Natural insecticide and preparation method thereof

Abstract

The invention provides a natural insecticide and a preparation method thereof. The natural insecticide is mainly prepared from the following substances: beauveria bassiana, diatomite, chitinase, montmorillonite, fish scale collagen peptide, a dispersing agent, a humectant and water. Wherein the mass ratio of the beauveria bassiana to the chitinase is (2-3): 1, and the mass ratio of the montmorillonite additive to the fish scale collagen peptide is 1: (1-2). Beauveria bassiana is used as a main insecticidal substance, chitinase is combined, so that the insecticidal efficiency of the Beauveria bassiana is further improved, and the montmorillonite additive and fish scale collagen peptide enable the Beauveria bassiana to resist ultraviolet rays, so that the Beauveria bassiana is not easy to inactivate when irradiated by the ultraviolet rays, and the insecticidal effect is good. By using the beauveria bassiana to prevent the hippophae rhamnoides moth from infringing the hippophae rhamnoides, the hippophae rhamnoides moth can be prevented and treated when the hippophae rhamnoides moth does not moth tree roots, the pressure of prevention and treatment is greatly relieved, and pesticide pollution to soil and pesticide residues on tree bodies are reduced.

Description

Technical Field

[0001] The present invention relates to the field of agricultural technology, in particular to a natural insecticide and a preparation method thereof. Background Art

[0002] Seabuckthorn not only has the functions of preventing wind and fixing sand and conserving water and soil, but also has a high medical and health care function; it is reported that seabuckthorn oil contains more than 200 active substances that are beneficial to humans and mammals, which can enhance the immunity of consumers, protect and repair gastric mucosa, and reduce the cholesterol content in blood vessel walls; now a variety of related products such as food, beverages, medicine, health care, cosmetics, feed, etc. have been developed, with huge market potential. Therefore, seabuckthorn not only has potential ecological benefits, but also has great economic benefits; but once this type of pest occurs, it is difficult for the plant to recover, and once it occurs, the existing prevention and control measures have not been ideal; according to investigations, the main stem and root borers that harm seabuckthorn are seabuckthorn wood borers, red-margined longhorn beetles, aromatic wood borers, and sand willow wood borers, among which seabuckthorn wood borers are the most harmful, causing large-scale deaths in seabuckthorn forests; due to the harm of seabuckthorn wood borers, the mortality rate of seabuckthorn over 8 years old is more than 85%; so effective prevention and control of seabuckthorn wood borers is imminent.

[0003] According to the survey conducted by Zhou Zhangyi et al. in 2001, the vertical distribution pattern of seabuckthorn borer larvae on seabuckthorn trees is consistent, whether they are 13-year-old or 21-year-old seabuckthorn trees. About 80% of the larvae are distributed in the roots, of which 0-10cm roots below the ground account for 40.5%-55.8%, 10-20cm roots account for 24.8%-35.9%, and roots above 20cm account for 0.6%-1.3%. The remaining 20% ​​or so are infested at the root neck. In short, once seabuckthorn borer bores into the roots, it is difficult to prevent and control, and a large amount of pesticides must be injected to control the damage. Therefore, if seabuckthorn borer can be prevented and controlled before it bores into the roots, it will greatly reduce the pressure of prevention and control and reduce soil pesticide pollution and pesticide residues in the tree.

[0004] As a natural fungus, Beauveria bassiana can adhere well to suitable insect or mite hosts. In the sea buckthorn wood borer control project, by finding the naturally parasitic Beauveria bassiana insects, Beauveria bassiana passes through the host and multiplies in large quantities, and absorbs nutrients from the host's body through hyphae, causing the host to die. However, since Beauveria bassiana grows germ tubes at the intersegmental membranes of the insect's body wall where the chitin is thinner, the germ tubes secrete chitinase to dissolve the chitin into a small hole, and the germination tubes enter the insect body to infect, the process is relatively slow, and Beauveria bassiana has high requirements for the environment. Changes in humidity and ultraviolet rays can cause it to lose its activity, thereby affecting its insecticidal effect. Therefore, how to use Beauveria bassiana to prepare a natural, environmentally friendly insecticide that can improve the insecticidal efficiency while enabling it to adapt to environmental changes and maintain activity to achieve excellent insecticidal effects is the key to preparing natural insecticides.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The first purpose of the present invention is to provide a natural insecticide, which uses Beauveria bassiana as the main insecticidal raw material to prepare a natural and pollution-free insecticide, and through the mutual compatibility of various raw materials, the Beauveria bassiana is not easily inactivated when the surrounding environment changes, thereby improving the insecticidal efficiency of the insecticide.

[0007] The second object of the present invention is to provide a method for preparing a natural insecticide, which is simple to operate and has mild operating conditions.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted: The invention provides a natural insecticide, which is mainly prepared from the following substances: Beauveria bassiana, diatomaceous earth, chitinase, montmorillonite, fish scale collagen peptide, dispersant, moisturizer and water; The mass ratio of Beauveria bassiana to chitinase is (2-3):1, and the mass ratio of montmorillonite to fish scale collagen peptide is 1:(1-2).

