A control agent for grape thrips and a preparation method and use method thereof

Abstract

This invention discloses a grape thrips control agent and its preparation and application methods, belonging to the field of thrips control technology. The grape thrips control agent of this invention includes a blue composite gel and thrips control granules. The blue composite gel is obtained by in-situ synthesis of a gel from sodium alginate, copper sulfate, and dopamine, followed by surface loading of hexadecyltrimethylammonium chloride. The thrips control granules are prepared using an insecticide as the core material and starch, glucose, glutamic acid, gardenia blue, and complex cyclodextrin as the wall material. The complex cyclodextrin is obtained by combining α-cyclodextrin and methyl isonicotinic acid. The grape thrips control agent prepared by this invention exhibits good grape thrips control effects.

Description

Technical Field

[0001] This invention relates to the field of thrips control technology, specifically to a grape thrips control agent and its preparation and application methods. Background Technology

[0002] Grape thrips, belonging to the family Thripidae in the order Thysanoptera, is an important agricultural pest of the genus Thrips in the subfamily Thripinae. It is also commonly known as tobacco thrips, cotton thrips, or onion thrips. This insect has a wide host range and is extremely destructive to economic crops such as grapes, and is widely recognized as one of the major pests in grape production.

[0003] Grape thrips and their close relatives are most active during the grape flowering and fruit ripening stages. During their overwintering life cycle, they typically exist as adults or nymphs, hiding in weeds, dead leaves, or topsoil in the field. The following spring, as temperatures rise, thrips migrate to the new grape leaves to feed and reproduce rapidly. In major grape-producing areas in southern China, such as Guangxi Zhuang Autonomous Region, where grapes are harvested twice a year, thrips populations exhibit a distinct bimodal dynamic, with peak activity concentrated between March and early June and August and October, and damage lasting until mid-December when grape leaves fall.

[0004] Both adult and nymph thrips possess rasping-sucking mouthparts, causing damage by scratching plant epidermal cells and sucking sap. Affected grape leaves exhibit localized chlorophyll degradation, forming irregular yellow spots; in severe cases, leaves curl, wrinkle, dry out, and may even perforate. New shoot growth is inhibited, resulting in stunted development. On young fruit, affected areas dry out and develop black necrotic spots, which gradually expand into corky brown rust spots as the fruit enlarges; in extreme cases, this can lead to fruit skin cracking. This type of damage not only significantly reduces the commercial appearance of grapes but also directly impacts their market value and economic benefits.

[0005] Currently, the control of grape thrips still relies mainly on chemical pesticides. However, frequent application can easily lead to increased pesticide resistance, environmental pollution, and damage from non-target organisms. Furthermore, traditional pesticides have short-lasting effects and poor penetration into the highly concealed thrips nymphs, making long-term control difficult. Therefore, there is an urgent need to develop an environmentally friendly and long-lasting grape thrips control agent, particularly suitable for application to the surface of grape leaves, that can effectively block thrips feeding and reproductive behaviors and provide continuous protection during the critical growth stages of grapes, thereby ensuring grape yield and quality safety. Summary of the Invention

[0006] The purpose of this invention is to provide a grape thrips control agent and its preparation and application methods to solve the technical problems mentioned in the background section.

[0007] The technical solution to achieve the objective of this invention is: In a first aspect, the present invention provides a grape thrips control agent, comprising a blue composite gel and thrips control granules; the blue composite gel is obtained by in-situ synthesis of a gel from sodium alginate, copper sulfate, and dopamine, followed by surface loading of hexadecyltrimethylammonium chloride; the thrips control granules are prepared using an insecticide as the core material and starch, glucose, glutamic acid, gardenia blue, and compound cyclodextrin as the wall material.

[0008] Furthermore, the raw material components of the insecticide include, by weight, 25-35 parts dried pyrethrum flowers, 20-30 parts rotenone root powder, 10-20 parts patchouli, 15-25 parts rosemary, and 8-12 parts angelica.

[0009] Among them, pyrethrum flowers, rich in pyrethrin, act as a fast-acting neurotoxin that can rapidly destroy the insect's nervous system, exerting strong contact and stomach poison effects to achieve rapid knockdown; rotenone provided by rotenone root powder inhibits the mitochondrial respiratory chain of pest cells, blocking energy metabolism, and serves as the core lethal component to ensure sustained killing power; rosemary extract essential oil dissolves and destroys the waxy protective layer on the thrips' body surface, significantly reducing the insect's barrier function and accelerating pesticide penetration; angelica has a dual function in this system, acting as a penetration enhancer to assist the active ingredients in penetrating the insect's epidermis, and as an antioxidant to prevent the oxidative decomposition of photosensitive components such as rotenone, thereby achieving highly efficient killing of grape thrips while protecting the stability of the pesticide efficacy.

[0010] Furthermore, the complex cyclodextrin is obtained by combining α-cyclodextrin with a thrips attractant.

[0011] Furthermore, the thrips attractant includes geraniol, nerol, and methyl isonicotinic acid.

[0012] In a second aspect, the present invention provides a method for preparing a grape thrips control agent as described in the first aspect. The preparation steps are as follows: a blue composite gel is mixed and stirred with double deionized water to prepare a mixture of 20-40 mg / mL. Then, 0.5-1% (w / v) thrips control granules are added and stirred and dispersed evenly to obtain the grape thrips control agent.

