Microbial enzyme synergistic flonicamid clothianidin suspending agent and preparation method thereof

Abstract

The suspending agent is prepared from the following components in percentage by weight: 10 to 20 percent of clothianidin, 4 to 6 percent of flonicamid, 1 to 5 percent of compound enzyme microcapsules, 1 to 5 percent of an emulsifying agent, 6 to 15 percent of a dispersing agent, 0.1 to 0.6 percent of a thickening agent, 0.1 to 1 percent of a suspending aid, 3 to 6 percent of an anti-freezing agent, 0.1 to 0.5 percent of a de-foaming agent and the balance of water. The invention also provides a preparation method of the composition. Compared with the prior art, the insecticidal composition has the advantages that the epidermis or digestive system of pests is destroyed by enzyme generated by specific microorganisms, and the synergistic suspending agent is formed by combining flonicamid and clothianidin, so that the control effect can be improved, the use of chemical agents can be reduced, and the risk of drug resistance can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and in particular to a microbial enzyme enhanced flonicamid·thiamethoxam suspension concentrate and a preparation method thereof. Background Art

[0002] Rice planthoppers are an important pest that causes serious damage to rice crops and seriously affects rice yields. In order to effectively control this pest, it is crucial to understand its living habits. First of all, rice planthoppers belong to the family of Hemiptera, mainly feed on rice, reproduce quickly, can reproduce multiple generations in a year, and their number increases rapidly in a short period of time, making them a major threat to rice. Secondly, rice planthoppers choose different parasitic sites at different growth stages. Larvae usually suck sap from young rice leaves, causing the leaves to turn yellow, curl and wither. Adults often overwinter at the base of the plant or in the leaf sheaths and become active again in spring. This parasitic method causes direct damage to rice, especially during the rice filling and jointing stages. In addition, rice planthoppers also have the habit of migratory flight, and can fly long distances and migrate between different rice fields, which makes it difficult for them to be confined to a specific area and poses a potential threat to multiple rice-growing areas.

[0003] Flunicromax is a new type of low-toxic pyridinamide insect growth regulator insecticide. It appears as a white, odorless solid powder with a melting point of 157.5°C and is heat-stable. Flunicromax has contact and stomach poison effects, as well as neurotoxin and rapid antifeedant effects. It works by hindering the sucking action of pests. After the pests ingest the agent, they stop sucking quickly and eventually die of starvation. Flunicromax is effective against piercing-sucking mouthparts pests and has good penetration. It can penetrate from the roots to the stems and leaves, but the penetration from the leaves to the stems and roots is relatively weak. In addition, flunicromax is low toxic to bees and has no cross-resistance with other commercially available insecticides.

[0004] Clothianidin is a new type of nicotinoid insecticide developed jointly by Japan's Sumika Takeda and Bayer, with the characteristics of broad spectrum, low toxicity and high efficiency. It belongs to the broad-spectrum neonicotinoid insecticide, which acts similarly to nicotinic acetylcholine receptors and has contact, stomach poison and systemic activity. Clothianidin is mainly used to control pests such as aphids, leafhoppers, thrips and planthoppers on rice, vegetables, fruit trees and other crops. It has the advantages of high efficiency, broad spectrum, low dosage, low toxicity, long-lasting efficacy, no phytotoxicity to crops, safe use, and no cross-resistance with conventional pesticides. Both flonicamid and clothianidin can be used to control rice planthoppers. Fluonicamid is a pyridineamide insect growth regulator with contact and stomach poison effects, which can quickly prevent pests from sucking plant sap, causing them to die of starvation. Clothianidin is a neonicotinoid insecticide with contact, stomach poison and systemic activity, which has good control effect on rice planthoppers and a long lasting effect.

[0005] CN103621536A has developed a new type of insecticide composition, the main active ingredients of which are clothianidin and flonicamid. The ratio of clothianidin to flonicamid in the composition ranges from 1 to 100:1 to 100. This insecticide composition exhibits a significant synergistic effect, which can effectively overcome and delay the problem of insecticide resistance, while also reducing the cost of use. It can be formulated into a variety of dosage forms, including emulsifiable concentrates, wettable powders, microemulsions, emulsions in water, suspensions and water-dispersible granules, etc., and is suitable for preventing and controlling resistant Hemiptera, Coleoptera, Lepidoptera, Hymenoptera and other pests.

