A luteolin plant source pesticide microcapsule capable of effectively preventing and treating malacosoma americanum and a preparation method thereof

Abstract

This invention discloses a luteolin-based plant-derived pesticide microcapsule and its preparation method for effectively controlling the fall webworm, relating to the field of plant-derived pesticide formulation technology. The microcapsule is a core-shell particle with a three-layer wall structure, comprising: a core material containing the active ingredient luteolin, a synergist, and an oil phase carrier; and an inner wall material, a middle wall material, and an outer wall material sequentially coating the core material from the inside out. The inner wall material is an enzyme-responsive material that can be specifically degraded by chitinase in the gut of fall webworm larvae; the middle wall material is a pH-responsive material that can swell in an alkaline environment; and the outer wall material is an environmental barrier material that provides physical and chemical stability. This invention achieves precise targeted control of the fall webworm through a three-layer responsive core-shell structure, synergistic component formulation, leaf surface adhesion modification, and a green preparation process, and solves the problems of poor stability and easy resistance of luteolin.

Description

Technical Field

[0001] This invention relates to the field of plant-derived pesticide formulation technology, specifically to a luteolin plant-derived pesticide microcapsule and its preparation method that can effectively control the fall webworm. Background Technology

[0002] The fall webworm (Russian white moth) is a global quarantine pest that seriously damages agricultural and forestry crops. Its spread in my country poses a continuous threat to ecological security and the economic forestry industry. The fall webworm is omnivorous, reproduces rapidly, and has a strong ability to spread. Its larvae are extremely damaging to various host plants such as poplar, willow, and apple trees, severely disrupting the ecological environment and the safety of forestry and agricultural production. Currently, the control of the fall webworm still relies mainly on chemical pesticides, but long-term large-scale application has led to a series of prominent problems: First, the pest's resistance to pesticides continues to rise, resulting in a continuous increase in pesticide use, rising control costs, and declining efficacy year by year; second, large amounts of chemical pesticide residues remain in soil and water bodies, polluting the ecological environment; and third, it has high toxicity to non-target organisms such as bees, ladybugs, and earthworms, seriously threatening biodiversity.

[0003] Therefore, green and low-toxicity plant-derived pesticides have become a research hotspot. Among them, luteolin, a natural flavonoid compound extracted from plants such as Sophora japonica and honeysuckle, has significant insecticidal activity. It works by inhibiting the activity of digestive enzymes in pests and interfering with metabolic pathways. Moreover, it has good environmental compatibility and low toxicity to non-target organisms, making it an ideal alternative to chemical pesticides. However, luteolin has extremely poor water solubility, making it difficult to formulate into conventional water-based formulations. Dissolving it in organic solvents to make emulsifiable oils deviates from the original intention of green and environmentally friendly practices. At the same time, this compound is sensitive to light and heat, and is prone to photochemical degradation and oxidation in the natural environment, resulting in a short field residual effect. Frequent application is required, increasing costs and labor intensity. Furthermore, it is easily degraded by ultraviolet light when applied directly, making it difficult to remain on crop surfaces, which greatly limits its large-scale promotion.

[0004] Existing technologies attempt to encapsulate luteolin into microcapsules, but most focus on simple physical encapsulation or slow release based on diffusion mechanisms, such as using synthetic polymers like polyurea and polyamide as wall materials. While these methods can protect the active ingredient and prolong release time to some extent, their release behavior mainly relies on the slow dissolution of the wall material or the passive diffusion of the active ingredient, lacking environmental specificity. This means that regardless of the presence of target pests, microcapsules continuously release pesticides into the environment, not only wasting the active ingredient and causing environmental pollution, but also failing to achieve high-dose precision targeting at the critical moment when pests are feeding, resulting in low control efficiency. Furthermore, the midgut of the fall webworm larvae has a unique and stable highly alkaline environment (pH 9.5-10.5) and abundant digestive enzymes such as chitinase. Most existing pH-responsive pesticide carriers are designed for the gastrointestinal tract of mammals (with large pH gradients), and cannot effectively adapt to this specific physiological condition of insects. Similarly, few studies utilize highly active specific enzymes in the insect gut as trigger signals. Therefore, existing microencapsulation formulations cannot be highly stable in non-target environments, nor can they be rapidly and completely released into the target pests, lacking intelligent targeting design based on the physiological characteristics of the target pests.