[0009] In the natural insecticide of the present invention, Beauveria bassiana is mainly used as the main insecticide. As an entomogenous fungus of the ascomycetes class, Beauveria bassiana mainly enters the insect body through insect feeding or stomata, or contacts the insect body surface to secrete a variety of cuticle degrading enzymes, and then produces germ tubes to penetrate the insect body wall to enter the insect body cavity, absorbs nutrients from the host insect body through the germ tubes and reproduces in large quantities in the host insect body. In this process, Beauveria bassiana will secrete a large amount of Beauveria bassiana toxins and enzymes, and the generated Beauveria bassiana toxins and enzymes can further destroy the insect's organs. body tissues, thereby causing the pests to die due to being unable to maintain normal life activities. Therefore, by using Beauveria bassiana as the main insecticide, it can effectively prevent and control the damage of seabuckthorn wood borer to seabuckthorn wood. Moreover, since it is a microbial agent, its insecticidal method is mainly to infect pests and kill them. Compared with traditional insecticides, it is more environmentally friendly and will not cause any pollution to agricultural products, the environment and the soil. Therefore, by using Beauveria bassiana as the main insecticide, a natural insecticide is prepared, which has high insecticidal efficiency and excellent environmental friendliness.

[0010] In order to make the prepared insecticide have a better insecticidal efficiency, the present invention adds diatomaceous earth, and achieves a better insecticidal effect through the joint action of diatomaceous earth and Beauveria bassiana, wherein Beauveria bassiana germinates under suitable temperature and conditions after the spores contact the insect body, and the growth bud tube penetrates the insect body wall and extends into the body of the pest, produces a large number of hyphae and secretes toxins, affects blood circulation, interferes with metabolism, makes the pest sick and eventually dies. The sharp edge of diatomaceous earth can scratch the insect body, causing it to dehydrate and die. The insecticide prepared by combining the two can kill pests more effectively, and because of the hole structure of diatomaceous earth, the spores of Beauveria bassiana can be protected from being affected by the environment and thus lose activity when the two are used in combination, affecting its insecticidal effect.

[0011] The present invention also adds montmorillonite and fish scale collagen peptides so that the prepared insecticide can resist ultraviolet radiation, thereby ensuring that the insecticide can be used in a variety of environments. Due to the layered structure and charge characteristics of the montmorillonite molecules, the areas between the montmorillonite molecules can easily adsorb microorganisms, thereby playing a protective and light-shielding function, thereby protecting Beauveria bassiana from ultraviolet radiation that affects its activity. The adsorption of microorganisms by montmorillonite can also well prolong the effective period of the insecticide, allowing it to adapt to a variety of environments. Montmorillonite can also be interlocked with fish scale collagen peptides, so that the fish scale collagen peptides can form a dense protective film on the surface of the montmorillonite, further protecting Beauveria bassiana and allowing it to greatly avoid ultraviolet radiation.

[0012] Preferably, as a further specific embodiment, the mass ratio of Beauveria bassiana to diatomaceous earth is 1:(1-1.5); Preferably, the mass ratio of Beauveria bassiana to diatomaceous earth is 1:1.2.

[0013] Therefore, it can be seen that for the present invention, the mass ratio between Beauveria bassiana and diatomaceous earth is very important. This is because the way in which diatomaceous earth protects Beauveria bassiana is mainly to hide the spores of Beauveria bassiana through the porous structure of diatomaceous earth, so as to avoid inactivation caused by direct sunlight, thereby prolonging the use effect of Beauveria bassiana. Therefore, when the two are in an appropriate ratio, that is, the mass ratio of Beauveria bassiana to diatomaceous earth is 1: (1-1.5), preferably when the mass ratio of Beauveria bassiana to diatomaceous earth is 1: 1.2, the insecticide prepared by mixing the two can not only better resist ultraviolet radiation, but also further enhance the insecticidal effect. If the diatomaceous earth is excessive, the excess diatomaceous earth will be stacked, thereby affecting the release of Beauveria bassiana, and the excess diatomaceous earth will cause pollution to the environment. If the amount of diatomaceous earth is too little, a part of Beauveria bassiana will not be hidden in the pore structure of the diatomaceous earth, so that it is possible to lose activity after being irradiated by ultraviolet rays, affecting its insecticidal effect.

[0014] Preferably, as a further specific embodiment, the moisturizing agent is one or more of glycerin, hyaluronic acid, polyethylene glycol, panthenol, sorbitol, sodium carboxymethyl cellulose and sodium alginate; Preferably, the moisturizing agent is one or more of glycerol, hyaluronic acid, polyethylene glycol and sodium alginate; Preferably, the moisturizing agent is a mixture of glycerin, hyaluronic acid and sodium alginate.

[0015] Preferably, as a further specific embodiment, the mass ratio of glycerol, hyaluronic acid and sodium alginate is (1-2): (2-3): 1.

