Rice planthopper control method

Abstract

The method for preventing and treating the rice planthoppers is easy and convenient to operate and short in time consumption, the preparation raw materials of the Mars components come from the nature, are easy to obtain and degrade, are environmentally friendly and non-toxic, have extremely small influence on the ecological system, and do not affect farmers to culture fishes and shrimps in the rice field while effectively preventing and treating the rice planthoppers.

Description

Technical Field

[0001] The present invention relates to the control of crop diseases and insect pests, and in particular to a method for controlling rice planthoppers. The present invention further relates to a compound and a composition capable of controlling rice planthoppers. Background Art

[0002] Rice planthoppers are the main pests that harm rice production and are listed in the first category of crop pests and diseases by the Ministry of Agriculture and Rural Affairs. They belong to the family of Homoptera, and are small in size, with a needle-shaped mouth and a generally pointed head. Rice planthoppers have migratory habits and cause serious harm to rice production in both the north and south of my country. The pests suck the sap of rice in the form of adults and nymphs, causing yellow leaves and plant withering, which hinders the growth of rice and causes the leaves to turn yellow, thus affecting photosynthesis and reducing the yield and quality of rice. Rice planthoppers not only directly harm rice, but also spread a variety of viruses, such as rice stripe leaf blight and black streaked dwarf disease. These diseases are extremely harmful to rice and difficult to control. During the rice panicle stage, the damage caused by rice planthoppers has the greatest impact on yield, resulting in a decrease in the number of grains per panicle and the thousand-grain weight. In severe cases, it can cause the rice plants to die and fall over, resulting in a total crop failure.

[0003] At present, spraying chemical pesticides is the main method for controlling rice leafhoppers, such as imidacloprid, thiamethoxam, pymetrozine, dinotefuran, chlorpyrifos, cypermethrin, avermectin, dichlorvos, triflubenzuron, etc. These pesticides have good control effects on rice leafhoppers. However, the use of chemical pesticides to control rice leafhoppers also brings various problems: first, the natural degradation time of many chemical pesticides is very long. Pesticides will not only remain in farmland, but also pollute the air, soil and water, and even remain in crops. Long-term excessive consumption may cause poisoning of humans and animals, posing a threat to human and animal health. Secondly, most chemical pesticides are broad-spectrum insecticides and lack selectivity. While controlling rice leafhoppers, they also kill beneficial microorganisms and natural enemy insects in farmland, destroying the ecological balance. Finally, the long-term single use of chemical pesticides will cause rice leafhoppers to develop resistance, which will gradually reduce the control effect, cause the continuous increase in the use of pesticides, and increase the difficulty of control. Summary of the invention

[0004] The main advantage of the present invention is to provide a compound for controlling rice planthoppers by disrupting the growth habits of rice planthoppers.

[0005] Another advantage of the present invention is to provide a compound for controlling rice planthoppers, the raw materials for its preparation come from nature, are easy to obtain and degrade, are environmentally friendly and non-toxic, and have little impact on the ecosystem. The compound for controlling rice planthoppers of the present invention can effectively control rice planthoppers while not affecting farmers' fish and shrimp farming in rice fields.

[0006] The present invention further provides a method for controlling rice planthoppers.

[0007] Other objects and features of the present invention will be fully reflected in the following detailed description.

[0008] According to one aspect of the present invention, a method for controlling rice planthoppers of the present invention, which can achieve the aforementioned objects and other objects and advantages, comprises the following steps:

[0009] Pour the unsaturated fatty acids evenly on the water surface of the rice field along the water surface near the ridge of the rice field;

[0010] The water surface of the paddy field is rippling for 15-20 minutes to form water waves and to form a continuously distributed oil film of the unsaturated fatty acid on the water surface of the paddy field and an oil film covering the rice plants from the water surface upward, wherein the unsaturated fatty acid has the following chemical formula:

[0011] CmHnO2, wherein m is 18, 20 or 22, n is 30, 32 or 34, and the amount of the unsaturated fatty acid is (1 to 2.5 kg) / mu.

[0012] Furthermore, the compound is cis-9-octadecenoic acid, cis-9, cis-12-octadecadienoic acid or cis-9 or cis-12, cis-15-octadecatrienoic acid.

[0013] Further objects and advantages of the present invention will be fully apparent from an understanding of the following description and the accompanying drawings.

[0014] These and other objects, features and advantages of the present invention will be more fully understood from the following detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Shown are the normal living habits of rice planthoppers in rice fields.

