Microbial Enzyme-Enhanced Flonicamid•Clothianidin Suspension Concentrate and Its Preparation Method

Abstract

The present invention discloses a microbial enzyme-enhanced flonicamid·clothianidin suspension concentrate, which suspension concentrate comprises the following components in percentage by weight: clothianidin 10-20%, flonicamid 4-6%, composite enzyme microcapsule 1-5%, emulsifier 1-5%, dispersant 6-15%, thickener 0.1-0.6%, suspending agent 0.1-1%, antifreeze 3-6%, defoamer 0.1-0.5%, and the balance is water. The present invention also provides a preparation method thereof. Compared with the prior art, the enzyme produced by a specific microorganism in the present invention has a destructive effect on the epidermis or digestive system of pests, and at the same time, in combination with flonicamid and clothianidin, a synergistic suspension concentrate is formed, which can not only improve the control effect, but also reduce the use of chemical agents and the risk of drug resistance generation.

Description

Technical Field

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

[0002] The rice planthopper (Phylloptera planthopper) is a major pest that severely damages rice crops, significantly affecting rice yields. Understanding its life habits is crucial for effective control. First, rice planthoppers belong to the family Delphacidae in the order Hemiptera. They primarily feed on rice and reproduce rapidly, producing multiple generations in a single year. Their numbers increase rapidly, making them a major threat to rice crops. Second, rice planthoppers choose different parasitic sites at different stages of growth. Larvae typically feed on young rice leaves, causing them to yellow, curl, and wither. Adults often overwinter at the base of the plant or within leaf sheaths, becoming active again in the spring. This parasitic pattern causes direct damage to rice, with the impact being particularly pronounced during the grain filling and jointing stages. Furthermore, rice planthoppers are migratory, capable of long-distance flights and moving between rice fields. This makes them difficult to confine to specific areas, posing a potential threat to multiple rice-growing regions.

[0003] Flunicroimide is a new, 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. Flunicroimide has contact and stomach poisoning effects, as well as neurotoxic and rapid antifeedant effects. It works by hindering the sucking action of pests. After ingesting the agent, the pests quickly stop sucking and eventually die of starvation. Flunicroimide is effective against piercing-sucking pests and has good penetration, penetrating from roots to stems and leaves, but its penetration from leaves to stems and roots is relatively weak. In addition, flunicroimide is low toxic to bees and has no cross-resistance with other commercially available insecticides.

[0004] Clothianidin is a new nicotinoid insecticide jointly developed by Sumika Takeda and Bayer of Japan. It features a broad spectrum, low toxicity, and high efficacy. It belongs to the broad-spectrum neonicotinoid class of insecticides, acting similarly to nicotinic acetylcholine receptors, with contact, stomach, and systemic activity. Clothianidin is primarily used to control pests such as aphids, leafhoppers, thrips, and planthoppers on rice, vegetables, fruit trees, and other crops. It boasts high efficacy, a broad spectrum, low dosage, low toxicity, long-lasting efficacy, no crop damage, safety, and no cross-resistance with conventional pesticides. Both flonicamid and clothianidin can be used to control rice planthoppers. Flonicaid is a pyridineamide insect growth regulator with contact and stomach effects, rapidly preventing pests from feeding on plant sap, leading to their death by starvation. Clothianidin is a neonicotinoid insecticide with contact, stomach, and systemic activity, offering good control against rice planthoppers and a long-lasting effect.

[0005] CN103621536A has developed a new insecticidal composition, the main active ingredients of which are clothianidin and flonicamid. The ratio range of clothianidin to flonicamid in this composition is 1-100:1-100. This insecticidal composition exhibits significant synergistic effects, can effectively overcome and delay the problem of pest resistance, and at the same time can reduce the use cost. It can be formulated into various dosage forms, including emulsifiable concentrate, wettable powder, microemulsion, emulsion in water, suspension concentrate and water dispersible granule, etc., and is suitable for controlling various pests such as resistant Hemiptera, Coleoptera, Lepidoptera, Hymenoptera, etc.