[0016] Preferably, as a further specific embodiment, the mass ratio of glycerol, hyaluronic acid and sodium alginate is 2:3:1.

[0017] In the present invention, since the main insecticide Beauveria bassiana used has extremely high requirements for the environment, among which humidity has a crucial impact on the growth of Beauveria bassiana, suitable humidity can well catalyze the spore germination and mycelial growth of Beauveria bassiana, a moisturizer is added to maintain the humidity required by Beauveria bassiana during its growth. In the present invention, there are certain requirements for the selection of moisturizing agents. When the moisturizing agent is one or more of glycerol, hyaluronic acid, polyethylene glycol, panthenol, sorbitol, sodium carboxymethyl cellulose and sodium alginate, preferably one or more of glycerol, hyaluronic acid, polyethylene glycol and sodium alginate, and more preferably a mixture of glycerol, hyaluronic acid and sodium alginate, the insecticide prepared by mixing it with Beauveria bassiana has excellent insecticidal effect. At the same time, when the mass ratio of the glycerol, hyaluronic acid and sodium alginate is (1-2): (2-3): 1, preferably the mass ratio is 2:3:1, the moisturizing agent prepared by mixing glycerol, hyaluronic acid and sodium alginate can better maintain the humidity requirements of Beauveria bassiana during its growth process, and avoid the growth and germination of Beauveria bassiana being affected by changes in humidity, thereby affecting the insecticidal effect. In the moisturizing agent of the present invention, glycerol is used to form a thin film on the surface of Beauveria bassiana to effectively block the evaporation of water, and glycerol can also absorb water from the air while blocking the evaporation of water. Absorbing water to maintain humidity for Beauveria bassiana, and hyaluronic acid itself has strong adsorption and water-locking ability, and can work together with glycerol to form a tighter film on the surface of Beauveria bassiana, thereby achieving a better water-locking effect, and due to the strong water-absorbing ability of glycerol, the humidity required for the growth and germination of Beauveria bassiana can be well maintained, and sodium alginate has a certain viscosity itself, and when it works together with glycerol and hyaluronic acid, it can form a thin film on the surface of Beauveria bassiana, which can have a certain protective effect on Beauveria bassiana. Therefore, the present invention uses a mixture of the three as a humectant to achieve the desired humidity for the growth and germination of Beauveria bassiana, while also having a certain protective effect on Beauveria bassiana. If the amount of sodium alginate is excessive, the prepared humectant will be too viscous, and then adhere to the surface of Beauveria bassiana, which is not conducive to the growth and germination of Beauveria bassiana hyphae. If the amount of glycerol is excessive, a large amount of glycerol will absorb too much moisture in the air, so that the humidity is too high, thereby affecting the growth and germination of Beauveria bassiana.

[0018] Preferably, as a further specific embodiment, the dispersant is a mixture of sodium lignin sulfonate and polyurethane.

[0019] Preferably, as a further specific embodiment, the mass ratio of the sodium lignin sulfonate to the polyurethane is 1:(1-2); Preferably, the mass ratio of the sodium lignin sulfonate to the polyurethane is 1:2.

[0020] The insecticide of the present invention is also added with a dispersant so that the Beauveria bassiana can remain stable during the preparation process of the insecticide, avoiding uneven dispersion during the stirring process. The selection of the dispersant for the present invention is also limited. When the dispersant is a mixture of sodium lignin sulfonate and polyurethane, and the mass ratio of sodium lignin sulfonate to polyurethane is 1:2, the insecticide prepared therefrom has excellent insecticidal effect. This is because sodium lignin sulfonate can be adsorbed on the surface of solid particles to form a protective film to prevent the mutual aggregation of various raw materials, and sodium lignin sulfonate can further reduce the surface tension of water, thereby maintaining the humidity required for the growth and germination of Beauveria bassiana. The sodium lignin sulfonate can further improve the dispersion performance by working together with the polyurethane, effectively preventing the aggregation and agglomeration of the raw material particles in the insecticide, causing the raw materials to be unevenly dispersed, thereby affecting the insecticidal effect.

[0021] The present invention also provides a method for preparing the above-mentioned natural insecticide, comprising the following steps: The montmorillonite and diatomaceous earth are crushed respectively to obtain montmorillonite powder and diatomaceous earth powder; Mix diatomaceous earth powder, Beauveria bassiana and water, and stir evenly to obtain a suspension; Mixing montmorillonite powder, fish scale collagen peptide and water to obtain montmorillonite additive; The suspension, montmorillonite additive, dispersant, moisturizing agent and chitinase are added in sequence and the mixture is kept at a constant temperature to obtain the product.

[0022] Preferably, as a further specific implementation, the mass ratio of the suspension to the montmorillonite additive is 1:(1-2).

[0023] Preferably, as a further specific implementation, the mass ratio of the suspension to the montmorillonite additive is 1:2.