[0016] Figure 2 It is shown that after the compound or composition for controlling rice planthoppers is placed in the rice field, the life habits of the rice planthoppers are interrupted, and the rice planthoppers are even stuck to and physically killed by the compound for controlling rice planthoppers.

[0017] Figure 3 It is a schematic diagram of placing the compound (or composition) for controlling rice planthoppers of the present invention in a rice field.

[0018] Figure 4 The present invention is a flow chart of a method for placing a compound (or composition) for controlling rice planthoppers. DETAILED DESCRIPTION

[0019] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0020] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0021] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0022] As shown in the accompanying drawings of the present invention Figure 1 As shown in Figure 1, rice planthoppers migrate to rice fields with air currents and reproduce in the fields. The adults and nymphs of rice planthoppers prefer a humid environment and usually live on rice plants within 10 cm of the water surface, sucking the juice of the rice plants with their piercing-sucking mouthparts, affecting the growth of rice.

[0023] As shown in the accompanying drawings of the present invention Figure 2 As shown, the compound (or unsaturated fatty acid) for controlling rice planthoppers of the present invention is evenly distributed on the water surface, forming an oil film floating on the water surface (in fact, it should be a lot of small oil droplets floating on the water surface). After the oil film on the water surface contacts the rice plant, due to capillary action, an oil film extending upward from the water surface to cover the rice plant is formed. The viscosity of the unsaturated fatty acid for controlling rice planthoppers of the present invention is much greater than that of water (about 230 billion times that of water). Whether the rice planthoppers located on the water surface fall on the water surface or on the rice plant (rice planthoppers often live on rice plants within 10 cm from the water surface), once they contact the oil film, they will be stuck by the oil film and unable to move, and finally die because they cannot suck rice plants or their stomata are blocked.

[0024] Since the compound for controlling rice planthoppers of the present invention is based on the living habits of rice planthoppers, the rice planthoppers are killed by the oil film formed by the compound for controlling rice planthoppers of the present invention. Therefore, the compound for controlling rice planthoppers of the present invention has a particularly significant killing effect on rice planthopper nymphs, and can achieve a good control effect at the early stage of rice planthopper infestation.

[0025] It is noteworthy that the compound used for controlling rice planthoppers of the present invention is mainly unsaturated fatty acids, for example, cis-9-octadecenoic acid, cis-9, cis-12-octadecadienoic acid and cis-9, cis-12, cis-15-octadecatrienoic acid, which has a density less than water, is insoluble in water or only soluble in water, and is biodegradable when exposed to the natural environment. In addition, the compound used for controlling rice planthoppers of the present invention has a wide source, is easy to extract, is inexpensive, and has no odor.

[0026] However, although the compound for controlling rice planthoppers of the present invention can naturally unfold to form an oil film after being placed on the water surface, the speed of natural formation of the oil film is slow, and the rice plants in the rice field will also affect the formation of the oil film. In order to promote or accelerate the formation of the oil film of the compound for controlling rice planthoppers of the present invention and reduce the time cost of manual application of pesticides, the compound for controlling rice planthoppers of the present invention can be compounded with a film-forming agent and / or an extender to form a corresponding composition for use. Film-forming agents and diffusers can promote the formation of oil films, and promote the oil film to bypass rice plants, help the oil film climb the poles and form a coated oil film on the above-water part of the rice plants. The following are commonly used film-forming agents and their biochemical characteristics in the field of plant protection (see Table 1 for details) and commonly used diffusers and their biochemical characteristics in the field of plant protection (see Table 2 for details):

[0027] Table 1: Biochemical properties of commonly used film-forming agents

[0028] name Melting point Boiling Point Flash point toxicity degradation Dodecyl alcohol ester -50℃ 244℃ 120℃ Low toxicity Biodegradable Methyl laurate 5.2℃ 262℃ 94℃ Toxic to aquatic life Biodegradable Propylene glycol phenyl ether 19℃ 242.7℃ 115℃ Low toxicity Biodegradable Diethylene glycol butyl ether acetate -32℃ 246.4℃ 116℃ Irritating, toxic Biodegradable

[0029] Table 2: Biochemical characteristics of commonly used diffusers

[0030] name Melting point Boiling Point Flash point toxicity degradation Nonylphenol polyoxyethylene ether 46℃ 466℃ 242℃ Toxic to aquatic life Biodegradable Fatty alcohol polyoxyethylene ether 43℃ 100℃ 230℃ Non-toxic Biodegradable Castor Oil Polyoxyethylene Ether 4℃ 232℃ 257℃ Low toxicity Biodegradable Styrenylphenol polyoxyethylene ether 25℃ 585℃ 271℃ Low toxicity Biodegradable

[0031] The film-forming agent of the composition for controlling rice planthoppers of the present invention is preferably dodecyl alcohol ester and propylene glycol phenyl ether, and the diffusing agent is preferably castor oil polyoxyethylene ether and styrylphenol polyoxyethylene ether, which have low toxicity to aquatic organisms, are biodegradable, have low residue, have a low melting point, a high boiling point, are not easy to volatilize, have a high flash point, and are not flammable.