[0006] CN118415191A discloses a composite microbial metabolic liquid for controlling rice pests, which is a mixture of a sterile metabolic liquid of Trichoderma, a sterile metabolic liquid of Metarhizium anisopliae and a sterile metabolic liquid of Bacillus. The composite metabolic liquid contains the following components: 6-pentyl-2-pyrone at a concentration of 180-190 ng / mL, alamethicin at a concentration of 0.2-0.3 ppb, hydrophobic protein at a concentration of 55-65 μg / L, gibberellin at a concentration of 400-450 pg / mL, chitinase at a concentration of 170-180 pg / mL, glucanase at a concentration of 400-430 ng / L, salicylic acid at a concentration of 1440-1460 pmol / L, calmodulin at a concentration of 7.0-8.0 μg / L and IAA at a concentration of 80-90 μg / L. The compound metabolic liquid has a mortality rate of 50-55% for the third-instar larvae of the Chilo suppressalis, and can significantly damage the structural integrity of the mitochondrial ridges in the midgut of healthy larvae. In addition, the metabolic liquid can effectively inhibit the bacteria of sheath blight and ear rot. When used in combination with chemical pesticides with a 30%-40% reduction in dosage, the control effect on rice planthoppers in the field can reach more than 60%, the control effect on rice leaf rollers can reach more than 75%, and it can also control rice sheath blight and ear rot at the same time.

[0007] Rice planthoppers are one of the common pests of rice. They have the characteristics of wide distribution, strong reproductive capacity and great harm, which poses a serious threat to the safe production of rice. At present, the control of crop pests such as rice planthoppers is mainly based on chemical control, which leads to the increase of pest resistance. Over the years, the continuous and large-scale application of pesticides has not only increased the difficulty of pest control, but also caused a series of adverse effects on the ecological environment and food safety. Summary of the invention

[0008] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to provide a microbial enzyme enhanced flonicamid·thiamethoxam suspension and a preparation method thereof.

[0009] The enzyme produced by specific microorganisms is used to produce a destructive effect on the epidermis or digestive system of pests, and at the same time, flonicamid and clothianidin are combined to form a synergistic suspension, which can not only improve the control effect, but also reduce the use of chemical agents, and reduce the risk of drug resistance. In the present invention, by adding cellulase, chitinase and glucanase, the suspension is enhanced, and cellulase can degrade the cellulose in the plant cell wall, so that pesticides can be more easily penetrated into plant tissues, and the utilization rate of pesticides is improved. Chitinase can degrade insect chitin exoskeleton, destroy the protective barrier of pests, make flonicamid and clothianidin more easily enter the pest body, and improve the insecticidal effect. Glucanase can degrade the polysaccharide in the plant cell wall, increase the permeability of pesticides, and make it better act on pests. These microbial enzymes can significantly enhance the insecticidal effect of flonicamid and clothianidin by promoting the metabolism of pesticides, improving permeability and destroying the protective structure of pests, and improve the utilization efficiency and control effect of pesticides.

[0010] However, enzymes are easily inactivated by environmental factors such as temperature, pH value, and light in suspensions, so the present invention fixes free enzymes by microencapsulation to improve the performance of biological enzymes. The present invention provides a modified polymer, which improves the defects of strong hydrophobicity and high crystallinity of polycaprolactone by adding modified monomers during polymerization. The modified polymer has side chains, so it can avoid the defects of slow release of internal substances caused by high polymer crystallinity, and the introduced polyethylene glycol and other hydrophilic groups make the modified polymer amphiphilic, so it has better dispersibility, more stable structure, and faster release rate, which is very important for improving drug efficacy.

[0011] To achieve the above-mentioned purpose, the present invention provides a microbial enzyme synergistic flonicamid·clothianidin suspension, comprising the following components in weight percentage: 10-20% of clothianidin, 4-6% of flonicamid, 1-5% of complex enzyme microcapsules, 1-5% of emulsifier, 6-15% of dispersant, 0.1-0.6% of thickener, 0.1-1% of suspending agent, 3-6% of antifreeze agent, 0.1-0.5% of defoamer, and the balance is water.