[0013] Further, the preparation steps of the blue composite gel are as follows: Double deionized water and phosphate buffer solution with pH 8.5 are mixed at a volume ratio of 9:1, then sodium alginate is added and stirred at room temperature for 50-70 min to obtain a 2% (w / v) sodium alginate solution; then, the sodium alginate solution is dropwise added to paraffin oil containing 1% v / v Span-80 and 0.3% v / v Tween-80, at a volume of 3 times the sodium alginate solution, and stirred at 800-1000 rpm / min for 50-60 min; finally, 0.1 times the volume of the sodium alginate solution is added to a solution containing 0.1% sodium alginate by mass. A double deionized aqueous solution containing 0.007-0.008 times the volume of copper sulfate and 0.002-0.004 times the mass of sodium alginate and calcium chloride was added and stirred for at least 4 hours. Then, a double deionized aqueous solution containing 0.1-0.2 times the mass of sodium alginate and dopamine was added at 2-3 times the volume of the sodium alginate solution and stirred for 50-70 minutes. Finally, a double deionized aqueous solution containing 0.05-0.07 times the volume of the sodium alginate solution and hexadecyltrimethylammonium chloride at 0.1-0.2 times the mass of sodium alginate was added and stirred for 50-70 minutes. The solution was then centrifuged, washed, and freeze-dried to obtain a blue composite gel. Further, the preparation steps of the thrips control granules are as follows: 2 parts by mass of starch nanoparticles are mixed with 100 parts by mass of water, and after being ultrasonically dispersed evenly, an equal volume of anhydrous ethanol solution of insecticide is added and mixed evenly. The ethanol is removed by vacuum distillation and rotary evaporation at 55°C. Then, the surface residual curcumin is washed away with ethanol, and the mixture is centrifuged and vacuum freeze-dried to obtain the thrips control granules.

[0014] The preparation steps of the anhydrous ethanol solution of the insecticide are as follows: 25-35 parts by weight of dried pyrethrum flowers, 20-30 parts by weight of rotenone root powder, 10-20 parts by weight of patchouli, 15-25 parts by weight of rosemary, and 8-12 parts by weight of angelica are pulverized separately, passed through a 60-mesh sieve, and mixed evenly to obtain a mixed powder; then the mixed powder is mixed with anhydrous ethanol and propylene glycol at a mass ratio of 1:(6-8):(1-1.5), extracted at 50-60℃ for 4-6 hours, filtered to remove the residue, and then concentrated to remove ethanol and propylene glycol to obtain the insecticide; the insecticide is mixed with anhydrous ethanol to obtain a 0.6-1% (w / v) anhydrous ethanol solution of the insecticide.

[0015] Further, the preparation steps of the starch nanoparticles are as follows: 2 parts by weight of debranched starch are mixed with 100 parts by weight of water and stirred until homogeneous. Then, 0.32-0.4 parts by weight of glucose are added and stirred until homogeneous. Next, 0.08-0.16 parts by weight of glycine are added and mixed until homogeneous. Then, 0.12-0.16 parts by weight of complex cyclodextrin are added and stirred until homogeneous. Subsequently, the mixture is heated in an oil bath at 150°C for 30 minutes to completely gelatinize the debranched starch. Finally, it is ultrasonically treated with a probe for 20-30 minutes to obtain... Add 1.5 to 2 times the volume of soybean oil and 1 to 2% of the volume of Span80 to the starch chain mixture. After homogenization, treat with ultrasonic pulse for 30 minutes. The ultrasonic pulse amplitude is 50%, and the pulse is turned on for 2 seconds and off for 1 second to obtain a uniform W / O emulsion. Place the emulsion in a refrigerator at 4°C for at least 12 hours. Then, repeat the freeze-thaw process at least 3 times to separate the oil and water phases. Remove the upper oil phase, wash, centrifuge, and freeze-dry to obtain starch nanoparticles.

[0016] Further, the preparation steps of the complex cyclodextrin are as follows: α-cyclodextrin is added to distilled water and heated in a water bath at 50~60℃ until completely dissolved, to prepare an α-cyclodextrin solution with a concentration of 0.1 g / mL; thrips attractant is mixed with anhydrous ethanol to prepare an ethanol solution of thrips attractant with a concentration of 0.05 g / mL; the ethanol solution of thrips attractant is added dropwise to the α-cyclodextrin solution at a reaction temperature of 40~60℃ and a stirring speed of 800~1000 r / min, wherein the mass ratio of thrips attractant to α-cyclodextrin is 0.1~0.3:1. After reacting for 2~4 h, the mixture is allowed to stand in a refrigerator at 4℃ for 23~25 h, then filtered, washed three times with anhydrous ethanol, and freeze-dried to obtain the complex cyclodextrin.

[0017] Thirdly, the present invention provides a method for using the grape thrips control agent as described in the first aspect, comprising the following steps: applying the grape thrips control agent to the upper and lower surfaces of young grape leaves and allowing them to dry.