[0032] In order to demonstrate the implementation of the present invention, the following examples have been prepared and tested. However, these examples should not be considered to limit the scope of protection of the present invention.

[0033] The compounds for controlling rice planthoppers of the present invention will be described below with reference to specific examples.

[0034] Example 1: cis-9-octadecenoic acid

[0035] Cis-9-octadecenoic acid is a natural unsaturated fatty acid with the chemical formula C 18 H 34 O 2 , melting point is 13.4℃, boiling point is 283℃, flash point is 270.1℃, viscosity is 26cp at 25℃, and it has a slight lard smell.

[0036] Cis-9-octadecenoic acid is widely present in animal and vegetable oils and fats, such as meat, dairy products, olive oil, sunflower oil, corn oil, etc. Therefore, the raw material of cis-9-octadecenoic acid is widely available and has low cost.

[0037] Experiment on using cis-9-octadecenoic acid to kill rice planthoppers:

[0038] Take appropriate amount (1.0, 1.2, 1.5, 2.0 and 2.5 kg) of cis-9-octadecenoic acid, and pour it evenly on the water surface near the ridge of the experimental rice field (the area of ​​the experimental rice field is 1 mu), then walk along the ridge and use a bamboo rake to ripple the water surface to form water waves, and ripple the water surface for 15-20 minutes until cis-9-octadecenoic acid forms a continuously distributed oil film on the water surface of the rice field, and forms an oil film covering the rice plants from the water surface upward, then, At least 6 areas were randomly selected in the rice field (each area contained at least 3 clumps of rice plants and active rice planthoppers). Then, the parallel jump sampling method was used to observe the number of rice planthoppers in the selected rice field areas at 24 hours, 48 ​​hours, 72 hours and 96 hours. The number of rice planthoppers was counted and the insect population reduction rate was calculated according to the formula: insect population reduction rate (100%) = (number of insects before application - number of insects after application) / number of insects before application * 100%. The specific results are shown in Table 3 below.

[0039] Table 3: Results of the cis-9-octadecenoic acid application test

[0040]

[0041] Statistical results show that the insect population reduction rate gradually increased 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film was formed. After 96 hours of the oil film formation, the insect population was significantly reduced, effectively killing rice planthoppers.

[0042] The viscosity of cis-9-octadecenoic acid is much greater than that of water. No matter whether the rice planthopper falls on the oil film on the water surface or on the rice plant, once it comes into contact with the oil film, it will be stuck to the oil film and unable to move. Finally, it will die because it cannot suck the rice plant or its stomata are blocked. The melting point of cis-9-octadecenoic acid is 13.4℃, which can remain in liquid state during the rice growth cycle and effectively form an oil film. The boiling point is 283℃, which is not easy to volatilize. The flash point is 270.1℃, which is not easy to burn. It has a slight lard smell and will not form odor pollution and cause discomfort to people. The viscosity of cis-9-octadecenoic acid is appropriate, so that the oil film is formed by extremely small oil droplets, which will not cause the water in the rice field to quickly run out of oxygen in a short time, affecting the growth of fish and shrimp. In addition, since cis-9-octadecenoic acid is a natural unsaturated fatty acid, not only is the raw material for preparation easy to obtain, but its degradation rate is also fast, and it is not easy to cause environmental pollution.

[0043] Therefore, cis-9-octadecenoic acid is a suitable physical killing oil agent (or compound) according to the living habits of rice planthoppers, and it has no pollution or toxic effects on the environment, no residue, is safe and effective, and does not affect the growth of fish and shrimp in rice fields.

[0044] Example 2: cis-9-octadecenoic acid composition A

[0045] Preparation of cis-9-octadecenoic acid composition: 65 parts by weight of cis-9-octadecenoic acid are added into a container, and then 20 parts by weight of a film-forming agent (dodecyl alcohol ester and / or propylene glycol phenyl ether) and 15 parts by weight of a diffusing agent (castor oil polyoxyethylene ether and / or styrylphenol polyoxyethylene ether) are added, and stirred evenly until transparent to obtain cis-9-octadecenoic acid composition A.