[0024] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a natural insecticide, which uses Beauveria bassiana as the main insecticide raw material to prepare a natural and pollution-free insecticide. The various raw materials are compatible with each other, so that Beauveria bassiana is not easily inactivated when the surrounding environment changes, thereby improving the insecticidal efficiency of the insecticide.

[0025] (2) The present invention provides a method for preparing a natural insecticide, which is simple to operate and has mild operating conditions. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below in conjunction with specific implementation methods, but those skilled in the art will understand that the embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] In order to more clearly explain the technical solution of the present invention, it is described in the form of specific embodiments below.

[0028] Example 1 A method for preparing a natural insecticide of the present invention is specifically as follows: The Beauveria bassiana used in the present invention is Beauveria bassiana, wherein the Beauveria bassiana is a Beauveria bassiana suspension, purchased from Deqiang Biological Co., Ltd. at a concentration of 30 billion spores / gram of Beauveria bassiana; The raw materials are respectively prepared with a mass ratio of Beauveria bassiana to chitinase of 2:1 and a mass ratio of Beauveria bassiana to diatomaceous earth of 1:1; The montmorillonite and diatomaceous earth are crushed respectively to obtain montmorillonite powder and diatomaceous earth powder; Add diatomaceous earth powder, Beauveria bassiana and water to the reaction kettle in sequence, open the reaction kettle to stir, and mix evenly to obtain a suspension; Then, the montmorillonite powder and the fish scale collagen peptide were taken out for use in a mass ratio of 1:1, mixed with water and poured into another reactor, the reactor was opened for stirring, and the montmorillonite additive was obtained after mixing evenly; Then, the suspension, montmorillonite additive, sodium lignin sulfonate, glycerol and chitinase were added in sequence, wherein the mass ratio between the suspension and the montmorillonite additive was 1:1, and the mixture was obtained after being kept at a constant temperature of 80° C. for 2 hours.

[0029] Example 2 A method for preparing a natural insecticide of the present invention is specifically as follows: The Beauveria bassiana used in the present invention is Beauveria bassiana, wherein the Beauveria bassiana is a Beauveria bassiana suspension, purchased from Deqiang Biological Co., Ltd. at a concentration of 30 billion spores / gram of Beauveria bassiana; The raw materials are respectively prepared with a mass ratio of Beauveria bassiana to chitinase of 3:1 and a mass ratio of Beauveria bassiana to diatomaceous earth of 1:1.5; The montmorillonite and diatomaceous earth are crushed respectively to obtain montmorillonite powder and diatomaceous earth powder; Add diatomaceous earth powder, Beauveria bassiana and water to the reaction kettle in sequence, open the reaction kettle to stir, and mix evenly to obtain a suspension; Then, the montmorillonite powder and the fish scale collagen peptide were taken out for use in a mass ratio of 1:2, mixed with water and poured into another reactor, the reactor was opened for stirring, and the montmorillonite additive was obtained after mixing evenly; Then, the suspension, montmorillonite additive, sodium lignin sulfonate, glycerol and chitinase were added in sequence, wherein the mass ratio of the suspension to the montmorillonite additive was 1:2, and the mixture was obtained after being kept at a constant temperature of 80° C. for 2 hours.

[0030] Example 3 A method for preparing a natural insecticide of the present invention is specifically as follows: The Beauveria bassiana used in the present invention is Beauveria bassiana, wherein the Beauveria bassiana is a Beauveria bassiana suspension, purchased from Deqiang Biological Co., Ltd. at a concentration of 30 billion spores / gram of Beauveria bassiana; The raw materials are respectively prepared with a mass ratio of Beauveria bassiana to chitinase of 2:1 and a mass ratio of Beauveria bassiana to diatomaceous earth of 1:1.2; The montmorillonite and diatomaceous earth are crushed respectively to obtain montmorillonite powder and diatomaceous earth powder; Add diatomaceous earth powder, Beauveria bassiana and water to the reaction kettle in sequence, open the reaction kettle to stir, and mix evenly to obtain a suspension; Then, the montmorillonite powder and the fish scale collagen peptide were taken out for use in a mass ratio of 1:1.5, mixed with water and poured into another reactor, the reactor was opened for stirring, and the montmorillonite additive was obtained after mixing evenly; Then, the suspension, montmorillonite additive, sodium lignin sulfonate, glycerol and chitinase were added in sequence, wherein the mass ratio of the suspension to the montmorillonite additive was 1:2, and the mixture was obtained after being kept at a constant temperature of 80° C. for 2 hours.

[0031] Example 4 The specific implementation steps are the same as those in Example 3, except that the mass ratio of Beauveria bassiana to chitinase is adjusted to 1:1.

[0032] Example 5 The specific implementation steps are the same as those in Example 3, except that the mass ratio of Beauveria bassiana to chitinase is adjusted to 4:1.

[0033] Example 6 The specific implementation steps are the same as those in Example 3, except that the mass ratio of montmorillonite powder to fish scale collagen peptide is adjusted to 1:0.5.

[0034] Example 7 The specific implementation steps are the same as those in Example 3, except that the mass ratio of montmorillonite powder to fish scale collagen peptide is adjusted to 1:3.

