A spraying agent for preventing and controlling Spodoptera exigua in a greenhouse and its preparation process

Abstract

The present invention relates to the technical field of pesticide insecticides, and particularly relates to a spraying agent for preventing and controlling Spodoptera exigua in greenhouse asparagus and a preparation process thereof. The process includes the following steps: preparation of a fiber wetting and strengthening agent; compounding of a photothermal-responsive elastic film material and preparation of a suspension; preparation of the spraying agent for preventing and controlling Spodoptera exigua. By preparing a blocked urea bond monomer, reacting it with 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene and adding mercapto-functionalized carbon nanotubes, and stretching and fixing to obtain a photothermal-responsive elastic film material, and adding it to a sustained-release hydrogel, the invention can kill insects according to the characteristic of Spodoptera exigua being active at night and hiding during the day, avoid the ineffective release of the compound insecticide during the day, greatly improve the utilization rate of the compound insecticide, extend the effective insecticidal period, improve the control efficiency against Spodoptera exigua, reduce the spraying frequency and spraying amount of pesticides, and have double ecological and economic benefits.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide insecticides, and particularly to a spraying agent for preventing and controlling Spodoptera exigua in greenhouse asparagus and a preparation process thereof. Background Art

[0002] In recent years, with the rapid development of protected agriculture, greenhouse asparagus has become an important cash crop due to its advantages of off-season and high output value. However, the environmental characteristics of high humidity and significant temperature difference between day and night in the greenhouse (the temperature can reach 25 - 30°C during the day and often drops to 15 - 20°C at night) provide a breeding ground for lepidopteran noctuid pests. Among them, the representative Spodoptera exigua has the typical habit of being active at night and hiding during the day, often migrating to the tender stems of asparagus to feed at night, and pesticides often need to be sprayed to kill its larvae and adults.

[0003] After traditional pesticides are sprayed, they are easily inactivated quickly in the environment under the influence of environmental factors such as temperature and light, resulting in low pesticide utilization rate, easy frequent application of pesticides, exacerbating the risk of pest resistance and soil residue. In response to this, the prior art often adopts a slow-release method to delay the release rate of the pesticide, avoid its ineffective release in the environment, and thus improve the pesticide utilization rate.

[0004] Current pesticide slow-release technologies include conventional slow-release, thermosensitive slow-release, pH-responsive slow-release, etc. Conventional slow-release often can only fix the release rate of the pesticide within a small range and cannot further achieve precise and efficient control. Thermosensitive slow-release usually uses the PNIPAM hydrogel slow-release system, whose release rate increases at high temperature and decreases at low temperature, without considering the habit of noctuid pests being active at night and hiding during the day. And pH-responsive slow-release has uncontrollability in pest control, and its slow-release effect is easily changed with environmental factors such as humidity, and it also cannot achieve precise and efficient control of pests. Summary of the Invention

[0005] In order to solve the above technical deficiencies, the present invention has developed a spraying agent for preventing and controlling Spodoptera exigua in greenhouse asparagus and a preparation process thereof. By adding materials that shrink at high temperature and recover at low temperature to the slow-release hydrogel, it can match the habit of noctuid pests being active at night and hiding during the day for targeted insecticidal action, achieve the purpose of precise and efficient control, reduce the application amount of pesticides, and can better protect the ecological environment.

[0006] A preparation process of a spraying agent for preventing and controlling Spodoptera exigua in greenhouse asparagus includes the following steps:

[0007] Preparation of S1 fiber wetting enhancer: Grind Intsia wood into powder, then carry out enzymatic hydrolysis and ethanol extraction to obtain Intsia wood extract powder. Dissolve the Intsia wood extract powder and epigallocatechin gallate in absolute ethanol, add an aqueous potassium dihydrogen phosphate solution containing laccase and mix evenly. Then add cellulose nanofibers for a water bath reaction, centrifuge to obtain the precipitate and dry it to obtain the fiber wetting enhancer;

[0008] S2 Composite of photothermal-responsive elastic film material and preparation of suspension: React isocyanatoethyl methacrylate and N,N'-di-tert-butylethylenediamine in anhydrous dichloromethane under heat preservation to obtain a blocked urea bond monomer, then react with 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene and add thiolated carbon nanotubes to obtain a photothermal liquid crystal polymer film. After stretching and curing, shear it in deionized water to obtain a suspension of the photothermal-responsive elastic film material;

[0009] S3 Preparation of Spodoptera exigua control spraying agent: Mix chlorantraniliprole, pogostone and graphene oxide solution and stir in a water bath. After centrifugation and washing, obtain a composite insecticide drug carrier. Prepolymerize acrylic acid and acrylamide, then add the suspension of the photothermal-responsive elastic film material, the fiber wetting enhancer and the composite insecticide drug carrier and stir evenly. After heating and polymerization, mix evenly with deionized water to obtain the Spodoptera exigua control spraying agent.