[0005] Meanwhile, existing technologies typically encapsulate luteolin as a single active ingredient without fully considering how to enhance its biological activity and achieve multi-site attack through reasonable compounding and formulation design, thereby delaying the development of pesticide resistance in pests. Furthermore, the foliar adhesion and rain washout resistance of the formulations are often overlooked, affecting the actual control effect. Summary of the Invention

[0006] The purpose of this invention is to provide a luteolin-derived plant pesticide microcapsule and its preparation method that can effectively control the fall webworm, in order to solve the problems of poor stability, short duration of action, easy development of resistance, and poor leaf adhesion of existing luteolin pesticide formulations.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] According to a first aspect of this disclosure, a luteolin-derived plant-based pesticide microcapsule is provided that can effectively control the fall webworm, wherein the microcapsule is a core-shell particle with a three-layered wall structure, comprising:

[0009] The core material contains the active ingredient luteolin, synergists, and an oil phase carrier;

[0010] The inner wall material, the middle wall material, and the outer wall material are sequentially wrapped around the core material from the inside out.

[0011] The inner wall material is an enzyme-responsive material that can be specifically degraded by chitinase in the gut of the American white moth larvae.

[0012] The intermediate layer wall material is a pH-responsive material that can swell in an alkaline environment;

[0013] The outer wall material is an environmental barrier material that provides physical and chemical stability.

[0014] Furthermore, the synergistic agent comprises a targeting penetrant and an enzyme inhibitor; the targeting penetrant is a saponin surfactant, and the enzyme inhibitor is a chitinase inhibitor; the oil phase carrier is a mixture of ethyl lactate and medium-chain triglycerides.

[0015] Furthermore, based on the total mass of the core material, the mass percentage of luteolin is 10%-20%, the mass percentage of saponin surfactant is 0.5%-1%, the mass percentage of chitinase inhibitor is 0.3%-0.8%, and the mass ratio of ethyl lactate to medium-chain triglycerides is 1:2 to 1:4.

[0016] Furthermore, the inner wall material is butyrylated chitin;

[0017] The intermediate layer wall material is chitosan modified with phenylboronic acid;

[0018] The outer wall material is a composite gel membrane formed by ionic crosslinking and covalent crosslinking of sodium alginate and gelatin.

[0019] Furthermore, the microcapsules have a particle size D50 of 5-15 micrometers; the encapsulation efficiency of the luteolin is not less than 90%, and the drug loading is not less than 15%.

[0020] Furthermore, the outer surface of the microcapsule is also coated with a leaf surface adhesive, which is diatomaceous earth nanoparticles.

[0021] According to a second aspect of this disclosure, a method for preparing luteolin-derived plant pesticide microcapsules that can effectively control the fall webworm is also provided, comprising the following steps:

[0022] S1. Luteolin and synergist are dissolved in an oil phase carrier to form an oil phase; the inner wall material is dissolved in a weakly acidic aqueous solution to form an inner aqueous phase; the inner aqueous phase is emulsified and dispersed in the oil phase to form a W1 / O type primary emulsion; the primary emulsion is placed in a coagulation bath to solidify the inner wall material at the emulsion droplet interface to form drug-loaded core microspheres with inner wall material;

[0023] S2. The drug-loaded core microspheres are dispersed in a solution containing an intermediate wall material, and the intermediate wall material is coated on their surface by adsorption, and then preliminary cross-linking and curing are carried out.

[0024] S3. Disperse microspheres coated with intermediate wall material in a solution containing outer wall material raw material, coat the outer wall material raw material on its surface through adsorption, and then place it in an ion crosslinking bath for ion crosslinking to form outer wall material.

[0025] S4. The microcapsules obtained in step S3 are subjected to overall cross-linking enhancement and surface functionalization modification, followed by separation, washing and drying to finally obtain the finished microcapsules.

[0026] Furthermore, in step S1, the coagulation bath is an aqueous solution of polyethylene glycol;

[0027] In step S2, the crosslinking agent used for the initial crosslinking curing is a calcium ion solution;

[0028] In step S3, the ion crosslinking bath is a solution containing calcium ions.

[0029] Furthermore, in step S2, the pH value of the solution containing the intermediate wall material is 6.0-7.0;

[0030] In step S3, the solution containing the outer wall material raw material includes sodium alginate and gelatin, with a mass ratio of 1:1 to 3:1.

[0031] Furthermore, in step S4, the overall cross-linking enhancement is achieved by cross-linking the microcapsules with the natural cross-linking agent genipin at 40-60°C for 0.5-2 hours.

[0032] The surface functionalization modification involves mixing the microcapsules with a suspension of diatomaceous earth nanoparticles, causing the nanoparticles to adhere to the surface of the microcapsules.