[0012] The preparation method of the composite enzyme microcapsule comprises the following steps:

[0013] X1. Caprolactone, a modifier, 2,2'-dithiodiethanol and a catalyst are sealed and heated and stirred for 40 to 50 hours. After the reaction is completed, they are mixed with methoxy-polyethylene glycol-carboxyl, 4-dimethylaminopyridine and a solvent through post-treatment. A dichloromethane solution of N,N'-dicyclohexylcarbodiimide is added under an inert atmosphere, and the mixture is polymerized at room temperature for 40 to 50 hours. After the reaction is completed, the modified polymer is obtained through post-treatment.

[0014] X2. Add the modified polymer to dichloromethane to obtain an oil phase, add cellulase, chitinase and glucanase to water to obtain an aqueous phase, mix the oil phase with the aqueous phase and Span 80, and homogenize, then add to a 3-5wt% polyvinyl alcohol aqueous solution, continue to homogenize, heat until the solvent evaporates, centrifuge, wash, freeze-dry and sieve to obtain the composite enzyme microcapsules.

[0015] Furthermore, the mass ratio of the caprolactone, the modifier, the 2,2'-dithiodiethanol, the catalyst, the methoxy-polyethylene glycol-carboxyl, the 4-dimethylaminopyridine, the solvent, and the dichloromethane solution of N,N'-dicyclohexylcarbodiimide is 1:0.8-1.5:0.05-0.1:0.0001-0.0005:0.4-2:0.001-0.005:5-15:3-8.

[0016] Furthermore, the catalyst is stannous octoate.

[0017] Preferably, the modifier is one of 4-oxo-2-oxetanecarboxylic acid, β-propyl-β-propiolactone or 3-amino-4-methyl-, (3s-trans)-2-oxetanecarboxylic acid.

[0018] Furthermore, the temperature range of the heating in step X1 is 120-140°C.

[0019] Furthermore, the mass ratio of the modified polymer to dichloromethane is 1:10-15, and the mass ratio of the oil phase, the water phase, Span 80, and the polyvinyl alcohol aqueous solution is 1:4-5:0.05-0.18:5-6.

[0020] Furthermore, the mass ratio of the cellulase, chitinase, glucanase and water is 1:1-2:1-2:30-50.

[0021] Furthermore, the temperature range of the heating and stirring in step X2 is 34 to 37°C.

[0022] Furthermore, the emulsifier is one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether or nonylphenol polyoxyethylene ether.

[0023] Furthermore, the dispersant is one of fatty alcohol polyoxyethylene ether phosphate, lignin sodium salt or sodium polycarboxylate.

[0024] Furthermore, the thickener is one of xanthan gum, carboxymethyl cellulose or guar gum.

[0025] Furthermore, the suspending agent is one of magnesium aluminum silicate, attapulgite or white carbon black.

[0026] Furthermore, the antifreeze agent is one of ethylene glycol, propylene glycol or glycerol.

[0027] Furthermore, the defoaming agent is a silicone defoaming agent.

[0028] The present invention also discloses a method for preparing a microbial enzyme enhanced flonicamid·thiamethoxam suspension concentrate, comprising the following steps:

[0029] The flonicamid, clothianidin, emulsifier, dispersant, thickener, suspending agent, antifreeze agent, defoamer and water are dispersed, ground and sheared evenly, and then mixed evenly with the composite enzyme microcapsule to obtain the microcapsule.

[0030] Beneficial effects of the present invention:

[0031] The present invention utilizes enzymes produced by specific microorganisms to destroy the pest epidermis or digestive system, and combines flonicamid and clothianidin to form a synergistic suspension concentrate, which can not only improve the control effect, but also reduce the use of chemical agents and reduce the risk of drug resistance. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The sources and parameters of some raw materials in the examples are as follows:

[0034] Methoxy-polyethylene glycol-carboxyl, Mw=5000, Shaanxi Xinyan Bomei Biotechnology Co., Ltd.