[0018] By adopting the above technical solution, the present invention has the following beneficial effects: (1) The grape thrips control agent of the present invention includes a blue composite gel and thrips control granules. The blue composite gel is obtained by in-situ synthesis of a gel from sodium alginate, copper sulfate and dopamine, followed by surface loading of hexadecyltrimethylammonium chloride. The thrips control granules are made with an insecticide as the core material and starch, glucose, glutamic acid, gardenia blue and compound cyclodextrin as the wall material. The resulting grape thrips control agent has a good control effect on grape thrips and can achieve long-term control.

[0019] (2) The blue composite gel of the present invention is obtained by in-situ synthesis of sodium alginate, copper sulfate, and dopamine into a gel and then loading hexadecyltrimethylammonium chloride onto the surface. First, the blue appearance of the blue composite gel can effectively attract grape thrips with blue-taxis, thereby initially improving the contact efficiency of thrips control particles on grape thrips. Second, the copper ions released in the blue composite gel and the hexadecyltrimethylammonium chloride loaded on the surface both have broad-spectrum antibacterial activity. When the grape thrips control agent containing the blue composite gel is applied to the surface of grape leaves, it can significantly inhibit harmful pathogens attached to or infecting the leaves, reduce the occurrence of diseases, and ensure healthy leaf growth. Finally, dopamine undergoes self-polymerization to generate polydopamine during the gel formation process. The latter is rich in catechol and amino functional groups, which can form a strong adhesion with the surface of plant leaves, significantly improving the adhesion stability of the blue composite gel on grape leaves.

[0020] (3) The thrips control granules of the present invention are made with insecticide as core material and starch, glucose, glutamic acid, gardenia blue, and compound cyclodextrin as wall material; the compound cyclodextrin is obtained by combining α-cyclodextrin with thrips attractant, which can achieve slow release of attractant components; firstly, natural blue pigment gardenia blue is introduced into the wall material based on starch, so that the granules have a blue appearance, effectively utilizing the grape thrips' attraction to blue for visual attraction; secondly, the compound cyclodextrin loaded with thrips attractant further enhances the chemical attraction effect on grape thrips, and achieves long-term attraction through the slow release mechanism; glucose and glutamic acid are the basic nutrients required for the growth and development of grape thrips: among them, glucose, as a monosaccharide, can provide it with a rapid energy source; glutamic acid, as an amino acid, is the basic unit of protein synthesis, which is essential for the growth and development of grape thrips. The normal physiological activities of horses are crucial; amino acids and sugars are the core components of thrips attractants, which can effectively stimulate their appetite and increase their food intake; adding these two substances to the wall material of the control granules is equivalent to releasing a "food signal," which can directly attract grape thrips to feed, thereby further enhancing the attraction effect; when the attracted grape thrips move on the surface of the granules and scratch the wall material with their rasping and sucking mouthparts, the insecticide in the internal core material is released, allowing them to directly contact the pesticide and be accurately killed; in addition, the introduction of glucose and glutamic acid not only participates in the attraction system, but also interacts with starch molecules, enhancing the flexibility and structural stability of the wall material, effectively inhibiting the retrogradation of starch during storage or use, thereby extending the service life of the thrips control granules and ensuring their continuous control effect on grape thrips.

[0021] (4) When preparing the grape thrips control agent of the present invention, the blue composite gel is mixed with double deionized water and stirred and dispersed, then the thrips control particles are added and stirred until they are evenly dispersed, so that the thrips control particles are evenly dispersed in the wet gel system formed by the blue composite gel. When using the grape thrips control agent, it is coated on the surface of grape leaves, which can not only achieve long-term control of grape thrips, but also effectively inhibit the invasion of grape leaf pathogens, thereby ensuring the healthy growth of grape plants. Detailed Implementation

[0022] To better understand the above technical solution, the following will provide a detailed explanation of the technical solution in conjunction with specific implementation methods.

[0023] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0024] The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.

[0025] The preparation steps of debranched starch are as follows: Heat 3g / 100mL of glutinous corn starch aqueous solution to 85℃ and maintain for 30min to completely gelatinize the glutinous corn starch. After cooling, adjust the pH of the glutinous corn starch aqueous solution to 5.0 with phosphate buffer, add 4NPUN / g pullulanase, place in a constant temperature water bath at 58℃ for 24h for enzymatic hydrolysis, then boil in a water bath for 15min to completely denature and inactivate the pullulanase. After centrifugation at 5000×g for 10min, remove the enzyme, take the supernatant, add 2 times the volume of anhydrous ethanol to the supernatant, let stand for 30min, take the precipitate and freeze dry under vacuum for later use.

[0026] The thrips attractant used isonicotinic acid methyl ester.

[0027] Example 1 A method for preparing a grape thrips control agent includes the following steps: mixing and dispersing a blue composite gel with double deionized water to prepare a 20 mg / mL mixture, then adding 0.5% (w / v) thrips control granules, and continuing to stir and disperse evenly to obtain the grape thrips control agent.