[0046] Take an appropriate amount of cis-9-octadecenoic acid composition A (1.5, 2.0, 2.5, 3.0 and 3.5 kg), respectively, and pour it horizontally and evenly on the water surface near the ridge of the experimental rice field (the rice field area is 1 mu), then walk along the ridge while rippling the water surface with a bamboo rake to form water waves, and rippling the water surface for 5-8 minutes, the cis-9-octadecenoic acid composition A can form a continuously distributed oil film on the water surface of the rice field, and form an oil film covering the rice plants from the water surface upward, and then Afterwards, at least 6 areas were randomly selected in the rice field (each area contained at least 3 clumps of rice plants and there were active rice planthoppers). Afterwards, the parallel jump sampling method was used to observe the number of rice planthoppers in the selected rice field areas at 24 hours, 48 ​​hours, 72 hours and 96 hours. The number of rice planthoppers was counted and the insect population reduction rate was calculated according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%. The specific results are shown in Table 4 below.

[0047] Table 4: Results of the application test of cis-9-octadecenoic acid composition A

[0048]

[0049] Statistical results show that the insect population reduction rate gradually increases 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film is formed. After 96 hours of the oil film formation, the insect population is significantly reduced, effectively killing rice planthoppers. In addition, the diffusant and film-forming agent can accelerate the diffusion of the composition on the water surface and significantly shorten the oil film formation time, and improve the killing efficiency of rice planthoppers.

[0050] Example 3: cis-9-octadecenoic acid composition B

[0051] Preparation of cis-9-octadecenoic acid composition: 93 parts by weight of cis-9-octadecenoic acid are added into a container, and then 5 parts by weight of a film-forming agent (dodecyl alcohol ester and / or propylene glycol phenyl ether) and 2 parts by weight of a diffusing agent (castor oil polyoxyethylene ether and / or styrylphenol polyoxyethylene ether) are added, and stirred evenly until transparent to obtain cis-9-octadecenoic acid composition B.

[0052] Take appropriate amount of cis-9-octadecenoic acid composition B (1.5, 2.0, 2.5, 3.0 and 3.5 kg), respectively pour it horizontally and evenly on the water surface near the ridge of the experimental rice field (the rice field area is 1 mu), then walk along the ridge while rippling the water surface with a bamboo rake to form water waves, and rippling the water surface for 7-10 minutes, the cis-9-octadecenoic acid composition B can form a continuously distributed oil film on the water surface of the rice field, and form an oil film covering the rice plants from the water surface upward, Then, at least 6 areas were randomly selected in the rice field (each area contained at least 3 clumps of rice plants and there were active rice planthoppers). After that, the parallel jump sampling method was used to observe the number of rice planthoppers in the selected rice field areas at 24 hours, 48 ​​hours, 72 hours and 96 hours. The number of rice planthoppers was counted and the insect population reduction rate was calculated according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%. The specific results are shown in Table 5 below.

[0053] Table 5: Results of the application test of cis-9-octadecenoic acid composition B

[0054]

[0055]

[0056] Statistical results show that the insect population reduction rate gradually increases 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film is formed. After 96 hours of the oil film formation, the insect population is significantly reduced, effectively killing rice planthoppers. In addition, the diffusant and film-forming agent can accelerate the diffusion of the composition on the water surface and significantly shorten the oil film formation time, and improve the killing efficiency of rice planthoppers.

[0057] Example 4: cis-9, cis-12-octadecadienoic acid

[0058] Cis-9, cis-12-octadecadienoic acid is a natural unsaturated fatty acid with the chemical formula C 18 H 32 O 2 , melting point is -5℃, boiling point is 129℃, flash point is 273℃, viscosity is 20cp at 25℃, and has a slight odor.

[0059] Cis-9, cis-12-octadecadienoic acid is widely present in vegetable oils and animal fats, and its content in vegetable oils is relatively high, especially in walnut oil, sunflower seed oil, soybean oil, cottonseed oil, etc., where its content can reach more than 50%. Therefore, the raw material sources of cis-9, cis-12-octadecadienoic acid are extensive and the cost is low.

[0060] Experiment on using cis-9, cis-12-octadecadienoic acid to kill rice planthoppers:

[0061] Take appropriate amount (1.0, 1.2, 1.5, 2.0 and 2.5 kg) of cis-9, cis-12-octadecadienoic acid, pour it evenly on the water surface near the ridge of the experimental rice field (the area of ​​the experimental rice field is 1 mu), then walk along the ridge and use a bamboo rake to ripple the water surface to form water waves, and ripple the water surface for 15-20 minutes until cis-9, cis-12-octadecadienoic acid forms a continuously distributed oil film on the water surface of the rice field and forms a coating on the rice plants from the water surface upward. Oil film, then, randomly select at least 6 areas in the rice field (each area contains at least 3 clumps of rice plants and there are active rice planthoppers), then use the parallel jump sampling method to observe the number of rice planthoppers in the selected rice field area at 24 hours, 48 ​​hours, 72 hours and 96 hours, count the number of rice planthoppers, and calculate the insect population reduction rate according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%, the specific results are shown in Table 6 below.

