevention and control of diseases and insect pests by household and small farmers is the current difficulty in plant protection work.
During the interview, the reporter also noticed that the township agricultural technicians have a better understanding of the situation of the peasant households in the jurisdiction, which is the "last kilometer" of the grass-roots plant protection work, but the plant protection work is only one of the work of the township agricultural technicians, and the personnel strength is still slightly insufficient.
Lu Jianfei said that the monitoring and reporting work itself is very demanding. If you want to provide accurate and timely forecasting services, you must not only understand some biology, ecology and other knowledge and methods, but also have practical experience to provide accurate and timely forecasting services for farmers. The current lack of professional and technical personnel in plant protection is also a major difficulty in the development of plant protection work.
When the reporter interviewed Shangyu and Jinyun, there were only 4 local plant protection department personnel, and it was also difficult to deal with such a large area of emergency prevention and control work.
"Ensuring national food security is an eternal theme, and plant protection work is always on the road." Lu Jianfei said, "We still have a lot of work to do to control the grassland night moth. ”