CATDOLL : CATDOLL: Locusts are common insects that harm a variety of crops such as corn, sorghum and rice. They are well-known agricultural pests. Locusts breathe by:

Locusts are relatively common insects. They harm a variety of crops such as corn, sorghum and rice, and are well-known agricultural pests. Locusts breathe by:

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Question analysis: On both sides of the first segment of the locust's abdomen, there is a pair of half-moon-shaped hail-compartment membranes, which are the locust's auditory organs. There is a row of small holes arranged neatly on the left and right sides.

It is the spiracles that are randomly collapsed. From the middle thorax to the 8th segment of the abdomen, each body segment has a pair of spiracles, a total of 10 pairs, and each spiracles is connected to the trachea inward. In the locust body, there are tracheae of varying thicknesses that are connected vertically and horizontally. The tracheae branch again and again, and finally connect with each cell through the branches beside the fine source to exchange gases. Therefore, the spiracles are the gateway for gases to enter and exit the locust body, but the trachea is the actual site for gas exchange.

History of locust control

1. [History of locusts in China] I want to know about the history of locusts in China from the 1940s to the 1960s. China has been a country with frequent locust plagues since ancient times, and the scope and degree of the disasters are the highest in the world. Therefore, the study of locust plagues and locust control in China has become one of the topics of concern to scholars from ancient times to the present. As early as the Ming and Qing Dynasties, there appeared many far-reaching agricultural books on locust control, which had a preliminary scientific understanding and summary of locust habits, the laws of locust plagues, and locust control techniques. For example, Xu Guangqi, a famous scientist in the Ming Dynasty, obtained a correct understanding of the seasons and breeding grounds of ancient locust plagues through statistics and analysis of locust plagues before the Ming Dynasty, which became an outstanding achievement in the study of ancient locust plagues in my country. After entering the 20th century, with the development of national economic construction, scholars from different professions have devoted themselves to the study of locust plagues and locust control in China, and have achieved many remarkable results. Especially in the 1990s, in response to the "Decade for Disaster Reduction" proposed by the United Nations, the academic community has set off a wave of research on Chinese disasters and disaster history, and the study of locust plague history has also become one of the hot spots, with many articles and monographs. According to the author According to preliminary statistics, more than 100 special papers have been published since the 20th century, and more than 30 monographs on locust history research have been published. Looking back on the research process over the past century, there are roughly three development stages: from the early 20th century to the late 1940s; from the 1950s to the 1970s; and from the 1980s to the present. Research status from the early 20th century to the late 1940s In the early 20th century, with the introduction of modern Western science, some scholars who returned from studying abroad in the West, such as Wu Fuzhen, Chen Jiaxiang, and Zou Zhonglin, conducted research on the classification and distribution of modern locusts, and the life history and living habits of locusts. While carrying out the observation, prediction and prevention of migratory locusts, the research also extended its tentacles to the historical data of locusts, in order to have a deeper understanding of the occurrence of locust plagues. Representative research results include: Chen Jiaxiang's "Records of Locust Plagues in Chinese Literature" (written in 1928 and published in English in 1938), Li Fengsun's "Ancient Methods of Catching Locusts" (Insects and Plant Diseases, Vol. 1, 1933), Ma Junchao's "Inference on the Relationship between Drought and Locust Plagues in Jiangsu Province in the Qing Dynasty" (Insects and Plant Diseases, No. 18, 1936). At the same time, some historians also published in their works Statistics on locust plagues began to be collected. For example, History of Famine Relief in China (written by Deng Yunte, Commercial Press, 1937), which is regarded as a pioneering work in the history of famine relief in China, counted the number and frequency of natural disasters in my country, including locust plagues. Table of Natural and Man-made Disasters in China (one of the series of books of National Jinan University, 1939), compiled by Chen Gaoyong, compiled records of locust plagues in 257 years. The number of locust plagues counted by Deng was mostly cited by later generations. Research status from the 1950s to the 1970s The real research on the history of locusts began in 5 The background was that my country's large-scale pesticide control of locusts was in full swing. In order to more comprehensively understand the occurrence patterns of locust plagues, many scholars at that time sorted out and analyzed the historical data of locust plagues. Cao Ji's "Analysis of Records of Locust Plagues in Successive Dynasties" (Si Lu "China Agricultural Research" 1950 Vol. 1 No. 1) discussed the occurrence of locust plagues in six provinces, including Hebei, Shandong, Henan, Jiangsu, Zhejiang, and Anhui from 200 BC to 1901 AD, and its relationship with drought, flood, temperature, natural enemies, human control and other factors; and used data to analyze the occurrence of locust plagues in six provinces, including Hebei, Shandong, Henan, Jiangsu, Zhejiang, and Anhui from 200 BC to 1901 AD. The method of quantitative statistics and comparative analysis was used to draw a variety of relationship curves. This was an early attempt to use natural science methods to count ancient disasters, and it was also a method that was used more frequently by later researchers. Guo Fu's "Achievements in the Study of Locusts in Ancient China" ("Journal of Entomology", Vol. 5, No. 2, 1955) analyzed the achievements of locust control in ancient my country. The article "Preliminary Arrangement of Historical Records of Locust Plagues in Anhui" ("Anhui Historical Newsletter", No. 2, 1959) compiled by the Natural Disaster Collection Group of the Anhui Provincial Institute of Literature and History was a review of the "Natural Disaster Records of Anhui Province in the Past Thousand Years" compiled by the institute. The analysis of the records of locust plagues in the "Statistical Table of Disaster Zoning" concluded that the occurrence of locust plagues in the area showed continuity and widespread, and that there was a certain correlation between locust plagues and droughts. In addition, there are Qin Bai's "Records of Locust Hunting in Successive Dynasties" (Anhui Daily, August 17, 1961), Zhao Yin's "Another Contribution of Chen Zhenlong to Agriculture - Introduction to "Records of Locust Control" (Fujian Daily, October 29, 1961), Wang Zichun and Liu Changzhi's "Xu Guangqi's Understanding of the Living Habits of Locusts" (Biological Bulletin, Issue 5, 1964), etc.