[0006] CN118415191A discloses a composite microbial metabolite solution for controlling rice pests, which is composed of Trichoderma sterile metabolite solution, Metarhizium anisopliae sterile metabolite solution and Bacillus sterile metabolite solution. This composite metabolite solution contains the following components: the concentration of 6-pentyl-2-pyrone is 180-190 ng / mL, the concentration of brefeldin A is 0.2-0.3 ppb, the concentration of hydrophobin is 55-65 μg / L, the concentration of gibberellin is 400-450 pg / mL, the concentration of chitinase is 170-180 pg / mL, the concentration of glucanase is 400-430 ng / L, the concentration of salicylic acid is 1440-1460 pmol / L, the concentration of calmodulin is 7.0-8.0 μg / L and the concentration of IAA is 80-90 μg / L. The lethal rate of this composite metabolite solution against the 3rd instar larvae of Chilo suppressalis can reach 50-55%, and can significantly damage the structural integrity of the mitochondrial cristae in the midgut of its healthy larvae. In addition, this metabolite solution can also effectively inhibit Rhizoctonia solani and Fusarium graminearum. When compounded with chemical pesticides at a reduction of 30%-40%, the control effect on Nilaparvata lugens in the field can reach more than 60%, the control effect on Cnaphalocrocis medinalis can reach more than 75%, and can simultaneously control rice sheath blight and ear rot.

[0007] Nilaparvata lugens is one of the common pests in rice, with characteristics such as a wide distribution range, strong reproductive ability and great harm, posing a serious threat to the safe production of rice. At present, the control of crop pests such as Nilaparvata lugens mainly relies on chemical agents, resulting in an increase in 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 synergistic flonicamid·clothianidin suspension concentrate and its preparation method.

[0009] The enzymes produced by specific microorganisms can damage the epidermis or digestive system of pests. At the same time, by combining flonicamid and clothianidin, a synergistic suspending agent is formed, which can not only improve the control effect, but also reduce the use of chemical agents and the risk of resistance generation. In this invention, the suspending agent is synergized by adding cellulase, chitinase and glucanase. Cellulase can degrade the cellulose in the plant cell wall, making it easier for pesticides to penetrate into plant tissues and improving the utilization rate of pesticides. Chitinase can degrade the chitin exoskeleton of insects, destroying the protection barrier of pests and making it easier for flonicamid and clothianidin to enter the pests' bodies, thus improving the insecticidal effect. Glucanase can degrade the polysaccharides in the plant cell wall, increasing the permeability of pesticides and making them act better on pests. These microbial enzymes can significantly enhance the insecticidal effects of flonicamid and clothianidin, improve the utilization efficiency of pesticides and the control effect by promoting the metabolism of pesticides, increasing permeability and destroying the protection structure of pests.

[0010] However, enzymes are easily inactivated by environmental factors such as temperature, pH value, light, etc. in the suspending agent. Therefore, in this invention, the free enzymes are fixed by microencapsulation, which can improve the performance of bioenzymes. This invention provides a modified polymer, and by adding modified monomers during polymerization, the defects of strong hydrophobicity and high crystallinity of polycaprolactone are improved. Since the modified polymer has side chains, it can avoid the defect of slow release of internal substances caused by high crystallinity of the polymer. The introduced polyethylene glycol and other hydrophilic groups make the modified polymer amphiphilic, so it has better dispersibility, more stable structure and faster release speed, which is crucial for enhancing the drug efficacy.

[0011] To achieve the above object, this invention provides a microbial enzyme synergistic flonicamid·clothianidin suspending agent, which comprises the following components in weight percentages: clothianidin 10-20%, flonicamid 4-6%, composite enzyme microcapsule 1-5%, emulsifier 1-5%, dispersant 6-15%, thickener 0.1-0.6%, suspending aid 0.1-1%, antifreeze 3-6%, defoamer 0.1-0.5%, and the balance is water.

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

[0013] X1. Caprolactone, modifier, 2,2'-dithioglycol and catalyst are sealed and heated with stirring for 40-50 h. After the reaction is completed, it is post-treated and mixed with methoxy-polyethylene glycol-carboxyl, 4-dimethylaminopyridine and solvent. Under an inert atmosphere, a dichloromethane solution of N,N'-dicyclohexylcarbodiimide is added, and polymerization is carried out at room temperature for 40-50 h. After the reaction is completed, the modified polymer is obtained through post-treatment;

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

[0015] Further, the mass ratio of the caprolactone, the modifier, 2,2'-dithiobisethanol, the catalyst, methoxy-polyethylene glycol-carboxyl, 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] Further, 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-oxetanone.