[0010] Furthermore, the preparation of the S1 fiber wetting enhancer in step S1 includes the following steps:

[0011] S1.1: Dry Intsia wood and grind it into powder to obtain Intsia wood powder. Then mix 30-40 parts by weight of Intsia wood powder, 150-200 parts by weight of aqueous citric acid solution and 3-5 parts by weight of cellulase evenly, carry out a constant temperature water bath at 50-55 °C for 24-30 hours, filter to obtain filtrate I and residue I for standby;

[0012] S1.2: Mix the residue I in step S1.1 and an ethanol aqueous solution with a volume fraction of 75-80% at a mass ratio of 1:(40-50), then carry out reflux extraction at 80-85 °C for 8-10 hours, filter to obtain filtrate II and residue II. Combine filtrate I and filtrate II in step S1.1 and place them in a rotary evaporator. Adjust the temperature to 35-40 °C and the vacuum degree to 0.08-0.09 MPa for rotary evaporation until a paste is formed. Vacuum dry the paste at 65-70 °C and a vacuum degree of 0.075-0.08 MPa until constant weight, pulverize and pass through a 60-70 mesh sieve to obtain Intsia wood extract powder;

[0013] S1.3: Dissolve the teak extract powder and epigallocatechin gallate in absolute ethanol, then add an aqueous solution of potassium dihydrogen phosphate containing laccase to obtain a composite solution. In the composite solution, the concentration of the teak extract powder is 60 - 80 g / L, the concentration of epigallocatechin gallate is 15 - 20 g / L, the volume fraction of absolute ethanol is 20 - 25%, add 1 - 2 wt% of cellulose nanofibers to the composite solution, introduce oxygen at a flow rate of 0.2 - 0.3 L / min, then under the water bath condition of 35 - 40 °C, oscillate at 180 - 200 rpm for 10 - 12 hours, then centrifuge to obtain the precipitate, and obtain the fiber wetting enhancer after vacuum drying.

[0014] Further, for step S2, the compounding of the photothermal-responsive elastic film material and the preparation of the suspension

[0015] S2.1: Place 3.8 - 3.85 parts by weight of isocyanatoethyl methacrylate and 48 - 50 parts by weight of anhydrous dichloromethane in a three-necked flask, protect it by introducing nitrogen, then slowly drop 2.1 - 2.15 parts by weight of N,N'-di-tert-butylethylenediamine and 8 - 10 parts by weight of anhydrous dichloromethane into the three-necked flask, keep the reaction at room temperature for 1 - 1.2 hours, use a rotary evaporator to spin-dry the anhydrous dichloromethane and then cool to obtain the blocked urea bond monomer;

[0016] S2.2: Add 14 - 14.5 parts by weight of the blocked urea bond monomer and 75.4 - 75.6 parts by weight of 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene to 200 - 250 parts by weight of toluene, heat to complete dissolution at 80 - 85 °C, after cooling to room temperature, add 1 - 1.2 wt% of mercapto-functionalized carbon nanotubes, 13 - 13.2 parts by weight of 3,6-dioxa-1,8-octanedithiol and 8.5 - 9 parts by weight of 1,5-diaminopentane in sequence, place it in an ultrasonic oscillator to mix and defoam for 4 - 5 minutes, then pour it into a polytetrafluoroethylene mold, react at room temperature for 24 - 25 hours, and then react at 90 - 92 °C for 1 - 1.2 hours to obtain the photothermal liquid crystal polymer film;

[0017] S2.3: Control the tensile strength to be 2 - 3 MPa, stretch the photothermal liquid crystal polymer film to 140 - 142% of its original length and then fix it, then heat-treat it at 138 - 140 °C for 1 - 1.5 hours, naturally cool to room temperature to obtain the photothermal-responsive elastic film material, mix the photothermal-responsive elastic film material and deionized water at a solid-liquid ratio of 1:(10 - 15) g / mL, and then perform high-speed shearing at a shear rate of 3000 - 4000 rpm to obtain the photothermal-responsive elastic film material suspension, and store it in a dark place.

[0018] Further, for step S3, the preparation of the spraying agent for Spodoptera exigua control includes the following steps:

[0019] S3.1: Dissolve 3 - 4 parts by weight of chlorantraniliprole and 5 - 6 parts by weight of pogostone in 160 - 180 parts by weight of acetone. Add 0.2 - 0.3 parts by weight of polysorbate - 20, then add 3 - 3.5 parts by weight of graphene oxide solution with a concentration of 1 - 1.5 g / L. After magnetic stirring evenly, place it in a dark environment and continuously stir for 20 - 24 hours under the water bath conditions of 24 - 26 °C and 200 - 250 rpm. Then centrifuge at a centrifugal speed of 10000 - 12000 rpm for 10 - 15 minutes. After collecting the precipitate, wash it with sterile water 2 - 3 times to obtain the composite insecticide drug carrier;

[0020] S3.2: Add acrylic acid and acrylamide to deionized water in a mass ratio of 1:(5 - 6), and stir magnetically until acrylic acid and acrylamide are completely dissolved to obtain a mixed solution with a concentration of 40 - 50 wt%. Then, based on the mass percentage of acrylic acid and acrylamide, add 0.1 - 0.2% of dimethylformamide, 0.8 - 1% of ammonium persulfate, and 0.4 - 0.6% of tetramethyldiethylamine in sequence. Stir for 4 - 5 minutes after each addition. Then, based on the mass of the reaction system, add 1 - 1.5 times the photothermal-responsive elastic membrane material suspension, 8 - 10% of fiber wetting and strengthening agent, and 30 - 40% of the composite insecticide drug carrier and stir evenly. Raise the temperature to 40 - 45 °C and react for 3 - 4 hours to obtain the photothermal-responsive sustained-release hydrogel loaded with the drug;

[0021] S3.3: Mix the photothermal-responsive sustained-release hydrogel loaded with the drug and sterile water evenly at a solid-liquid ratio of 1:(80 - 100) g / mL to obtain the spraying agent for controlling Spodoptera exigua in greenhouse asparagus.