2. Review of the history of locust control in my country: What is the locust plague like? It is one of the major natural disasters in my country's history. In the thousands of years of history of the Chinese people's struggle against natural disasters, locust plagues are the most prominent problem, and their harm is more serious than floods and droughts.

People used to describe the severity of the locust plague as "a thousand miles of barren land, and streets full of starving people". After the founding of New China, the Party and the Central Government attached great importance to locust control, strengthened the organizational leadership of locust control, invested a lot of manpower, material and financial resources, and with the joint efforts of the Central Government and the general public, the long-term serious locust plague was quickly controlled.

From 1949 to 1959, my country achieved great results in locust control and basically brought the locust plague under control, ending the record of two locust plagues every five years since the Song Dynasty.

After ten years of fighting against locusts, our locust control workers have basically mastered the occurrence patterns of locusts and accumulated a lot of rich organizational experience and prevention and control experience. The density and range of locust occurrence have been greatly reduced, fundamentally changing the tragic scene of "covering the sky and the sun, and all the grass was gone" when the disaster occurred before the founding of New China. The area of ​​locusts in some areas has steadily decreased.

3. There have been several major locust plagues in Chinese history. Since the natural environmental conditions for locust plagues are basically the same in ancient and modern times, the locust plagues in my country have not disappeared due to the modernization of agriculture. On the contrary, as long as the conditions are right, the locust plagues will come back.

For example, since the beginning of summer in 2002, locusts have occurred to varying degrees in more than 100 counties in 13 provinces, autonomous regions and municipalities, including Hebei, Henan, Shandong, Tianjin and Xinjiang. By the end of June, the area of ​​locusts in farming and pastoral areas reached 90 million mu.

Historical review of locust plagues: Pre-Qin ancient books such as the Book of Songs often referred to locusts as 螽 (螽 is the general name for locusts, including katydids) or m, where m is the nymph of locusts (the larvae of incomplete metamorphosis are called nymphs). After the Warring States Period, they were mostly called locusts.

Both locusts and maggots harm crops. The earliest record of a locust plague in ancient books is in the Spring and Autumn Annals, which records the 15th year of Duke Xuan of Lu (594 BC): At the beginning of the tax on mu, in winter, maggots grew.

The earliest record of locusts is in the fourth chapter of the "Mengxia Chronicle" of Lüshi Chunqiu: "When the spring order is carried out...then locusts will be defeated." And in the same book, "Shenshi Pian": "...the hemp that is obtained at the right time...if it is like this, there will be no locusts."

The Book of Rites also records locusts as a disaster, but I won't quote them here. After the Song Dynasty, the term "m" was changed to "蝻", and the term "蝻" was used together, and it is still used today.