[0062] Table 6: Results of the cis-9, cis-12-octadecadienoic acid application test

[0063]

[0064] Statistical results show that the insect population reduction rate gradually increased 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film was formed. After 96 hours of the oil film formation, the insect population was significantly reduced, effectively killing rice planthoppers.

[0065] The viscosity of cis-9, cis-12-octadecadienoic acid is much greater than that of water. No matter whether the rice planthopper falls on the oil film on the water surface or on the rice plant, once it contacts the oil film, it will be stuck to the oil film and unable to move. Finally, it will die because it cannot suck the rice plant or the stomata are blocked; the melting point of cis-9, cis-12-octadecadienoic acid is -5°C, which can remain liquid during the rice growth cycle and effectively form an oil film; the boiling point is 129°C, which is not easy to volatilize; the flash point is 273°C, which is not easy to burn; the odor is slight, and it is not easy to form odor pollution and cause discomfort to people; the viscosity of cis-9, cis-12-octadecadienoic acid is appropriate, so that the oil film is formed by extremely small oil droplets, which will not cause the water in the rice field to quickly deplete oxygen in a short time, affecting the growth of fish and shrimp. In addition, since cis-9, cis-12-octadecadienoic acid is a natural unsaturated fatty acid, not only is the raw material easy to obtain, but its degradation rate is also fast, and it is not easy to form environmental pollution.

[0066] Therefore, cis-9, cis-12-octadecadienoic acid is a suitable physical killing oil agent (or compound) according to the living habits of rice planthoppers, and it has no pollution or toxic effects on the environment, no residue, is safe and effective, and does not affect the growth of fish and shrimp in rice fields.

[0067] Example 5: Cis-9, cis-12-octadecadienoic acid composition A

[0068] Preparation of cis-9, cis-12-octadecadienoic acid composition: 65 parts by weight of cis-9, cis-12-octadecadienoic acid are added into a container, and then 20 parts by weight of a film-forming agent (dodecyl alcohol ester and / or propylene glycol phenyl ether) and 15 parts by weight of a diffusing agent (castor oil polyoxyethylene ether and / or styrylphenol polyoxyethylene ether) are added, and stirred evenly until transparent to obtain a cis-9, cis-12-octadecadienoic acid composition A.

[0069] Take an appropriate amount of cis-9, cis-12-octadecadienoic acid composition A (1.5, 2.0, 2.5, 3.0 and 3.5 kg), and pour it evenly on the water surface near the ridge of the experimental rice field (the rice field area is 1 mu), then walk along the ridge while rippling the water surface with a bamboo rake to form water waves, and rippling the water surface for 4-7 minutes, the cis-9, cis-12-octadecadienoic acid composition A can form a continuously distributed oil film on the water surface of the rice field, and form a coating on the rice plants from the water surface upward. Then, at least 6 areas were randomly selected in the paddy field (each area contained at least 3 clumps of rice plants and there were active rice planthoppers). After that, the number of rice planthoppers in the selected paddy field area was observed at 24 hours, 48 ​​hours, 72 hours and 96 hours by using the parallel jump sampling method. The number of rice planthoppers was counted and the insect population reduction rate was calculated according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%. The specific results are shown in Table 7 below.

[0070] Table 7: Results of the application test of cis-9, cis-12-octadecadienoic acid composition A

[0071]

[0072] Statistical results show that the insect population reduction rate gradually increases 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film is formed. After 96 hours of the oil film formation, the insect population is significantly reduced, effectively killing rice planthoppers. In addition, the diffusant and film-forming agent can accelerate the diffusion of the composition on the water surface and significantly shorten the oil film formation time, and improve the killing efficiency of rice planthoppers.

[0073] Example 6: cis-9, cis-12-octadecadienoic acid composition B

[0074] Preparation of cis-9, cis-12-octadecadienoic acid composition: 93 parts by weight of cis-9, cis-12-octadecadienoic acid are added into a container, and then 5 parts by weight of a film-forming agent (dodecyl alcohol ester and / or propylene glycol phenyl ether) and 2 parts by weight of a diffusing agent (castor oil polyoxyethylene ether and / or styrylphenol polyoxyethylene ether) are added, and stirred evenly until transparent to obtain a cis-9, cis-12-octadecadienoic acid composition B.