[0035] Polycaprolactone, Mw=50000.

[0036] Cellulase, 20000U / g, Sichuan Huatang Jurui Biotechnology Co., Ltd.

[0037] Chitinase, 200U / g, Beijing Biolab Technology Co., Ltd.

[0038] β-Glucanase, 40 U / mg, Shanghai Yuanye Biotechnology Co., Ltd.

[0039] Fatty alcohol polyoxyethylene ether phosphate, model: AEO-3P, Shandong Meihang Chemical Co., Ltd.

[0040] 4-Oxo-2-oxetanecarboxylic acid, CAS: 90730-97-5.

[0041] 3-Amino-4-methyl-,(3s-trans)-2-oxetanone,CAS:

[0042] Silicone defoamer, model: AFE-1410, Dow Corning.

[0043] Polyvinyl alcohol, model: BP-17, Changchun, Taiwan.

[0044] The present invention is further explained below in conjunction with specific implementation modes.

[0045] Example 1

[0046] A method for preparing a microbial enzyme-enhanced flonicamid·thiamethoxam suspension concentrate comprises the following steps, measured in parts by weight:

[0047] Mix 5 parts of flonicamid, 15 parts of clothianidin, 3 parts of nonylphenol polyoxyethylene ether, 10 parts of fatty alcohol polyoxyethylene ether phosphate, 0.3 parts of guar gum, 0.5 parts of magnesium aluminum silicate, 5 parts of propylene glycol, 0.5 parts of silicone defoamer and 57.7 parts of water, grind and shear evenly, and mix evenly with 3 parts of complex enzyme microcapsules to obtain a product.

[0048] The preparation method of the composite enzyme microcapsule comprises the following steps, measured in parts by weight:

[0049] X1. Mix 1 part of caprolactone, 1.1 parts of β-propyl-β-propiolactone, 0.08 parts of 2,2'-dithiodiethanol and 0.0001 parts of stannous octoate, raise the temperature to 130°C and stir for 45 hours under a sealed state. After the reaction is completed, add 10 parts of dichloromethane to dissolve, add ether to dilute until precipitation occurs, filter and dry, mix with 1.5 parts of methoxy-polyethylene glycol-carboxyl, 0.004 parts of 4-dimethylaminopyridine and 10 parts of dichloromethane, add 5 parts of dichloromethane solution of N,N'-dicyclohexylcarbodiimide under an inert atmosphere, polymerize at room temperature for 45 hours, filter after the reaction is completed, concentrate the filtrate, precipitate with ether and dialyze to obtain a modified polymer; the dichloromethane solution of N,N'-dicyclohexylcarbodiimide is obtained by mixing 1.6 parts of N,N'-dicyclohexylcarbodiimide and 3.4 parts of dichloromethane;

[0050] X2. Add 0.3 parts of modified polymer to 4 parts of dichloromethane to obtain oil phase, add 0.1 parts of cellulase, 0.1 parts of chitinase and 0.1 parts of β-glucanase to 4 parts of water to obtain water phase, mix 1 part of oil phase with 4.5 parts of water phase, add 0.11 parts of Span 80 and continue homogenizing, add to 5.5 parts of 4wt% polyvinyl alcohol aqueous solution after homogenization, continue homogenizing, heat to 37°C to evaporate the solvent, solidify the emulsion, and obtain microcapsules which are centrifuged, washed, freeze-dried and sieved to obtain composite enzyme microcapsules.

[0051] Example 2

[0052] The method is basically the same as Example 1, except that the β-propyl-β-propiolactone in Example 1 is replaced by 3-amino-4-methyl-, (3s-trans)-2-oxetanone.

[0053] Example 3

[0054] The method is substantially the same as Example 1, except that the β-propyl-β-propiolactone in Example 1 is replaced by 4-oxo-2-oxetanecarboxylic acid.