[0018] Further, the temperature range for heating up in the step X1 is 120-140 °C.

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

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

[0021] Further, the temperature range for heating and stirring in the step X2 is 34-37 °C.

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

[0023] Further, the dispersant is one of fatty alcohol polyoxyethylene ether phosphate, sodium lignosulfonate or sodium polycarboxylate.

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

[0025] Further, the suspending agent is one of magnesium aluminum silicate, attapulgite or silica white.

[0026] Further, the antifreeze 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-clothianidin suspension concentrate, comprising the following steps:

[0029] The product is prepared by dispersing flonicamid, clothianidin, an emulsifier, a dispersant, a thickener, a suspending agent, an antifreeze agent, a defoaming agent and water, grinding and shearing the dispersion, and uniformly mixing the dispersion with the complex enzyme microcapsules.

[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 at the same time 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 embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort 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, 200 U / 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 Plastics Co., Ltd. (Taiwan)

[0044] The present invention will be further explained and illustrated below in conjunction with specific embodiments

[0045] Example 1

[0046] A preparation method of a microbial enzyme-enhanced flonicamid·clothianidin suspension, comprising the following steps, 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 aluminum magnesium silicate, 5 parts of propylene glycol, 0.5 parts of silicone defoamer and 57.7 parts of water, grind and shear evenly, and then mix evenly with 3 parts of composite enzyme microcapsules

[0048] The preparation method of the composite enzyme microcapsules comprises the following steps, by weight:

[0049] X1. Mix 1 part of ε-caprolactone, 1.1 parts of β-propyl-β-propiolactone, 0.08 parts of 2,2'-dithiobisethanol and 0.0001 parts of stannous octoate evenly, heat up to 130°C under sealing and stir for 45 h. After the reaction is completed, add 10 parts of dichloromethane to dissolve, then add ether to dilute until precipitation occurs, filter and dry, and then mix with 1.5 parts of methoxy-polyethylene glycol-carboxyl, 0.004 parts of 4-dimethylaminopyridine and 10 parts of dichloromethane. Under an inert atmosphere, add 5 parts of a dichloromethane solution of N,N'-dicyclohexylcarbodiimide, polymerize at room temperature for 45 h. After the reaction is completed, filter, concentrate the filtrate, precipitate with ether and then 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 evenly;

[0050] X2. Add 0.3 parts of the modified polymer to 4 parts of dichloromethane to obtain an 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 an aqueous phase, mix 1 part of the oil phase and 4.5 parts of the aqueous phase, add 0.11 parts of Span 80 and continue homogenization. After homogenization is completed, add it to 5.5 parts of a 4 wt% polyvinyl alcohol aqueous solution, continue homogenization, heat up to 37°C, volatilize the solvent and solidify the emulsion. The obtained microcapsules are centrifuged, washed, freeze-dried and sieved to obtain the composite enzyme microcapsules

[0051] Example 2

[0052] It is basically the same as Example 1, with the only difference being that β-propyl-β-propiolactone in Example 1 is replaced by 3-amino-4-methyl-,(3s-trans)-2-oxetanone.

[0053] Example 3

[0054] It is basically the same as Example 1, with the only difference being that β-propyl-β-propiolactone in Example 1 is replaced by 4-oxo-2-oxetanecarboxylic acid.

[0055] Control Example 1

[0056] A preparation method of a microbial enzyme synergistic flonicamid·clothianidin suspension includes the following steps, 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, then grind and shear evenly, and mix evenly with 3 parts of composite enzyme microcapsules to obtain the product.

[0058] The preparation method of the composite enzyme microcapsules includes the following steps, in parts by weight:

[0059] Add 0.3 parts of polycaprolactone to 4 parts of dichloromethane to obtain an 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 a water phase, mix 1 part of the oil phase with 4.5 parts of the water phase, then add 0.11 parts of Span 80 and continue homogenization. After the homogenization is completed, add it to 5.5 parts of a 4wt% polyvinyl alcohol aqueous solution, continue homogenization, raise the temperature to 37°C, and after the solvent volatilizes and the emulsion solidifies, the obtained microcapsules are centrifuged, washed, freeze-dried and sieved to obtain the composite enzyme microcapsules.