In the Ming Dynasty, Xu Guangqi's "Complete Book of Agricultural Administration: Extermination of Locusts" counted the number of locust plagues during the Spring and Autumn Period (770-476 BC), pointing out that there were 111 plagues in the 294th year of the Spring and Autumn Period, and the monthly distribution is as follows: Month (Lunar Calendar) 2 3 4 5 6 7 8 9 10 11 12 Number of Occurrences 2 3 19 20 31 20 12 1 0 0 3 The above numerical distribution is very consistent with the normal distribution law in statistics. It shows that locusts are most rampant between April and September (Lunar Calendar). Xu Guangqi said: The most severe period is between summer and autumn, which coincides with the time when all kinds of grains grow and mature, so the damage is the most widespread.

Xu Guangqi's statistics are very consistent with the research conducted by the Jiangsu and Zhejiang Provincial Insect Bureaus in 1920 on the occurrence seasons of locusts in various parts of the country. As far as migratory locusts are concerned, the most serious locust plague period is from May to August (solar calendar). Summer locusts are at their peak from mid-May to early July, and autumn locusts are at their peak in early to mid-August.

June and July are the periods of summer and autumn locust plagues. The author re-counted the locust plague registration table in the appendix of Zhou Yao's "History of Chinese Entomology" and found that there were 508 locust plagues in the 2614 years from 707 BC (the 13th year of Duke Huan of Lu) to 1907 AD (the 33rd year of Emperor Guangxu of the Qing Dynasty) (the book was misprinted and the statistics were 2618 years and 538 times).

The book "Eliminating Locusts" has a very scientific view on the relationship between the occurrence of locusts and environmental and climatic conditions: I heard from an old farmer that locusts are as small as millet when they are born, and they grow as big as flies in a few days. They can jump and move in groups, and are called nymphs.

After a few days, they began to fly in groups, and were called locusts. Wherever they stopped, their beaks kept biting... After a few days, they laid their eggs on the ground.

The sons of the underground will become larvae again on the 18th day, and the larvae will become locusts again, and so on. This is why the disaster is so widespread... Locusts are born at the edge of a large swamp... and in places where the water dries up suddenly... Therefore, the dry swamp is the origin of locusts. If you want to get rid of locusts, you should map this place. After the Tang and Song dynasties, paper and printing conditions improved, and records of locust plagues became more detailed. The following are a few examples to give you a glimpse: In the first year of Zhenyuan (785 AD), summer locusts covered the sky from the sea in the east to the river valley in the west, and did not stop for ten days.

There was no grass, trees or animal hair left, and the roads were covered with starving people. In autumn, there was a large locust infestation in Guanfu, which ate up all the crops. The people were hungry and caught locusts for food.

In the third year of Chunhua (992 AD), on the 1st day of the sixth month, locusts came from the northeast, covering the sky, and then left via the southwest. That night, it rained heavily, and all the locusts died.

In the seventh month of autumn, locusts appeared in the eight states of Xu, Ru, Gun, Shan, Cang, Cai, Qi, and Bei. Locusts started from the northeast and moved to the southwest, covering the sky like clouds covering the sun... In May of the 19th year of Zhizheng in the Yuan Dynasty (1353), locusts covered the sky in Shandong, Hedong, Henan, Guanzhong, etc., making it impossible for people and horses to move, and all the ditches and trenches were flattened.

The locusts devoured all crops and plants, blocking out the sun wherever they went, making it impossible for people and horses to move forward.

The pits and trenches were filled. The hungry people caught locusts for food, or dried them and stored them... In the 21st year of Chenghua (Ming Dynasty), there was a severe drought, and locusts came in droves, and people ate each other.

Most of the people were exiled, and the hungry people gathered in the mountains and forests. Locusts flew in Taiping County, covering the sky, eating up all the ears of grain and leaves, and the people were all destitute.

That year, most of the people in Yuanqu fled and gathered in the mountains and forests. In March, Pingyang was infested with locusts.

In April, there are locusts in Henan. In July, there are locusts in Shuntian.

In the seventh year of Emperor Xianfeng’s reign (1857), in spring, locusts appeared in Changping, Tangshan, Wangdu, Leting, and Pingxiang, nymphs were born in Pinggu, and there was no wheat in that spring. Nymphs were born in Qingxian, and there was a severe drought in Funing, Quyang, Yuanshi, Qingyuan, and Wuji, and locusts… In Wuchang, locusts covered the sky.