[0055] Comparative Example 1

[0056] A method for preparing a microbial enzyme-enhanced flonicamid·thiamethoxam suspension concentrate comprises the following steps, measured in parts by weight:

[0057] Mix 5 parts of flonicamid, 15 parts of clothianidin, 3 parts of nonylphenol polyoxyethylene ether, 10 parts of fatty alcohol polyoxyethylene ether phosphate, 0.3 parts of guar gum, 0.5 parts of magnesium aluminum silicate, 5 parts of propylene glycol, 0.5 parts of silicone defoamer and 57.7 parts of water, grind and shear evenly, and mix evenly with 3 parts of complex enzyme microcapsules to obtain a product.

[0058] The preparation method of the composite enzyme microcapsule comprises the following steps, measured in parts by weight:

[0059] 0.3 parts of polycaprolactone are added to 4 parts of dichloromethane to obtain an oil phase, 0.1 parts of cellulase, 0.1 parts of chitinase and 0.1 parts of β-glucanase are added to 4 parts of water to obtain an aqueous phase, 1 part of the oil phase is mixed with 4.5 parts of the aqueous phase, and then 0.11 parts of Span 80 are added to continue homogenization. After the homogenization is completed, it is added to 5.5 parts of a 4wt% polyvinyl alcohol aqueous solution, and the homogenization is continued. The temperature is raised to 37°C to evaporate the solvent, and the microcapsules obtained after the emulsion solidifies are centrifuged, washed, freeze-dried, and sieved to obtain composite enzyme microcapsules.

[0060] Comparative Example 2

[0061] A method for preparing a microbial enzyme-enhanced flonicamid·thiamethoxam suspension concentrate comprises the following steps, measured in parts by weight:

[0062] Mix 5 parts of flonicamid, 15 parts of clothianidin, 3 parts of nonylphenol polyoxyethylene ether, 10 parts of fatty alcohol polyoxyethylene ether phosphate, 0.3 parts of guar gum, 0.5 parts of magnesium aluminum silicate, 5 parts of propylene glycol, 0.5 parts of silicone defoamer and 60.4 parts of water, grind and shear evenly, and mix evenly with 0.1 parts of cellulase, 0.1 parts of chitinase and 0.1 parts of β-glucanase to obtain a product.

[0063] Test Example 1

[0064] The suspensions in the examples and control examples were tested for their efficacy. The test site was located in a rice field. The pesticide was applied during the peak period of rice planthopper damage by spraying. Clean water and a commercially available 20% flonicamid·thiamethoxam suspension (5% flonicamid, 15% clothianidin, Shenzhen Langtai Biotechnology Co., Ltd.) were used as the control group. The test was conducted with 5 pesticide treatments, each with 3 replicates, for a total of 15 plots with a plot area of ​​100m 2 , 1m wide protection row was set between the plots, and the dosage was 30mL / mu. Before applying the pesticide, the insect population base was investigated at five points on the diagonal of each treatment area, and 30 rice plants were investigated at each point. The control effect was investigated once 7 days, 14 days, and 30 days after application, the number of diseased plants was recorded, and the control effect was calculated. The test results are shown in Table 1.

[0065] Table 1 Field efficacy test results of suspension concentrate

[0066]

[0067]

[0068] As can be seen from Table 1, compared with the commercially available 20% flonicamid·thiamethoxam suspension, the suspension of the present invention has a better field control index, which may be due to the addition of microbial enzymes that can destroy the pest body surface or digestive system, enhance the insecticidal effect of pesticides, and cellulase can degrade cellulose in plant cell walls, making pesticides more easily penetrate into plant tissues and improve the utilization rate of pesticides. Chitinase can degrade insect chitin exoskeleton, destroy the protective barrier of pests, make flonicamid and thiamethoxam easier to enter the pest body, and improve the insecticidal effect. β-Glucanase can degrade polysaccharides in plant cell walls, increase the permeability of pesticides, and make them better act on pests. These microbial enzymes can significantly enhance the insecticidal effect of flonicamid and thiamethoxam by promoting the metabolism of pesticides, improving permeability and destroying the protective structure of pests, and improve the utilization efficiency and control effect of pesticides.