[0035] Example 8 The specific implementation steps are the same as those in Example 3, except that the mass ratio of Beauveria bassiana to diatomaceous earth is adjusted to 1:0.5.

[0036] Example 9 The specific implementation steps are the same as those in Example 3, except that the mass ratio of Beauveria bassiana to diatomaceous earth is adjusted to 1:2.

[0037] Example 10 The specific implementation steps are the same as those in Example 3, except that the moisturizer is replaced by hyaluronic acid.

[0038] Embodiment 11 The specific implementation steps are the same as those in Example 3, except that the moisturizer is replaced by sodium alginate.

[0039] Example 12 The specific implementation steps are the same as those in Example 3, except that the moisturizer is replaced by a mixture of sodium alginate and panthenol.

[0040] Embodiment 13 The specific implementation steps are the same as those in Example 3, except that the moisturizer is replaced by a mixture of hyaluronic acid and glycerin.

[0041] Embodiment 14 The specific implementation steps are the same as those in Example 3, except that the moisturizer is replaced by a mixture of sodium carboxymethyl cellulose, sodium alginate and polyethylene glycol.

[0042] Embodiment 15 The specific implementation steps are the same as those of Example 3, except that the moisturizer is replaced by a mixture of glycerol, hyaluronic acid and sodium alginate, and the mass ratio of glycerol, hyaluronic acid and sodium alginate is 1:2:1.

[0043] Example 16 The specific implementation steps are the same as those of Example 3, except that the moisturizer is replaced by a mixture of glycerol, hyaluronic acid and sodium alginate, and the mass ratio of glycerol, hyaluronic acid and sodium alginate is 2:3:1.

[0044] Embodiment 17 The specific implementation steps are the same as those of Example 16, except that the moisturizer is replaced by a mixture of glycerol, hyaluronic acid and sodium alginate, and the mass ratio of glycerol, hyaluronic acid and sodium alginate is 1:1:1.

[0045] Embodiment 18 The specific implementation steps are the same as those in Example 16, except that the dispersant is replaced by polyurethane.

[0046] Embodiment 19 The specific implementation steps are consistent with Example 16, except that the dispersant is replaced by a mixture of sodium lignin sulfonate and polyurethane, and the mass ratio of sodium lignin sulfonate to polyurethane is 1:1.

[0047] Embodiment 20 The specific implementation steps are the same as those in Example 19, except that the mass ratio of sodium lignin sulfonate to polyurethane is adjusted to 1:2.

[0048] Comparative Example 1 The specific implementation steps are the same as those in Example 20, except that diatomaceous earth is not used.

[0049] Comparative Example 2 The specific implementation steps are the same as those in Example 20, except that montmorillonite additive is not used.

[0050] Comparative Example 3 The specific implementation steps are the same as those in Example 20, except that no moisturizer is used.

[0051] Comparative Example 4 The specific implementation steps are the same as those in Example 20, except that no dispersant is used. Comparative Example 5 The specific implementation steps are the same as those in Example 20, except that chitinase is not used.

[0052] Comparative Example 6 The specific implementation steps are the same as those in Example 20, except that montmorillonite powder is not used, that is, only fish scale collagen peptide and water are used.

[0053] Comparative Example 7 The specific implementation steps are the same as those in Example 20, except that fish scale collagen peptide is not used, that is, only montmorillonite powder and water are used.

[0054] Experimental Example 1 Insecticidal efficiency determination 1 Experimental Materials 1.1 Insect sources for testing The sea buckthorn borer moth isolated from sea buckthorn trees in Ordos City; 1.2 Tested insecticides The natural insecticides prepared in Examples 1-20 and Comparative Examples 1-7 of the present invention and the common insecticides on the market 2. Experimental Procedure The natural insecticides prepared in Examples 1-20 and Comparative Examples 1-7 were added with sterile water to prepare a 10 mg / mL dilution, and the commercially available insecticides were diluted 1000 times. 100 μL of different insecticides were added to the well plate, and seabuckthorn wood borer was added, with distilled water as the blank group. The mortality rate of seabuckthorn wood borer was observed at 12h, 24h, and 48h respectively. The death standard of seabuckthorn wood borer: The seabuckthorn wood borer whose body remains motionless is dead when the insect body is physically stimulated, and the corrected mortality rate is calculated. Death was confirmed after the physical stimulation was repeated three times, and the results are shown in Table 1 below:

[0055] Experimental Example 2 Screening of Moisturizers In this experimental example, the selection of the moisturizer and the ratio adjustment between the moisturizer raw materials are mainly determined based on the spore germination rate of Beauveria bassiana. If the spore germination rate is lower than the preset germination rate, it means that the moisturizer is not conducive to the germination of the Beauveria bassiana spores. The preset germination rate is 80%; The calculation formula of the spore germination rate β is as follows: ; Wherein, N0 is the number of all successfully germinated spores in the spore suspension extracted based on the preset extraction volume, and N1 is the number of all spores in the spore suspension extracted based on the preset extraction volume.