[0022] Furthermore, in step S1.1, the pH of the citric acid aqueous solution is 4.5 - 5.

[0023] Furthermore, in the potassium dihydrogen phosphate aqueous solution containing laccase in step S1.3, the concentration of potassium dihydrogen phosphate is 0.1 - 0.15 mol / L, and the concentration of laccase is 0.8 - 1 g / L.

[0024] Furthermore, in step S2.2, the inner diameter of the thiolated carbon nanotubes is 5 - 12 nm, and the outer diameter is 30 - 50 nm.

[0025] Furthermore, in step S2.2, the thickness of the photothermal liquid crystal polymer film is 80 - 100 μm.

[0026] A spraying agent for controlling Spodoptera exigua in greenhouse asparagus is prepared by the preparation process of the above-mentioned spraying agent for controlling Spodoptera exigua in greenhouse asparagus.

[0027] The beneficial effects are as follows: 1. By preparing the blocked urea bond monomer, reacting the blocked urea bond monomer with 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene and adding mercapto-functionalized carbon nanotubes, a photothermal liquid crystal polymer film is obtained. After stretching, curing, and orientation, a photothermal-responsive elastic film material is obtained. When the temperature of the oriented photothermal liquid crystal polymer film rises, the liquid crystal molecules tend to be disordered, resulting in the contraction of the liquid crystal elastomer along the orientation direction. By regulating the content of the blocked urea bond monomer, the activation energy of the photothermal-responsive elastic film material can be significantly reduced, so that the phase transition temperature of the photothermal-responsive elastic film material is controlled at about 30°C. During the day, when the temperature in the greenhouse is controlled at the optimal growth temperature of asparagus, which is 20-30°C, under the photothermal effect of the carbon nanotubes, the temperature of the photothermal-responsive elastic film material exceeds 30°C, and the film material remains contracted, reducing the release of the compound insecticide. When the temperature in the greenhouse drops at night and the carbon nanotubes lose the photothermal effect, the film material returns to its original state. The photothermal-responsive sustained-release hydrogel has a good release effect on the compound insecticide, can well match the characteristics of noctuid moths and noctuid larvae being active at night and hiding during the day, can avoid the ineffective release of the compound insecticide during the day, greatly improve the utilization rate of the compound insecticide, extend the effective insecticidal period, improve the control efficiency against Spodoptera exigua, reduce the spraying frequency and spraying amount of pesticides, and have double ecological and economic benefits.

[0028] 2. Under the action of laccase, by catalytically grafting the powder of Intsia bijuga extract and epigallocatechin gallate onto the surface of cellulose nanofibers, the catechol group of epigallocatechin gallate can be oxidized to a quinone structure, forming a strong adhesion with the chitin of the insect cuticle. At the same time, the cellulose nanofibers and the asparagus epidermis can be fixedly connected through the Intsia bijuga extract, enhancing the wettability and contact area of the control spraying agent on the asparagus and the insect body surface, and further improving the utilization rate of the compound insecticide. Description of the Drawings

[0029] Figure 1 It is a process flow chart of the preparation of the greenhouse asparagus Spodoptera exigua control spraying agent adopted in the embodiment of the present invention. Detailed Embodiments

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0031] Example 1: A greenhouse asparagus Spodoptera exigua control spraying agent and its preparation process, as Figure 1 shown, includes the following steps:

[0032] S1: Preparation of Fiber Wetting Enhancer

[0033] S1.1: Dry the Intsia wood and grind it into powder to obtain Intsia wood powder. Then, mix 30 parts by weight of Intsia wood powder, 150 parts by weight of citric acid aqueous solution with a pH of 4.5, and 3 parts by weight of cellulase evenly, and keep it in a constant temperature water bath at 50°C for 24 hours. Filter to obtain filtrate I and residue I for standby;

[0034] S1.2: Mix the residue I from step S1.1 and ethanol aqueous solution with a volume fraction of 75% at a mass ratio of 1:40, and then carry out reflux extraction at 80°C for 8 hours. Filter to obtain filtrate II and residue II. Combine the filtrate I and filtrate II from step S1.1 and place them in a rotary evaporator. Adjust the temperature to 35°C and the vacuum degree to 0.08 MPa for rotary evaporation until a paste is formed. Vacuum dry the paste at 65°C and a vacuum degree of 0.075 MPa until constant weight, crush it through a 60-mesh sieve to obtain Intsia wood extract powder;

[0035] S1.3: Dissolve the Intsia wood extract powder and epigallocatechin gallate in absolute ethanol, and then add potassium dihydrogen phosphate aqueous solution containing laccase. The concentration of potassium dihydrogen phosphate in the potassium dihydrogen phosphate aqueous solution containing laccase is 0.1 mol / L, and the concentration of laccase is 0.8 g / L to obtain a composite solution. The concentration of Intsia wood extract powder in the composite solution is 60 g / L, the concentration of epigallocatechin gallate is 15 g / L, and the volume fraction of absolute ethanol is 20%. Add 1 wt% of cellulose nanofibers to the composite solution, introduce oxygen at a flow rate of 0.2 L / min, and then oscillate at 180 rpm for 10 hours under the water bath condition of 35°C. Then, centrifuge to take the precipitate and vacuum dry it to obtain the fiber wetting enhancer.