[0069] Compared with Reference Example 2, the Examples all have higher protection indexes, which may be due to the fact that the enzyme is easily inactivated by environmental factors such as temperature, pH value, and light in the suspension, and the free enzyme is fixed by microencapsulation in the Examples, thereby improving the performance of the biological enzyme and making it less likely to be inactivated. Compared with Reference Example 1, the Examples use modified polymers, and the defects of strong hydrophobicity and high crystallinity of polycaprolactone are improved by adding modified monomers during polymerization. The modified polymers have side chains, so they can avoid the defects of slow release of internal substances caused by high polymer crystallinity, and the introduced polyethylene glycol and other hydrophilic groups make the modified polymers amphiphilic, so they have better dispersibility, more stable structure, and faster release rate, which is crucial for improving drug efficacy. Compared with Examples 1 to 2, Example 3 has the highest prevention effect index. This may be because the modifier in Example 3 has a hydrophilic carboxyl group, which is more hydrophilic than other examples. The addition of hydrophilic side chains can not only reduce the defects caused by high crystallinity, but also improve the solubility of microcapsules in the liquid medicine, thereby allowing the microbial enzyme to play a better role, and thus the prevention and control effect is the best.

[0070] Test Example 2

[0071] The antioxidant enzyme activity of the rice planthopper in Test Example 1 was determined. 24 and 48 hours after the first drug application, 30 rice planthoppers were collected, and 10 were placed in a 2mL centrifuge tube as a replicate. Three replicates were set for each treatment and stored in liquid nitrogen until transferred to a -80°C refrigerator for standby use. 1mL of PBS buffer in an ice bath was added to each sample, and the sample was homogenized in an ice bath. The supernatant obtained by centrifugation was the crude enzyme solution, and the activity of the antioxidant enzyme was determined using a test kit. See Table 2 for details.

[0072] Table 2 Effects of suspension concentrate on antioxidant enzymes of rice planthoppers

[0073]

[0074] When pests come into contact with chemical agents, the active ingredients in the agents will trigger oxidative stress reactions in cells, leading to the generation of reactive oxygen species (ROS). Reactive oxygen species are highly chemically active and oxidizing, and can react with macromolecules such as lipids, proteins, and DNA in cells, triggering peroxidation reactions. Peroxidation reactions can destroy the lipid bilayer structure of the cell membrane, leading to increased membrane permeability and loss of intracellular substances; at the same time, damage to proteins and DNA can affect the normal function of cells and the transmission of genetic information, ultimately leading to cell dysfunction or even death.

[0075] Among them, the main function of catalase (CAT) is to decompose hydrogen peroxide into water and oxygen to eliminate the toxicity of hydrogen peroxide to cells. Hydrogen peroxide is a common reactive oxygen species that can cause serious oxidative damage. CAT reduces its concentration in cells by decomposing hydrogen peroxide, thereby alleviating oxidative damage. Superoxide dismutase (SOD) can dismutate superoxide anions into oxygen and hydrogen peroxide. Superoxide anions are a form of reactive oxygen species that are highly oxidizing and can trigger chain reactions, leading to more oxidative damage. SOD converts superoxide anions into relatively less toxic substances through dismutation reactions, reducing their direct damage to cells. Peroxidase (POD) can catalyze the reaction of hydrogen peroxide with certain organic substances (such as phenolic compounds) to produce non-toxic or low-toxic substances. Through this reaction, POD not only consumes hydrogen peroxide, but also converts other potentially toxic organic substances, further reducing the toxicity of chemical agents to cells. Therefore, the activity of antioxidant enzymes can well reflect whether rice planthoppers are resistant to the agents.

[0076] As can be seen from Table 2, the antioxidant enzyme activity in rice planthoppers with added microbial enzyme suspension is lower. This may be because these enzymes can destroy the exoskeleton structure of the pest or the cell wall of the plant, thereby increasing the permeability of the chemical agent and making it easier for it to enter the pest body or plant cells. This helps to improve the effectiveness of the agent and reduce the pest's tolerance to the agent, thereby indirectly slowing down the development of resistance. By improving the effectiveness of the agent, the amount of chemical agent used can be reduced to a certain extent. This helps to reduce the frequency and concentration of pest contact with the agent, thereby slowing down the development of resistance.