[0033] Compared with existing technologies, this invention provides a microcapsule of luteolin, a plant-derived pesticide, and its preparation method for effectively controlling the fall webworm. It employs a three-layer core-shell structure, using an inner enzyme-responsive material, a middle pH-responsive material, and an outer environmental barrier material to achieve precise targeted release. This is further enhanced by the synergistic design of saponin penetrants and chitinase inhibitors in the core material, and by diatomaceous earth nanoparticle modification to improve leaf adhesion. This not only allows luteolin to be stably stored in the natural environment and rapidly released in the larval gut, effectively improving utilization, but also delays pest resistance through multi-target action. Its UV stability and field efficacy are significantly improved. Furthermore, all materials used are natural and biodegradable, the process is mild and environmentally friendly, it has low toxicity to non-target organisms, and poses no risk of environmental residue. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0035] Figure 1 This is a flowchart of the method for preparing luteolin plant-derived pesticide microcapsules according to Example 1 of the present invention;

[0036] Figure 2 This is a schematic diagram showing the release curves of the luteolin plant-derived pesticide microcapsules prepared in Example 1 of the present invention under different environments.

[0037] Figure 3 This is a schematic diagram showing the photostability comparison curves of the luteolin plant-derived pesticide microcapsules prepared in Example 1 of the present invention and free luteolin. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0039] Example 1:

[0040] This invention provides a method for preparing luteolin-derived plant-based pesticide microcapsules that can effectively control the fall webworm.

[0041] 1. Material preparation

[0042] Core material raw materials: luteolin (purity ≥98%, obtained by purification of Sophora japonica extract), saponin surfactant (soybean saponin, purity ≥95%), chitinase inhibitor (N-acetylglucosamine, purity ≥99%), ethyl lactate (food grade, purity ≥99%), medium chain triglycerides (food grade, viscosity 5-10 mPa·s).

[0043] Wall material raw materials: butyrylated chitin (degree of deacetylation ≥85%, degree of butyrylation substitution 0.6), phenylboronic acid modified chitosan (degree of substitution 0.3, molecular weight 5000-10000 Da), sodium alginate (viscosity 200-300 mPa·s), gelatin (type A, isoelectric point 4.8-5.0);

[0044] Crosslinking agent and auxiliary materials: polyethylene glycol (PEG-6000), calcium chloride (analytical grade), genipin (purity ≥98%), diatomaceous earth nanoparticles (particle size 50-100nm), acetic acid (analytical grade), deionized water.

[0045] Specific preparation steps

[0046] In this embodiment, the total mass of the core material is 100g, and the amount of each component is calculated as a percentage by mass: luteolin 15% (15g), soybean saponins 0.8% (0.8g), N-acetylglucosamine 0.5% (0.5g), ethyl lactate 25g, and medium-chain triglycerides 58.7g (the mass ratio of ethyl lactate to medium-chain triglycerides is 1:2.35).

[0047] Step S1: Preparation of drug-loaded core microspheres

[0048] Oil phase preparation: 15g luteolin, 0.8g soybean saponins and 0.5g N-acetylglucosamine were added to a mixture of 25g ethyl lactate and 58.7g medium-chain triglycerides. The mixture was placed in a 50℃ constant temperature water bath and magnetically stirred at 300r / min for 30min to completely dissolve all components and obtain a homogeneous oil phase.

[0049] Preparation of the internal aqueous phase: Weigh 5g of butyrylated chitin and add it to 100mL of 1% acetic acid aqueous solution (weakly acidic, pH 4.0-4.5). Stir magnetically at 500r / min for 60min at room temperature until completely dissolved to obtain the internal aqueous phase.

[0050] Preparation of W1 / O type colostrum: The inner aqueous phase is slowly added to the oil phase at a dropping rate of 2 mL / min, while the high-speed shear emulsifier is turned on and sheared at 10000 r / min for 30 min to form a uniform W1 / O type colostrum (colostrum particle size controlled at 2-5 μm).

[0051] Coagulation and solidification: Prepare a 5% polyethylene glycol (PEG-6000) aqueous solution as a coagulation bath. Slowly drop the primary emulsion into the coagulation bath at a rate of 3 mL / min. Stir magnetically at 200 r / min for 60 min at room temperature. Butyrylated chitin coagulates at the emulsion droplet interface to form drug-loaded core microspheres with an inner wall material.