[0036] S2: Composite of Photothermal Responsive Elastic Film Material and Preparation of Suspension

[0037] S2.1: Place 3.8 parts by weight of isocyanatoethyl methacrylate and 48 parts by weight of anhydrous dichloromethane in a three-necked flask, protect it by introducing nitrogen, and then slowly drop 2.1 parts by weight of N,N'-di-tert-butylethylenediamine and 8 parts by weight of anhydrous dichloromethane into the three-necked flask. Keep the reaction at room temperature for 1 hour, use a rotary evaporator to spin dry the anhydrous dichloromethane and then cool it to obtain the blocked urea bond monomer;

[0038] S2.2: Add 14 parts by weight of the hindered urea bond monomer and 75.4 parts by weight of 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene to 200 parts by weight of toluene, heat to complete dissolution at 80 °C, and after cooling to room temperature, successively add 1 wt% of thiolated carbon nanotubes. The inner diameter of the thiolated carbon nanotubes is 5 nm and the outer diameter is 30 nm, 13 parts by weight of 3,6-dioxa-1,8-octanedithiol, and 8.5 parts by weight of 1,5-diaminopentane. Place it in an ultrasonic oscillator to mix and defoam for 4 minutes, then pour it into a polytetrafluoroethylene mold, react at room temperature for 24 hours, and then react at 90 °C for 1 hour to obtain a photothermal liquid crystal polymer film with a thickness of 80 μm;

[0039] S2.3: Control the tensile strength to be 2 MPa, stretch the photothermal liquid crystal polymer film to 140% of its original length and fix it, then heat-treat it at 138 °C for 1 hour, and naturally cool to room temperature to obtain a photothermal-responsive elastic film material. Mix the photothermal-responsive elastic film material and deionized water at a solid-liquid ratio of 1:10 g / mL, and then perform high-speed shearing at a shear rate of 3000 rpm to obtain a photothermal-responsive elastic film material suspension, which is stored in a dark place.

[0040] S3: Prepare a spraying agent for controlling Spodoptera exigua

[0041] S3.1: Dissolve 3 parts by weight of chlorantraniliprole and 5 parts by weight of pogostone in 160 parts by weight of acetone, add 0.2 parts by weight of polysorbate-20, then add 3 parts by weight of a graphene oxide solution with a concentration of 1 g / L, stir magnetically until evenly mixed, and then place it in a dark environment. Continuously stir under the water bath conditions of 24 °C and 200 rpm for 20 hours, then centrifuge at a centrifugal speed of 10000 rpm for 10 minutes, collect the precipitate, and wash it 2 times with sterile water to obtain a composite insecticide drug carrier;

[0042] S3.2: Add acrylic acid and acrylamide to deionized water at a mass ratio of 1:5, stir magnetically until acrylic acid and acrylamide are completely dissolved to obtain a mixed solution with a concentration of 40 wt%. Then, based on the mass percentage of acrylic acid and acrylamide, successively add 0.1% of dimethylformamide, 0.8% of ammonium persulfate, and 0.4% of tetramethyldiethylamine. Stir for 4 minutes after each addition. Then, based on the mass of the reaction system, add 1 times the photothermal-responsive elastic film material suspension, 8% of a fiber wetting and strengthening agent, and 30% of the composite insecticide drug carrier, stir evenly, and raise the temperature to 40 °C and react for 3 hours to obtain a photothermal-responsive sustained-release hydrogel loaded with the drug;

[0043] S3.3: Mix the photothermal-responsive sustained-release hydrogel loaded with the drug and sterile water at a solid-liquid ratio of 1:80 g / mL evenly to obtain a spraying agent for controlling Spodoptera exigua.

[0044] Example 2: A spraying agent for controlling Spodoptera exigua in a greenhouse and its preparation process, as Figure 1 shown, including the following steps:

[0045] S1: Preparation of fiber wetting and strengthening agent

[0046] S1.1: Dry the Intsia bijuga wood and grind it into powder to obtain Intsia bijuga powder. Then, mix 40 parts by weight of Intsia bijuga powder, 200 parts by weight of citric acid aqueous solution with a pH of 4.5, and 5 parts by weight of cellulase evenly, and keep it in a constant temperature water bath at 50 °C for 24 hours. Filter to obtain filtrate I and residue I for standby;

[0047] S1.2: Mix the residue I from step S1.1 and ethanol aqueous solution with a volume fraction of 75% at a mass ratio of 1:50, and then carry out reflux extraction at 80 °C for 8 hours. Filter to obtain filtrate II and residue II. Combine the filtrate I and filtrate II from step S1.1 and place them in a rotary evaporator. Adjust the temperature to 35 °C and the vacuum degree to 0.08 MPa for rotary evaporation until a paste is formed. Vacuum dry the paste at 65 °C and a vacuum degree of 0.075 MPa until constant weight, and crush it through a 60-mesh sieve to obtain Intsia bijuga extract powder;

[0048] S1.3: Dissolve the Intsia bijuga extract powder and epigallocatechin gallate in absolute ethanol, and then add potassium dihydrogen phosphate aqueous solution containing laccase. The concentration of potassium dihydrogen phosphate in the potassium dihydrogen phosphate aqueous solution containing laccase is 0.15 mol / L, and the concentration of laccase is 1 g / L to obtain a composite solution. The concentration of Intsia bijuga extract powder in the composite solution is 80 g / L, the concentration of epigallocatechin gallate is 20 g / L, and the volume fraction of absolute ethanol is 25%. Add 2 wt% of cellulose nanofibers to the composite solution, introduce oxygen at a flow rate of 0.2 L / min, and then under the water bath condition of 35 °C, oscillate at 180 rpm for 10 hours. Then, centrifuge to obtain the precipitate, and vacuum dry it to obtain the fiber wetting and strengthening agent.