[0028] The preparation steps of the blue composite gel are as follows: Double deionized water and phosphate buffer solution with pH 8.5 are mixed at a volume ratio of 9:1, and then sodium alginate is added and stirred at room temperature for 50 min to obtain a sodium alginate solution with a content of 2% (w / v); then the sodium alginate solution is added dropwise to paraffin oil containing 1% v / v Span-80 and 0.3% v / v Tween-80 at a volume of 3 times that of the sodium alginate solution, and stirred at 800 rpm / min for 50 min, and then 0.1 times the volume of the sodium alginate solution is added to a solution containing 0.1% sodium alginate by mass. A double deionized aqueous solution containing 0.007 times the mass of copper sulfate and 0.002 times the mass of sodium alginate and calcium chloride was added and stirred for 4 hours. Then, a double deionized aqueous solution containing 0.1 times the mass of sodium alginate and dopamine was added at 2 times the volume of the sodium alginate solution and stirred for 50 minutes. Finally, a double deionized aqueous solution containing 0.05 times the volume of sodium alginate and hexadecyltrimethylammonium chloride was added and stirred for 50 minutes. The mixture was then centrifuged at 8000 rpm for 30 minutes, washed three times with double deionized water, and freeze-dried to obtain a blue composite gel.

[0029] The preparation steps of thrips control granules are as follows: 2 parts by mass of starch nanoparticles are mixed with 100 parts by mass of water, and after ultrasonic dispersion, an equal volume of anhydrous ethanol solution of insecticide is added and mixed evenly. The ethanol is removed by vacuum distillation and rotary evaporation at 55°C. Then, the surface residual curcumin is washed away with ethanol, and the granules are obtained by centrifugation and vacuum freeze-drying.

[0030] The preparation steps of the anhydrous ethanol solution of the insecticide are as follows: 25 parts by weight of dried pyrethrum flowers, 30 parts by weight of rotenone root powder, 10 parts by weight of patchouli, 25 parts by weight of rosemary, and 12 parts by weight of angelica are pulverized separately, passed through a 60-mesh sieve, and mixed evenly to obtain a mixed powder; then the mixed powder is mixed with anhydrous ethanol and propylene glycol at a mass ratio of 1:6:1, extracted at 50℃ for 6 hours, filtered to remove the residue, and then concentrated to remove ethanol and propylene glycol to obtain the insecticide; the insecticide is mixed with anhydrous ethanol to obtain a 0.6% (w / v) anhydrous ethanol solution of the insecticide.

[0031] The preparation steps of starch nanoparticles are as follows: 2 parts by mass of debranched starch are mixed with 100 parts by mass of water and stirred evenly. Then, 0.32 parts by mass of glucose are added and stirred evenly. Next, 0.08 parts by mass of glycine are added and mixed evenly. Then, 0.12 parts by mass of complex cyclodextrin are added and stirred evenly. Subsequently, the mixture is heated in an oil bath at 150℃ for 30 minutes to completely gelatinize the debranched starch. Then, it is ultrasonically treated with a probe for 20 minutes to obtain a starch chain mixture. 1.5 times the volume of soybean oil and 1% of the volume of Span80 are added to the starch chain mixture. After homogenization, it is ultrasonically pulsed for 30 minutes with an amplitude of 50%, on for 2 seconds and off for 1 second to obtain a uniform W / O emulsion. The emulsion is placed in a refrigerator at 4℃ for at least 12 hours and then subjected to repeated freeze-thaw treatment at least 3 times to separate the oil and water. After removing the upper oil phase, it is washed with ether and water, centrifuged at 8000×g for 10 minutes, and then freeze-dried to obtain starch nanoparticles.

[0032] The preparation steps of the complex cyclodextrin are as follows: α-cyclodextrin is added to distilled water and heated in a water bath at 50°C until completely dissolved to prepare an α-cyclodextrin solution with a concentration of 0.1 g / mL; thrips attractant is mixed with anhydrous ethanol to prepare an ethanol solution of thrips attractant with a concentration of 0.05 g / mL; the ethanol solution of thrips attractant is added dropwise to the α-cyclodextrin solution at a reaction temperature of 40°C and a stirring speed of 800 r / min, wherein the mass ratio of thrips attractant to α-cyclodextrin is 0.1:1. After reacting for 2 h, the mixture is allowed to stand in a refrigerator at 4°C for 23 h, then filtered, washed three times with anhydrous ethanol, and freeze-dried to obtain the complex cyclodextrin.

[0033] Example 2 A method for preparing a grape thrips control agent includes the following steps: mixing and dispersing a blue composite gel with double deionized water to prepare a 40 mg / mL mixture, then adding 0.8% (w / v) thrips control granules, and continuing to stir and disperse evenly to obtain the grape thrips control agent.

[0034] The preparation steps of the blue composite gel are as follows: Double deionized water and phosphate buffer solution with pH 8.5 are mixed at a volume ratio of 9:1. Sodium alginate is then added and stirred at room temperature for 60 min to obtain a 2% (w / v) sodium alginate solution. Next, the sodium alginate solution is added dropwise to three times its volume of paraffin oil containing 1% v / v Span-80 and 0.3% v / v Tween-80, and stirred at 1000 rpm / min for 60 min. Finally, 0.1 times its volume of sodium alginate solution is added to a solution containing 0.007g of dissolved sodium alginate. A double deionized aqueous solution containing 5 times the volume of copper sulfate and 0.003 times the mass of sodium alginate and calcium chloride was added and stirred for at least 4 hours. Then, a double deionized aqueous solution containing 0.15 times the mass of sodium alginate and dopamine was added at 2.5 times the volume of sodium alginate solution and stirred for 60 minutes. Finally, a double deionized aqueous solution containing 0.06 times the volume of sodium alginate and hexadecyltrimethylammonium chloride was added and stirred for 60 minutes. The mixture was then centrifuged at 8000 rpm for 30 minutes, washed three times with double deionized water, and freeze-dried to obtain a blue composite gel.