[0052] Preliminary separation and washing: The above suspension was vacuum filtered (filter membrane pore size 0.45μm), the drug-loaded core microspheres were collected, and washed twice with deionized water to remove unsolidified wall material and oil phase impurities on the surface.

[0053] Step S2: Coating and initially crosslinking the intermediate wall material

[0054] Preparation of intermediate layer wall material solution: Weigh 3g of phenylboronic acid modified chitosan, add it to 100mL of deionized water, adjust the pH to 6.5 with 1% acetic acid solution, and stir magnetically at 400r / min for 40min at room temperature to obtain a uniform intermediate layer wall material solution.

[0055] Coating and crosslinking: The drug-loaded core microspheres obtained in step S1 were added to the intermediate wall material solution and magnetically stirred at 300 r / min for 120 min at room temperature, so that the chitosan modified with phenylboronic acid was coated on the surface of the microspheres through electrostatic adsorption; then 5 mL of 1 mol / L calcium chloride solution (crosslinking agent) was added and stirring was continued for 60 min to achieve preliminary crosslinking and curing.

[0056] Separation and washing: The microspheres coated with the intermediate layer are collected by vacuum filtration and washed twice with deionized water to remove the unadsorbed intermediate layer wall material and residual calcium chloride.

[0057] Step S3: Coating and ion-crosslinking the outer wall material

[0058] Preparation of outer wall material raw material solution: Weigh 4g sodium alginate and 2g gelatin (sodium alginate to gelatin mass ratio 2:1), add to 100mL deionized water, heat to 50℃, and stir magnetically at 500r / min for 40min until completely dissolved to obtain outer wall material raw material solution.

[0059] Coating: The microspheres obtained in step S2 are added to the outer wall material raw material solution and magnetically stirred at 300 r / min for 90 min at 50°C, so that sodium alginate and gelatin are coated on the surface of the microspheres through adsorption.

[0060] Ionic crosslinking: Prepare a 2 mol / L calcium chloride solution as an ionic crosslinking bath, slowly drop the above suspension into the crosslinking bath, and continue stirring at 50°C for 60 min. Sodium alginate and calcium ions undergo ionic crosslinking to form a dense outer composite gel film.

[0061] Separation and washing: The microspheres coated with the outer layer are collected by vacuum filtration and washed three times with deionized water to remove the uncrosslinked outer wall material raw material and residual calcium chloride.

[0062] Step S4: Overall cross-linking strengthening and surface functionalization modification

[0063] Overall cross-linking reinforcement: Disperse the microspheres obtained in step S3 in 100mL of deionized water, add 0.5g of genipin (natural cross-linking agent), heat to 50℃ (within the range of 40-60℃), and magnetically stir at 200r / min for 1h to achieve covalent cross-linking of gelatin and chitosan, thereby strengthening the structural stability of the wall material.

[0064] Surface functionalization modification: Prepare a 5% diatomaceous earth nanoparticle suspension, add the cross-linked microspheres to the suspension, and stir magnetically at 300 r / min for 60 min at room temperature so that the diatomaceous earth nanoparticles are attached to the surface of the microcapsules through electrostatic adsorption.

[0065] Separation and washing: The microcapsules are collected by vacuum filtration and washed twice with deionized water to remove unattached diatomaceous earth nanoparticles.

[0066] Drying: The washed microcapsules were placed in a freeze dryer and pre-frozen at -40℃ for 2 hours, and then dried at a vacuum degree ≤10Pa and a temperature of -50℃ for 12 hours to obtain the finished microcapsules.

[0067] Performance testing of finished microcapsules

[0068] The performance of the finished microcapsules prepared in this embodiment was tested. The test methods and results are as follows:

[0069] Particle size test: The particle size was determined by a laser particle size analyzer. An appropriate amount of the finished microcapsules was dispersed in deionized water and ultrasonically dispersed for 10 minutes before testing.

[0070] The results showed that the microcapsule particle size D50 was 10.2 μm.

[0071] Encapsulation efficiency and drug loading test: HPLC method was used to determine the encapsulation efficiency and drug loading. 0.1g of finished microcapsules were accurately weighed, added to 50mL of methanol and ultrasonically extracted for 30min. After filtration, the filtrate was taken for HPLC analysis to calculate the encapsulation efficiency and drug loading.

[0072] The results showed that the encapsulation efficiency of luteolin was 93.5%, and the drug loading was 15.8%.