[0056] It is understood that the spore germination rate of Beauveria bassiana is the ratio of spores that can successfully germinate and grow into mycelium under certain conditions. If the spore germination rate is lower than the preset germination rate, it means that the moisturizer is not suitable and cannot provide a certain humidity environment for the growth of Beauveria bassiana. The spores do not absorb enough water, making it difficult to germinate into mycelium.

[0057] The specific steps are: The test for obtaining the spore germination rate generally includes collecting spores from the culture medium and appropriately diluting them to prepare a spore suspension, extracting the spore suspension based on a preset extraction volume, and recording the number of successfully germinated spores using a hemocytometer. The germination standard is that the spores produce obvious germ tubes, and the length of the germ tube exceeds half of the diameter of the spore itself. The preset extraction volume is 10 μL; The specific steps are: Preparation of moisturizing culture medium: selecting nutrient raw materials required for the growth of Beauveria bassiana, sterilizing them at high temperature, mixing them with 80g of distilled water, and stirring them evenly to form a basal culture medium; then selecting humectants as glycerol, hyaluronic acid, polyethylene glycol, panthenol, sorbitol, sodium carboxymethyl cellulose, and sodium alginate as experimental groups 1-8; glycerol and hyaluronic acid mixed in a mass ratio of 1:1, hyaluronic acid and sodium alginate mixed in a mass ratio of 1:1, glycerol, sorbitol and sodium alginate mixed in a mass ratio of 1:1:1, glycerol, hyaluronic acid and sodium alginate mixed in a mass ratio of 1:2:1, glycerol, hyaluronic acid and sodium alginate mixed in a mass ratio of 1:3:1, glycerol, hyaluronic acid and sodium alginate mixed in a mass ratio of 2:2:1, glycerol, hyaluronic acid and sodium alginate mixed in a mass ratio of 2:3:1 as experimental groups 9-15 to prepare moisturizing substances, and then pouring the moisturizing substances into a glass culture dish with a diameter of 15 cm; Inoculation: Use a pipette to draw 1 mL of Beauveria bassiana spore suspension, and inoculate it evenly on the surface of the culture medium in each glassware under sterile conditions. Place the inoculated glass culture dishes in a constant temperature incubator at 30°C and a relative humidity of 50% for incubation; Measurement: Observe, measure and calculate the inoculated glass culture dishes under different target conditions. The target conditions and measurement indicators are as follows: A: Average spore germination rate 3 hours, 6 hours and 12 hours after inoculation, take out 0.1g of culture medium from the glass culture dish, add 0.1% Tween-80 solution to fully dissolve and filter. Prepare a spore suspension with a concentration of 1.0×105 / mL from the filtered bacterial liquid. Take 10μL of the suspension onto a hemocytometer, observe the spore germination under a microscope, and calculate the average spore germination rate. B: Average spore content 7 days after the inoculation, the glass culture dish was baked at 60°C for 48 hours, 0.1 g of the culture medium was taken out from the glass culture dish and ground, 100 mL of 0.1% Tween-80 solution was added to fully dissolve it, and then filtered, and the average spore content was determined by hemocytometer. C: Average colony diameter Seven days after inoculation, the diameters of the colonies in nine glass dishes were measured using a vernier caliper and the data were recorded to evaluate the effect of the culture medium on spore germination and growth.

[0058] D: Average infection rate Seven days after the inoculation, the glass culture dish was baked at 60°C for 48 hours, 0.1 g of the culture medium was taken out from the glass culture dish and ground, and 0.1% Tween-80 solution was added to the ground medium to prepare a concentration of 5×10 8 / mL spore suspension.

[0059] Take 30 larvae of seabuckthorn borer, use a sprayer to evenly spray the spore suspension on the seabuckthorn borer, observe the death of the seabuckthorn borer every day, and place the dead individuals on the PDA culture medium to continue to observe whether white hyphae appear. Individuals with white hyphae are determined to be infected individuals. The infection rate calculation formula is:

[0060] In the formula: In the formula: IR—Infection rate (%) N—Number of seabuckthorn wood borers with white mycelium (heads) M—Total number of sea buckthorn borer moths (heads) The results are shown in Table 2 below:

[0061] Experimental Example 3 UV resistance test A total of 8 pesticide samples of Example 20 and Comparative Examples 1-7 were weighed, 500 g of each sample was placed in a glass culture dish, and each sample was treated 3 times, and was placed under an ultraviolet lamp (36W, 254nm) for full exposure to ultraviolet rays. Samples were taken at regular intervals, and the plate count method was used to detect the change in the number of viable bacteria of the microbial samples, and the reduction rate of the number of viable bacteria and the anti-ultraviolet protection effect were calculated. The final results are shown in the following table; The formula for calculating the mortality rate of live bacteria is:

[0062]