[0035] The preparation steps of thrips control granules are as follows: 2 parts by mass of starch nanoparticles are mixed with 100 parts by mass of water, and after ultrasonic dispersion, an equal volume of anhydrous ethanol solution of insecticide is added and mixed evenly. The ethanol is removed by vacuum distillation and rotary evaporation at 55°C. Then, the surface residual curcumin is washed away with ethanol, and the granules are obtained by centrifugation and vacuum freeze-drying.

[0036] The preparation steps of the anhydrous ethanol solution of the insecticide are as follows: 30 parts by weight of dried pyrethrum flowers, 25 parts by weight of rotenone root powder, 15 parts by weight of patchouli, 20 parts by weight of rosemary, and 10 parts by weight of angelica are pulverized separately, passed through a 60-mesh sieve, and mixed evenly to obtain a mixed powder; then the mixed powder is mixed with anhydrous ethanol and propylene glycol at a mass ratio of 1:7:1.3, extracted at 55℃ for 5 hours, filtered to remove the residue, and then concentrated to remove ethanol and propylene glycol to obtain the insecticide; the insecticide is mixed with anhydrous ethanol to obtain a 1% (w / v) anhydrous ethanol solution of the insecticide.

[0037] The preparation steps of starch nanoparticles are as follows: 2 parts by mass of debranched starch are mixed with 100 parts by mass of water and stirred evenly. Then, 0.36 parts by mass of glucose are added and stirred evenly. Next, 0.12 parts by mass of glycine are added and mixed evenly. Then, 0.14 parts by mass of complex cyclodextrin are added and stirred evenly. Subsequently, the mixture is heated in an oil bath at 150℃ for 30 minutes to completely gelatinize the debranched starch. Then, it is ultrasonically treated with a probe for 25 minutes to obtain a starch chain mixture. 1.5 times the volume of soybean oil and 2% of the volume of Span80 are added to the starch chain mixture. After homogenization, it is ultrasonically pulsed for 30 minutes with an amplitude of 50%, on for 2 seconds and off for 1 second to obtain a uniform W / O emulsion. The emulsion is refrigerated in a refrigerator at 4℃ for at least 12 hours. Then, it is repeatedly freeze-thawed at least 3 times to separate the oil and water. After removing the upper oil phase, it is washed with ether and water, centrifuged at 8000×g for 10 minutes, and then freeze-dried to obtain starch nanoparticles.

[0038] The preparation steps of the complex cyclodextrin are as follows: α-cyclodextrin is added to distilled water and heated in a water bath at 55°C until completely dissolved to prepare an α-cyclodextrin solution with a concentration of 0.1 g / mL; thrips attractant is mixed with anhydrous ethanol to prepare an ethanol solution of thrips attractant with a concentration of 0.05 g / mL; the ethanol solution of thrips attractant is added dropwise to the α-cyclodextrin solution at a reaction temperature of 40°C and a stirring speed of 900 r / min, wherein the mass ratio of thrips attractant to α-cyclodextrin is 0.2:1. After reacting for 3 h, the mixture is allowed to stand in a refrigerator at 4°C for 24 h, then filtered, washed three times with anhydrous ethanol, and freeze-dried to obtain the complex cyclodextrin.

[0039] Example 3 A method for preparing a grape thrips control agent includes the following steps: mixing and dispersing a blue composite gel with double deionized water to prepare a 40 mg / mL mixture, then adding 1% (w / v) thrips control granules, and continuing to stir and disperse evenly to obtain the grape thrips control agent.

[0040] The preparation steps of the blue composite gel are as follows: Double deionized water and phosphate buffer solution with pH 8.5 are mixed at a volume ratio of 9:1. Sodium alginate is then added and stirred at room temperature for 70 min to obtain a 2% (w / v) sodium alginate solution. Next, the sodium alginate solution is added dropwise to three times its volume of paraffin oil containing 1% v / v Span-80 and 0.3% v / v Tween-80. The mixture is stirred at 1000 rpm / min for 60 min. Finally, 0.1 times its volume of sodium alginate solution is added to a solution containing 0.0% sodium alginate. A double deionized aqueous solution containing 0.08 times the volume of copper sulfate and 0.004 times the mass of sodium alginate and calcium chloride was added and stirred for at least 4 hours. Then, a double deionized aqueous solution containing 0.2 times the mass of sodium alginate and dopamine was added at 3 times the volume of the sodium alginate solution and stirred for 70 minutes. Finally, a double deionized aqueous solution containing 0.07 times the volume of sodium alginate and hexadecyltrimethylammonium chloride was added and stirred for 70 minutes. The mixture was then centrifuged at 8000 rpm for 30 minutes, washed three times with double deionized water, and freeze-dried to obtain a blue composite gel.