[0075] Take an appropriate amount of cis-9, cis-12-octadecadienoic acid composition B (1.5, 2.0, 2.5, 3.0 and 3.5 kg), respectively, and pour it horizontally and evenly on the water surface near the ridge of the experimental rice field (the rice field area is 1 mu), then walk along the ridge while rippling the water surface with a bamboo rake to form water waves, and rippling the water surface for 6-9 minutes, the cis-9, cis-12-octadecadienoic acid composition B can form a continuously distributed oil film on the water surface of the rice field, and form a coating on the rice plants from the water surface upward. Then, at least 6 areas were randomly selected in the paddy field (each area contained at least 3 clumps of rice plants and there were active rice planthoppers). After that, the number of rice planthoppers in the selected paddy field area was observed at 24 hours, 48 ​​hours, 72 hours and 96 hours by using the parallel jump sampling method. The number of rice planthoppers was counted and the insect population reduction rate was calculated according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%. The specific results are shown in Table 8 below.

[0076] Table 8: Results of the application test of cis-9, cis-12-octadecadienoic acid composition B

[0077]

[0078] Statistical results show that the insect population reduction rate gradually increases 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film is formed. After 96 hours of the oil film formation, the insect population is significantly reduced, effectively killing rice planthoppers. In addition, the diffusant and film-forming agent can accelerate the diffusion of the composition on the water surface and significantly shorten the oil film formation time, and improve the killing efficiency of rice planthoppers.

[0079] Example 7: cis-9, cis-12, cis-15-octadecatrienoic acid

[0080] Cis-9, cis-12, cis-15-octadecatrienoic acid is a natural unsaturated fatty acid with the chemical formula C 18 H 30 O 2 , melting point is -11℃, boiling point is 231℃, flash point is 287.4℃, viscosity is 28cp at 25℃, and it has a slight nutty flavor.

[0081] Cis-9, cis-12, cis-15-octadecatrienoic acid is widely present in nature, mainly from terrestrial plants. For example, Xanthoceras sorbifolia oil, walnut oil, soybean oil, rapeseed oil, etc. Cis-9, cis-12, cis-15-octadecatrienoic acid accounts for 67% in perilla seed oil, 55% in linseed oil, 42% in peony seed oil, 32% in seabuckthorn seed oil, 20% in Bama hemp oil, 10% in rapeseed oil, 8% in soybean oil, and 50% in star oil vine oil. Therefore, cis-9, cis-12, cis-15-octadecatrienoic acid has a wide range of raw materials and low cost.

[0082] Experiment on using cis-9, cis-12, cis-15-octadecatrienoic acid to kill rice planthoppers:

[0083] Take appropriate amounts (1.0, 1.2, 1.5, 2.0 and 2.5 kg) of cis-9, cis-12, cis-15-octadecatrienoic acid and pour them evenly on the water surface near the ridge of the experimental rice field (the area of ​​the experimental rice field is 1 mu), then walk along the ridge while rippling the water surface with a bamboo rake to form water waves, and rippling the water surface for 15-20 minutes until cis-9, cis-12, cis-15-octadecatrienoic acid forms a continuously distributed oil film on the water surface of the rice field and forms a layer of oil on the rice plants from the water surface upward. The oil film was coated on the rice plants. Then, at least 6 areas were randomly selected in the rice field (each area contained at least 3 clumps of rice plants and active rice planthoppers). After that, the parallel jump sampling method was used to observe the number of rice planthoppers in the selected rice field areas at 24 hours, 48 ​​hours, 72 hours and 96 hours. The number of rice planthoppers was counted and the insect population reduction rate was calculated according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%. The specific results are shown in Table 9 below.

[0084] Table 9: Results of the application test of cis-9, cis-12, cis-15-octadecatrienoic acid

[0085]

[0086] Statistical results show that the insect population reduction rate gradually increased 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film was formed. After 96 hours of the oil film formation, the insect population was significantly reduced, effectively killing rice planthoppers.