[0063] It can be seen from the above experimental results that by comparing Examples 3-5 and Comparative Example 5, it can be known that the addition of chitinase is very important for the present invention. This is because for the insecticide of the present invention, it mainly uses Beauveria bassiana as the main insecticide. Beauveria bassiana is an entomogenous fungus of the ascomycetes class. It mainly enters the insect body through insect feeding or stomata, or contacts the insect body surface to secrete a variety of cuticle degrading enzymes, and then produces germ tubes to penetrate the insect body wall to enter the insect body cavity, thereby absorbing nutrients from the host insect body through the germ tubes and The host insect rapidly reproduces in large quantities, and in this process, Beauveria bassiana secretes a large amount of Beauveria toxins and enzymes, which can further damage the body tissues of the pests, thereby causing the pests to die due to the inability to maintain normal life activities. However, since Beauveria bassiana is extremely slow in penetrating the body wall of the pest, it often takes a lot of time to complete the process. Therefore, the present invention adds chitinase to hydrolyze the chitin in the body wall of the pest, thereby accelerating the process of Beauveria bassiana infecting the pest, thereby greatly accelerating the insecticidal rate of the insecticide.

[0064] By comparing Example 3, Example 6-7 with Comparative Example 2, Comparative Example 6-7, it can be known that the addition of montmorillonite and fish scale collagen peptide is very important for the present invention, and both are indispensable. This is because Beauveria bassiana has extremely stringent requirements on the environment during growth and germination, and ultraviolet rays have a great influence on the growth and germination of Beauveria bassiana. Therefore, the present invention has found through a lot of creative work that by adjusting the mass ratio between montmorillonite powder and fish scale collagen peptide, and mixing the two with Beauveria bassiana, Beauveria bassiana can be well protected from the influence of ultraviolet rays. This is because montmorillonite and fish scale collagen peptide can make Beauveria bassiana not easily inactivated when exposed to ultraviolet rays. This ensures that the insecticide can be used in a variety of environments. Due to the layered structure and charge characteristics of montmorillonite molecules, the areas between montmorillonite molecules can easily adsorb microorganisms, thereby playing a protective and light-shielding function, thereby protecting Beauveria bassiana from ultraviolet radiation, which affects its activity. The adsorption of microorganisms by montmorillonite can also well prolong the effective period of the insecticide, allowing it to adapt to a variety of environments. Montmorillonite can also be interlocked with fish scale collagen peptides, so that fish scale collagen peptides can form a dense protective film on the surface of montmorillonite, further protecting Beauveria bassiana and allowing it to greatly avoid ultraviolet radiation. ‌

[0065] By comparing Example 3 with Examples 8-9, it can be known that the mass ratio between diatomite and Beauveria bassiana is very important for the present invention. This is because the way in which diatomite protects Beauveria bassiana is mainly to hide the spores of Beauveria bassiana through the porous structure of diatomite, so as to avoid inactivation caused by direct sunlight, thereby prolonging the use effect of Beauveria bassiana. Therefore, when the two are in an appropriate ratio, that is, the mass ratio of Beauveria bassiana to diatomite is 1: (1-1.5), preferably when the mass ratio of Beauveria bassiana to diatomite is 1: 1.2, the insecticide prepared by mixing the two can not only improve the use effect of Beauveria bassiana, but also further enhance the insecticidal effect. If the diatomite is excessive, the excessive diatomite will be stacked, thereby affecting the release of Beauveria bassiana, and the excessive diatomite will cause pollution to the environment. If the amount of diatomite is too little, a part of Beauveria bassiana will not be hidden in the pore structure of the diatomite, so that it may lose its activity after being irradiated by ultraviolet rays, affecting its insecticidal effect.

[0066] By comparing Example 3 with Examples 10-17 and Comparative Example 3, it can be known that the selection and mass ratio of the moisturizer are very important for the present invention. This is because Beauveria bassiana itself has extremely high requirements for the environment, and humidity has a vital impact on the growth of Beauveria bassiana. Appropriate humidity can well catalyze the spore germination and mycelial growth of Beauveria bassiana. Therefore, the humidity required by Beauveria bassiana during its growth is maintained by adding a moisturizer. In the present invention, there are certain requirements for the selection of moisturizers. When the moisturizer is glycerol, hyaluronic acid, polyethylene glycol, panthenol, sorbitol, sodium carboxymethyl cellulose and alginic acid One or more of sodium, preferably one or more of glycerol, hyaluronic acid, polyethylene glycol and sodium alginate, more preferably a mixture of glycerol, hyaluronic acid and sodium alginate, the insecticide prepared by mixing it with Beauveria bassiana has excellent insecticide effect, and the mass ratio of glycerol, hyaluronic acid and sodium alginate is (1-2): (2-3): 1, preferably when the mass ratio is 2:3:1, the humectant prepared by mixing glycerol, hyaluronic acid and sodium alginate can better maintain the humidity requirements of Beauveria bassiana during its growth process, and avoid the growth and germination of Beauveria bassiana being affected by changes in humidity. The insecticidal effect is thereby affected. In the moisturizing agent of the present invention, glycerol is used to form a thin film on the surface of Beauveria bassiana to effectively block the evaporation of water. While blocking the evaporation of water, glycerol can also absorb water from the air to maintain the humidity for Beauveria bassiana. Hyaluronic acid itself has a strong adsorption and water-locking ability. It can work together with glycerol to form a tighter film on the surface of Beauveria bassiana, thereby achieving a better water-locking effect. In addition, due to the strong water-absorbing ability of glycerol, the humidity required for the growth and germination of Beauveria bassiana can be better maintained. Sodium alginate has a certain viscosity. When combined with glycerol and hyaluronic acid, it can absorb moisture from the air to maintain the humidity of Beauveria bassiana. When hyaluronic acid and sodium alginate work together to form a thin film on the surface of Beauveria bassiana, sodium alginate itself can have a certain protective effect on Beauveria bassiana. Therefore, the present invention uses a mixture of the three as a humectant to achieve the goal of maintaining the humidity required for the growth and germination of Beauveria bassiana while also having a certain protective effect on Beauveria bassiana. If there is an excessive amount of sodium alginate, the prepared humectant will be too viscous and will adhere to the surface of Beauveria bassiana, which is not conducive to the growth and germination of Beauveria bassiana hyphae. If there is an excessive amount of glycerin, a large amount of glycerin will absorb too much moisture in the air, thereby making the humidity too high, thereby affecting the growth and germination of Beauveria bassiana.