[0041] The preparation steps of thrips control granules are as follows: 2 parts by mass of starch nanoparticles are mixed with 100 parts by mass of water, and after ultrasonic dispersion, an equal volume of anhydrous ethanol solution of insecticide is added and mixed evenly. The ethanol is removed by vacuum distillation and rotary evaporation at 55°C. Then, the surface residual curcumin is washed away with ethanol, and the granules are obtained by centrifugation and vacuum freeze-drying.

[0042] The preparation steps of the anhydrous ethanol solution of the insecticide are as follows: 35 parts by weight of dried pyrethrum flowers, 20 parts by weight of rotenone root powder, 20 parts by weight of patchouli, 15 parts by weight of rosemary, and 8 parts by weight of angelica are pulverized separately, passed through a 60-mesh sieve, and mixed evenly to obtain a mixed powder; then the mixed powder is mixed with anhydrous ethanol and propylene glycol at a mass ratio of 1:8:1.5, extracted at 60℃ for 4 hours, then filtered to remove the residue, and then concentrated to remove ethanol and propylene glycol to obtain the insecticide; the insecticide is mixed with anhydrous ethanol to obtain a 1% (w / v) anhydrous ethanol solution of the insecticide.

[0043] The preparation steps of starch nanoparticles are as follows: 2 parts by mass of debranched starch are mixed with 100 parts by mass of water and stirred evenly. Then, 0.4 parts by mass of glucose are added and stirred evenly. Next, 0.16 parts by mass of glycine are added and mixed evenly. Then, 0.16 parts by mass of complex cyclodextrin are added and stirred evenly. Subsequently, the mixture is heated in an oil bath at 150℃ for 30 minutes to completely gelatinize the debranched starch. Then, it is ultrasonically treated with a probe for 30 minutes to obtain a starch chain mixture. Soybean oil with a volume of 2 times that of the starch chain mixture and Span80 with a volume of 2% of the starch chain mixture are added to the starch chain mixture. After homogenization, ultrasonic pulse treatment is performed for 30 minutes. The ultrasonic pulse treatment amplitude is 50%, on for 2 seconds and off for 1 second to obtain a uniform W / O emulsion. The emulsion is placed in a refrigerator at 4℃ for at least 12 hours. Then, it is subjected to repeated freeze-thaw treatment at least 3 times to separate the oil and water. After removing the upper oil phase, it is washed with ether and water respectively, centrifuged at 8000×g for 10 minutes, and then freeze-dried to obtain starch nanoparticles.

[0044] The preparation steps of the complex cyclodextrin are as follows: α-cyclodextrin is added to distilled water and heated in a water bath at 60°C until completely dissolved to prepare an α-cyclodextrin solution with a concentration of 0.1 g / mL; thrips attractant is mixed with anhydrous ethanol to prepare an ethanol solution of thrips attractant with a concentration of 0.05 g / mL; the ethanol solution of thrips attractant is added dropwise to the α-cyclodextrin solution at a reaction temperature of 60°C and a stirring speed of 1000 r / min, wherein the mass ratio of thrips attractant to α-cyclodextrin is 0.3:1. After reacting for 4 h, the mixture is allowed to stand in a refrigerator at 4°C for 25 h, then filtered, washed three times with anhydrous ethanol, and freeze-dried to obtain the complex cyclodextrin.

[0045] Comparative Example 1 The only difference between Comparative Example 1 and Example 2 is that the thrips control granules are made with insecticide as the core material and starch, glutamic acid, gardenia blue, and compound cyclodextrin as the wall material.

[0046] Comparative Example 2 The only difference between Comparative Example 2 and Example 2 is that the thrips control granules are made with insecticide as the core material and starch, glucose, gardenia blue, and compound cyclodextrin as the wall material.

[0047] Comparative Example 3 The only difference between Comparative Example 3 and Example 2 is that the thrips control granules are made with insecticide as the core material and starch, gardenia blue, and compound cyclodextrin as the wall material.

[0048] Comparative Example 4 The only difference between Comparative Example 4 and Example 2 is that the grape thrips control agent is directly obtained by mixing blue composite gel, insecticide, compound cyclodextrin, glucose, glutamic acid, and double deionized water.

[0049] Comparative Examples 5-8 The only difference between Comparative Examples 5-8 and Example 2 is that the grape thrips control agent was prepared by mixing the blue composite gel with double deionized water to form a 40 mg / mL mixture, and the thrips control granules were added at amounts of 0.2% (w / v), 0.4% (w / v), 1.2% (w / v), and 1.4% (w / v), respectively.

[0050] Comparative Example 9 The only difference between Comparative Example 9 and Example 2 is that the insecticide used is abamectin.

[0051] Example of effect Adhesion performance: The grape thrips control agents prepared in Examples 1-3 and Comparative Examples 1-9 were coated on the upper and lower surfaces of young grape leaves and allowed to air dry naturally. The number of thrips control particles on the leaf surface was observed. 30 mL of double-deionized water was sprayed onto the grape leaves to simulate rainfall. After spraying 5 times, the leaves were allowed to dry again, and the number of thrips control particles after the rain was observed. Thrips control particle retention rate = 100% * number of thrips control particles after rain / number of thrips control particles on the leaf surface.

