Adult meadow moth (male).
In the advanced larval stage of the grassland moth, the head has a Y-shaped pattern; the tail has four black dots arranged in a square arrangement.
The initial infestation of young larvae causes "white spots" on the leaves of maize.
The elderly larvae hide near the base of the maize plant.
China Jiangsu Netnews There is a kind of "moth", which is harmful! It has caused more than $10 billion in losses worldwide.
There is a kind of "moth", the king of the big stomach! Corn, rice, wheat, barley, sorghum... See what to eat.
There is a kind of "moth" that flies fast! It can be used to carry out long-distance directional migration with the help of wind at a height of several hundred meters, and can fly 100 kilometers per night, and 500 kilometers before spawning.
There is a kind of "moth", super powerful! 100-200 eggs can be laid at a time.
……
This kind of "moth" is called the grass night moth. From May 23 to 24, when the Jiangsu Plant Protection Department carried out the investigation of the grassland night moth, the suspected grassland night moth larvae were found in the maize fields of Yixing and Liyang near Anhui and Zhejiang, and later identified by experts from the Ministry of Agriculture and Rural Affairs to confirm that the grassland night moth had invaded Jiangsu.
Yangzi Evening News/Yang Eye reporter Yu Danji Yuxuan
Photo courtesy of the Provincial Academy of Agricultural Sciences
Introduction to "Moths"
The "Invincible Destruction King" is very harmful and very "perverted"
The grassland moth was included in the world's top ten plant pest "blacklist" and was also a major migratory pest warned by the Food and Agriculture Organization of the United Nations last year. Its "happy home" is widely distributed across the American continent in tropical and subtropical regions of the Americas, and in September 2017 the International Center for Agriculture and Biological Sciences reported that in 12 maize-growing countries in invaded Africa alone, the grassland moth reduced maize yields by 8.3 million tonnes to 20.6 million tonnes. In recent years, it has caused serious damage in India, Bangladesh, Sri Lanka and Myanmar.
The grassland nightcrawler has the characteristics of extensive host, fast diffusion speed, wide range of impact and harm, and strong reproductive ability. And this terrible moth has come to China! On January 18, 2019, China's Ministry of Agriculture and Rural Affairs announced that the grassland moth has invaded China from Myanmar, and their traces have been found in Yunnan and Guangxi.
Once in China, this "moth" is an "invasive alien species", and if the breeding develops to a certain number and cannot be controlled, it will become an "invincible destruction king" - a huge and irreparable harm to the local biosecurity.
Not only is the harm huge, the grassland night moth is also very "perverted", but the "perversion" referred to here is not the same as what everyone thinks. "Metamorphosis" is a term in entomology, and the grass moth is a completely metamorphosed insect whose growth process consists of four insect states (egg, larvae, pupae, and adult), a cycle called a generation. At 28 °C, the grassland moth can complete a generation in about 30 days. Female moths are super fertile, laying 100-200 eggs at a time and 900-1000 eggs in a lifetime.
How to pick out this "moth"
It is necessary to be vigilant when it is found that there are sporadic "white spots" on the leaves of corn
On May 25, experts from the Institute of Plant Protection of Jiangsu Academy of Agricultural Sciences went to Yixing and Liyang in Jiangsu Province to conduct field investigations, and made the following suggestions on the identification and prevention and control of grassland moths:
First of all, as soon as possible, the corn field sporadic harm is used to make an intuitive preliminary judgment. Experts from the Provincial Academy of Agricultural Sciences said that the larvae of the grassland night moth have a large amount of food, and the early infestation of young larvae can cause "white spots" on the leaves of corn, and the translucent "window holes" formed by the leaf flesh are left to the leaf epidermis after being eaten. The infestation of the elderly larvae causes a wide range of holes in the leaves. Therefore, experts suggest that when field observations find sporadic "white spots" on the leaves of corn, it is necessary to immediately conduct a careful investigation of pests.
Second, accurately identify the peeling of harmful corn in a timely manner. During the daytime investigation, the young larvae are relatively widely distributed on the corn plant, and there are larvae in the far and near areas of the centrifugal leaves, while the elderly larvae are concentrated near the base of the corn plant, and a large amount of insect feces can be seen by breaking the leaves.
It should also be noted that the body color of the field grassland nightcrawler larvae is not set in stone, and the identification points are the two main features of grasping the "Y" shape of the head and the four black spots arranged squarely at the end of the abdomen (see figure above).
It is important to note that not only corn but also other crops should be inspected, and the possibility of the grassland moth spreading to other crops such as rice needs to be closely monitored. Experts said that the Institute of Plant Protection of the Provincial Academy of Agricultural Sciences is actively carrying out research on the biological control of grassland night moth and other related studies.
Jiangsu sounded the "alarm"
Last week it was confirmed that it had invaded our province and the risk of spreading with the wind increased
According to the latest news from the Ministry of Agriculture and Rural Affairs, as of May 24, the occurrence area of the grassland night moth 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.
The reporter learned that on May 14, the Department of Agriculture and Rural Affairs of Jiangsu Province issued an early warning information about the approaching of the grassland night moth to Jiangsu. From May 23 to 24, when the Jiangsu Plant Protection Department carried out the investigation of the grassland night moth, the suspected grassland night moth larvae were found in the maize fields of Yixing and Liyang near Anhui and Zhejiang, and later identified by experts from the Ministry of Agriculture and Rural Affairs to confirm that the grassland night moth had invaded Jiangsu. On the morning of the 26th, suspected pests were found in Jintan District of Changzhou and are being confirmed. From the perspective of field damage, the rate of damaged plants in maize plots is 20%-30%, and the rate of damaged plants in some seriously damaged plots is more than 50%.
The agricultural ecology and planting layout of our province are suitable for the habitat and colonization of the grassland night moth, which is a transitional zone for moving north to south, and the grassland night moth is not only harmful to the crops such as corn in the season in our province, but also the "insect source" that spreads north. With the strengthening of the southwest monsoon, the local insect source and the foreign insect source are superimposed, and the risk of the next stage of migration and spread to the main corn-producing areas of our province increases.
The "war of counterattack" has begun
Worms eat food! The Provincial Department of Agriculture and Rural Affairs issued prevention and control measures
Since the grassland moth is a new major migratory pest, the identification of this insect is very small, and the next step is to focus on the prevention and control of three aspects:
First, conscientiously organize investigations. At present, the counties (cities, districts) where the grassland moth is found in our province are all non-main corn-producing areas, and the planting area is small and scattered, which is easy to miss. All localities should further organize special forces, mobilize the masses, divide and pack pieces, and check the corn and other crops in their jurisdictions one by one to ensure that not a single piece of corn field is missed. In view of the omnivorous nature and high risk of harm of the grassland moth, while doing a good job in the investigation of crops such as corn, it is necessary to increase the investigation of other crops such as rice and vegetables, and comprehensively find out the harm risk of the grassland moth to other crops.
Second, early warning and early disposal. Early warning and early disposal at the beginning of the invasion of the grassland night moth and sporadic occurrence, and the scientific and rational use of drugs at the stage of the occurrence of young larvae can effectively control its spread hazard and minimize the source base of the northward migration insects.
Third, strengthen pest monitoring and reporting. Implement the weekly reporting system and real-time reporting system of insect situations, and report to the higher-level business departments and local governments at the first time to prevent missing inspections and omissions in reporting and delaying the timing of prevention and control; for suspected pests and harmful symptoms, experts should be organized to identify and diagnose at the first time, and once confirmed, timely prevention and control measures should be taken.