[0060] Control Example 2

[0061] A preparation method of a microbial enzyme synergistic flonicamid·clothianidin suspension includes the following steps, 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 evenly, then 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 the product.

[0063] Test Example 1

[0064] The efficacy test of the suspending agents in the examples and control examples was carried out in a certain paddy field. The medicine was applied during the peak period of the damage by planthoppers using the spraying method. Water and a commercially available 20% flonicamid·clothianidin suspending agent (5% flonicamid, 15% clothianidin, Shenzhen Langtai Biotech Co., Ltd.) were used as the control group. A total of 5 medicament treatments were set in the test, with 3 replicates for each treatment, totaling 15 plots. The plot area was 100 m 2 , and a 1 m-wide protective row was set between the plots. The dosage was 30 mL / mu. Before applying the medicine, the population base of insects 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 at 7 days, 14 days, and 30 days after applying the medicine, 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 the suspending agent

[0066]

[0067]

[0068] As can be seen from Table 1, compared with the commercially available 20% flonicamid·clothianidin suspending agent, the suspending agent of the present invention has a better field efficacy index. This may be because the addition of microbial enzymes can damage the body surface or digestive system of pests, enhancing the insecticidal effect of pesticides. Cellulase can degrade the cellulose in the plant cell wall, making it easier for pesticides to penetrate into plant tissues and improving the utilization rate of pesticides. Chitinase can degrade the chitin exoskeleton of insects, destroying the protective barrier of pests, making it easier for flonicamid and clothianidin to enter the pests' bodies and improving the insecticidal effect. β-glucanase can degrade the polysaccharides in the plant cell wall, increasing the permeability of pesticides and making them act better on pests. These microbial enzymes can significantly enhance the insecticidal effects of flonicamid and clothianidin, improve the utilization efficiency of pesticides and the control effect by promoting the metabolism of pesticides, increasing permeability and destroying the protective structure of pests.

[0069] Compared with Comparative Example 2, the examples all have a higher control efficacy index. This may be because enzymes are easily inactivated by environmental factors such as temperature, pH value, and light in the suspending agent. In the examples, the free enzyme is immobilized by microencapsulation, thus improving the performance of the biological enzyme and making it less likely to be inactivated. Compared with Comparative Example 1, the examples use a modified polymer. By adding a modified monomer during polymerization, the defects of strong hydrophobicity and high crystallinity of polycaprolactone are improved. Since the modified polymer has side chains, it can avoid the defect of slow release of internal substances caused by high crystallinity of the polymer. The introduced polyethylene glycol and other hydrophilic groups make the modified polymer amphiphilic, so it has better dispersibility, a more stable structure, and a faster release rate, which is crucial for enhancing the drug efficacy. Compared with Examples 1-2, Example 3 has the highest control efficacy index. This may be because the modifier in Example 3 has a hydrophilic group, carboxyl group, which has better hydrophilicity compared with other examples. The addition of the hydrophilic side chain can not only reduce the defects caused by high crystallinity but also improve the solubility of the microcapsules in the liquid medicine, thus enabling the microbial enzyme to play a better role and resulting in the best control effect.

[0070] Test Example 2

[0071] For the determination of the antioxidant enzyme activity of planthoppers in Test Example 1, 30 planthoppers were collected respectively 24 and 48 hours after the first application of the drug. Every 10 planthoppers were put into a 2 mL centrifuge tube as 1 replicate, and 3 replicates were set for each treatment. They were stored in liquid nitrogen until transferred to a -80 °C refrigerator for standby. 1 mL of ice-bathed PBS buffer was added to each sample, and homogenized in an ice bath. The supernatant obtained by centrifugation was the crude enzyme solution, and the antioxidant enzyme activity was measured using a determination kit. See Table 2 for details.