[0052] The experimental site was located at the Mingyang Double-Season Grape Demonstration Base of the Guangxi Zhuang Autonomous Region Academy of Agricultural Sciences. Six-year-old "Nina Queen" grape varieties were selected, planted in east-west rows with a spacing of 3m x 6m, using a "T"-shaped trellis system, and cultivated in a multi-span greenhouse. The main trunk of the grapevines was 1.5m high, with cement supports extending 2m above the ground. The experiment consisted of 36 plots, randomly assigned to each plot. Three plots formed one treatment group, each treated with a specific grape thrips control agent from either the treatment or comparative examples. A blank control group received no thrips control treatment. At a height of at least 1.5m above the ground, 10 young leaves were randomly selected from each grapevine, and their upper and lower surfaces were evenly coated with the thrips control agent. After drying, the control effect was assessed at 1, 7, and 14 days after application. Before the color-changing stage, 60 bunches of grapes were randomly selected, and the rate of brown rust spots on each bunch was calculated, with the average value. The control effect was calculated as: [(Pest population reduction rate in the treatment area - Pest population reduction rate in the control area) / (1 - Pest population reduction rate in the control area)] × 100%; where the pest population reduction rate was calculated as: [(Pre-treatment pest population - Post-treatment surviving pest population) / Pre-treatment pest population] × 100%.

[0053] Table 1 below shows the performance test results of the grape thrips control agents prepared in Examples 1-3 and Comparative Examples 1-9: Table 1 Thrips control particle retention rate (%) Control efficacy (%) 1 day after application Control efficacy (%) 7 days after application Control efficacy (%) 14 days after application Percentage of brown rust spots on each bunch of fruit (%) Example 1 99.2 93.4 92.0 90.3 0.8 Example 2 99.8 98.3 97.4 95.4 0.3 Example 3 99.6 99.3 98.1 96.7 0.1 Comparative Example 1 98.3 93.4 84.0 75.6 7.9 Comparative Example 2 97.9 95.4 87.7 80.7 4.8 Comparative Example 3 96.5 88.5 77.9 68.5 14.6 Comparative Example 4 - 86.4 73.4 54.4 37.3 Comparative Example 5 99.8 90.9 89.1 87.2 1.7 Comparative Example 6 99.7 92.1 90.5 88.8 1.1 Comparative Example 7 99.1 99.6 98.6 97.4 0 Comparative Example 8 98.6 99.9 99.1 98.2 0 Comparative Example 9 99.3 72.8 71.6 70.3 11.1 Table 1 shows that the grape thrips control agents prepared in Examples 1-3 have good long-term control effects on grape thrips and can stably adhere to the leaf surface.

[0054] As shown in Table 1, the thrips control granules in Examples 1-3 and Comparative Examples 5-6 remained firmly attached to the surface of grape leaves after being washed away by rainwater. However, the retention rate of the thrips control granules in Comparative Examples 1-3 decreased significantly after being washed away by rainwater. This may be due to the lack of glucose and glutamic acid, which can enhance the structural stability of the starch-based wall material and prevent the granules from breaking apart or falling off the leaf surface under the influence of rainwater. In addition, in Comparative Examples 7-8, as the amount of thrips control granules added increased, the proportion of blue composite gel decreased, which was insufficient to effectively adhere the granules firmly to the grape leaves, thus affecting their adhesion stability on the grape leaves.

[0055] The grape thrips control agents of Examples 1-3 and Comparative Examples 7-8 all showed good long-term control effects against grape thrips. In contrast, the control effect of Comparative Examples 1-3 was relatively weak. The reason for this is that glucose and glutamic acid were added to the thrips control granules of the examples. These two substances can effectively toughen the starch-based granules and inhibit their retrogradation, thereby maintaining the integrity and stability of the granule structure. This helps to ensure the continuous release of the insecticide and the long-term effect of the attractant components, thus improving the long-term control effect against grape thrips.

[0056] The grape thrips control agent of Comparative Example 4 was prepared by directly mixing blue composite gel, insecticide, compound cyclodextrin, glucose, glutamic acid and double deionized water. It did not adopt the thrips control particle structure, which caused the insecticide to be released rapidly after application and could not achieve slow-release protection. At the same time, it was difficult to accurately kill grape thrips through the attraction-contact mechanism. Therefore, its control effect and long-term control performance were poor.

[0057] Comparative Example 9: The grape thrips control agent using conventional abamectin showed significantly lower control efficacy against common thrips than the grape thrips control agent made from insecticides derived from dried pyrethrum flowers, rotenone root powder, patchouli, rosemary, and angelica.

[0058] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A grape thrips control agent, characterized in that, The invention includes a blue composite gel and thrips control granules. The blue composite gel is obtained by in-situ synthesis of a gel from sodium alginate, copper sulfate, and dopamine, followed by surface loading of hexadecyltrimethylammonium chloride. The thrips control granules are made with an insecticide as the core material and starch, glucose, glutamic acid, gardenia blue, and compound cyclodextrin as the wall material.