[0049] S2: Composite of photothermal-responsive elastic film material and preparation of suspension

[0050] S2.1: Place 3.85 parts by weight of isocyanatoethyl methacrylate and 50 parts by weight of anhydrous dichloromethane in a three-necked flask, protect it by introducing nitrogen, and then slowly drop 2.15 parts by weight of N,N'-di-tert-butylethylenediamine and 10 parts by weight of anhydrous dichloromethane into the three-necked flask. Keep the reaction at room temperature for 1 hour, spin-dry the anhydrous dichloromethane using a rotary evaporator and then cool to obtain the blocked urea bond monomer;

[0051] S2.2: Add 14.5 parts by weight of the hindered urea bond monomer and 75.6 parts by weight of 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene to 250 parts by weight of toluene, heat to complete dissolution at 80 °C, and after cooling to room temperature, successively add 1.2 wt% of thiolated carbon nanotubes. The inner diameter of the thiolated carbon nanotubes is 5 nm, and the outer diameter is 30 nm, 13.2 parts by weight of 3,6-dioxa-1,8-octanedithiol, and 9 parts by weight of 1,5-diaminopentane. Place it in an ultrasonic oscillator to mix and defoam for 4 minutes, then pour it into a polytetrafluoroethylene mold, react at room temperature for 24 hours, and then react at 90 °C for 1 hour to obtain a photothermal liquid crystal polymer film with a thickness of 80 μm;

[0052] S2.3: Control the tensile strength to be 2 MPa, stretch the photothermal liquid crystal polymer film to 140% of its original length and fix it, then heat-treat it at 138 °C for 1 hour, and naturally cool to room temperature to obtain a photothermal-responsive elastic film material. Mix the photothermal-responsive elastic film material and deionized water at a solid-liquid ratio of 1:15 g / mL, and then perform high-speed shearing at a shear rate of 3000 rpm to obtain a photothermal-responsive elastic film material suspension, which is stored in the dark.

[0053] S3: Prepare a spraying agent for controlling Spodoptera exigua

[0054] S3.1: Dissolve 4 parts by weight of chlorantraniliprole and 6 parts by weight of pogostone in 180 parts by weight of acetone, add 0.3 parts by weight of polysorbate-20, then add 3.5 parts by weight of a graphene oxide solution with a concentration of 1 g / L, stir magnetically until evenly mixed, and then place it in a dark environment. Continuously stir under the water bath conditions of 24 °C and 200 rpm for 20 hours, then centrifuge at a centrifugal speed of 10000 rpm for 10 minutes, collect the precipitate, and wash it 2 times with sterile water to obtain a composite insecticide drug carrier;

[0055] S3.2: Add acrylic acid and acrylamide to deionized water at a mass ratio of 1:6, stir magnetically until acrylic acid and acrylamide are completely dissolved to obtain a mixed solution with a concentration of 40 wt%. Then, based on the mass percentage of acrylic acid and acrylamide, successively add 0.2% of dimethylformamide, 1% of ammonium persulfate, and 0.6% of tetramethyldiethylamine. Stir for 4 minutes after each addition. Then, based on the mass of the reaction system, add 1.5 times the photothermal-responsive elastic film material suspension, 10% of the fiber wetting and strengthening agent, and 30% of the composite insecticide drug carrier, stir evenly, and raise the temperature to 40 °C and react for 3 hours to obtain a photothermal-responsive slow-release hydrogel loaded with the drug;

[0056] S3.3: Mix the photothermal-responsive slow-release hydrogel loaded with the drug and sterile water at a solid-liquid ratio of 1:80 g / mL evenly to obtain a spraying agent for controlling Spodoptera exigua.

[0057] Example 3: A spraying agent for controlling Spodoptera exigua in a greenhouse and its preparation process, as Figure 1 shown, including the following steps:

[0058] S1: Preparation of fiber wetting and strengthening agent

[0059] S1.1: Dry the Intsia bijuga wood and grind it into powder to obtain Intsia bijuga powder. Then, mix 30 parts by weight of Intsia bijuga powder, 150 parts by weight of citric acid aqueous solution with a pH of 4.5, and 3 parts by weight of cellulase evenly, and carry out a constant temperature water bath at 55 °C for 30 hours. Filter to obtain filtrate I and residue I, and reserve them;

[0060] S1.2: Mix the residue I from step S1.1 and the ethanol aqueous solution with a volume fraction of 80% at a mass ratio of 1:40, and then carry out reflux extraction at 85 °C for 10 hours. Filter to obtain filtrate II and residue II. Combine the filtrate I and filtrate II from step S1.1 and place them in a rotary evaporator. Adjust the temperature to 40 °C and the vacuum degree to 0.09 MPa for rotary evaporation until a paste is formed. Vacuum dry the paste at 70 °C and a vacuum degree of 0.08 MPa until constant weight, and pulverize and pass through a 70-mesh sieve to obtain Intsia bijuga extract powder;

[0061] S1.3: Dissolve the Intsia bijuga extract powder and epigallocatechin gallate in absolute ethanol, and then add an aqueous potassium dihydrogen phosphate solution containing laccase. The concentration of potassium dihydrogen phosphate in the aqueous potassium dihydrogen phosphate solution containing laccase is 0.1 mol / L, and the concentration of laccase is 0.8 g / L to obtain a composite solution. The concentration of Intsia bijuga extract powder in the composite solution is 60 g / L, the concentration of epigallocatechin gallate is 15 g / L, and the volume fraction of absolute ethanol is 20%. Add 1 wt% of cellulose nanofibers to the composite solution, introduce oxygen at a flow rate of 0.3 L / min, and then under the water bath condition of 40 °C, oscillate at 180 rpm for 12 hours, and then centrifuge to take the precipitate and vacuum dry to obtain the fiber wetting and strengthening agent.