Fangxian, Zhijiang, Songzi drought locusts, Yidu locusts more than three inches long. In autumn, Huangan, Qishui, Huanggang, Suizhou locusts; Yingshan locusts, the ground is about a foot thick, Zhongxiang flying locusts cover the sky, tens of miles ... The geographical distribution of locust plagues is cited from 707 BC (the fifth year of Duke Huan of Lu) to 1907 AD (the 33rd year of Emperor Guangxu of the Qing Dynasty). There were 508 locust plagues in the 2614 years. The geographical distribution of the number of occurrences is as follows: Yellow River Basin: 436 times, accounting for 85.82%; Yangtze River Basin: 69 times, accounting for 13.57%; South and Southwest China: 3 times, accounting for 0.58%.

This distribution is basically consistent with the distribution of locust temples studied by Chen Zhengxiang. Geologist Chen Zhengxiang consulted more than 3,000 Chinese local chronicles collected at home and abroad, found those that recorded the locations of locust temples, marked them on the map, and finally made a historical geography map of the distribution of locust temples in China (Locust God is a general term, including Ba La, Insect King, General Liu Meng, etc.).

The locust plague distribution map drawn using the distribution of locust temples has an advantage over written records, because wherever there is a locust temple, it reflects that the local locust plague has a history of recurring, so farmers have to build temples for worship. Chen Zhengxiang summarized the characteristics of the locust temple distribution map as follows: (1) The locust plague is most common in the lower reaches of the Yellow River, especially in Hebei, Shandong, and Henan provinces.

(2) South of central China, locust plagues gradually decreased, and by the southeast coast, there were almost no locust plagues. (3) The southern limit of the distribution of locust temples roughly coincided with the spring and annual average relative humidity contours of 80%.

(4) The central part of the Yunnan Plateau is similar to the Taihu Lake Basin, so locust plagues are also common. The shortcoming of this map is that it does not reflect the places where locust plagues occasionally occur, because there are often no locust temples built in areas where locust plagues occur occasionally, so they cannot be reflected on the map.

In history, locusts were not classified. Guo Fu et al. studied the biological classification of modern Chinese locusts and pointed out that there are three major categories, namely the East Asian migratory locust, the Asian migratory locust and the Japanese migratory locust. Guo Fu et al. also mapped the distribution of locust plagues in China as the Chinese migratory locust.

4. How did the Chinese deal with locust plagues in history? 1: Manual swatting method This is the most ancient method of killing locusts in ancient Chinese history.

According to the book "Essential Methods of Catching Locusts", this method mainly involves villagers using bamboo poles to hold up an eight-foot-long white cloth, chasing the locusts from three sides in the direction of the wind, driving the locusts to one place, and then concentrating their efforts to swat them. This is a "hand-to-hand combat" that farmers have used to fight locust plagues since the Spring and Autumn Period and the Warring States Period.

Although this method is physically demanding, it has simple tools and methods, and is suitable for large numbers of villagers to fight together. Therefore, it has been very popular in rural China for two thousand years.

Method 2: Trench Burial Method Although the manual swatting method is simple, it consumes too much manpower and physical strength. So during the Han Dynasty, the exhausted Chinese people had an idea: Why do we need to fight hand-to-hand with locusts? Isn't it enough to dig a pit for the locusts? So the "trench burial method" came into being.

According to the Eastern Han Dynasty's Lun Heng and other classics, this method requires digging a large number of two-foot-deep and wide pits in the area where the locusts are going to pass, and then, after the locusts arrive, they are lured into the pits by beating them, and then concentrated efforts are made to bury them. This method has a very good effect of "annihilating the enemy", and usually a large area can be buried at once.

The operation is difficult: if the soil is buried too shallowly, locusts can get out. The "Book of Jin" records that there was a locust plague in the Hedong area at that time. People used the "trench burial method" to kill locusts. The locusts buried in the soil flew out in a blink of an eye and ate up all the crops.

Therefore, a more ruthless method became popular during the Tang Dynasty: bonfire luring and killing. Method 3: Bonfire luring and killing In fact, the desire to burn locusts with fire was very strong during the Spring and Autumn Period and the Warring States Period.

In the Book of Songs, there is a cry of "burning locusts with fire". In the Tang Dynasty, this "burning locusts with fire" operation finally matured.

According to the "Atlas of Catching Locusts" and "Complete Methods of Controlling Locusts", if you want to "burn locusts with fire", you must light a bonfire at night, and in addition to the bonfire, you must also set up lights along the roads where locusts are densely populated, using closely coordinated lights to attract a large number of locusts. Then the locusts burned by the fire will lose their ability to fly.

A large number of people took the opportunity to catch and kill the locusts. They could also bury the killed locusts in the trenches.