[0073] Release characteristics test: Release tests were conducted in neutral buffer (pH 7.0, simulating the natural environment) and alkaline buffer (pH 9.5, containing 12 U / mg chitinase, simulating the midgut environment of fall webworm larvae);

[0074] The results showed that the release rate was 8.2% in neutral buffer at 24 hours and 12.5% ​​at 72 hours; the release rate was 58.3% in alkaline enzyme-containing buffer at 2 hours and 86.7% at 4 hours, achieving precise targeted release.

[0075] Photostability test: The finished microcapsules and free luteolin were placed under a 300W ultraviolet lamp (30cm away) for 6 hours, and the content of the remaining active ingredients was determined by HPLC.

[0076] The results showed that the luteolin activity retention rate in the finished microcapsules was 88.6%, while the free luteolin activity retention rate was only 32.4%, indicating a significant improvement in stability.

[0077] Leaf adhesion test: The finished microcapsules were prepared into a suspension and sprayed on the surface of poplar leaves. After natural drying, rainwater washing simulation was carried out (the leaves were washed with clean water at a rate of 10 mL / min for 30 s). The amount of microcapsules remaining on the leaf surface before and after washing was measured.

[0078] The results showed that the residual rate after rinsing was 92.3%.

[0079] Bioactivity test: Using third-instar larvae of the fall webworm as the test object, the leaf-poisoning method was used. Poplar leaves sprayed with the finished microcapsule suspension (luteolin concentration 200 mg / L) were fed to the larvae, and the mortality rate was recorded after 72 hours.

[0080] The results showed that the larval mortality rate was 91.2%, which was significantly higher than that of the same concentration of free luteolin (mortality rate 56.7%). At the same time, after three generations of continuous application, the pest resistance index was only 1.2, which was significantly better than the single luteolin preparation (resistance index 2.8) in delaying resistance.

[0081] Example 2:

[0082] This embodiment is basically the same as Example 1, except that the mass ratio of ethyl lactate to medium-chain triglycerides in the oil phase carrier is changed to 1:2, 1:3, and 1:4, respectively. All other conditions remain the same. After preparing the finished microcapsules, the encapsulation efficiency and drug loading were tested, and the results are shown in the table below:

[0083] Group Ethyl lactate: medium-chain triglycerides (mass ratio) Encapsulation rate (%) Drug loading (%) 1 1:2 92.1 15.5 2 1:3 94.3 16.2 3 1:4 93.7 15.9

[0084] As shown in the table above, when the mass ratio of ethyl lactate to medium-chain triglycerides is 1:3, the encapsulation efficiency and drug loading of the microcapsules are the highest. This indicates that the oil has the best solubility effect on luteolin at this ratio, and the droplet stability is the best during the emulsification process, which is beneficial to the coating of the wall material.

[0085] Example 3:

[0086] This embodiment is basically the same as Example 1, except that the mass ratio of sodium alginate to gelatin in the outer wall material is changed to three groups: 1:1, 2:1, and 3:1. All other conditions remain unchanged. After preparing the finished microcapsules, the retention rate of luteolin activity after 6 hours of UV irradiation was tested. The results are shown in the table below.

[0087] Group Sodium alginate: gelatin (mass ratio) Activity retention rate (%) after 6 hours of UV irradiation 1 1:1 85.2 2 2:1 88.6 3 3:1 87.3

[0088] As shown in the table above, the photostability of the microcapsules is best when the mass ratio of sodium alginate to gelatin is 2:1. This is because the composite gel film formed at this ratio has the best density, which can effectively block ultraviolet light penetration and protect luteolin from degradation.

[0089] Example 4

[0090] This embodiment is basically the same as Embodiment 1, except that the temperature for overall cross-linking strengthening in step S4 is changed to three groups: 40℃, 50℃, and 60℃. All other conditions remain the same. The compressive strength of the finished microcapsules was tested using a universal testing machine, and the results are shown in the table below:

[0091] Group Crosslinking temperature (°C) Compressive strength (μN) 1 40 185 2 50 223 3 60 218

[0092] As shown in the table above, the microcapsules exhibit the highest compressive strength when the crosslinking temperature is 50℃. This indicates that the crosslinking activity of genipin is optimal at this temperature, enabling the formation of a more stable crosslinking network in the wall material, thereby enhancing the mechanical strength of the microcapsules and making them more resistant to mechanical impacts such as wind and rain in the field.