[0087] The viscosity of cis-9, cis-12, cis-15-octadecatrienoic acid is much greater than that of water. No matter the rice planthoppers falling on the oil film on the water surface or on the rice plants, once they come into contact with the oil film, they will be stuck to the oil film and unable to move, and finally die because they cannot suck the rice plants. The melting point of cis-9, cis-12, cis-15-octadecatrienoic acid is -11°C, and it can remain in liquid form during the rice growth cycle, effectively forming an oil film; the boiling point is 231°C, and it is not easy to evaporate; the flash point is 287.4°C, and it is not easy to burn; it has a slight nutty taste and will not form odor pollution and cause discomfort to people; the viscosity of cis-9, cis-12, cis-15-octadecatrienoic acid is appropriate, so that the oil film is formed by extremely small oil droplets, which will not cause the water in the rice field to quickly run out of oxygen in a short period of time, affecting the growth of fish and shrimp. In addition, since cis-9, cis-12, and cis-15-octadecatrienoic acid are natural unsaturated fatty acids, not only are the raw materials for preparation easy to obtain, but the degradation rate is also relatively fast, and it is not easy to cause environmental pollution.

[0088] Therefore, cis-9, cis-12, cis-15-octadecatrienoic acid is a suitable physical killing oil agent (or compound) according to the living habits of rice planthoppers, and it has no pollution or toxic effects on the environment, no residue, is safe and effective, and does not affect the growth of fish and shrimp in rice fields.

[0089] Example 8: cis-9, cis-12, cis-15-octadecatrienoic acid composition A

[0090] Preparation of cis-9, cis-12, cis-15-octadecatrienoic acid composition: 65 parts by weight of cis-9, cis-12, cis-15-octadecatrienoic acid are added into a container, and then 20 parts by weight of a film-forming agent (dodecyl alcohol ester and / or propylene glycol phenyl ether) and 15 parts by weight of a diffusing agent (castor oil polyoxyethylene ether and / or styrylphenol polyoxyethylene ether) are added, and the mixture is stirred evenly until transparent to obtain a cis-9, cis-12, cis-15-octadecatrienoic acid composition A.

[0091] Take an appropriate amount of cis-9, cis-12, cis-15-octadecatrienoic acid composition A (1.5, 2.0, 2.5, 3.0 and 3.5 kg), respectively, and pour it horizontally and evenly on the water surface near the ridge of the experimental rice field (the rice field area is 1 mu), then walk along the ridge while rippling the water surface with a bamboo rake to form water waves, and rippling the water surface for 4-7 minutes, the cis-9, cis-12, cis-15-octadecatrienoic acid composition A can form a continuously distributed oil film on the water surface of the rice field, and the oil film can be dispersed on the rice plants from the water surface upward. An oil film covering the rice plants was formed, and then at least 6 areas were randomly selected in the rice field (each area contained at least 3 clumps of rice plants and active rice planthoppers). After that, the parallel jump sampling method was used to observe the number of rice planthoppers in the selected rice field area at 24 hours, 48 ​​hours, 72 hours and 96 hours. The number of rice planthoppers was counted and the insect population reduction rate was calculated according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%. The specific results are shown in Table 10 below.

[0092] Table 10: Results of the application test of cis-9, cis-12, cis-15-octadecatrienoic acid composition A

[0093]

[0094] Statistical results show that the insect population reduction rate gradually increases 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film is formed. After 96 hours of the oil film formation, the insect population is significantly reduced, effectively killing rice planthoppers. In addition, the diffusant and film-forming agent can accelerate the diffusion of the composition on the water surface and significantly shorten the oil film formation time, and improve the killing efficiency of rice planthoppers.

[0095] Example 9: cis-9, cis-12, cis-15-octadecatrienoic acid composition B

[0096] Preparation of cis-9, cis-12, cis-15-octadecatrienoic acid composition: 93 parts by weight of cis-9, cis-12, cis-15-octadecatrienoic acid are added into a container, and then 5 parts by weight of a film-forming agent (dodecyl alcohol ester and / or propylene glycol phenyl ether) and 2 parts by weight of a diffusing agent (castor oil polyoxyethylene ether and / or styrylphenol polyoxyethylene ether) are added, and the mixture is stirred evenly until transparent to obtain a cis-9, cis-12, cis-15-octadecatrienoic acid composition B.

[0097] Take an appropriate amount of cis-9, cis-12, cis-15-octadecatrienoic acid composition B (1.5, 2.0, 2.5, 3.0 and 3.5 kg), respectively, and pour it horizontally and evenly on the water surface near the ridge of the experimental rice field (the rice field area is 1 mu), then walk along the ridge while rippling the water surface with a bamboo rake to form water waves, and rippling the water surface for 6-9 minutes, the cis-9, cis-12, cis-15-octadecatrienoic acid composition B can form a continuously distributed oil film on the water surface of the rice field, and the oil film can be dispersed on the rice plants from the water surface upward. An oil film covering the rice plants is formed, and then at least 6 areas are randomly selected in the rice field (each area contains at least 3 clumps of rice plants and active rice planthoppers). After that, the parallel jump sampling method is used to observe the number of rice planthoppers in the selected rice field area at 24 hours, 48 ​​hours, 72 hours and 96 hours. The number of rice planthoppers is counted and the insect population reduction rate is calculated according to the formula: insect population reduction rate (100%) = (insect number before application - insect number after application) / insect number before application * 100%. The specific results are shown in Table 11 below.