During the Kaiyuan Period of the Tang Dynasty, facing the great locust plague sweeping across the Central Plains, the Tang Dynasty Prime Minister Yao Chong decisively adopted the "bonfire killing method" and successfully put out the disaster in a short period of time! In the Song Dynasty, when agricultural technology was more advanced, large-scale locust killing and burning was also adopted: burning the breeding grounds of locusts not only cut off the hidden dangers of disasters, but also allowed the burned land to be cultivated, which can be said to kill two birds with one stone. Method 4: Insect egg removal method It was also in the Song Dynasty, when agricultural technology was booming, that disaster prevention awareness was deeply rooted in people's hearts: rather than working hard to kill locusts during a disaster, it is better to cut the grass and eradicate the roots in advance.

Taking advantage of the winter, we can destroy the locusts' egg breeding grounds. Therefore, there is the "insect-egg removal method".

According to the "History of Song Dynasty", farmers in the Song Dynasty often looked for locust breeding grounds in winter. "The Complete Method of Controlling Locusts" also summarized the experience of "eliminating eggs according to the insects" since the Song Dynasty: Wherever locust eggs breed, there are often countless small holes on the ground like honeycombs, which must be dug up and removed decisively.

During the Ming and Qing dynasties, people developed primitive "pesticides", such as "concentrated juice of spathiphyllum" and "mixed solution of aged vinegar", which were specially used to kill insect eggs. However, this method of finding insect eggs was so exhausting that Shen Kuo and other famous officials in the Northern Song Dynasty complained that it was "exhausting".

Sometimes, after working so hard to dig out the eggs, the locust plague would still come in the next year. During the Ming Dynasty, people understood a fact better: farming was actually a better way to eliminate the hidden dangers than looking for insect eggs - reclaiming wasteland to eliminate locusts.

Strictly speaking, the method of reclaiming wasteland to eliminate locusts actually originated in the Yuan Dynasty. According to the "Book of Agriculture", farmers in the Yuan Dynasty often reclaimed wasteland and planted crops such as taro and mulberry to resist locust plagues. By the Ming Dynasty, it was more systematic: places where locusts breed are all "dry marsh" areas, which must be transformed into farmland. In the process of reclamation, insect eggs are killed by various means, and plants such as mung beans and peas that locusts do not eat are planted to prepare for famine during locust plagues.

In Xu Guangqi's "Complete Book of Agricultural Administration", this "method of reclaiming wasteland and eliminating locusts" was not only fully recorded, but also spread to Europe and the United States as the book became world-renowned. It also had an important impact on the modern pest control research in the West.

But then again, although each of the above methods is reliable, under the technological conditions of ancient times, these methods can only alleviate the disaster and minimize food losses. It was not until modern society that countries around the world used various modern scientific and technological means to barely control the locust plague.

Calling this horrible disaster seems far away from modern life. Some people's jokes about "foodies saving the locust plague" can be said to be a serious ignorance of the disaster of pests and diseases.

However, even in the ancient times when technology was limited, the resilient Chinese people continued to update their experience in controlling and eliminating locusts from generation to generation, bravely facing every disaster. Such wisdom and courage are the important reasons why Chinese civilization has continued to thrive.

5. How to determine locust prevention and control indicators? After understanding the types and densities of locusts through various methods, the prevention and control indicators can be determined.

However, there is no unified regulation on the number of pests per square meter. We have comprehensively considered the pest control indicators of various places and strived to find an economically suitable target. In some areas, manual pest control can be set at 2 to 12 pests per square meter, and in large-scale aerial pest control, it can be set at 15 to 20 pests per square meter.

No matter what kind of pests are controlled in grassland areas, the first thing to consider is the economic benefits. If the cost of control is balanced with the economic losses caused by pests, then this method is of little significance.

If the cost of pest control exceeds the economic loss caused by pests, this is not allowed. Secondly, consider various local factors, including human, material, financial resources, terrain and grassland utilization methods.

6. How to identify and prevent locusts. Locusts are common pests worldwide. The Chinese locust, the stupid locust, the negative locust, etc. harm crops such as peanuts, beans, potatoes, and sweet potatoes.

Locusts mainly feed on leaves and stems of plants. They mainly feed on grass plants such as wheat, corn, sorghum, rice, millet, reeds, barnyard grass, etc. When hungry, they also feed on dicotyledonous plants such as peanuts. The locusts that harm peanuts are mainly Chinese locusts.

The Chinese locust, also known as the Chinese rice locust, belongs to the family Trichocera of the order Orthoptera. It occurs in all parts of my country, especially in the Yangtze River Basin and the Huanghuai region.