2. The Cirsium japonicum thrips control agent according to claim 1, characterized by, The raw material components of the insecticide, by weight, include 25-35 parts dried pyrethrum flowers, 20-30 parts rotenone root powder, 10-20 parts patchouli, 15-25 parts rosemary, and 8-12 parts angelica.

3. The grape thrips control agent according to claim 1, characterized in that, The complex cyclodextrin is obtained by combining α-cyclodextrin with a thrips attractant.

4. The grape thrips control agent according to claim 3, characterized in that, The thrips attractant includes geraniol, nerol, and methyl isonicotinic acid.

5. A method for preparing a grape thrips control agent as described in any one of claims 1 to 4, characterized in that, The preparation steps are as follows: Mix and disperse the blue composite gel with double deionized water to prepare a mixture of 20~40mg / mL, then add 0.5~1% (w / v) thrips control granules, and continue to stir and disperse evenly to obtain grape thrips control agent.

6. The method for preparing the grape thrips control agent according to claim 5, characterized in that, The preparation steps of the blue composite gel are as follows: Double deionized water and phosphate buffer solution with pH 8.5 are mixed at a volume ratio of 9:

1. Sodium alginate is then added and stirred at room temperature for 50-70 minutes to obtain a 2% (w / v) sodium alginate solution. The sodium alginate solution is then added dropwise to three times its volume of paraffin oil containing 1% v / v Span-80 and 0.3% v / v Tween-80. The mixture is stirred at 800-1000 rpm / min for 50-60 minutes. Finally, 0.1 times its volume of sodium alginate solution is added to a solution containing 0.00g of dissolved sodium alginate. Add 7-0.008 times the volume of copper sulfate and 0.002-0.004 times the mass of sodium alginate to a double deionized aqueous solution containing calcium chloride, and continue stirring for at least 4 hours. Then add 2-3 times the volume of the sodium alginate solution containing 0.1-0.2 times the mass of sodium alginate to a double deionized aqueous solution containing dopamine, and stir for 50-70 minutes. Finally, add 0.05-0.07 times the volume of the sodium alginate solution containing 0.1-0.2 times the mass of sodium alginate to a double deionized aqueous solution containing hexadecyltrimethylammonium chloride, and continue stirring for 50-70 minutes. Then centrifuge, wash, and freeze-dry to obtain a blue composite gel.

7. The method for preparing the grape thrips control agent according to claim 5, characterized in that, The preparation steps of the thrips control granules are as follows: 2 parts by weight of starch nanoparticles are mixed with 100 parts by weight of water, and after being ultrasonically dispersed evenly, an equal volume of anhydrous ethanol solution of insecticide is added and mixed evenly. The ethanol is removed by vacuum distillation and rotary evaporation at 55°C. Then, the surface residual curcumin is washed away with ethanol, and the granules are obtained by centrifugation and vacuum freeze-drying.

8. The method for preparing the grape thrips control agent according to claim 7, characterized in that, The preparation steps of the starch nanoparticles are as follows: 2 parts by mass of debranched starch are mixed with 100 parts by mass of water and stirred evenly. Then, 0.32-0.4 parts by mass of glucose are added and stirred evenly. Next, 0.08-0.16 parts by mass of glycine are added and mixed evenly. Then, 0.12-0.16 parts by mass of complex cyclodextrin are added and stirred evenly. Subsequently, the mixture is heated in an oil bath at 150°C for 30 minutes to completely gelatinize the debranched starch. Then, it is ultrasonically treated with a probe for 20-30 minutes to obtain a starch chain mixture. 1.5-2 times the volume of soybean oil and 1-2% of the volume of Span80 are added to the starch chain mixture. After homogenization, it is ultrasonically pulsed for 30 minutes with an amplitude of 50%, on for 2 seconds and off for 1 second to obtain a uniform W / O emulsion. The emulsion is refrigerated in a refrigerator at 4°C for at least 12 hours. Then, it is repeatedly freeze-thawed at least 3 times until the oil and water separate. After removing the upper oil phase, the mixture is washed, centrifuged, and freeze-dried to obtain starch nanoparticles.

9. The method for preparing the grape thrips control agent according to claim 5, characterized in that, The preparation steps of the complex cyclodextrin are as follows: α-cyclodextrin is added to distilled water and heated in a water bath at 50-60℃ until completely dissolved to prepare an α-cyclodextrin solution with a concentration of 0.1 g / mL; thrips attractant is mixed with anhydrous ethanol to prepare an ethanol solution of thrips attractant with a concentration of 0.05 g / mL; the ethanol solution of thrips attractant is added dropwise to the α-cyclodextrin solution at a reaction temperature of 40-60℃ and a stirring speed of 800-1000 r / min, wherein the mass ratio of thrips attractant to α-cyclodextrin is 0.1-0.3:

1. After reacting for 2-4 h, the mixture is allowed to stand in a refrigerator at 4℃ for 23-25 ​​h, then filtered, washed three times with anhydrous ethanol, and freeze-dried to obtain the complex cyclodextrin.

10. A method of using the grape thrips control agent as described in any one of claims 1 to 4, characterized in that, Application steps: Apply the grape thrips control agent to the upper and lower surfaces of young grape leaves and let it dry.