[0067] By comparing Example 16 with Examples 18-20 and Comparative Example 4, it can be known that the mass ratio between the dispersants is very important for the present invention. This is because the dispersant can keep Beauveria bassiana stable during the preparation of the insecticide, avoiding uneven dispersion during the stirring process. The selection of the dispersant for the present invention is also limited. When the dispersant is a mixture of sodium lignin sulfonate and polyurethane, and the mass ratio of sodium lignin sulfonate to polyurethane is 1:2, the insecticide prepared therefrom has excellent insecticidal effect. This is because sodium lignin sulfonate can be adsorbed on the surface of solid particles to form a protective film to prevent the mutual aggregation of various raw materials, and sodium lignin sulfonate can further reduce the surface tension of water, thereby maintaining the humidity required for the growth and germination of Beauveria bassiana. The combined effect with polyurethane can further improve the dispersion performance, effectively prevent the aggregation and agglomeration of raw material particles in the insecticide, and make the raw materials unevenly dispersed, thereby affecting the insecticidal effect.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A natural insecticide, characterized in that: It is mainly made of the following substances: Beauveria bassiana, diatomaceous earth, chitinase, montmorillonite, fish scale collagen peptide, dispersant, moisturizer and water; The mass ratio of Beauveria bassiana to chitinase is (2-3):1, and the mass ratio of montmorillonite to fish scale collagen peptide is 1:(1-2).

2. The natural insecticide according to claim 1, characterized in that The mass ratio of Beauveria bassiana to diatomaceous earth is 1:(1-1.5); Preferably, the mass ratio of Beauveria bassiana to diatomaceous earth is 1:1.

2.

3. The natural insecticide according to claim 1, characterized in that The moisturizing agent is one or more of glycerin, hyaluronic acid, polyethylene glycol, panthenol, sorbitol, sodium carboxymethyl cellulose and sodium alginate; Preferably, the moisturizing agent is one or more of glycerol, hyaluronic acid, polyethylene glycol and sodium alginate; Preferably, the moisturizing agent is a mixture of glycerin, hyaluronic acid and sodium alginate.

4. The natural insecticide according to claim 3, characterized in that The mass ratio of the glycerol, hyaluronic acid and sodium alginate is (1-2): (2-3):

1.

5. The natural insecticide according to claim 4, characterized in that The mass ratio of the glycerol, hyaluronic acid and sodium alginate is 2:3:

1.

6. The natural insecticide according to claim 1, characterized in that The dispersant is a mixture of sodium lignin sulfonate and polyurethane.

7. The natural insecticide according to claim 6, characterized in that The mass ratio of sodium lignin sulfonate to polyurethane is 1:(1-2); Preferably, the mass ratio of the sodium lignin sulfonate to the polyurethane is 1:

2.

8. A method for preparing the natural insecticide according to any one of claims 1 to 7, characterized in that: The following steps are involved: The montmorillonite and diatomaceous earth are crushed respectively to obtain montmorillonite powder and diatomaceous earth powder; Mix diatomaceous earth powder, Beauveria bassiana and water, and stir evenly to obtain a suspension; Mixing montmorillonite powder, fish scale collagen peptide and water to obtain montmorillonite additive; The suspension, montmorillonite additive, dispersant, moisturizing agent and chitinase are added in sequence and the mixture is kept at a constant temperature to obtain the product.

9. The preparation method according to claim 8, characterized in that: The mass ratio of the suspension to the montmorillonite additive is 1:(1-2).

10. The preparation method according to claim 9, characterized in that: The mass ratio of the suspension to the montmorillonite additive is 1:2.

Images