[0098] Table 11: Results of the application test of cis-9, cis-12, cis-15-octadecatrienoic acid composition B

[0099]

[0100]

[0101] The statistical results show that the insect population reduction rate gradually increases 24 hours, 48 ​​hours, 72 hours and 96 hours after the oil film is formed. After 96 hours of the oil film formation, the insect population is significantly reduced, and the rice planthopper is effectively killed. In addition, the diffusant and the film-forming agent can accelerate the diffusion of the composition on the water surface and significantly shorten the oil film formation time, and improve the killing efficiency of rice planthoppers. In addition, the statistical results show that cis-9, cis-12, cis-15-octadecatrienoic acid is better than cis-9-octadecenoic acid and cis-9, cis-12-octadecadienoic acid in killing rice planthoppers. This may be because the viscosity of cis-9, cis-12, cis-15-octadecatrienoic acid is slightly larger, or because rice planthoppers are more affinity to cis-9, cis-12, cis-15-octadecatrienoic acid.

[0102] There are about 40 kinds of fatty acids in nature, but most of them are not suitable for killing rice planthoppers in paddy fields because of their high melting points and solid state at room temperature; or because of their high volatility; or because of their low viscosity, the oil film formed is too continuous, affecting the growth of aquatic organisms; or because of their high viscosity, they cannot form an oil film; or because of their low flash point; or because of their odor; or because they are too stable and degrade too slowly; or because of their low content and high extraction cost; or because of their toxicity, etc.

[0103] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are only for illustrative purposes and are not intended to limit the present invention.

[0104] The purpose of the present invention has been completely and effectively achieved. The functional and structural principles of the present invention have been demonstrated and explained in the embodiments, and the embodiments of the present invention may be deformed or modified in any way without departing from the principles.

Claims

1. A method for controlling rice planthoppers, characterized in that: The steps include: Pour the unsaturated fatty acids evenly on the water surface of the rice field along the water surface near the ridge of the rice field; The water surface of the paddy field is rippling for 15-20 minutes to form water waves and to form a continuously distributed oil film of the unsaturated fatty acid on the water surface of the paddy field and an oil film covering the rice plants from the water surface upward, wherein the unsaturated fatty acid has the following chemical formula: C m H n O2, wherein m is 18, 20 or 22, n is 30, 32 or 34, and the amount of the unsaturated fatty acid is (1 to 2.5 kg) / mu.

2. The method for controlling rice planthoppers according to claim 1, characterized in that: The unsaturated fatty acid is cis-9-octadecenoic acid, cis-9, cis-12-octadecadienoic acid or cis-9 or cis-12, cis-15-octadecatrienoic acid.

3. The method for controlling rice planthoppers according to claim 2, characterized in that: The unsaturated fatty acid is cis-12, cis-15-octadecatrienoic acid.

4. A method for controlling rice planthoppers, characterized in that: The steps include: Pour the composite composition evenly and horizontally on the water surface of the rice field along the water surface near the ridge of the rice field; The water surface of the paddy field is rippling for 15-20 minutes to form water waves and to form a continuously distributed oil film of the composite composition on the water surface of the paddy field and an oil film covering the rice plants upward from the water surface, wherein the amount of the composite composition is (1.5-3.5 kg) / mu, wherein the composite composition contains: 65 to 93 parts by weight of active ingredient; 5 to 20 parts by weight of a film-forming agent; and 2 to 15 parts by weight of a dispersant, wherein the active ingredient is an unsaturated fatty acid having the following chemical formula: C m H n O2, wherein m is 18, 20 or 22, n is 30, 32 or 34, the film-forming agent is dodecyl alcohol ester and / or propylene glycol phenyl ether, and the diffusing agent is castor oil polyoxyethylene ether and / or styrylphenol polyoxyethylene ether.

5. The method for controlling rice planthoppers according to claim 3, characterized in that: The unsaturated fatty acid is cis-9-octadecenoic acid, cis-9, cis-12-octadecadienoic acid or cis-9 or cis-12, cis-15-octadecatrienoic acid.

6. The method for controlling rice planthoppers according to claim 5, characterized in that: The unsaturated fatty acid is cis-12, cis-15-octadecatrienoic acid.

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