[0093] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A luteolin-derived plant-based pesticide microcapsule that can effectively control the fall webworm, characterized in that, The microcapsules are core-shell particles with a three-layer wall structure, comprising: The core material contains the active ingredient luteolin, synergists, and an oil phase carrier; The inner wall material, the middle wall material, and the outer wall material are sequentially wrapped around the core material from the inside out. The inner wall material is an enzyme-responsive material that can be specifically degraded by chitinase in the gut of the American white moth larvae. The intermediate layer wall material is a pH-responsive material that can swell in an alkaline environment; The outer wall material is an environmental barrier material that provides physical and chemical stability.

2. The luteolin-derived plant-based pesticide microcapsule for effectively controlling the fall webworm, as described in claim 1, is characterized in that... The synergistic agent comprises a targeting penetrant and an enzyme inhibitor; the targeting penetrant is a saponin surfactant, and the enzyme inhibitor is a chitinase inhibitor; the oil phase carrier is a mixture of ethyl lactate and medium-chain triglycerides.

3. The luteolin-derived plant-based pesticide microcapsule for effectively controlling the fall webworm, as described in claim 2, is characterized in that... Based on the total mass of the core material, the mass percentage of luteolin is 10%-20%, the mass percentage of saponin surfactant is 0.5%-1%, the mass percentage of chitinase inhibitor is 0.3%-0.8%, and the mass ratio of ethyl lactate to medium-chain triglycerides is 1:2 to 1:

4.

4. The luteolin-derived plant-based pesticide microcapsule for effectively controlling the fall webworm, as described in claim 1, is characterized in that... The inner wall material is butyrylated chitin; The intermediate layer wall material is chitosan modified with phenylboronic acid; The outer wall material is a composite gel membrane formed by ionic crosslinking and covalent crosslinking of sodium alginate and gelatin.

5. The luteolin-derived plant-based pesticide microcapsule for effectively controlling the fall webworm, as described in claim 1, is characterized in that... The microcapsules have a particle size D50 of 5-15 micrometers; the encapsulation efficiency of the luteolin is not less than 90%, and the drug loading is not less than 15%.

6. The luteolin-derived plant-based pesticide microcapsule for effectively controlling the fall webworm, as described in claim 1, is characterized in that... The outer surface of the microcapsule is also coated with a leaf surface adhesive, which is diatomaceous earth nanoparticles.

7. A method for preparing microcapsules of luteolin-derived pesticide, which can effectively control the fall webworm, characterized in that, Includes the following steps: S1. Luteolin and synergist are dissolved in an oil phase carrier to form an oil phase; the inner wall material is dissolved in a weakly acidic aqueous solution to form an inner aqueous phase; the inner aqueous phase is emulsified and dispersed in the oil phase to form a W1 / O type primary emulsion; the primary emulsion is placed in a coagulation bath to solidify the inner wall material at the emulsion droplet interface to form drug-loaded core microspheres with inner wall material; S2. The drug-loaded core microspheres are dispersed in a solution containing an intermediate wall material, and the intermediate wall material is coated on their surface by adsorption, and then preliminary cross-linking and curing are carried out. S3. Disperse microspheres coated with intermediate wall material in a solution containing outer wall material raw material, coat the outer wall material raw material on its surface through adsorption, and then place it in an ion crosslinking bath for ion crosslinking to form outer wall material. S4. The microcapsules obtained in step S3 are subjected to overall cross-linking enhancement and surface functionalization modification, followed by separation, washing and drying to finally obtain the finished microcapsules.

8. A method for preparing luteolin-derived plant-based pesticide microcapsules capable of effectively controlling the fall webworm, as described in claim 7, characterized in that... In step S1, the coagulation bath is an aqueous solution of polyethylene glycol; In step S2, the crosslinking agent used for the initial crosslinking curing is a calcium ion solution; In step S3, the ion crosslinking bath is a solution containing calcium ions.

9. A method for preparing luteolin-derived plant-based pesticide microcapsules capable of effectively controlling the fall webworm, as described in claim 7, characterized in that... In step S2, the pH value of the solution containing the intermediate wall material is 6.0-7.0; In step S3, the solution containing the outer wall material raw material includes sodium alginate and gelatin, with a mass ratio of 1:1 to 3:

1.

10. A method for preparing luteolin-derived plant-based pesticide microcapsules capable of effectively controlling the fall webworm, as described in claim 7, characterized in that... In step S4, the overall cross-linking enhancement is achieved by cross-linking the microcapsules with the natural cross-linking agent genipin at 40-60°C for 0.5-2 hours. The surface functionalization modification involves mixing the microcapsules with a suspension of diatomaceous earth nanoparticles, causing the nanoparticles to adhere to the surface of the microcapsules.

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