(1) Damage characteristics: Adults and nymphs feed on the stems and leaves of peanuts. In severe cases, the stems are bitten off, the leaves are notched, and the entire leaf is eaten, leaving only the veins. In addition to peanuts, it also harms other plants in the Leguminosae family and a variety of crops in the Convolvulaceae, Solanaceae, and Gramineae families. The third-instar nymphs begin to spread their feeding and their food intake gradually increases; the food intake of the nymphs increases greatly after the fourth instar, and the food intake is the largest when they become adults, often causing notches on the peanut leaves, and in severe cases, only the main veins are left.

(2) Key points for identification ① The adult male is 15 to 33 mm long, while the female is 20 to 40 mm long. The body color is yellow-green, brown-green, yellow-brown, green, etc. It is shiny, with a broad, oval head and oval compound eyes.

Antennae are filamentous. The head is stretched forward and the facial ridge is wide.

There is a dark brown longitudinal band behind the compound eyes on each side, passing through the sides of the pronotum and reaching the base of the forewings. There is a cone-shaped tumor-like protrusion on the pronotum.

The front wings are longer than the end of the hind leg segment. ② The egg is long and cylindrical, about 12 mm long and 8 mm wide, slightly curved in the middle.

With brown colloid oocysts, the eggs are arranged in two longitudinal rows obliquely inside the oocysts.

The egg capsule is eggplant-shaped, and the eggs are separated by dark brown gelatinous substances. ③ Nymphs are also called locust nymphs.

Most are 5-6 instar, a few are 7 instar. The 1st instar nymph is about 7 mm long, gray-green and shiny.

The head is large. The body gradually grows after the 2nd instar, and wing buds appear at the 3rd instar, growing larger with each age, and folding back to the back at the 5th instar.

(3) Occurrence Pattern: The Chinese locust has one generation per year in Zhejiang, Shanghai, and areas north of Jiangsu, and two generations per year in areas south of Jiangsu. In all regions, eggs overwinter in egg capsules in the soil of field ridges and nearby wastelands or at the root zone of weeds.

The overwintering eggs hatch in mid-to-late May to mid-June of the following year. The egg period lasts about 6 months, with the peak period from July to September, and the eggs are laid around October to overwinter.

It likes to emerge in the morning, is active before sexual maturity, has strong flying ability, and is most active between 8:00 and 10:00 and 16:00 and 19:00. It has a clear tendency to white light and purple light.

The eggs are laid in clumps in low-temperature, grassy, ​​sunny, loose soil fields or ridges. Newly hatched nymphs are mostly concentrated on young weeds on ridges or roadsides.

Adults are fond of feeding on plants of the Gramineae and Cyperaceae families, followed by Cruciferae, Leguminosae, Amaranthaceae, Chenopodiaceae, etc. Adults are active at sunrise and have the habit of flying towards lights when it is hot at night.

When the ground temperature is 7-10°C, locusts lie on the stems and leaves of peanuts to absorb light and heat. When the ground temperature is 10-15°C, they start to feed. When the ground temperature rises to 15-25°C, locusts are most active in feeding. If it is cloudy, windy, rainy or the temperature is very low, locusts will stay still all day, not moving or eating, and will resume normal activities only when there is no wind or rain.

(4) Prevention and control methods: The control target for Chinese locust is 0.5 heads per square meter, and the best period for prevention and control is the peak period of the 3rd and 4th instar locusts.

In the medium and low density outbreak areas with a locust density of less than 5 per square meter, biological control will be the focus. In the outbreak areas with a locust density of more than 5 per square meter, chemical emergency control will be the focus.

① Agricultural control: Before winter, people should use the fallow season to plough and sun-dry the ridges in ditches and canals where the insects are abundant, destroy the ecological environment of overwintering insect eggs, and reduce the number of overwintering insect eggs. ② Protect natural enemies: Using predatory natural enemies such as frogs and toads, the insects can be basically suppressed in the general occurrence years.

③ In years with heavy chemical control, spraying can be carried out from early to mid-late July, and then every 10 days depending on the insect situation. Option 2 can be selected.

Spray 2000-3000 times diluted 5% highly effective chlorfenapyr emulsifiable concentrate, or 1000-1500 times diluted 5.7% cypermethrin emulsifiable concentrate, or 600-800 times diluted 20% avermectin microemulsion (use with caution in mulberry silk areas), or 1000 times diluted 48% chlorpyrifos emulsifiable concentrate for prevention and control.