[0077] 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 microbial enzyme enhanced flonicamid·thiamethoxam suspension concentrate, characterized in that: The invention comprises the following components in percentage by weight: 10-20% of clothianidin, 4-6% of flonicamid, 1-5% of complex enzyme microcapsules, 1-5% of emulsifier, 6-15% of dispersant, 0.1-0.6% of thickener, 0.1-1% of suspending agent, 3-6% of antifreeze agent, 0.1-0.5% of defoamer, and the balance is water.

2. The microbial enzyme synergistic flonicamid·thiamethoxam suspension concentrate according to claim 1, characterized in that: The preparation method of the composite enzyme microcapsule comprises the following steps: X1. Heat caprolactone, modifier, 2,2'-dithiodiethanol and catalyst to 120-140°C in a sealed state and stir at 120-140°C for 40-50h. After the reaction, mix with methoxy-polyethylene glycol-carboxyl, 4-dimethylaminopyridine and solvent after post-treatment. Add dichloromethane solution of N,N'-dicyclohexylcarbodiimide under inert atmosphere and polymerize at room temperature for 40-50h. After the reaction, post-treat to obtain a modified polymer. X2. Add the modified polymer to dichloromethane to obtain an oil phase; add cellulase, chitinase and glucanase to water to obtain an aqueous phase; mix the oil phase with the aqueous phase and Span 80 and homogenize; then add to a 3-5wt% polyvinyl alcohol aqueous solution and continue homogenizing; heat to 34-37°C, centrifuge after the solvent evaporates, wash, freeze-dry and sieve to obtain the composite enzyme microcapsules.

3. The microbial enzyme synergistic flonicamid·thiamethoxam suspension concentrate according to claim 2, characterized in that: The mass ratio of the caprolactone, the modifier, the 2,2'-dithiodiethanol, the catalyst, the methoxy-polyethylene glycol-carboxyl, the 4-dimethylaminopyridine, the solvent, and the dichloromethane solution of N,N'-dicyclohexylcarbodiimide is 1:0.8-1.5:0.05-0.1:0.0001-0.0005:0.4-2:0.001-0.005:5-15:3-8.

4. The microbial enzyme-enhanced flonicamid·thiamethoxam suspension concentrate according to claim 2, characterized in that: The catalyst is stannous octoate; the modifier is one of 4-oxo-2-oxetanecarboxylic acid, β-propyl-β-propiolactone or 3-amino-4-methyl-, (3s-trans)-2-oxetane ketone.

5. The microbial enzyme enhanced flonicamid·thiamethoxam suspension concentrate according to claim 2, characterized in that: The mass ratio of the modified polymer to dichloromethane is 1:10-15, and the mass ratio of the oil phase, the water phase, Span 80, and the polyvinyl alcohol aqueous solution is 1:4-5:0.05-0.18:5-6.

6. The microbial enzyme-enhanced flonicamid·thiamethoxam suspension concentrate according to claim 2, characterized in that: The mass ratio of the cellulase, chitinase, glucanase and water is 1:1-2:1-2:30-50.

7. The microbial enzyme enhanced flonicamid·thiamethoxam suspension concentrate according to claim 1, characterized in that: The emulsifier is one of fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether or nonylphenol polyoxyethylene ether; the dispersant is one of fatty alcohol polyoxyethylene ether phosphate, lignin sodium salt or sodium polycarboxylate.

8. The microbial enzyme enhanced flonicamid·thiamethoxam suspension concentrate according to claim 1, characterized in that: The thickener is one of xanthan gum, carboxymethyl cellulose or guar gum.

9. The microbial enzyme enhanced flonicamid·thiamethoxam suspension concentrate according to claim 1, characterized in that: The suspending agent is one of magnesium aluminum silicate, attapulgite or white carbon black; the antifreeze agent is one of ethylene glycol, propylene glycol or glycerol; and the defoaming agent is an organic silicon defoaming agent.

10. A method for preparing the microbial enzyme enhanced flonicamid·clothianidin suspension concentrate according to any one of claims 1 to 9, characterized in that: The steps include: The flonicamid, clothianidin, emulsifier, dispersant, thickener, suspending agent, antifreeze agent, defoamer and water are dispersed, ground and sheared evenly, and then mixed evenly with the composite enzyme microcapsule to obtain the microcapsule.

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