[0062] S2: Composite of photothermal-responsive elastic film material and preparation of suspension

[0063] S2.1: Place 3.8 parts by weight of isocyanatoethyl methacrylate and 48 parts by weight of anhydrous dichloromethane in a three-necked flask, protect it by introducing nitrogen, and then slowly drop 2.1 parts by weight of N,N'-di-tert-butylethylenediamine and 8 parts by weight of anhydrous dichloromethane into the three-necked flask, and keep the reaction at room temperature for 1.2 hours. After using a rotary evaporator to spin-dry the anhydrous dichloromethane and then cooling, obtain the blocked urea bond monomer;

[0064] S2.2: Add 14 parts by weight of the hindered urea bond monomer and 75.4 parts by weight of 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene to 200 parts by weight of toluene, heat to complete dissolution at 85 °C, and after cooling to room temperature, successively add 1 wt% of thiolated carbon nanotubes. The inner diameter of the thiolated carbon nanotubes is 12 nm and the outer diameter is 50 nm, 13 parts by weight of 3,6-dioxa-1,8-octanedithiol, and 8.5 parts by weight of 1,5-diaminopentane. Place it in an ultrasonic oscillator, mix and defoam for 5 minutes, then pour it into a polytetrafluoroethylene mold, react at room temperature for 25 hours, and then react at 92 °C for 1.2 hours to obtain a photothermal liquid crystal polymer film with a thickness of 100 μm;

[0065] S2.3: Control the tensile strength to be 3 MPa, stretch the photothermal liquid crystal polymer film to 142% of its original length and fix it, then heat-treat it at 140 °C for 1.5 hours, and naturally cool to room temperature to obtain a photothermal-responsive elastic film material. Mix the photothermal-responsive elastic film material and deionized water at a solid-liquid ratio of 1:10 g / mL, and then perform high-speed shearing at a shear rate of 4000 rpm to obtain a photothermal-responsive elastic film material suspension, which is stored in a dark place.

[0066] S3: Prepare a spraying agent for controlling Spodoptera exigua

[0067] S3.1: Dissolve 3 parts by weight of chlorantraniliprole and 5 parts by weight of pogostone in 160 parts by weight of acetone, add 0.2 parts by weight of polysorbate-20, then add 3 parts by weight of a graphene oxide solution with a concentration of 1.5 g / L, stir magnetically until homogeneous, and place it in a dark environment. Continuously stir under the water bath conditions of 26 °C and 250 rpm for 24 hours, then centrifuge at a centrifugal speed of 12000 rpm for 15 minutes, collect the precipitate and wash it 3 times with sterile water to obtain a composite insecticide drug carrier;

[0068] S3.2: Add acrylic acid and acrylamide to deionized water at a mass ratio of 1:5, stir magnetically until acrylic acid and acrylamide are completely dissolved to obtain a mixed solution with a concentration of 50 wt%. Then, based on the mass percentage of acrylic acid and acrylamide, successively add 0.1% of dimethylformamide, 0.8% of ammonium persulfate, and 0.4% of tetramethyldiethylamine. Stir for 5 minutes after each addition. Then, based on the mass of the reaction system, add 1 times the photothermal-responsive elastic film material suspension, 8% of a fiber wetting and strengthening agent, and 30% of the composite insecticide drug carrier, stir evenly, and raise the temperature to 45 °C and react for 4 hours to obtain a photothermal-responsive slow-release hydrogel loaded with the drug;

[0069] S3.3: Mix the photothermal-responsive slow-release hydrogel loaded with the drug and sterile water at a solid-liquid ratio of 1:100 g / mL evenly to obtain a spraying agent for controlling Spodoptera exigua.

[0070] Comparative Example 1: A spraying agent for controlling Spodoptera exigua in greenhouse asparagus and its preparation process. Compared with the implementation method of Example 1, the difference is that in Comparative Example 1, step S2 is removed, and the photothermal-responsive elastic film material suspension is not added in step S3.2, and the spraying agent for controlling Spodoptera exigua is prepared, denoted as Comparative Example 1.

[0071] Comparative Example 2: A spraying agent for controlling Spodoptera exigua in greenhouse asparagus and its preparation process. Compared with the implementation method of Example 1, the difference is that in Comparative Example 2, step S1 is removed, and the fiber wetting and strengthening agent is not added in step S3.2, and the spraying agent for controlling Spodoptera exigua is prepared, denoted as Comparative Example 2.

[0072] Slow-release performance test: Take the spraying agent for controlling Spodoptera exigua prepared in Example 1 and the spraying agent for controlling Spodoptera exigua prepared in Comparative Example 1 as samples. Divide the samples into multiple equal sample groups, and place them in glass containers under simulated sunlight - incandescent lamp (13000W / m 2 ) and in a dark environment respectively. Adjust the temperature of the glass containers to 15, 30 and 40 °C respectively. Take out the same appropriate amount of samples every 12 hours, measure the concentrations of chlorantraniliprole and pogostone in the samples with a high-performance liquid chromatograph, and calculate the total release amount of the chlorantraniliprole agent and the pogostone compound insecticide at each time point. Repeat 3 parallel tests, and take the average value of each temperature and each time point. The test data are shown in Tables 1 and 2.