7. Several major locust plagues in Chinese history 1. Causes 2. Prevention and control methods 3. Locust plagues in Chinese history 4. Introduction to locusts 5. The great locust plague in Israel [edit this section] 1. Causes People noticed early on that severe locust plagues are often accompanied by severe droughts.

There are records of "extreme drought and locusts" in ancient Chinese books. In recent years, several major locust plagues in Africa have been related to severe droughts in the area.

The main reason for this phenomenon is that locusts are insects that like warm and dry environments, and arid environments have many benefits for their reproduction, growth, and survival. Because locusts lay their eggs in the soil, the soil is relatively solid, and the water content of 10% to 20% is most suitable for them to lay eggs.

There are two reasons why the locusts reproduce and grow rapidly due to drought. On the one hand, in drought years, due to the drop in water levels, the soil becomes more solid, the water content decreases, and the vegetation on the ground is sparse, so the number of locust eggs increases greatly. In some cases, 4,000 to 5,000 egg masses are laid per square meter of soil, each egg mass contains 50 to 80 eggs, that is, 200,000 to 400,000 eggs per square meter.

At the same time, in drought years, the surface of rivers and lakes shrinks, and low-lying areas disappear, providing more suitable places for locusts to lay eggs. On the other hand, plants grown in arid environments have lower water content, which locusts feed on, grow faster, and have higher fertility.

On the contrary, rainy and humid environments have many adverse effects on locust reproduction. The high water content of plants that locusts feed on will delay their growth and reduce their reproductive capacity. Rainy and humid environments can also cause locust diseases to spread, and rain and snow can directly kill locust eggs.

In addition, the increase in natural enemies such as frogs will also increase the mortality rate of locusts. When a locust is touched on a certain part of its hind legs, it will change its original solitary habit and become more gregarious.

Locusts are usually timid and solitary, causing limited harm. But sometimes they change their habits and prefer to live in groups, eventually gathering in large numbers and migrating collectively, forming a terrifying locust plague that causes great damage to agriculture.

Scientists at Oxford University said they conducted experiments on desert locusts in their solitary stage, repeatedly touching multiple parts of their bodies to find out if there were some tactile factors that caused the locusts to change their habits. The results showed that when a certain part of the locusts' hind legs was stimulated, they suddenly became gregarious, while touching other parts of the body such as the antennae, mouth or abdomen did not have this effect.

Scientists believe that the hind legs of locusts that accidentally gather in a natural environment touch each other, which may cause them to change their habits and start living in groups, and their members increase in large numbers in the same way, thus forming a locust plague. If we can find out which chemical signals stimulate the locust's nervous system to cause its behavior to change, we may be able to develop new pesticides to prevent locusts from gathering.

In summary, why do locusts cause disasters? 1. From an environmental perspective, it is mainly caused by drought. 2. From their living habits, it is mainly because: (1) They have the habit of living in groups.

(2) It has a strong reproductive capacity. (3) It is polyphagous, which means it can eat many kinds of plants.

(4) It has strong flying ability and is difficult to control. (5) Its eggs are hidden deep underground and are difficult to destroy.

3. Locust plagues are rampant after warm winters. Global warming, especially the rise in winter temperatures, is conducive to the increase of locust overwintering eggs, providing "insect eggs" for the outbreak of locust plagues in the second year; in addition, the superposition of multiple factors such as climate warming, intensified drought, and grassland degradation will provide a suitable place for locusts to lay eggs, and locusts have a strong ability to adapt to drought. This is because other insects and birds cannot survive in this situation, and a filamentous fungus that can cause locust diseases is suppressed, so its number increases greatly.

Therefore, experts predict that with the trend of global warming, the scale of locust plagues will become larger and larger in the future, which will have a serious impact on my country's grain production. 4. Excessive insect population density will cause locust plagues.

In a paper published in the June 2 issue of Science, James Buhl and his colleagues show that the key factor is a specific population density, at which the locusts line up and begin moving in the same direction.

Locusts are solitary, wingless "nymphs" early in their life cycle that tend to avoid each other. But if resources become scarce, they are forced to interact with each other.

They can then form organized local swarms that have the ability to move in unison, move into neighboring habitats, and recruit more and more locusts, eventually forming a massive swarm.

Predicting the onset of swarming is therefore crucial to controlling locust outbreaks. The researchers placed increasing numbers of swarms in a circular arena, recording their behaviour and tracking their movements using computer software.

At medium densities (25 to 62 locusts per square meter), the locusts line up and begin moving in the same direction, or even suddenly change direction in unison. In the experiment, when the number of locusts per square meter exceeded 74, the orderly moving swarm stopped changing direction and continued to move in the same direction for 8 hours.