[0072] Table 2 Effects of the suspending agent on the antioxidant enzymes of planthoppers

[0073]

[0074] When pests come into contact with chemical agents, the active ingredients in the agents will trigger an oxidative stress response inside the cells, leading to the generation of reactive oxygen species (ROS). Reactive oxygen species have high chemical activity and oxidizing properties and can react with macromolecules such as lipids, proteins, and DNA inside the cells, triggering peroxidation reactions. The peroxidation reaction will damage the lipid bilayer structure of the cell membrane, resulting in an increase in membrane permeability and the loss of intracellular substances. At the same time, the damage to proteins and DNA will affect the normal functions of the cells and the transmission of genetic information, ultimately leading to cell dysfunction and even death.

[0075] Among them, the main function of catalase (CAT) is to decompose hydrogen peroxide into water and oxygen, thereby eliminating the toxicity of hydrogen peroxide to cells. Hydrogen peroxide is a common reactive oxygen species that can cause severe oxidative damage. By decomposing hydrogen peroxide, CAT reduces its concentration in cells and alleviates oxidative damage. Superoxide dismutase (SOD) can disproportionate superoxide anions into oxygen and hydrogen peroxide. Superoxide anions are a form of reactive oxygen species with strong oxidizing properties that can trigger chain reactions, leading to more oxidative damage. SOD converts superoxide anions into substances with relatively lower toxicity through disproportionation 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 planthoppers develop resistance to chemical agents.

[0076] As can be seen from Table 2, the antioxidant enzyme activity in the bodies of planthoppers of the suspending agent added with microbial enzymes is lower. This may be because these enzymes can damage the exoskeleton structure of pests or plant cell walls, thereby increasing the permeability of chemical agents and making it easier for them to enter the bodies of pests or plant cells. This helps to improve the effectiveness of chemical agents, reduce the tolerance of pests to chemical agents, and indirectly slow down the development of resistance. By improving the effectiveness of chemical agents, the amount of chemical agents used can be reduced to a certain extent. This helps to reduce the frequency and concentration of pests' exposure to chemical agents, 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 foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A microbial enzyme-enhanced flonicamid / clothianidin suspension concentrate, characterized by: (1) The components and weight percentages are: clothianidin 10-20%, flonicamid 4-6%, complex enzyme microcapsule 1-5%, emulsifier 1-5%, dispersant 6-15%, thickener 0.1-0.6%, suspending agent 0.1-1%, antifreeze 3-6%, defoamer 0.1-0.5%, and the balance is water; (2) The composite enzyme microcapsules are prepared by the following method, calculated by weight ratio: X1, 1 part of caprolactone, 0.8-1.5 parts of modifier, 0.05-0.1 parts of 2,2'-dithiodiethanol and 0.0001-0.0005 parts of catalyst are sealed and heated to 120-140°C and stirred at 120-140°C for 40-50 hours. After the reaction is completed, 0.4-2 parts of methoxy-polyethylene glycol-carboxyl, 0.001-0.005 parts of 4-dimethylaminopyridine and 5-15 parts of solvent are mixed after post-treatment, 3-8 parts of N,N'-dicyclohexylcarbodiimide dichloromethane solution is added under inert atmosphere, and polymerization is carried out at room temperature for 40-50 hours. After the reaction is completed, a modified polymer is obtained after post-treatment; 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 the mixture to a 3-5 wt% polyvinyl alcohol aqueous solution and continue homogenizing; heat to 34-37°C, evaporate the solvent, centrifuge, wash, freeze-dry and sieve to obtain the complex enzyme microcapsules.

2. The microbial enzyme synergistic flonicamid-clothianidin suspension concentrate according to claim 1, 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-oxetaneone.

3. The microbial enzyme synergistic flonicamid-clothianidin suspension concentrate according to claim 1, 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.

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

5. The microbial enzyme synergistic flonicamid-clothianidin 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.

6. The microbial enzyme synergistic flonicamid-clothianidin suspension concentrate according to claim 1, characterized in that: The thickener is one of xanthan gum, carboxymethyl cellulose or guar gum.

7. The microbial enzyme synergistic flonicamid-clothianidin 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.

8. A method for preparing the microbial enzyme-enhanced flonicamid-clothianidin suspension concentrate according to any one of claims 1 to 7, characterized in that: The steps include: The flonicamid, clothianidin, emulsifier, dispersant, thickener, suspending agent, antifreeze, defoamer and water are dispersed, then ground and sheared evenly, and then mixed evenly with the complex enzyme microcapsules to obtain the product.

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