[0073] Table 1: Agent release amounts at each temperature and each time point in the light and dark environments of Example 1

[0074]

[0075] Table 2: Agent release amounts at each temperature and each time point in the light and dark environments of Comparative Example 1

[0076]

[0077] It can be seen from the data of the examples in Table 1 that the release rate of the compound insecticide released by the Spodoptera exigua control spraying agent prepared in Example 1 significantly decreases with the increase of temperature. And in the light environment, the decreasing amplitude is larger than that in the dark environment. It can be proved that the spraying agent prepared in Example 1 can reduce the release of the compound insecticide during the day and have a good release effect at night. It can be seen from the data of Comparative Example 1 in Table 2 that when the photothermal-responsive elastic film material is not added to the hydrogel, whether it is day or night, whether it is high temperature or low temperature, the release rates of the compound insecticide at each time point are not much different. And there is data to prove that adding the photothermal-responsive elastic film material to the hydrogel realizes the control effect of reducing the release rate of the compound insecticide under high temperature conditions during the day and maintaining a high release rate of the compound insecticide in the low temperature environment at night, effectively targeting the characteristics of the nocturnal behavior of Spodoptera exigua and improving the utilization rate of the compound insecticide.

[0078] Contact angle test: Use a contact angle measuring instrument to measure the contact angles of water, the Spodoptera exigua control spraying agents prepared in Examples 1-3, and the Spodoptera exigua control spraying agent prepared in Comparative Example 2 with asparagus and the insect body surface (3rd instar larvae of Spodoptera exigua) at 25 °C respectively. The contact angle is measured within 3 s after the test sample is dropped on the asparagus and the insect body surface, and repeated three times, and the average value is taken. The test results are shown in Table 3.

[0079] Table 3: Contact angles with asparagus and the insect body surface

[0080]

[0081] It can be seen from the data in Table 3 that the contact angles of the Spodoptera exigua control spraying agents prepared in Examples 1-3 with asparagus and the insect body surface are much smaller than the contact angles of water with asparagus and the insect body surface, indicating that the wettability of the Spodoptera exigua control spraying agent on asparagus and the insect body surface is much stronger than that of water, and it can better adhere to asparagus and the insect body surface, increasing the effective contact area of the medicament and improving the utilization rate. And it can be seen from the data of Comparative Example 2 that preparing a fiber wetting enhancer can enhance the wettability of the spraying agent and further improve the utilization rate of the compound insecticide.

[0082] The above examples only illustratively explain the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above examples without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A preparation process of a spraying agent for preventing and controlling Spodoptera exigua in a greenhouse, which is characterized in that, It includes the following steps: Preparation of fiber wetting enhancer: S1.1: Dry the Intsia bijuga wood and grind it into powder to obtain Intsia bijuga powder. Then, mix 30 - 40 parts by weight of Intsia bijuga powder, 150 - 200 parts by weight of citric acid aqueous solution and 3 - 5 parts by weight of cellulase evenly, and carry out constant temperature water bath at 50 - 55 °C for 24 - 30 hours. Filter to obtain filtrate Ⅰ and residue Ⅰ for standby; S1.2: Mix the residue Ⅰ from step S1.1 and ethanol aqueous solution with a volume fraction of 75 - 80% at a mass ratio of 1:(40 - 50), and then carry out reflux extraction at 80 - 85 °C for 8 - 10 hours. Filter to obtain filtrate Ⅱ and residue Ⅱ. Combine the filtrate Ⅰ and filtrate Ⅱ from step S1.1 and place them in a rotary evaporator. Adjust the temperature to 35 - 40 °C and the vacuum degree to 0.08 - 0.09 MPa for rotary evaporation until a paste is formed. Vacuum dry the paste at 65 - 70 °C and a vacuum degree of 0.075 - 0.08 MPa until constant weight, and crush and sieve through a 60 - 70 mesh sieve to obtain Intsia bijuga extract powder; S1.3: Dissolve the Intsia bijuga extract powder and epigallocatechin gallate in absolute ethanol, and then add a potassium dihydrogen phosphate aqueous solution containing laccase with a potassium dihydrogen phosphate concentration of 0.1 - 0.15 mol / L and a laccase concentration of 0.8 - 1 g / L to obtain a composite solution. In the composite solution, the concentration of Intsia bijuga extract powder is 60 - 80 g / L, the concentration of epigallocatechin gallate is 15 - 20 g / L, the volume fraction of absolute ethanol is 20 - 25%. Add 1 - 2 wt% of cellulose nanofibers to the composite solution, and introduce oxygen at a flow rate of 0.2 - 0.3 L / min. Then, under the water bath condition of 35 - 40 °C, oscillate at 180 - 200 rpm for 10 - 12 hours, and then centrifuge to take the precipitate. After vacuum drying, obtain the fiber wetting enhancer; Compound of photothermal response elastic film material and preparation of suspension: S2.1: Place 3.8 - 3.85 parts by weight of isocyanatoethyl methacrylate and 48 - 50 parts by weight of anhydrous dichloromethane in a three - necked flask, protect it by introducing nitrogen, and then slowly drop 2.1 - 2.15 parts by weight of N,N'-di - tert - butylethylenediamine and 8 - 10 parts by weight of anhydrous dichloromethane into the three - necked flask. Keep the reaction at room temperature for 1 - 1.2 hours. After using the rotary evaporator to spin - dry the anhydrous dichloromethane and cool, obtain the blocked urea bond monomer; S2.2: Add 14 - 14.5 parts by weight of the hindered urea bond monomer and 75.4 - 75.6 parts by weight of 1,4 - bis - [4 - (6 - acryloyloxyhexyloxy)benzoyloxy]-2 - methylbenzene to 200 - 250 parts by weight of toluene, heat to complete dissolution at 80 - 85 °C, and after cooling to room temperature, sequentially add 1 - 1.2 wt% of thiolated carbon nanotubes, 13 - 13.2 parts by weight of 3,6 - dioxo - 1,8 - octanedithiol, and 8.5 - 9 parts by weight of 1,5 - diamino pentane. Place it in an ultrasonic oscillator to mix and defoam for 4 - 5 minutes, then pour it into a polytetrafluoroethylene mold, react at room temperature for 24 - 25 hours, and then react at 90 - 92 °C for 1 - 1.2 hours to obtain a photothermal liquid crystal polymer film; S2.3: Control the tensile strength to be 2 - 3 MPa, stretch the photothermal liquid crystal polymer film to 140 - 142% of its original length and fix it, then heat - treat it at 138 - 140 °C for 1 - 1.5 hours, and naturally cool to room temperature to obtain a photothermal - responsive elastic film material. Mix the photothermal - responsive elastic film material and deionized water at a solid - liquid ratio of 1:(10 - 15) g / mL, and then perform high - speed shearing at a shear rate of 3000 - 4000 rpm to obtain a photothermal - responsive elastic film material suspension, and store it in a dark place; S3 Preparation of the spraying agent for Spodoptera exigua control: Mix chlorantraniliprole, pogostone, and graphene oxide solution and stir in a water bath. After centrifugal washing, obtain a composite insecticide drug - carrier. Pre - polymerize acrylic acid and acrylamide, then add the photothermal - responsive elastic film material suspension, fiber wetting and strengthening agent, and the composite insecticide drug - carrier and stir evenly. After heating and polymerization, mix evenly with deionized water to obtain the spraying agent for Spodoptera exigua control.