The observations confirm the predictions of a computer model called the self-propelled particle model. Buhl and his colleagues think that using such models could help devise ways to control locust outbreaks.

Their research results also support the definition of locust nymph populations by the Food and Agriculture Organization of the United Nations. At this density, locust swarms are likely to cross the "tipping point" and trigger a locust plague.

[Edit this paragraph] 2. Prevention and control methods 1. Environmental protection is the fundamental solution. The occurrence of locust plagues is mainly caused by natural factors, but it is undeniable that there are a considerable number of human factors.

Locusts must lay eggs on land with a vegetation coverage rate of less than 50%. If a place is beautiful and has no fertile land, locusts cannot reproduce. At present, some places have a weak ecological awareness. Some simply believe that pollution control is the only way to protect the environment. As for improving the vegetation, soil and microclimate in the locust habitat, they do not pay much attention to it because they cannot see the benefits in the short term.

Therefore, to fundamentally prevent and control locust plagues, we should pay great attention to the protection of the ecological environment. 2. Chemical control is the most important means.

It is recommended to use high-efficiency, low-toxic, low-residue counterpart pesticides, such as 5% Scrappy suspension, 20-30 ml per mu mixed with 50-60 kg of water for spraying. It can also be used in locust larvae (.

8. Locust plagues occurred frequently in Chinese history. How did the ancients deal with locust plagues? Because the dry environment is suitable for the reproduction of locusts, the outbreak of locust plagues is usually accompanied by drought. In ancient China, there is a saying that "locusts will appear when drought is extreme." The ancients believed that the reason for drought was a monster called "Hanba (pronounced as "ba")" and the reason for locust plagues was that the "Locust God" was showing its power. Therefore, when drought and locust plagues broke out, the people generally carried out activities such as "beating Hanba" and "worshiping the Locust God." This practice obviously has no effect. They can only wait for the locusts to destroy the crops and migrate to other places.

With the growth of experience, the ancients gradually began to use some positive methods to deal with locusts. For example, Yao Chong, a wise prime minister of the Kaiyuan period, faced with a large locust plague in Shandong Province, he broke the superstition and fought against the locusts by driving them away, catching and burning them, and digging pits and burying them. The effect was quite remarkable. In the Yuan Dynasty, people began to think about ways to prevent locust plagues on the basis of inheriting the previous generations' control of locust plagues: in early autumn, locust eggs hidden in the fields were dug out with hoes, and they were dried to death in the strong sunlight of the "autumn tiger". This method was very effective in preventing locust plagues. In the Ming Dynasty, Xu Guangqi systematically summarized the methods of controlling locust plagues in the past dynasties, and set up "Memorandum on Locust Control" in "Complete Book of Agricultural Administration" to specifically record methods of locust control.

The method recorded in "Daoxian Officialdom Ups and Downs" by Zhang Jixin in the Qing Dynasty: The method of catching locusts is like marching. Ten people form a team, two people hold shovels and dig a long trench more than one meter long and three or four feet deep. The floating soil is piled on the opposite side. Four people are behind and two people are beside. They use long brooms to blast into the ditch. Two people behind the six people use long-handled leather palms to kill those who are not cleaned by the blast. An official leads 200 people and 20 teams, which can get dozens of loads every day. When the locusts enter the ditch, they will lift the piled floating soil into the ditch and pound it. Why worry about not dying? Those in the wheat field are driven out by women and children, or sold or exchanged for wheat, all at the convenience of the people. Those hiding in the rocks near the river are mostly boiled with lime water. Those on the cliffs that cannot be reached by the long broom are blasted upward with a spray gun. In places where there are locusts, if it is not a sandy field, after catching the jumping ones, hire cattle to plow and pick out the seeds. Locusts are the same as peanuts, with 100 in each field. After all the locusts were picked up, the ground was flattened with a stone roller, and then it was dug out with an iron palladium. All of them were rotten. The methods established by the predecessors all refer to flat land, and never discuss the mountains. The flat land is plowed with oxen, and hundreds of sheep are used to trample it. In an instant, it becomes mud. This has been proven in practice.

This is a memorial submitted by Zhang Jixin to his superiors when he was the prefect of Shuoping, Shanxi Province in the 17th year of Daoguang (1837). He himself recorded that he had "been very hard at catching locusts in the past month", but there were still many eggs, which made him very anxious. It can be seen from this that the locusts caught could be sold for money. In fact, it was almost like a work-for-relief policy.