2. The preparation process of a spraying agent for controlling Spodoptera exigua in a greenhouse asparagus according to claim 1, characterized in that, Step S3 for preparing the spraying agent for Spodoptera exigua control includes the following steps: S3.1: Dissolve 3 - 4 parts by weight of chlorantraniliprole and 5 - 6 parts by weight of pogostone in 160 - 180 parts by weight of acetone, add 0.2 - 0.3 parts by weight of polysorbate - 20, then add 3 - 3.5 parts by weight of graphene oxide solution with a concentration of 1 - 1.5 g / L. After magnetic stirring evenly, place it in a dark environment, continuously stir under the water - bath conditions of 24 - 26 °C and 200 - 250 rpm for 20 - 24 hours, then centrifuge at a centrifugal speed of 10000 - 12000 rpm for 10 - 15 minutes, collect the precipitate, and wash it 2 - 3 times with sterile water to obtain a composite insecticide drug - carrier; S3.2: Add acrylic acid and acrylamide into deionized water at a mass ratio of 1:(5 - 6), and stir magnetically until acrylic acid and acrylamide are completely dissolved to obtain a mixed solution with a concentration of 40 - 50 wt%. Then, based on the mass percentage of acrylic acid and acrylamide, sequentially add 0.1 - 0.2% of dimethylformamide, 0.8 - 1% of ammonium persulfate, and 0.4 - 0.6% of tetramethylethylenediamine. Stir for 4 - 5 minutes after each addition. Then, based on the mass of the reaction system, add 1 - 1.5 times the photothermal-responsive elastic film material suspension, 8 - 10% of the fiber wetting and strengthening agent, and 30 - 40% of the composite pesticide carrier, and stir evenly. Heat up to 40 - 45 °C and react for 3 - 4 hours to obtain a photothermal-responsive slow-release hydrogel loaded with the medicament. S3.3: Mix the photothermal-responsive slow-release hydrogel loaded with the medicament and sterile water evenly at a solid-liquid ratio of 1:(80 - 100) g / mL to obtain a spraying agent for controlling Spodoptera exigua.

3. The preparation process of a spraying agent for preventing and controlling Spodoptera exigua in a greenhouse asparagus according to claim 1, characterized in that, In step S1.1, the pH of the citric acid aqueous solution is 4.5 - 5.

4. The preparation process of a spraying agent for preventing and controlling Spodoptera exigua in a greenhouse asparagus as claimed in claim 1, characterized in that, In step S2.2, the inner diameter of the thiolated carbon nanotubes is 5 - 12 nm, and the outer diameter is 30 - 50 nm.

5. The preparation process of a spraying agent for controlling Spodoptera exigua in a greenhouse asparagus according to claim 1, characterized in that, In step S2.2, the thickness of the photothermal liquid crystal polymer film is 80 - 100 μm.

6. A spraying agent for preventing and controlling Spodoptera exigua in a greenhouse, characterized in that, Prepared by the preparation process of a spraying agent for controlling Spodoptera exigua in greenhouse asparagus according to any one of claims 1 - 5.

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